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Old 03-30-2014, 05:34 PM   #244
Mobius1
n00b
 
Joined: Mar 2014
Oddometer: 1
Greetings

Greetings all. Violetpop, Compliments on your beautiful build. My first post here (didn't see an intro page). I recently received a commision to build an r/65 mono which is why I am so interested in your build, and how I came to find it here. Interestingly, my client imported his bike from Australia. They are rare here in the US. I am compelled to write because of the linkage for your rear brake. There will be pronounced motion of the brake pedal as the suspension travels through its range. You can see this for yourself if you support the bike (like it was on a center stand), remove the shock and move the swing arm up and down. When you do, you will see the brake pedal move also. I know this has already been commented on, but there is possibility of a serious safety issue - even if you do not use the brake. Most mechanical systems come stock with an adjustable stop that determines how high the pedal is when not depressed. The brake is then adjusted to for the desired travel. If your setup has such a stop, it is possible that the brake will be engaged, maybe strongly, when the suspension is sufficiently compressed. At the least, the pedal will oscillate in sympathy with the suspension motion, causing it to be rather hard to use. The stock set up does not have this problem (actually it does, just so negligible it becomes unimportant) because of the location where the pull rod (push rod in your case) is actuated from. The pull point must be as close to the swing arm pivot point and on a line between that pivot and brake lever arm pivot as possible. If it is close enough, the kinematic issue is too small to be a problem. I would like to add, that using that long rod in compression, while it can be engineered to work safely, is generally not the best idea. Imagine you really stomped on the pedal for some reason (or if it struck something). Could it collapse and bend into the rotating components? Not trying to be a doomsayer here, and please don't take any of this as criticism. It is possible the arm is plenty strong, and the oscillation will be merely annoying, but I would hate to have a brother motorcyclist possibly get hurt and have said nothing. Again, love your build and am inspired anticipating delivery of of the beemer - my next victim! - as soon as it clears customs!

cheers

Mobius1 screwed with this post 03-30-2014 at 05:52 PM
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