Wheelsport Ultegra Di2 2x11 Speed: Part 7 - Wheelsport Smart 1.0 451 Wheelset + Schwalbe One 451 Tires

Part 1: Frame Design and Carbon Fork
Part 2: Compatibility Check for Wheelset and Brake Calipers
Part 3: Component Selection
Part 4: Installation Issues and Solutions
Part 5: Final Assembly
Part 6: Accessories and Geometry Comparison

After riding the Wheelsport Fantasy Ultegra Di2 2x11 Speed mini velo for a while, I realised that the bike rode very well, but the braking performance was not good enough for me. To recap, this bike was built using a set of 406 wheels, and this required using the Tektro R559 Extra Long Reach caliper brakes. This was because the frame was originally designed for 451 wheels and standard caliper brakes. Using a smaller rim would require longer reach brakes. Although these brakes work, the leverage and braking power suffered due to the extra long reach.

I have changed the brake pads to the better SwissStop brake pads, but the braking performance was still not good enough. The only way to get more braking power is to use better caliper brakes, which are all of standard reach. An example would be Shimano 105 or Ultegra caliper brakes.

In order to use standard reach caliper brakes, it would be necessary to use the larger 451 wheels. I have been resisting changing to 451 wheels, as I still want to use my custom wheelset with gold rims and Chris King rear hub. It will also allow me to have common sized inner tubes across three different bikes (the other two being Dahon MuEX and Dahon Vitesse).

However, it seems that I have no choice this time, if I want to improve the braking performance on this bike. The decision was thus made to change to 451 wheels, so that I can use better caliper brakes to improve braking performance.

As previously reviewed, the Wheelsport wheelsets are actually good value for money, and so I decided to get a new set of Wheelsport 451 wheels for use on this mini velo. Note that there are many specifications for a wheelset, such as rim size, hub width, 11 speed compatibility, etc. In this case, I would require a 451 wheelset, with 100mm/130mm hub width, 11 speed compatibility, and in black colour.

The specific wheelset has been found! 451 wheels, 100mm/130mm to fit this frame, and 11 speed compatibility for the Ultegra Di2 2x11 speed drivetrain.

Sweet pair of new Wheelsport Smart 1.0 451 wheels! Black and white matches the frame perfectly.

11 speed compatible free hub body

QR axles are included, but I will use my own QR axles that are better.

Stock plastic rim tape that came with the wheelset. Will change it out to cloth rim tape which is better for high pressure tires.

Velox cloth rim tape, best for high pressure tires. Prevents mysterious inner tube punctures.

793 grams for the 451 rear wheel with rim tape

584 grams for the 451 front wheel with rim tape

This gives a total of 1377 grams for the pair of 451 wheels, which is more than 200 grams heavier than the 1152 grams of the custom 406 wheelset. This change of wheelset would add 200 grams of rotating weight to the bike, which is not ideal for acceleration. Nevertheless, it is necessary to improve the braking performance.

Before installing the cassette, I decided to clean and regrease the ratchet mechanism in the free hub as it usually comes with very little lubrication. What I found was yet another free hub construction that differs slightly from the other two Wheelsport freehubs that I had previously seen.

Ratchet design is the same.

6 pawls are held down by 1 circular spring. I actually prefer to have 3 pawls with individual springs, as there would then be less freewheeling resistance and also redundancy design.

Regreasing the ratchet with fresh free hub grease

A new 451 wheelset also requires new tires! However, I was told that there are limitations as to what tires I can use on 451 wheels, as there is limited frame clearance for tires. When I was previously using 406 wheels, I could put on wider and taller tires as there is plenty of clearance. With 451 wheels, I can only use narrow and slim tires, which is why I decided to get the 23mm wide Schwalbe One tires. I am also using Schwalbe One tires on my Merida Scultura 5000 road bike, which works really well.

Pair of folding Schwalbe One tires for 451 wheels

23-451 means 23mm wide, or about 0.9 inches wide. These tires are even narrower than the 25mm tires I am using on my road bike!

These tires are lightweight at only 323 grams for a pair (about 162 grams each).

451 sized inner tubes are required too

A pair of Schwalbe SV7B inner tubes weigh 156 grams (78 grams each).

Recommended tire pressure is 100 to 160 PSI! That is quite high, and is only achievable using a floor pump. The advice given to me is to pump it to 120 PSI for a fast and comfortable ride.

With the Schwalbe One tires installed on the Wheelsport Smart 1.0 451 wheelset! Once again, a black and white design theme can be seen.

Comparing the 23mm wide, 451 sized Schwalbe One tire against the 35mm wide, 406 sized Kojak tire.

The Kojak tire bulges out quite a lot from the rim, creating a light bulb shape

The slim Schwalbe One tire is flush against the rim, making it more aerodynamic too.

Comparing the front wheels. 406 wheels with Kojak tires vs 451 wheels with Schwalbe One tires. The overall wheel diameter is actually quite similar!

New 451 wheel on the left vs old 406 wheel on the right

Changing from 406 wheels to 451 wheels also causes the overall gear ratio to increase, as the wheel size is now increased from 20 inch to effectively 22 inch. This is an increase of 10% which is quite significant. The tables and graph below will give you a better picture of how the gear ratio (in gear inches) is affected.

Gear ratio is increased by 10% across the board, which translates to bigger gaps at the higher gears as compared to the lower gears.

Entire gear range is pushed up by 10%.

Increasing the overall gear range would make the top end gear range higher than was previously intended, but I believe that this higher top gear will still be utilized as the faster 451 wheels would allow a higher speed to be achieved. The gear range has been increased from 65.7 gear inches (94.5 - 28.8) to 72.3 gear inches (104 - 31.7).

Now that the wheels have been upsized from 406 wheels to 451 wheels, the next step is to change to standard reach caliper brakes for better braking performance! To be continued in the next post.

Click here for Part 8