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!