95 cr125 linkage bolts?

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7/11/2017 8:50 AM
Edited Date/Time: 7/11/2017 10:07 AM

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Hi folks. 95 cr125.I found a good amount of slop in the upper "cushion arm bolt" (long bolt that goes through swingarm) . The bearings and bushings are new. The slop is between the bolt and new bushing. It's a lot of play at the rear wheel with bike on stand.
The bolt is very slightly worn, its odd that it creates that much play at the wheel. So, I'm looking for a source for the bolt 90128-kz4-710 these are discontinued from Honda. Wondering if there is an aftermarket option other than rusty eBay parts?( I also found play between the bolt and swing arm bosses. Is that normal, or is the fit supposed to be zero play from factory?)
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7/11/2017 3:11 PM

This is an issue I've recently had myself on a friends 96 CR.
Suspension bolts don't have to be 'bearing fit' tolerence like wheel spindles, as the system relys on the clamping force from the bolt being tightening to hold the centre bush/pivot tight for the bearing to work.
Sometimes the slot in the swing arm where that pivot point fits can get worn (or some times the center pin or collars can be a smidge shorter than they should be) and with the big lumps of alloy of the swing arm each side, the bolt simply won't pull them in enough to pinch the pivot up tight, causing the clunking and play which you can hear and feel at the wheel. The geometry of the suspension linkage means that the wheel movement is scaled down for the shock to control, in reverse it magnifies the movement. There's maybe only 0.06-0.12mm of movent on the actual pivot point, but at the wheel feels HUGE!!
I can make a new bolt with a tighter tolerence then the original (Titanium or Stainless) but i'm not sure it would cure the issue. I'd pull the 'arm off and measure the mounting slot, the pivot pin, and the collars. (Use a pair of vernia scales and a micrometer) A slightly thicker pair of collars or a shim behind them may do the trick, and would a lot cheaper than a new bolt!!

Stevie

Maybe I've done myself out of some work, but I would feel bad if it' was not the bolt causing your issues!!

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7/11/2017 5:32 PM

StevieD113 wrote:

This is an issue I've recently had myself on a friends 96 CR.
Suspension bolts don't have to be 'bearing fit' tolerence like wheel spindles, as the system relys on the clamping force from the bolt being tightening to hold the centre bush/pivot tight for the bearing to work.
Sometimes the slot in the swing arm where that pivot point fits can get worn (or some times the center pin or collars can be a smidge shorter than they should be) and with the big lumps of alloy of the swing arm each side, the bolt simply won't pull them in enough to pinch the pivot up tight, causing the clunking and play which you can hear and feel at the wheel. The geometry of the suspension linkage means that the wheel movement is scaled down for the shock to control, in reverse it magnifies the movement. There's maybe only 0.06-0.12mm of movent on the actual pivot point, but at the wheel feels HUGE!!
I can make a new bolt with a tighter tolerence then the original (Titanium or Stainless) but i'm not sure it would cure the issue. I'd pull the 'arm off and measure the mounting slot, the pivot pin, and the collars. (Use a pair of vernia scales and a micrometer) A slightly thicker pair of collars or a shim behind them may do the trick, and would a lot cheaper than a new bolt!!

Stevie

Maybe I've done myself out of some work, but I would feel bad if it' was not the bolt causing your issues!!

Responses like this are what make Vital awesome! I will take it down tomorrow and measure everything. It currently has aftermarket bearing kit in the arm, I bought some Honda oem to try just in case it's a supplier tolerance issue. Ill swap out the parts tomorrow and see what happens. I hadn't considered the side load clamping force to swing arm lugs. Perhaps a very thin shim. Will update. Many thanks

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7/12/2017 8:55 AM

a quick update, I found a small difference in size between the aftermarket bushing and the oem bushing, which may have been enough to cause the play at the wheel. With the oem bushing most of the play is now gone. I found a little play in the upper spherical shock bearing that will need taken care of as well, but its much better now, the linkage bolt will get replaced soon, but Im itching to ride, so it will go a few more laps.

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