Thursday, May 17, 2012

Caliper Brakes and Stem for the Vitesse P18-TT

In a previous post, I documented how a Dahon Vitesse P9 was converted to a Vitesse P18-TT. It is basically an 18 speed bike with road shifters and bullhorn bars, modeled after the Dahon Speed Pro TT and Vitesse P18. It combines the controls of the Speed Pro TT with the 2x9 drivetrain of the Vitesse P18.

After that upgrade, the bike worked well in all aspects, except for the brakes. The braking was unsatisfactory, due to the poor brake cable routing of the road shifter on the bullhorn bars and the extra friction contributed by the Travel Agents. There was a lot of friction within the system and braking was a chore as a lot of effort was needed to apply the brakes properly.

I have heard that some people have tried attaching a caliper brake to a Vitesse frame, but the rear caliper brake arm is far too short to reach the rims, even when extra long reach brake calipers are used. That was why I used Travel Agents with V brakes to attempt to solve this issue. However, the results were not good.

Finally, I had enough of the poor braking performance. I decided to try putting on caliper brakes on the Vitesse P18-TT, in a similar way to my own Dahon Boardwalk X20-R.

Besides the braking, the bullhorn bars also increased the reach from the flat handlebars. Usually this is good, as it allows you to stretch out more and ride in a more sporty position. However, if you are not vertically-blessed, this increased reach will make it strenuous to reach for the bullhorn bars. Therefore, I also decided to use a LitePro Stem to reduce the reach.

I shall let the pictures do the talking!

Tektro R559 Extra Long Reach calipers, with a very nice polished surface

Black LitePro Stem for 25.4mm handlebars

Right side of rear brake caliper. Using the default brake pads, the reach is slightly too short, which puts it too close to the tires.

With the special brake pads from Aican that extends the reach, the brake pad can be lowered to fit onto the rim properly.

The left side of the rear caliper does not require the special brake pad.

Most of the cases I have heard in which the rear brake calipers cannot reach the rim are on Vitesse frames. For this case, the insufficient reach was quite minor, and could be solved easily. It is possible that the mounting for the caliper brake is not consistent across different model years of Vitesse frames.

The front caliper brakes go on without much trouble. The front mounted bottle cage has been removed as it will interfere with the brake caliper arm when steering.

I tried the brakes with the stock Tektro brake pads, but the performance was quite horrible. It hardly provided any grip when the brake levers are squeezed. This is dangerous, which is why I had to solve it. Instead of getting the Koolstop brake pads which I am using on the Boardwalk, I decided to try out the SwissStop brake pads which is highly recommended.

Pricey, at almost S$40 a set from CRC

 I chose the green one as it seemed to fit my purpose and type of rims.

With the green brake pads from SwissStop, the braking performance was much improved. This has to be due to the better compound used to make the brake pads.

The other part of the upgrade is to add a stem to decrease the reach of the handlebar.

To insert the stem, one side of the bullhorn bar has to be completely cleared

Putting the stem such that the handlebar is behind the stem. This is rarely done, but seems to work fine. Fiber Grip is required to stop the stem rotating in the clamp.

Another view. Placing the stem behind the clamp theoretically has the effect of making the steering more sensitive. However, with the extra reach of the bullhorn bars, the gripping area is still in front of the clamp, and this should not be a big issue.

The brake cable housing coming out of the interrupter brake levers has to be moved as the stem interferes with proper braking function. This was solved by moving the interrupter brake levers further apart to get some clearance between the brake housing and the stem.

View of the rear brakes. With the caliper brakes, the cable routing looks neater compared to using V brakes with the Travel Agent.

Overall view of the Vitesse P18-TT

This is a successful upgrade that managed to improve the braking performance of the bike. Although it is still not very good due to the long cable housing involved, it is better than the previous version of Travel Agents and V brakes. The reach has also been reduced slightly, which makes it more comfortable for the rider.

The Dahon Boardwalk X20-R and the Vitesse P18-TT out on an extended test ride

No comments:

Post a Comment

Every comment is moderated before publishing due to spam bots. If you don't see your comment yet, it is likely that it is currently being reviewed. Thank you for your patience!