Originally Posted by
Alcanbrad
..... You mention using a larger disc in the rear. What is behind this choice? Is it to beef up the rear braking force or to dissipate more heat? Either way, given what I am saying I would contend that the front would benefit more from a larger disc. We are a 400lb team and have 203mm discs front and back and have plenty of stopping power, we live......
The larger disc offers several advantages:
A larger disc will have a little more heat capacity, but more importantly, much more surface area to dissipate heat.
A larger disc has more mechanical advantage, so will generate less heat during braking.
The additional mech. advantage offers better stopping power. However, I find this the least important of the advantages, as a 203mm rotor would easily exceed the rear tire's traction capacity.
The first two advantages I feel are the main reason to use a larger rotor. This SHOULD obviate the need for a rim brake. That said, a rim brake is a perfectly good additional heat sink to give the rotor and caliper time to cool. I'd do this if I had had issues with overheating on descents. Alternating between the two is a perfectly sensible idea. Or just rely on the disc brake and if things get dire, you have a bail out brake with full stopping power. That's win-win if you ask me!
Ok, back to the Co-Motion rebuild... that has an Aria drum that I just lovingly refreshed!!! I'm SO CLOSE to done!
To do:
Install computer. (Wanna track my miles from the very start.)
Install fresh tires & tubes (Co-Motion rim strips are BOMBER!)
Install chain
Final F & R derailleur adjustments
Install stoker bars.
Wrap handlebars (double wrap? Still deciding)
And TEST RIDE!!!