K2 / Proflex Riders Group
General => Tech Forum => Topic started by: 02gf74 on March 21, 2011, 12:48:40 am
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Fitted my DIY rear brake adapter t XP-8 swingarm.
Made up from 3 pieces of aluminium alloy; from top to bottom
1. 8 mm bracket to bolt to existing 5 mm hole in swing arm drop out; largest two holes are 6 mm for the caliper bolts.
2. middle piece is 6 mm thick spacer between (1) and caliper (with added weight reduction)
3. 8 mm piece bolts to (1) and has 6 mm bearing fitted; bolt goes though bearing and stay braket; it allows the stay to move relative to the siwngarm with minimal friction. (I didn't want to use the axle as a mounting point as is commonly done)
Last photo show how it all bolts together (additional shims were needed to centralise the caliper about the disc rotor.
Rode the bike and all was mostly well but I was getting the disc rubbing against the inside of the caliper (clearance was about 0.2 mm at the front) when bouncing the rear end* but was fixed by filing the caliper a little bit so all is as good as can be.
Only explantion I have for that is for e swingarm/drop out must be flexing :o
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well done - I like it ;D
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WOW, very well done. :)
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excuse my ignorance, I see that the 2 parts of the adapter on the right are needed to mount the caliper to the frame and also space the caliper out correctly for the disc, but what is the purpose of the part of the adapter on the left? the part which appears to mount onto the swingarm pivot point? Is that purely there for bracing?
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Just like brake calipers have two mounting points, the part on the left (with the bearing) is the second mounting point to the frame. If it was not there, the adapter would twist and it is unlikely the single 5 mm bolt wold be strong enough (that incidentally is a concern but got about 20 miles in and no probs so far).
Here are some better photos.
(http://img.photobucket.com/albums/v383/02GF74/XP8%20disc%20brake%20adapter/DSC07108.jpg)
(http://img.photobucket.com/albums/v383/02GF74/XP8%20disc%20brake%20adapter/DSC07109.jpg)
(http://img.photobucket.com/albums/v383/02GF74/XP8%20disc%20brake%20adapter/DSC07110.jpg)
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That looks awesome! However, I think you need to trim the side of the upper mounting point a bit so you can fit a Teflon washer between the bracket and the shock strut.
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I think you need to trim the side of the upper mounting point a bit so you can fit a Teflon washer between the bracket and the shock strut.
I know what you mean but I do not need one - to avoid exactly that is why I designed the bracket to take a bearing.
The bearing is pressed in and there is a thin shim between the inner race and the stay so that when the bolt is done up, the bracket pivots on the beaing - less friction than with a washer.