Friday, August 28, 2015

Wheelsport Fantasy Flat Handlebar 2x10 Speed: Part 2 - Bike Disassembly and Component Weight

Part 1: Original Bike Components

After documenting the stock components on the Wheelsport Fantasy 2.0 flat handlebar bike, it is now time to give it an upgrade! First, I will be removing all the components from the bike, and also clean up the frame. At the same time, I can weigh all the components. This will enable me to give an accurate part-by-part summation of the weight of the full bike. Another thing to note is that I only weighed the parts which I plan to use on the upgraded bike. Those components which I am not using again will not be weighed.

I started with removing the wheels from the bike frame. I did not remove the tires and tubes from the wheelset as I will be using the same tires and tubes. As such, the weight of the wheels are inclusive of the tire and tube.

Front wheel + tire + tube: 866 grams
Rear wheel + tire + tube: 1054 grams

Assuming a tire weight of 250 grams each, and a inner tube weight of 100 grams each, the weight of these 451 wheels can be estimated to be 516 grams for the front wheel, and 704 grams for the rear wheel. This gives a wheelset weight of 1220 grams which is a good weight. Compared to the 406 sized Wheelsport Sunny wheelset on the Dahon MuEX (484 grams for front, 709 for rear), the weight is quite similar.

Nice set of Wheelsport Sunny 451 wheelset with Kenda tires

Weight of the Wheelsport QR axles. Comparatively heavy compared to the more lightweight titanium QR axles

After removing the cassette, I took the chance to clean and lubricate the freehub mechanism. The construction is slightly different from the earlier Wheelsport hubs, as can be seen from this maintenance guide.

Close up look of the folding handlepost. It is similar in design to Dahon/Fnhon/Tern handleposts, with a centre compression bolt and 2 side clamp bolts.

Not too heavy at 401 grams

However, the fork is rather heavy, as it is aluminium with a steel steerer tube

Feels solid but is rather heavy at almost 700 grams

External type of headset bearings, different from Dahon/Tern internal type design

Close up look at the sealed bearings of the headset. The bearing size and angle can be found marked on the bearing.

The headset parts from left to right: Crown race, lower bearing, upper bearing, compression ring, shim, headset cover

Together, they weigh 54 grams (excluding the top cap and bolt which are not shown)

FSA aluminium stem with a decent weight of 134 grams

Stock aluminium handlebar, 235 grams

LitePro foam grips, lightweight at only 77 grams

Wellgo QRD M111 Quick Release Pedals

Original aluminium kickstand. Quite heavy at 100 grams more than the one I have on the Dahon Boardwalk

Original saddle, also quite heavy at over 300 grams

FSA Energy aluminium seatpost, with an OK weight of 275 grams

This frame can accept a seatpost of diameter 27.2mm

Finally, the bare frame with every component removed!

After removing all the components, the bare frame can now be weighed. Inclusive of all the hardware such as the seatpost clamp, RD hanger, headset cups, BB guide and cable adjust bolts, the frame weighs about 1.8kg. Adding the fork (697 grams) and handlepost (401 grams), the total Wheelsport Fantasy 2.0 frameset weight (folding handlepost version) is about 2.9kg.

For comparison, the Tyrell FX frame weighs 2.2kg, with a fork weight of 909 grams, giving a total frameset weight of around 3.1 kg. The difference is, the Tyrell FX comes with additional folding capabilities, which accounts for the higher weight due to the folding joints. Non-folding Tyrell frames such as the aluminium-carbon CSi or the titanium PKZ would be lighter in weight.

In the next part, I will be reassembling the bike with some of the original components and also some new components.

Click here for Part 3

Friday, August 21, 2015

Wheelsport Fantasy Flat Handlebar 2x10 Speed: Part 1 - Original Bike Components

Ever since I started this blog in January 2011, I have written over 250 blog posts over these 4+ years, and upgraded countless components on all my bikes. However, one curious thing that I realised is that of all the bikes that I have upgraded, none of them is a mini velo. In my definition, a mini velo is a bike with 20" wheels and a non-folding frame.

Now, I have a chance to upgrade a mini velo! The bike that is shown here is a friend's bike. Although this bike is not mine, I took up the project to upgrade this mini velo with some better components. As can be seen from the title, the target is to upgrade this bike to a 2x10 speed bike.

The bike that we have here is a Wheelsport Fantasy 2.0 mini velo, sold exclusively by MyBikeShop locally. In any case, this Wheelsport Fantasy mini velo can be bought as a complete bike or just as a frameset.

Before upgrading this bike, let us take a look at the stock setup on this mini velo. As a start, the complete bike weight is 9.5kg, including the kickstand and the pedals. Excluding the kickstand and pedals, this bike would weigh only 8.9kg! Pretty decent for a stock mini velo.

This is a lightweight bike, and is already lighter than high end folding bikes, such as the Tern Verge X10 (9.6kg without pedals). The reason is due to the absence of folding joints which will add quite a bit of weight to the bike frame.

Full view of the stock Wheelsport Fantasy 2.0 mini velo

Looking pretty good, especially with the nice red rims

The shifter cables run externally, along the bottom side of the downtube

The rear brake cable runs externally along the bottom side of the top tube

This model has a folding handlepost, with a knob for tightening the joint, much like a Brompton

Wheelsport Sunny 451 wheelset, with Kenda Kontender 23-451 tires

Alhonga road caliper brakes

A Sturmey-Archer crankset? Never seen it before...

Square taper BB, in a standard English threaded 68mm BB shell

The FD mount is already welded onto the frame, allowing a front double drivetrain to be installed easily.

SRAM DualDrive RD? Another unusual component here...

The stock drivetrain is a 1x9 speed system

The RD hanger seems to be bent slightly inward, which may have contributed to the non-ideal shifting on the stock drivetrain

SRAM 11-32T 9 speed cassette found on the stock drivetrain

Original FSA aluminium stem

V-Drive aluminium flat handlebar

Avid FR-5 brake levers, with SRAM DualDrive rear shifter to match with the rear derailleur

9 speed Optical Gear Display found on the gear shifter, similar to the SRAM Attack shifter that I had on the Dahon Boardwalk long ago

Simple and lightweight LitePro foam lock-on grips

FSA Energy aluminium seatpost and a rather generic saddle

Finally, the Wellgo QRD M111 Quick Release pedals. The pedals can be removed easily for more compact storage, just by pulling up on the red release button.

In the next part of this project, I will be disassembling all the components from this stock bike, and seeing which components are worth keeping, and which will be upgraded.

Click here for Part 2

Monday, August 17, 2015

Introduction to Shimano Road Hydraulic Brakes + Shifters: ST-R785 & ST-RS685

The most interesting and controversial development for road bikes in recent years has been the push towards disc brake systems. Current road bikes use caliper brakes, which has worked well for many years. So why is there a move towards disc brakes for road bikes, as can be seen from top cycling teams trying out disc brake road bikes in competitions?

Disc brakes for bicycles is not new. Mountain bikes have been using mechanical and hydraulic disc brakes for over 20 years, and it is already well accepted, almost compulsory in fact. Even entry level mountain bikes use hydraulic disc brakes, not just high end trail or downhill bikes.

Typical hardtail mountain bike with hydraulic disc brakes

Road bikes have not transitioned to using disc brakes, because of two main reasons. The first is because disc brake systems are currently heavier than caliper brake systems. This is true, but with recent developments in component technologies, the weight difference is getting smaller. As most road cyclists would understand, getting the road bike as lightweight as practically possible is important. Whether or not it really improves your speed is another matter altogether.

The second reason is because there is usually no need for the higher braking power of disc brakes. For many years, caliper brakes have provided sufficient braking power in most situations. However, when the weather turns wet, or when the terrain gets steep, caliper brakes are no longer able to provide sufficient braking power, especially when it is a wet downhill route. Disc brakes are able to cover this deficiency by providing good braking power in all weather conditions.

For a more detailed comparison of the pros and cons of different brake systems, refer to this link for more information.

Now, for road bikes, it is not as easy to change over from a caliper brake system to a disc brake system. First of all, the frame needs to be different, as disc brake mounts are required for mounting the disc brake calipers. Then, the brake levers might need to be different, especially when hydraulic disc brakes are to be used. Lastly, the wheel hubs also need to have disc brake rotor mounting.

Hydraulic disc brake on a road bike. Note the disc brake mounts required on the fork, and the brake rotor mounting required on the wheel hub.

Road bikes have been using brake/shifter lever combos for many years. These are also called road shifters, where the brake levers and shifters are integrated into one unit. The braking system has always been using steel brake inner cables, which can be connected to caliper brakes or in certain cases, mechanical disc brakes.

However, mechanical disc brakes have long suffered from poor braking power and a mushy lever feel, and is vastly underpowered compared to hydraulic disc brakes. In my opinion, if a disc brake system is used, it should be a hydraulic disc brake system.

The tricky part for implementing hydraulic brake levers on road bikes has been the challenge of integrating the hydraulic master cylinder into the road shifters. There is simply no space to fit both the master cylinder and the shifting mechanism into the road shifter, without making it too big and bulky.

This problem was solved with the introduction of Di2 electronic shifting systems, where the shifting mechanism is no longer required in the shifters. The Di2 road shifters have been slimmed down, and the complex shifting mechanism has been replaced by electronic shift buttons and a simple circuit board. With this breakthrough, there is now space for the hydraulic master cylinder to be placed in a Di2 road shifter!

As the first generation of road Di2 shifter with integrated hydraulic brake lever, the Shimano ST-R785 is a non series road shifter designed for Di2 equipped road bikes with a hydraulic disc brake system. It is being marketed as a Ultegra grade Di2 road shifter with hydraulic brakes. Let's take a closer look at this road shifter and see how the integration is done!

Shimano ST-R785, a Di2 road shifter with hydraulic brakes. Slightly taller at the front of the hood as compared to mechanical road shifters.

Being a Di2 shifter, what you get are two buttons instead of shifting levers. The buttons are textured differently for easy identification.

The bracket cover removed from the main bracket. Note the multiple protrusions from the rubber, designed to hold the cover securely to the bracket.

Side view of the bracket, which is cast out of aluminium, unlike the engineering composite used for mechanical road shifters. The hydraulic brake hose will connect to the rear of the bracket, above the clamp band.

Clamp band is still tightened to the handlebar in the same way, accessible from the side.

The Di2 electronics, which is just a little box with a wire that connects to the buttons. The other end of the box has one port for plugging in a Di2 wire.

The pivots for the hydraulic brake lever is located higher up than on mechanical road shifters. This gives a different braking feel due to the different movement arc of the brake levers. The free stroke adjustment screw is also shown here.

To bleed the hydraulic master cylinder, the chrome cover needs to be removed first. The master cylinder is integrated within the aluminium bracket.

Bleeding port is located way up on the bracket. The brake lever reach adjustment screw is also shown here.

Hydraulic piston located inside the bracket, which pushes the hydraulic fluid out of the bracket and towards the brake caliper.

Similar weight to the Shimano 105 ST-5800 mechanical road shifters, despite having no shifting mechanism. This is mainly due to the large aluminium bracket which is heavier than engineering composite material.

As shown above, that was the non series ST-R785 Di2 road shifter for hydraulic disc brakes. The master cylinder is able to fit into the bracket without making the entire shifter too big.

The thing is, not every rider is able to afford Di2 shifting components, and so there needs to be a way to integrate mechanical shifting with hydraulic brake levers. This is where it gets really challenging, which is to fit the shifting mechanism plus the hydraulic master cylinder into a road shifter, without making the road shifter too bulky. Amazingly, it has been done, and the result is the non series Shimano ST-RS685 road shifter, which has mechanical shifting and hydraulic brake levers.

Shimano ST-RS685 road shifter, with mechanical shifting and hydraulic brake levers.

Still looks similar to a normal mechanical road shifter, just that it has a longer bracket and a taller hood. Quite amazing that everything fits into the bracket!

Front view of this non series road shifter

Taller hood, but not as large as the size found on SRAM road shifters with hydraulic brakes

Once the rubber cover is removed, the full layout can be seen! There is a metal pipe that links the master cylinder at the front of the bracket to the hose connector at the rear.

The hydraulic hose will be plugged into the connector located at the rear of the bracket.

Triangular shaped master cylinder located at the top of the hoods

This hydraulic brake lever design also incorporates Servo-Wave technology, as shown here with the use of a cam mechanism.

Shifting mechanism is located well within the bracket. Shown here is the inner cable insertion point, similar to Shimano 11 speed mechanical road shifters.

The shifter inner cable passes through the bracket and leads here, then turns 90 degrees to exit from the back of the bracket.

With the bottom cover removed, the complex shifting mechanism can be seen, ingeniously squeezed into the bracket.

Weight of one side of the road shifter is 322 grams, which is quite heavy. Once again, this is due to the combined weight of the aluminium bracket, shifting mechanism and the master cylinder assembly.

With that, a brief introduction to Shimano road hydraulic brakes + shifters is complete! It is a feat of engineering to be able to fit all the mechanisms into the road shifter, without making it look too bulky or affecting the gripping ergonomics.

If you are buying a new road bike, it is worth considering hydraulic disc brake options, as that is the trend that road bikes are moving towards. With a disc brake compatible frame, you can be sure that you will be able to install the latest innovations in road disc brake technologies, and have a future proof bike.

Road bikes with hydraulic disc brakes are the next wave of new technology, and it is already here, as can be seen from major bike brands all offering disc brake road bike options. Professional cyclists are still using caliper brakes, as the UCI has not approved disc brakes for road cycling competitions yet. However, that is just a matter of time, as seen by the on-going disc brake trials going on in some road cycling competitions. Once disc brakes are approved for top tier road cycling competitions, you can be sure that things will move and change very fast. That said, traditional road bikes with caliper brakes are here to stay, and will not be phased out anytime soon, as they still have their own charm and advantages.