Saturday, November 30, 2013

Road or MTB Components for Dahon / Tern Folding Bikes? - Part 2

Continuing from the first part of this article, Road or MTB Components for Dahon / Tern Folding Bikes? - Part 1, let us now continue with the brake components. In this second part, we will look at the different types of brake calipers and brake levers, and learn which brake levers are compatible with which brake calipers. With this understanding of the different brake systems, you can better determine what brakes to use on your folding bike.

Before you read on, I strongly recommend that you check out Part 1 of this guide, and also the other Guide To Upgrading your Dahon / Tern folding bike. This will give you the necessary background and info for basic folding bike upgrading.

2) Brake Calipers + Brake Levers

On modern bicycles, there are 3 main types of brakes: Linear pull brakes (commonly known as V brakes), caliper brakes and disc brakes. Some other less common types are cantilever brakes (still found mostly on cyclocross bikes only), roller brakes, coaster brakes or drum brakes. For more info on each of these brakes you can refer to this link here.

Wikipedia: Bicycle Brakes

V brakes and disc brakes are normally classified under MTB components, while caliper brakes are normally seen only on road bikes. Sometimes, when we upgrade a folding bike, we will be faced with a choice of using V brakes or caliper brakes. This will be dependent on the type of brake lever that you have. Before we look at the compatibility, it will be good to have some background info about these different brake systems. If you are only interested in what works with what, then skip right past this section to the part below labeled "Compatibility Between Brake Levers and Brake Calipers".

Background Info for Brake Systems:
Each brake system is made up of two main parts: The brake lever that is installed on the handlebar, and the brake caliper that is installed around the wheel.

Each type of brake lever and brake caliper has two important attributes that determines compatibility between brake levers and brake calipers: Mechanical advantage (or leverage ratio) and cable pull.

Mechanical advantage refers to the leverage provided by the brake lever or brake caliper. This is derived based on the distance of the activation point to pivot, compared to the distance from the brake pad to the pivot. Using brake levers and calipers of incompatible mechanical advantage will lead to an abnormal braking feeling in the brake lever, and also undesirable braking performance.

Cable pull refers to the amount of brake cable that the brake lever or brake caliper needs in order to function properly. It is important to match the cable pull of brake lever and brake caliper, for the brake system to function effectively.

Mechanical advantage and cable pull are directly related: For example, a V brake caliper has a high mechanical advantage, and requires a long cable pull. On the other hand, a road caliper brake has a lower mechanical advantage and thus requires a shorter cable pull to function.

Confused? Don't worry, each brake system's mechanical advantage and cable pull will be listed below, and there will be a summary to show you the compatibility between different brake components.

For the 3 most common types of brake systems, there are advantages and disadvantages to each of it. Let us take a brief look at them before we move on.

Brake Calipers:
V Brakes:
 Avid Single Digit 7 V brakes on my Boardwalk. One of the first few upgrades.

V brakes are found on more than 95% of Dahon and Tern folding bikes. From an entry level Dahon Eco 2 (SGD 300+) to high end Tern Verge X20 (SGD 4000+) folding bikes, they come with V brakes of different levels. Why are V brakes so common on folding bikes?

Advantages of V brakes:
1) Cheap
2) Easy to set up
3) Spare parts such as brake pads are cheaply and easily available anywhere
4) Simple mechanism makes it very reliable
5) Sufficient stopping power for almost all usage (except for perhaps loaded touring or downhill bikes)
6) Relatively wide pad clearance to accomodate out-of-true rims
7) Comparatively lightweight
8) Large clearance for fenders

Disadvantages of V brakes:
1) Less stopping power than disc brakes
2) Poor braking performance in the wet
3) Brake pads disintegrates very fast in the wet
4) Maintenance and cleaning is necessary after riding in the rain or wet roads, as the brake pads will leave a lot of residue on the rims
5) Wears out wheel rims (usually not a problem as it takes a long time and high mileage)

Mechanical Advantage of V brake calipers: High
Cable Pull of V brake calipers: Long

Caliper Brakes:

Very few Dahon or Tern folding bikes come stock with road caliper brakes, with the rare exceptions being the Dahon Speed Pro TT or the Tern Verge X30h. The reason why these bikes come with caliper brakes is NOT because caliper brakes work better, but because they are needed to pair with the road shifter/brake lever combo, or Dual Control Levers (DCL) in other words.

These two bikes are equipped with bullhorn bars and Road DCL, which means that they need caliper brakes for proper brake compatibility. So what are the pros and cons of a road caliper brake?

Advantages of road caliper brakes:
1) Lower frontal profile for less aerodynamic drag (not sure if it is true?)
2) Brake pads are easily available
3) Reliable

Disadvantages of road caliper brakes:
1) More expensive than V brakes
2) Less pad clearance to accomodate out-of-true rims
3) Less clearance for wider tires and fenders
4) Small clearance between tires and brake arch causes mud buildup in wet conditions
5) Less stopping power than disc brakes
6) Poor braking performance in the wet
7) Brake pads disintegrates very fast in the wet
8) Maintenance and cleaning is necessary after riding in the rain or wet roads, as the brake pads will leave a lot of residue on the rims
9) Wears out wheel rims (usually not a problem as it takes a long time and high mileage)

Mechanical Advantage of road caliper brakes: Low
Cable Pull of road caliper brakes: Short

Disc Brakes (Mechanical and Hydraulic): 
Hayes Mechanical Disc Brake Caliper

Very few disc brake systems are found on Dahon or Tern folding bikes. Some bike models which come with disc brakes are the Dahon Formula S18 and the Dahon Dash P18, which both have a mechanical disc brake system.

Other brands of folding bikes such as JAVA and Bike Friday do have a few more models with disc brakes. However, disc brakes are still not common on folding bikes, as the rotors can be prone to damage or bending when the bikes are folded and transported around.

The advantages and disadvantages of disc brakes listed below are with respect to folding bikes, which may not necessarily apply to full sized bikes such as mountain bikes.

Advantages of disc brakes on folding bikes:
1) Excellent stopping power for all terrain and riding conditions
2) Works well in all weather
3) Little to no maintenance required after riding in the rain
4) Does not affect tire choice or impede fender installation
5) Less affected by muddy conditions as compared to V brakes or caliper brakes
6) Does not wear out wheel rims
7) Not affected by out-of-true rims as the braking surface is on the rotor and not the rims

Disadvantages of disc brakes on folding bikes:
1) Slightly heavier than V brakes or caliper brakes
2) More expensive
3) Difficult to bleed hydraulic systems as compared to fixing mechanical brake systems
4) Spare parts are less readily available and more tricky to install
5) More prone to brake rubbing due to small clearance between rotor and brake pad
6) May not be suitable for folding bikes due to possible tight bends on the hydraulic hose when folded
7) Rotor is prone to damage when the bike is folded and laid on its side
8) More difficult to DIY as compared to V brakes and caliper brakes
9) May interfere with some rear racks, if the rear brake caliper is mounted on the seatstay

Hydraulic disc brake systems are more powerful than mechanical disc brake systems, but the tradeoff is heavier weight and higher price.

For hydraulic disc brake calipers, they can obviously only be used with hydraulic brake levers. These usually come as a set (including the hose and already pre-bled) and so there is no compatibility issues. The only problem is the hydraulic hose length. If the hose length is too long or short, they will need to be cut or changed, which involves bleeding the hydraulic fluid in the brakes.

As for mechanical disc brakes, there are models that are compatible with V brake levers, and models that are compatible with road brake levers (such as drop bar DCL). As such, they have different mechanical advantage and cable pull.

For use with V brake levers:
Mechanical Advantage: High
Cable Pull: Long

For use with road brake levers:
Mechanical Advantage: Low
Cable Pull: Short

That was a lot of info regarding brake calipers! Now, we need to look at the different types of brake levers out there, and from there we can determine the compatibility with brake calipers.

Brake Levers:
There are 2 main types of brake levers, flat handlebar (FHB) brake levers and drop bar brake levers. FHB brake levers are for bikes with flat handlebars, such as most folding bikes and practically all MTB. Drop bar brake levers can be dedicated brake levers, or available as a DCL with the shifters. Examples are shown below.

Avid Speed Dial 7 brake levers for FHB. Customised with gold coloured cable adjust bolts.

Shimano drop bar shifter/brake lever DCL on the left, drop bar brake lever on the right

Flat handlebar brake levers:

Flat handlebar brake levers are available as V brake specific only, road caliper brake specific only, or both V brake and road caliper brake compatible. If your brake lever is from a MTB or Trekking groupset, such as Deore or SLX/LX, then the brake lever is likely to be V brake only. There will only be one hole or hook for the brake cable.

Avid FR-5 V brake levers, for use with V brake calipers only. From

 Shimano BL-R550, for use with road caliper brakes only. Note the short distance between the pivot and the brake cable hooking area (not shown). This is what gives it a short cable pull but high mechanical advantage.

There are also brake levers that are compatible with both V brakes and road caliper brakes. These brake levers feature a selectable position for the brake cable hook, which allows it to have the correct leverage ratio and cable pull for the different brake calipers.

Shimano BL-R780, with a slot on the lever itself. This makes it compatible with V brakes or caliper brakes. Picture from Ebay.

A clear illustration showing how to set the brake lever to be compatible with either V brakes or caliper brakes.

V brake levers are actually also compatible with most MTB spec mechanical disc brakes. However, they are not compatible with road-specific mechanical disc brake calipers, such as Avid BB7 or Shimano BR-R505.

Drop Bar Brake Levers:

Most drop bars use a drop bar brake lever such as the Shimano BL-R600, or the shifter/brake lever combo type of Dual Control Lever. These brake levers are only supposed to be used with caliper brakes and not V brakes.

Shimano BL-R600 for drop bars or bullhorn bars. Only a brake lever and not a shifter.

SRAM Apex shifter/brake levers. It is both a shifter and also a brake lever. Used on drop bars or bullhorn bars.

Mechanical Advantage (Leverage Ratio) and Cable Pull of Various Brake Levers:

Each type of brake lever also has a different mechanical advantage ratio and cable pull. This determines which type of brake caliper it is compatible with!

V brake specific brake lever:
Mechanical Advantage: Low
Cable Pull: Long
Examples: Avid FR-5, Deore BL-T610

Road caliper specific brake lever (Mostly drop bar brake levers):
Mechanical Advantage: High
Cable Pull: Short
Examples: Shimano BL-R550, Shimano Ultegra 6800, SRAM Force 22

Brake Lever with selectable cable pull:
Mechanical Advantage: Low (for V brake) / High (for caliper brake)
Cable Pull: High (for V brake) / Low (for caliper brake)
Examples: Avid Speed Dial 7, Shimano Tiagra BL-4600, Sora BL-3500

Compatibility Between Brake Levers and Brake Calipers

After all the background info, we will now go back to answering the question: Road or MTB components for Dahon / Tern folding bikes? To be more specific, V brakes or caliper brakes for Dahon / Tern folding bikes?

To ensure compatibility, the key here is to ensure that the cable pull of the brake lever and brake caliper matches. For example, if you are using a drop bar brake lever (such as Shimano 105 5700 road shifters) with a short cable pull, you will need to pair it with a brake caliper with a short cable pull (such as a road caliper brake).

The best way to understand and check the compatibility is to use a table such as the one I created below.

Compatibility table for brake levers and brake calipers

Another way to look at it is that a brake lever with low mechanical advantage must be paired with a brake caliper of high mechanical advantage. An example would be to pair a V brake lever (low mechanical advantage) with a V brake caliper (high mechanical advantage). The resulting mechanical advantage would be not be too high or too low for proper braking function.

So what happens when you pair incompatible brake levers and calipers together?

Scenario 1:
Your existing folding bike uses a V brake lever and V brake calipers, such as a Dahon MuP8. You upgrade the bike to use a drop bar with road shifter/brake levers, but you did not change to caliper brakes and instead continue to use V brakes.

Drop bar brake lever: High mechanical advantage, short cable pull
V brake calipers: High mechanical advantage, long cable pull

What happens in this case is that you get very high overall mechanical advantage, which means that the braking force is very high. However, this is much higher than designed, and you will get a very spongy feeling at the brake levers due to the excessive leverage. What you are feeling is the flexing of the brake calipers or stretching of the brake cables due to excessive leverage.

Also, the cable pull ratio does not match. The V brake calipers require a long cable pull to activate fully, but your brake lever can only supply a short cable pull. You will need to set your brake pads very close to the rims in order to ensure that the brake pads can touch the rims when the brake lever is pulled. Even then, the brake lever will go very close to the handlebar when activated, which can be dangerous if the brake lever "bottoms out" on the handlebar, which prevents you from pulling any harder on the brake lever if required.

End result: Spongy brake feeling, chance of brake lever hitting handlebar, high chance of brake pad rubbing the rim due to small clearance.

You could use something such as a Travel Agent on the V brake caliper to alter the cable pull ratio, but the end result is usually not satisfactory. For more info check out the links below.

Travel Agent on Dahon Boardwalk
Caliper Brakes on Dahon Boardwalk
Travel Agent on Dahon Vitesse
Caliper Brakes on Dahon Vitesse

Scenario 2:
Your existing bike is a Tern Verge X30h with bullhorn bars, using road shifter/brake levers and road caliper brakes. You decide to ditch the bullhorn bars and convert the bike to using a flat handlebar. Due to that change, you change to a standard V brake lever, but you continue to use caliper brakes as there is no mounting point available for V brake calipers.

Brake lever for V brakes: Low mechanical advantage, long cable pull
Road caliper brakes: Low mechanical advantage, short cable pull

What you have here is the exact opposite of Scenario 1. The overall mechanical advantage is very low, as both the brake lever and brake caliper has low mechanical advantage. The cable pull ratio also does not match; the caliper brake only requires a short cable pull, but your V brake lever is generating a long cable pull.

The effect of this set up is that you will only need to pull your brake levers a very short distance before the brake pads touch the rim. The braking feeling will be very firm, which may seem good, but the actual fact is that this is caused by the low mechanical advantage of this brake setup. You will be unable to apply sufficient braking force, due to the low mechanical advantage of this system. Even if you pull hard on the brake lever and the feeling is firm, the actual braking force acting on the rims will be quite low.

End result: Firm braking feeling but poor braking power. The fingers will need to pull extra-hard on the brake levers to generate sufficient braking force.

This scenario is much less common than Scenario 1, but there is such a possibility if someone changes from a drop bar to a flat handlebar.

This incompatibility issue can be easily solved by using the correct FHB brake lever. Just get those types are are specific to road (such as Shimano BL-R550), or those with selectable cable pulls (such as BL-3500, 4600, R780). You can use either V brake calipers or road caliper brakes, and setup the brake lever to match accordingly.

Shimano Tiagra BL-4600, with selectable cable pull ratios. This makes it compatible with all cable actuated brake systems.

After reading through this long article, you should now understand the advantages and disadvantages of each brake system. Also, the compatibility between different brake levers and brake calipers can be found easily using the compatibility table above.

Almost all Dahon / Tern folding bikes come stock with V brake calipers, and it is possible for some to use road caliper brakes. Before you change your brake levers to road DCL, it is best to check if your bike frame can accept caliper brakes.

My recommendation is to always use caliper brakes with road shifter/brake levers, and not resort to other methods such as Travel Agents or short arm V brakes, as these do not work well enough in my opinion.

In the next part of this series, we will look at the other components, such as the crankset and cassette, and see if it is better to use road or MTB variants of these components on Dahon / Tern folding bikes.

3rd Part of this series!

Saturday, November 23, 2013

Road or MTB Components for Dahon / Tern Folding Bikes? - Part 1

After the hugely popular blog post, Guide to Upgrading your Dahon / Tern folding bike, here is a follow up for that article! Assuming that you have read and understood the basics of bicycle upgrading, the next question is, what components should you install on your folding bike? There is such a wide variety of components available out there, with different specifications and requirements. Without any prior experience or in-depth knowledge, it is very difficult to figure out the correct type of components to use for your folding bike.

With this article, I hope to provide more information regarding the components that are suitable for a folding bike. Although the focus is mainly on Dahon or Tern folding bikes, this may well apply to other brands of folding bikes that have a similar setup or construction.

An empty Dahon Vitesse frame. What are the components that will be suitable? Read on to find out!

There are hardly any groupsets or components that are dedicated to folding bikes or small wheeled bikes (with the exception of Shimano Capreo), thus most folding bikes use Road or mountain bike (MTB) components. This works well most of the time, unless you mix and match incompatible components.

This article will compare and explain the differences between some road and MTB components, and the suitability for folding bikes. For a more focused and simple analysis, only conventional derailleur setups will be discussed. Other types of drivetrains such as single speed or internal gear hubs will not be discussed.

Before we go into the different components categories, some background information will be useful. For me, I feel that there is no need to get top level components, unless you are racing competitively. Of course, if you can afford it, by all means get the top end stuff if that is what you like! For the rest of us, second tier components are more than good enough, as they have most of the features of top level components but at a much more wallet friendly price. In fact, even mid range components will work well enough for everyday use.

The two major bicycle component makers are Shimano and SRAM, with Campagnolo, Microshift and a few other brands making up the rest. Again, for simplicity's sake, I will only be showing components from Shimano and SRAM.

Each of these two companies have two major types of components, road and MTB components. Some components may look and work very similarly, but others will differ greatly. Here are some second tier road and MTB components from Shimano and SRAM.

Shimano Ultegra 6800, 2x11 speed road groupset.

SRAM Force 22, 2x11 speed road groupset

Shimano Deore XT, 2/3 x 10 speed MTB groupset

SRAM X0, 2x10 speed MTB groupset

Listing down the groupsets, from top level to mid range,
(11s = 11 speed, 10s = 10 speed, 9s = 9 speed, 8s = 8 speed)

Shimano Road (2013): Dura-Ace (11s), Ultegra (11s), 105 (10s), Tiagra (10s), Sora (9s), Claris (8s).
SRAM Road (2013): Red (11s), Force (11s), Rival (10s), Apex (10s).

Shimano MTB (2013): XTR (10s), Deore XT (10s), SLX (10s), Deore (10s), Alivio (9s), Acera (9s), Altus (9s).
SRAM MTB (2013): XX (10s), X0 (10s), X9 (10s), X7 (10s), X5 (10s).

Before we continue, my stand on mixing and matching components between different brands is: Don't do it! There is no advantage to mixing components from different brands, as the cable pull ratios are different and will give poor shifting performance. Besides, the appearance of the parts will be mismatched. Always use components of the same brand, and preferably the same series/groupset for best performance and appearance.

Some acronyms:
RD = Rear Derailleur
FD = Front Derailleur
SS = Short Cage RD
GS = Mid Cage RD
SGS = Long Cage RD
DCL = Dual Control Levers, which refers to the drop bar road shifters / brake lever combo
BB = Bottom Bracket (bearing unit supporting the crankset)
FHB = Flat Handlebar, usually used to refer to MTB-style road shifters for flat handlebar road bikes

The different types of components will be discussed separately, and the suitability for folding bikes evaluated in each section. The gist of each section will be underlined for easy reference. For many components, the suitability will depend on other components used as well. For example, a wide range cassette is only suitable/possible if a MTB RD is used.

1a) Rear Shifter + RD (Front single setup)
1b) Shifters + RD + FD (Front double setup)
2) Brake Levers + Brake Calipers
3) Crankset + BB
4) Cassette
5) Chain

1) Shifter + RD (Front Single Setup)

Front single chainring drivetrains are very common for folding bikes, as they are relatively easy to maintain and have sufficient gears for normal city riding. The number of speeds will then purely depend on the rear cassette. It can vary from 6 speeds for an entry level Dahon Eco 2 to 10 speeds for a high end Tern Verge X10. 11 speed Dahon / Tern folding bikes are not available (yet).

6 and 7 speed bikes have virtually no chance of a meaningful upgrade, as components for 6 and 7 speeds are rare nowadays. Even 8 speed drivetrains are becoming less popular as the price of 9 speed drivetrains drop.

As a front single drivetrain setup, there is a lot of flexibility, as the only components you need to match are the rear shifter and RD. Of course your chain and cassette needs to be of the same speed, but that is not an issue here. For front single folding bikes, either road or MTB components (shifter + RD) will work equally well.

1 x 9 road drivetrain on my Dahon Boardwalk about 2 years ago

In the recent couple of years, Shimano has introduced a series of FHB road shifters, in addition to the standard DCL road shifters. There is the 10s Ultegra-grade SL-R780, 10s Tiagra SL-4600, 9s Sora SL-3500 and 8s Claris SL-2400. The shifter should be matched with the RD from the matching groupset for best performance.

Shimano Sora SL-3500 9 speed FHB road shifter

If you like to use MTB shifters (with Instant Release and Multi Release features for high end models), it is also viable. 10s MTB Dynasys shifters are available from XTR all the way to Deore, while 9 speed shifters are available in the Alivio, Acera and Altus series. Once again, use the RD from the same series for best performance.

Shimano Alivio SL-M430 9 speed MTB shifter

The main difference between road and MTB shifters are the cable pull ratios, or pitch. The pitch for road and MTB shifters are slightly different. There have been many cases where a MTB shifter is paired with a Road RD, or vice versa, and it seems to work OK. However, tuning the drivetrain nicely will be nearly impossible as it is difficult to get all of the gears to work properly. Avoid mixing road and MTB shifters + RD.

As for the RD, there are more differences. The most obvious one is the cage length, where MTB RD have a longer cage than road RD. Road RD are available in SS and GS cage lengths, whereas MTB RD are usually available in GS or SGS cage lengths. Some MTB RD have short cage lengths, such as Shimano Saint, Shimano Zee, and a few other SRAM MTB RD.

Shimano Saint RD-M820, short cage. Looks very tough!

SRAM X9 MTB RD, short cage. Comes stock on the Tern Verge X10.

The other difference is the tilt of the parallelogram, where the MTB RD tilts more in order to reach the larger sprockets on a MTB cassette. This is the part that determines the largest compatible sprocket, and not the cage length. The cage length merely determines the chain capacity, which is dependent mostly on the choice of front crankset and the cassette size.

If you are using a close range road cassette, such as a 11-25T or 11-28T cassette, a road RD will shift better (although a MTB RD will also work). If you are using a wide range MTB cassette, such as a 11-32T or 11-34T cassette, you will definitely need a MTB RD (a road RD will not work).

There is no compatibility issues with using road FHB shifters and RD on Dahon / Tern folding bikes. As for MTB shifters and RD, the only point to take note is that MTB cages are long, and in some cases it will go very close to the rear tire in the 1st gear. Therefore, if you want to use MTB shifters and RD on your folding bike, I would suggest using a short cage RD, such as a Shimano Saint or Zee RD.

2) Shifters + RD + FD (Front double setup)

As for a front double setup, it is more tricky as we have to deal with the compatibility issues of the FD and front shifter. Folding bikes that come with a front double crankset are less common. It usually starts from the mid range price point, such as the Dahon D18 (2x9 speeds) to top end models such as the Tern Verge X20 (2x10 speeds).

My opinion is that for a folding bike with a front double drivetrain setup, a road setup is the only way to go. A MTB setup just will not work. I am assuming that you are actually using front shifting, to get 2x9 or 2x10 speeds. If you did not install an FD, it means that you actually have a front single setup (even if you have double chainrings), in which case you can just refer to the section above for front single drivetrains.

Before I explain why a MTB setup is not suitable, let us see why a road setup works. Almost all Dahon and Tern folding bikes have a 68mm BB shell width, which is the BB shell width of road bike frames. This means that a road double crankset will fit nicely onto the frame, using a standard 68mm road BB. The chainline will then be optimum for a road double crankset, which is required for good front shifting performance. A brazed-on road double FD will also fit nicely, either on the welded FD hanger or the aftermarket LitePro FD adaptor.

Front double road crankset, with a 68mm BB on the Dahon Boardwalk frame

It is possible to install a MTB front double crankset on a folding bike. With the appropriate BB spacers, you could install a front double MTB crankset (such as Shimano Deore XT FC-M785), but you will not be able to install the required front double MTB FD. This is because MTB FD does not come in brazed-on mounting, and the clamp band options will not fit (largest clamp size is 34.9mm, which is far off from the seat tube diameter of 40/41mm for Dahon / Tern folding bikes). Only road double FD will fit on Dahon / Tern folding bikes.

Now, you may ask, can I use a road double FD with a MTB double crankset? The answer is no, the road double FD is not compatible with a MTB double crankset. Not only is the cable pull ratio all different, the curvature of the FD chainguide is also different. A road FD chainguide is optimised for a chainring curvature of 50-55T, while a MTB double FD can only cover a maximum of about 40T. With the wrong curvature, there will be a big gap between the FD chainguide and the chainring, and the shifting performance will be very bad.

Shimano XT FC-M785, MTB double crankset. Not recommended for folding bikes as you cannot fit a compatible MTB double FD.

After a bunch of explanation (hope you understood at least some of it!), the moral of the story is, you cannot have a MTB front double setup for a Dahon / Tern folding bike. Some people will try to be clever and ask, can I use a road front double setup, but a MTB rear setup? This is actually possible!

You could actually set up the drivetrain such that the front and rear are distinct groups. MTB rear shifter + MTB RD, and road front double shifter + road double FD + road double crankset. As for the cassette and chain, either the road or MTB version will work (surprise! to be elaborated on in Part 2 of this article).

This would give you a truly hybrid drivetrain setup, with a MTB rear and Road front system. It would work, but it will look really weird! The appearance of the RD and FD will not match, while the shifters on the left and right side of the handlebar also will not match. You could probably try this if you have a bunch of spare components lying around, but it is not recommended if you are buying new components. Just get components from the same brand and series and everything will work and look so much better.

Tern Verge P20, upcoming new model for year 2014. Should be of great value, and is all ready for upgrades!

In summary, if you want to have a front double drivetrain for your Dahon / Tern folding bike, just get a standard road groupset. All the components (except for maybe the caliper brakes) will go on nicely. Of course, depending on the frame you have, you may need an RD adaptor and/or FD adaptor. The FD should be of the brazed-on type and not the clamp band type.

This article is getting rather long, which is why I have to split it into two parts. The compatibility of the remaining components will be discussed in Part 2. Stay tuned!

Part 2 of the article is now up!
Brake Calipers + Brake Levers

Thursday, November 21, 2013

Selle Anatomica Watershed Leather Saddle

Introducing the Selle Anatomica saddle! As there is an end of year sale for all Selle Anatomica (SA) saddles, it is now available at a good price of USD 99. After getting some feedback from other riders using this saddle, the positive reviews persuaded me to give it a go, and get one to try out.

The SA saddle comes in 2 distinct types of leather, the tougher and harder TruLeather, and the soft Watershed leather which does not need to be broken in. After hearing many painful stories of riders attempting to break in their Brooks saddle, this soft leather saddle seems to be friendlier for the butt.

There are also 3 types of Titanico saddle; The regular Titanico saddle rated for riders up to 160 pounds (73 kg), the tougher Titanico X saddle for riders between 160-250 pounds (73-114 kg) and the heavyweight type, NSX for riders above 250 pounds (114 kg). For me, it seems that the Titanico saddle will be the most suitable.

As referenced from the Selle Anatomica website. Different types of saddles for different weight and riding styles.

All black saddle with the large cutout in the middle

Regular Titanico saddle in Watershed leather

The first thing that struck me when I took the saddle out of the box was the weight! It is so heavy, and I was not expecting that. I immediately put it on the weighing scale to see how heavy it is...

At 479 grams, it is more than twice as heavy as the previous Bontrager Evoke RL saddle!

Oh well, since I have the saddle already, I might as well try it out. Instead of removing my current saddle from the seatpost and installing the new SA saddle, I decided to mount it on another seatpost instead. This will allow me to try it out first, without affecting the position of the current Bontrager saddle.

Before that, let us take a closer look at the saddle, and how to set up the saddle for optimum comfort.

One of the few saddles that comes with a manual...

The leather tension is adjustable, which is good for controlling the firmness of the saddle.

The underside of the saddle, with the heavy steel rails.

Tension adjustment knob, for adjusting the tension of the leather. 

The rough and raw edges of the leather. Potential problem if it cuts into the thigh while pedaling... 

As mounted on the Dahon Boardwalk!

Top down view of the saddle. Look how wide it is!

Started with the saddle nose slightly below level, as I found that the area above the adjustment bolt is too hard and presses on the soft bits...

Another picture showing the rough edges of the leather, which is at the area where it will press into the hamstrings.

Adjusting the tension bolt to increase the tension of the leather, as it is found to be quite slack.

Side by side comparison of the SA saddle and the Bontrager saddle. See how much wider it is, especially at the curved area under the thigh.

The cutout is a nice touch, relieving pressure in the centre, but the width seems to be too wide.

The best way to adjust the saddle properly is to go for test rides, with the necessary tools to make adjustments along the way. There are 2 tricky adjustments to make, which are mainly the tilt, and the fore-aft setting of the saddle.

For me, the tilt of the saddle is something which I cannot seem to get right. Tilting it downwards slightly relieves the pressure at the front, but I find myself sliding forward. Tilting it upwards is slightly more comfortable for the butt, as I will not slide forward. However, the hard tip of the saddle makes it really uncomfortable when I lean forward to grip the drop bar road shifters.

I have also adjusted the fore-aft setting, trying different permutations along with the tilt adjustments. The tension of the leather was also increased to prevent myself sinking too deep into the saddle. As some people have said, you sit "in" a leather saddle, as compared to sitting "on" a regular saddle.

However, there seems to be no sweet spot where the saddle is completely comfortable. Still, this is not the biggest issue that I have.

The biggest issue with this saddle is that it is too wide, at the curved area under the hamstrings. As the leather is wider than normal at that area, and the leather edges are not nicely rounded, this means that with every pedal stroke, the leather edge tends to cut into the hamstring.

I have tested this saddle for around 30 km, with various adjustments done. The tilt and fore-aft setting of the saddle is still manageable, and I can get a setting where the discomfort is minimised. However, no matter how I adjust the leather tension or try out different saddle positions, the leather-cutting-into-hamstring issue just cannot be eliminated.

This is probably a problem for those with bigger thighs/hamstrings or narrower hips. If only the saddle is made such that the side flaps are not so wide, it would be much better.

All I can say is that for bike saddles, please try before buying, as everyone's anatomy is very different. What may feel like a sofa to your friend might feel like a coconut shell to you, or vice versa. I am wondering if the harder Titanico X saddle might feel better instead, as the rider does not sink into the saddle so much.

Saturday, November 16, 2013

Avanti Inc 3: Stem and Handlebar Adjustment

After settling all the issues with the belt drive system, I could finally enjoy the smooth and quiet ride of the Avanti Inc 3. With the commuting accessories installed, riding in light rain or wet roads is no longer a problem. This greatly increases the opportunities for me to ride a bike, especially with the wet weather nowadays. Of course, I would still not ride in heavy rain, as it is not practical, not fun, and definitely not safe.

While riding, I found that the riding posture felt a little bit strange. Not a big issue, but something that I would like to improve on. First of all, the handlebar felt very wide. I measured it and found that it was about 680mm, which is rather wide for a city commuting bike. This length would have been good on a mountain bike (which is the handlebar length that is on my Polygon Cosmic CX 3.0), but it is too wide for city riding. It would be more practical to have a narrower handlebar that allows me to squeeze through narrower spaces. It will also put me in a more upright riding posture as my arms will not spread as far to hold the ends of the handlebar.

Wide 680mm handlebar that comes stock on the Avanti Inc 3

Instead of buying a new handlebar, I decided to just take an existing handlebar that I have, and cut it down to size. This is definitely cheaper and I can also choose the exact length that I want. On my Polygon MTB, I had earlier changed out the handlebar to an Easton handlebar, and thus the stock Entity handlebar was available. It has an original length of about 640mm.

I tried a few other bikes and found that a good handlebar width for city commuting is about 600mm. Therefore, I decided to cut the length of the Entity handlebar from 640mm to 600mm.

Using a saw to cut the handlebar is the most straightforward way, but it is not a good way as it is difficult to get a clean cut. The ends of the handlebar may also be slanted if not done properly. I decided to get a proper tube cutter to do the cutting job properly, and it is also a good chance for me to try out this tool as I have not used it before. It can also be used to cut steerer tubes or seat posts.

Tube cutter from Tactix, can be found at Home DIY stores. Only $10! Fits up to 1 1/8 inch tubes (About 30mm)

At first I thought that this tool is not big enough to cut the 31.8mm handlebar, but then I realised that I am not cutting the centre clamp portion which is 31.8mm. What I need to cut are actually the ends of the handlebar, which are a standard 22.2mm in diameter.

As shown below, a standard tube cutter has a sharp circular blade, and two rollers to hold the tube in place. It basically works by running the blade around the tube many times, till it cuts through the tube walls.

The instruction says to tighten the knob, so that the roller pushes the tube against the blade. Tighten after every round, as the blade cuts into the tube.

 The blade and rollers of the tube cutter.

The ends of the handlebar, with width indications to tell you where to cut for the preferred handlebar width. I double confirmed with a measuring tape. Measure twice, cut once!

After running the tube cutter around the handlebar for a few rounds, a deep groove can be seen clearly.

The handlebar cut at the 600mm mark. The other line shown is not the cut, it is just a scratch caused by the rollers of the tube cutter.

With an aluminium handlebar, it didn't take very long to cut through the handlebar. It took less than 20 rounds to cut through it, tightening the clamp after every round. Of course, remember to cut both ends or the handlebar will be of unequal lengths on both sides. It will take much longer to cut through a thicker steerer tube.

Besides cutting the handlebar to a preferred narrower width, I also wanted to change out the stem. The stock stem is a short 75mm, which is because the Avanti Inc 3 that I have is a small sized frame. Larger sized frames will come with 90mm stems.

I was about to get a longer 90mm stem, when I realised that I can invert the stem, as this will make the effective reach longer. Currently the stem is angled upwards, and by tilting it downwards instead, the handlebar reach is increased.

Since this is a no cost change, it makes sense to just try it out first. After all, there is nothing to lose! I then installed the newly cut handlebar (600mm width), and inverted the stem at the same time.

Original stem orientation. Tilted upwards.

After flipping the stem, the stem is now angled downwards.

The new handlebar is 600mm wide, significantly narrower than the stock 680mm wide handlebar. It may not be obvious from this picture, but it is obvious when riding.

 After flipping the stem, the saddle and handlebar height is about the same.

With these changes in the bike cockpit, the bike now handles a bit differently. The narrower handlebar gives a more nimble ride which is quite similar to that of a small wheeled bike. This is useful for navigating tighter spaces and sharper corners in an urban setting.

On the other hand, the lower handlebar height improves stability, and the longer effective reach also allows me to stretch out my upper body more. Overall, the riding posture feels better. The bar ends are also used more often than before, as they can now be reached more easily, instead of being located at the ends of an already-wide handlebar.

You may also have noticed some other small changes from the previous pictures. I have added a Topeak F66 Fixer, which replaces the stock stem cap. This Topeak stem cap comes with a fixer for Topeak bags, such as the Topeak SmartPhone DryBag 5". I can mount my phone on the stem, which is more easily accessible and also frees up space on the handlebar for other accessories.

Replaces the original stem cap on the stem.

My Topeak pouch can now be clipped onto the stem!

Another little addition I made is this Fizik Seatpost Ring. It is just a simple rubber ring that goes onto the seatpost, to prevent water from going into your seat tube through the seatpost opening.

The other useful function is to mark your seatpost position, especially when you remove the seatpost for cleaning or any other reason. Just remember to get the correct sized ring for your seatpost, for a nice snug fit.

Fizik Seatpost Ring. Black colour is not available for this seatpost size.

The Topeak Wedge DryBag was also remounted on the rack, in the position shown below. There is more clearance for the saddle to be lowered (for shorter riders), and also improves the angle of the rear light.

Topeak Wedge DryBag mounted on the rear rack instead of the saddle.

With these improvements in the bike cockpit, the bike feels perfect now. With the belt drive, the bike rides silently and smoothly, and the riding posture is comfortable. It is low enough for a sporty feel, yet not too low for comfortable riding. The Ergon grips and bar ends offer a comfortable grip and a couple of hand positions. The stock saddle is surprisingly comfortable and I think I will just keep it and use it for now. SPD/Platform dual sided pedals enable cycling in all sorts of footwear, from slippers to SPD shoes. A set of full fenders minimises road spray when riding on wet roads, while the rear rack holds panniers for carry some load.

Current form of the Avanti Inc 3, with no plans for further upgrading (for now).

Keywords for the upgraded Avanti Inc 3: Silent, Clean, Comfortable.