Swingarm Bearing Test
- Thread starter Vince
- Start date
piranha-bro2
Hero member
- Location
- Melbourne
Surely you just put lateral force on, rocking from side to side and see if there's any play??? With the nuts loose you've got no chance!
chrisk
Hero member
- Location
- Brisbane, Australia
Piranha Brother 2 said:
The play will be mainly in the up and down movement. For example, try moving the wheel sideways with one hand at the top and one at the bottom of the wheel.
I was thinking with significant clamping force and a big enough area at the contact points plus any bracing from the shocks especially the older less racked mounting style it might disguise any play in the bearings, looks like I need to try it both ways and see. Anyone know the toque these nuts should have and what effect this has on friction. The only time I ever found play in steering head bearings by hand pushing the wheel the bearings were completely knackered,
small play could be felt through the bars under brakes. So I doubt small play in the swingarm bearings would take more force that shaking the wheel by hand.
small play could be felt through the bars under brakes. So I doubt small play in the swingarm bearings would take more force that shaking the wheel by hand.
Tippie
Hero member
- Location
- Dr?bak, Norway
The inner sleeve (spindle) is the contact point, not the outside of the bearings or bushes. There must be free movement of these inside the frame. Lateral play at the axle is enough to measure how much the bushes give. I failed scrutineering at Lakeside for my last ever race there way back when, when the guy heard a light clunk as he violently shook the bike by the back wheel, "swingarm bushes are stuffed mate, you're not allowed out". The bushes were almost new. I loaded the bike back up and went straight to the shop, measured 0.5mm end float and almost zero play in the bushes. A new ?81 Jota on the showroom floor had 2mm at the axle. I protested my exclusion and asked for my entry fees back, never heard back or got them. Found out years later that they had accepted my protest and ordered my entry refunded, someone didn't do it. Anyway to the point, my bike handled perfectly with the end float, and ?81 Jota handled fantastic with the allowance the needle rollers gave. On the other hand, if any CLQ members can remember the Coffs run where I borrowed a newly refurbished SF1, the swingarm bolt loosened and fell out of the right hand side of the frame on the way to Coffs, hoo haa that was interesting while overtaking a semi. I jammed a rock inside the brake pedal to limp into Coffs ad found a new nut, did it up super tight, but that too loosened and fell off, another rock got me back to Brisbane where investigation showed that the outside flats of the bushes had been powder coated and so the spindle was shorter and the frame clamped the bushes, as you describe, this meant that the swingarm bolt was not tight to the centre spindle but across the flats, allowing the nuts to loosen.
piranha-bro2
Hero member
- Location
- Melbourne
Shaeza! Swingarm bolt coming out of the frame! It must have been binding pretty badly for the bolt to be tight but the spindle/bearing assembly to not be making sufficient contact to prevent it loosening again. Not the first time errant paintwork has caused mechanical issues on a bike I'd reckon.
And you gotta 'love' some scrutineers - they just fukken want so badly to find fault!
And you gotta 'love' some scrutineers - they just fukken want so badly to find fault!
Tippie
Hero member
- Location
- Dr?bak, Norway
Scrutineers are very necessary and I applaud them, however......
...when they demand explosisafe in fuel tanks, shit that is known to deteriorate and wreak havoc.
...bike on slicks and no rain tyres even in the van "has to have a front mudguard".
...have to have a front brake lever protector so that Rossi can't kick you off by jamming his knee inside said protector.
....and more but they never check riding gear.
This at our local tracks, they have scrutineer training and they come up with new stuff all the time.
Fortunately at our classic meetings they just go for important safety issues (including riding gear), and often enough find something that a stressed rider has overlooked.
And leave Vince?s spelling alone, its easy enough to see what he means.
...when they demand explosisafe in fuel tanks, shit that is known to deteriorate and wreak havoc.
...bike on slicks and no rain tyres even in the van "has to have a front mudguard".
...have to have a front brake lever protector so that Rossi can't kick you off by jamming his knee inside said protector.
....and more but they never check riding gear.
This at our local tracks, they have scrutineer training and they come up with new stuff all the time.
Fortunately at our classic meetings they just go for important safety issues (including riding gear), and often enough find something that a stressed rider has overlooked.
And leave Vince?s spelling alone, its easy enough to see what he means.