|
| |
Picking Out a New Bike
[ Up ] [ Next ]
When my wife was picking out her Bike Friday, there were several design  requirements.
- To reduce spare part requirements it should use 406 wheels (a common BMX
size used on our other Bike Fridays).
- To provide a consistent user interface, it should have Campy Ergo levers
(so that it matched our "big wheel" tandem).
- It should have a Sachs/SRAM 3x7 hub.
- It should fit her.
- It should have a 28.6mm seat post (again, so that it would match our other
Fridays).
Doug at Green Gear helped by pointing out that the NWT fit all of those
requirements. All we had to do was add the drop bar option package. He
explained that the NWT used Shimano LX V-brakes with QBP Travel
Agents to allow the Ergo levers to pull enough cable to activate them. He
expressed greater satisfaction with Travel Agent than with the World Class V-dapter
that Green Gear had used in the past. We were thrilled and ordered the
bike.
|
|
The Ergo shifters outperformed our expectations and the fit was great. The
only issue was with the performance of the brakes. The first few rides around the block weren't too
bad, but the braking action deteriorated rapidly. Being the family bicycle
mechanic, the bike, and the problem brakes, were quickly turned over to me.
I started studying the brakes and found several deficiencies:
- Since
the rear brakes were installed on the chain stays, the Travel Agent pulley
created a perfect shelf to hold grit and grime. The grit and grime
added friction to the brake movement.
- The long runs of cable housing and the tight bends required to get around
the bottom bracket introduced extra cable drag.
- The inline brake adjusters didn't work well. The inside diameter of
the adjusters was slightly larger than the outside diameter of the cable
housing. This resulted in unnecessary play in the system. (Inline adjusters
are required here because Shimano assumes that your brake adjusters
are on the lever while Campy assumes that your brake adjusters are on the
caliper. When you mix Shimano calipers with Campy levers, you get no
brake adjusters.)
|
 |
When the rear brake was released, all of these factors combined to produce slack
cable along the mono-tube, and brake shoes that ran too close to the rims.
Every time you applied the brakes, several millimeters of slack cable had to be
taken up before you could start moving the calipers.
With some observations in hand, I started looking for solutions.
|
|
[ Up ] [ Next ]
|
|
