Thursday, September 24, 2015

Wheelsport Ultegra Di2 2x11 Speed: Part 2 - Compatibility Check for Wheelset and Brake Calipers

After introducing the Wheelsport Fantasy 2.0 mini velo frame and carbon fork in Part 1 of this upgrade series, it is now time to check the other components for compatibility with this frame. As I will be moving over most of the components from the Dahon Boardwalk folding bike, some of the components may not be compatible due to the different frame design.

Two areas which are critical would be the wheelset and brake caliper compatibility. The Dahon Boardwalk folding bike uses a front hub with a 74mm Over Locknut Dimension (OLD), while the Wheelsport Fantasy frame has a standard 100mm front OLD. Both the frames can accept a standard road rear hub of 130mm OLD.

Therefore, I will need to convert the width of the front hub from 74mm to 100mm, in order to continue using the same Chris King/Novatec wheelset on the Wheelsport frame. There are adapters available that can be used to extend the front hub from 74mm to 100mm. Some of them are the screw on type, which is meant to replace the current end cap on the front hub, while others are merely fitted onto the existing end cap and secured with the QR axle.

The first choice is of course to use screw on adapters that will be more secure and also stronger, but since different brands of hubs have different hub dimensions, it is difficult to find a suitable adapter. I tried the Wheelsport front hub adapter, but it does not fit as the thread size of the screw on end cap is different from the Novatec front hub end cap.

The longer Wheelsport end cap on the left (to convert 74mm to 100mm), and the original Novatec end cap (74mm). However, it cannot be used as the thread size is different.

Since the screw on type of adapter cannot be used, the alternative is to use a simple adapter that is just fitted onto the end of the existing front hub. This will increase the front OLD from 74mm to 100mm. This adapter can fit practically all QR front hubs as the cylindrical area that slots into the front fork ends are the same dimension for QR front hubs.

Elosix front hub adapter to convert the OLD from 74mm to 100mm

It fits onto the end of the existing front hub end cap, and once installed in the frame, it will be secured by the compression of the front fork and the QR axle.

Now that the front hub OLD issue has been solved, the next compatibility check would be the braking system. The Wheelsport Fantasy frame is designed for caliper brakes and 451 wheels (around 22 inch in diameter), but the current wheelset that I plan to use is a 406 wheelset (around 20 inch in diameter). As the wheel is smaller, using standard road caliper brakes will result in the brake pads being unable to reach the rims on the 406 wheels.

For the front fork, I first tried to install the Elosix Front Brake Adapter, which will move the mounting point of the caliper brake downwards. This might enable me to use standard road caliper brakes.

Elosix Front Brake Adapter, originally designed for Dahon bikes

Installation of this Elosix front brake adapter is successful, but now the front brake mounting point is too low and too close to the tire. When I tried installing the brake caliper, the brake arm will rub against the tire.

Using the Elosix Front Brake Adapter will move the mounting point too close to the tire. Not suitable for use.

In this case, I will have to use extra long reach caliper brakes, such as the Tektro R559 brake caliper that was previously used on the Dahon Boardwalk and Dahon Vitesse. The distance from the front brake mounting point to the wheel rim is about 70mm, so it should be possible as the Tektro R559 brakes has a maximum reach of 73mm.

Reach of 70mm is required for the front caliper brake, due to the large distance between the brake mounting point and the rim.

As for the rear brake, I measured the reach required to be 62mm. This also means that I will need to use the Extra Long Reach Tektro R559 for the rear brakes, as standard road caliper brakes have a reach of only 39-49mm.

Reach of 62mm is required for the rear brake.

In order to confirm these theoretical calculations, I moved the Tektro R559 brake calipers from the Dahon Boardwalk to the Wheelsport Fantasy frame. Before that, I took the opportunity to re-install some gold hardware onto the Tektro R559 brakes, such as the gold coloured cable adjust bolt and brake pad holders.

Tektro R559 caliper brakes with gold cable adjust bolts and brake pad holders

Overall weight of 350 grams for this pair of Tektro R559 caliper brakes

Tektro R559 installed on the front fork, and is able to reach the rim with no problem. Wheelsport Fantasy carbon fork with 406 wheels and Kojak tires.

One advantage of using 406 wheels in this fork (originally designed for 451 wheels) is that I can use wider tires. Seen here is the Schwalbe Kojak 20x1.35" tires which are 35mm wide.

Also plenty of tire clearance for the rear, and thus is able to run these 35mm wide Kojak tires with no issue. If a 451 wheelset is used, it can take a maximum tire size of about 25-28mm.

A standard bolt and nut fixing is used for the rear brake caliper due to the length of the axle on the brake caliper.

Seems that there is no problem with using 406 wheels and wide Kojak tires in this frame! There is plenty of tire clearance with the frame and brake calipers, and the extra long reach brake calipers is also able to reach the smaller 406 wheels.

While checking the compatibility of the wheelset and brakes, I also found that the rear derailleur hanger is a bit bent. Having a bent RD hanger will make it difficult to get good rear shifting performance, as the RD cannot be properly aligned to the cassette gears.

RD hanger is slightly bent, and now is the best time to fix it before installing more components.

RD hanger alignment tool

As described in an earlier post about the other Wheelsport Fantasy mini velo (2x10 speed, flat handlebar), the RD hanger alignment tool can be used to check the alignment of the RD hanger, and also make minor adjustments to the RD hanger to achieve good alignment with the cassette.

With that, this frame is now ready to accept the other components! Wheelset and brake compatibility issues have been studied and solved, and there should not be other major issues for this bike upgrade.

In the next part of this upgrade series, the components that have been selected for this Wheelsport Fantasy mini velo will be shown.

Part 3 here!

Friday, September 18, 2015

Wheelsport Ultegra Di2 2x11 Speed: Part 1 - Frame Design and Carbon Fork

My Dahon Boardwalk has served me well over these few years, from routine commuting purposes, to overseas touring trips, and is generally a very good all purpose bike. It had to fulfill a variety of purposes, as I could only have one bike due to limited space and cost. That explained the various upgrades and add-ons to the bike to allow multi-purpose usage.

With the addition of a few other more specialised bikes to my collection, such as the fast Merida Scultura 5000 road bike, the wet weather Avanti Inc 3 commuting bike, and the compact folding Dahon MuEX, the Dahon Boardwalk no longer needs to be a do-it-all bike. With the road bike being faster, the commuting bike being more weather resistant, and the Dahon MuEX having a more compact fold, the Dahon Boardwalk seems to be losing its relevance with respect to my usage.

With that in mind, my intention is to build a new bike that is different from the other bikes mentioned above. With the success story of upgrading the 2x10 speed flat handlebar Wheelsport Fantasy mini velo bike, I have come to realise that the Wheelsport Fantasy frame is actually a pretty good mini velo frameset. That gave me the idea to use this mini velo frame as the basis for a new bike project.

The overall plan is to transfer all the components from the Dahon Boardwalk to the new Wheelsport Fantasy mini velo frameset. This would create a new bike that is different from my other bikes. A fast and lightweight mini velo equipped with a Ultegra Di2 11 speed road groupset and fast rolling 20" wheels would differentiate it from my other bikes.

As a mini velo frame, this frame is not foldable. However, this is not a problem for me as I find that I hardly ever fold my Dahon Boardwalk nowadays. If I need a folding bike, I prefer to use the Dahon MuEX instead as it is more compact and lightweight.

Let's take a look at the new Wheelsport Fantasy 2.0 frameset!

Smart looking Wheelsport Fantasy 2.0 mini velo frameset in matte black

Designed for caliper brakes only, as can be seen from the brake mounting on the seatstays.

Welds on the aluminium frame have been sanded and polished, giving a very well finished look to the joining areas.

Nice and smooth welds look similar to those found on high end Tern and Tyrell frames.

Glossy black Wheelsport decal on the matte black frame for a very subtle look. Similar to that found on the Avanti Inc 3 frame.

Cable stoppers for shifter outer casings. Cable adjust bolts are included, but I removed them as they are not needed, since I am using Di2 shifting.

English threaded BB shell that is 68mm wide, which is the standard spec for road bikes.

Underside of the BB area on the frame. The cable guide has been removed as it is not required.

Overall weight of the frame alone (inclusive of headset cups, RD hanger and seatpost clamp) is about 1760 grams.

Compared to the Tyrell FX frameset weight (2.2kg for frame only), this Wheelsport Fantasy frame is lighter by about 400 grams, which is great. One difference is that the Tyrell frame has folding capabilities while this Wheelsport frame does not.

Next, let's look at the front fork of the Wheelsport Fantasy frameset. There are two types of forks available. The first is the aluminium type with a steel steerer tube, which is meant for use with a folding handlepost. Then, there is the more lightweight version, which is a carbon fork with a long aluminium steerer tube. This carbon fork is designed to be used with a long carbon spacer, and thus does not have a folding handlepost. For maximum weight savings, the carbon fork is the one to use.

Wheelsport Fantasy carbon fork with long aluminium steerer tube

Carbon fibre weaving on the fork can be seen through the clear coat.

The fork weighs 605 grams, not really lightweight. This is due to the long steerer tube required. However, it is still lighter than the Tyrell FX folding fork which is 900 grams.

Carbon spacer that will be used together with the carbon fork. Usage will be shown in the subsequent posts.

Weight of headset bearings and top cap is 70 grams.

With this, the total frameset weight is slightly over 2.5kg. Not really lightweight, as average road bike carbon framesets are usually 1.6kg or below. Still, the weight of this Wheelsport Fantasy frameset with carbon fork is lighter than the Tyrell FX frameset weight of 3.1kg. Also, it is cheaper than the Tyrell FX frameset.

Now that the new frameset is ready, it is time to move the components from the Dahon Boardwalk over to this new frame! However, due to me using some non-recommended components and setup, I will first need to check the compatibility of the wheelset and brakes.

Click here for Part 2!

Tuesday, September 15, 2015

Wheelsport Fantasy Flat Handlebar 2x10 Speed: Part 4 - Final Assembly and Comparison

Part 1: Original Bike Components
Part 2: Bike Disassembly and Component Weight
Part 3: Installation of New Components


Finally, this is the last part of the Wheelsport Fantasy 2x10 Speed Flat Handlebar bike upgrade! In the previous posts, the original bike components have been documented, and the stock bike disassembled. After that, the bike was rebuilt with a mixture of stock and new components.

In this post, I will finish up this bike upgrade, and compare it to the Dahon Boardwalk in terms of bike geometry.

Shimano 105 5700 10 Speed Crankset, 53/39T, taken from the Dahon MuEX

BB guide as shown mounted under the frame. The inner cable on the left leads upwards to the FD, while the inner cable on the right leads to the RD.

Rear shifter outer casing, shown here with a long nose end cap, to better protect the inner cable from wear and tear. Shimano 105 5700 10 Speed Rear Derailleur from the Dahon MuEX is used here.

Shimano 105 5700 Double FD as mounted onto the FD mount provided on the frame

With the full drivetrain mounted! All black to match well with the frame.

Gear range and ratios for this drivetrain setup, with 13 unique gears. 451 wheelset with 53/39T crankset and 12-30T cassette. This gear range should be good for any terrain.

Front brake calipers installed. Small clearance between tire and brake caliper, which means that wider tires (>25mm wide) cannot be used.

Rear brake calipers as installed on the bike. Once again, the small tire clearance limits the maximum tire size that can be used.

The length of the rear brake outer casing needs to be just right. Too short and it would stretch during braking, too long and there would be excessive friction.


Round 3M frame protection stickers have been pasted at strategic locations, to prevent the outer casing from rubbing away the paint on the frame.

With that, the upgrade from 1x9 speed to 2x10 speed is complete! Here is more info regarding the weight of the upgraded bike, and also some added accessories for the bike.

Full specs of the upgraded bike. Good weight of 8.8 kg without pedals! Just a little bit lighter than the original bike weight of 8.9 kg (excluding pedals and kickstand). This is despite adding around 300 grams with the addition of the front shifter, FD and cables.

The D-Light rear light fits perfectly on the seat tube, within the small triangle on the frame.

The D-Light front light also fits nicely on the handlepost, keeping the handlebar clutter-free. Mounted in a similar way to that on the Merida Scultura 5000.

Cateye Strada Wireless cycle computer mounted on the stem, in a very visible location

Side view of the upgraded bike

Looking pretty good!

With a folding handlepost, the handlebar can be folded down to make the bike really flat for storage, as seen here. This makes the bike a semi-folding bike?

When hanging the bike on the Minoura Bike Tower 10, the small frame does not really fit on the hooks properly

The front hook is OK, as it can grip the frame fully

However, the rear hook cannot hold the frame fully, as the frame top tube is too short. It will tend to touch the rear brake cable. Still, it is possible to hang the bike on this bike tower.

Lastly, the geometry of the Wheelsport Fantasy mini velo will be compared to the geometry of the Dahon Boardwalk. This will show the difference in geometry for this bike, as compared to the well established geometry of the Dahon folding bike. To compare the bikes, the BB is used as the datum and reference point. This means aligning the bikes such that the BB of the bikes are aligned beside each other.

The rear chainstay length of the bikes are slightly different. Dahon is 400mm, Wheelsport is 420mm. A longer chainstay contributes to a more stable bike at high speeds, but is also less agile.

Although the handlepost of the Wheelsport tilts much further backwards, unlike the vertical angle on the Dahon, the Wheelsport has a stem that brings the handlebar forward.

As seen here, the handlebar of the Wheelsport is located quite a bit higher and also rearwards. This creates a more upright riding position for the Wheelsport bike, which can be good or bad, depending on rider preference. Great for more leisurely rides, but not ideal for faster rides.

Side view of the bikes for comparison. Overall, the Dahon still has a longer wheelbase of 1020mm, while the Wheelsport mini velo has a wheelbase of 1000mm.

This upgrade is finally completed! I am glad to have had this chance to upgrade the Wheelsport Fantasy 2.0 mini velo, and I learnt quite a bit during the process. The bike has been nicely upgraded to a high performance 2x10 speed drivetrain, using mostly components taken from the Dahon MuEX (which has been upgraded to Ultegra/XTR Di2).