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View Full Version : Riser bush sleeve - how much clearance?


Nufkamp
10-02-2014, 07:03 PM
I'm about to change my existing riser bushes for poly ones, but I'm just wondering how much clearance there should be between the steel bush and the riser bolt? I've measured the bore of the old steel bush and it's 0.515", and to me the bolt (diameter 0.495") seems rather sloppy in the sleeve. One of the things that's annoyed me is the 'click-click' of the bars when I hit a lump or hole in the road and I'm wondering if this is due to the sloppy fit twixt bolt and sleeve. I was going to knock up a pair at work and reduce the clearance, but thought I'd better check if there is a reason for the clearance being this big, half a millimeter in new money.

Any thoughts?

noisygit
13-02-2014, 04:09 PM
That's only 20 thou clearance which equates to 10thou or 0.25mm per side so I would have thought that was about right, let's see what other people say though.

harry
13-02-2014, 10:18 PM
What type of forks are we talking about?

Nufkamp
14-02-2014, 06:28 PM
Standard Night Train forks, 39mm dia. Standard yokes.

rob
14-02-2014, 08:54 PM
why would you want any clearance between the bolt and the bush? surely you want a tight push fit?

Nufkamp
15-02-2014, 05:30 AM
why would you want any clearance between the bolt and the bush? surely you want a tight push fit?

The only possible reason that I can think of for a big clearance is that whoever makes the top clamps has no control over the pitch of the holes :D

Anyway I've made a pair with about 0.1mm clearance, see if that sorts it out.