1: improperly setup brakes. I can lock my front wheel with my dahon, and this is with rim brakes. The rear is sluggish due to the amount of cable housing length, can't be helped.
2: huh?
3: never seen this. Pics or it didn't happen.
1: V-brakes or caliper brakes? V-brakes are powerful enough to be sufficient even if they are crippled. Plus the geometry is different and I think the mounting bosses are stiffer than a regular caliper.
2: For a 27" wheel, 8" ahead of the fork crown the rim is basically still at the same height as it is directly under the fork crown, but for a 16" wheel, 8" ahead of the fork crown the rim is located all the way down by the axle. So for a brake which protrudes x mm ahead of the fork crown the brake arms need more "reach" to reach the rims on a smaller wheel. The smaller the wheel diameter the more pronounced the problem.
3:
19735469232_ORIG.jpg
I think the curvature of the smaller wheel does not have anything significant to contribute to downward bending forces on the brake bosses. It is the brake bosses you mean, isn't it?
No I'm talking about caliper brakes mounted with a bolt through the fork crown. See pic above.
Originally Posted by
rhenning
In a perfect world the center line of the brake bolt should be perpendicular to a line that goes through the center of the wheels axle. Most bikes are close but not perfect. Roger
...and the smaller the wheel the less close it is.
So first I notice the brakes are crap no matter how much adjustment. Second I get some new brakes, but they don't reach even though the "reach" measured from the bolt to the brake pads is the same as the old ones, reason: the arms of the new brakes are farther ahead of the fork crown where the rim is lower due to curvature. Last I notice the old brake bolt is bent down. So I'm wondering if the cause of all these problems is that the brake bolt is not "perpendicular to a line that goes through the center of the wheels axle" (ie not tangent to the rim).
Make it tangent = solve the problems? I dunno and I don't like to make destructive modifications unless I know they will work.