Mounting front fender bracket and swing arm torque

TeddyG

Full member
Location
Portland Oregon
Not sure if this is true but someone claimed that the front fender bracket need to be rubber mounted to prevent fracturing. Is this true and what's the procedure- it would require enlarging the holes to add a rubber grommet/washer but that seems extreme.

Also my swingarm has slight play wriggling it w/ the wheel and shocks removed. I tightened it some more but wiggle is still there and I feel less when grabbing the spindle w/ the swing arm removed. It has brass bushings, there was grease in the shaft and bike has 15K miles. I'm assuming some slop is OK. Factory book lists torque at 40 lbs but Parides chart lists 55.
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Only the later triple brackets were altered for rubber mounts, before the switch to Marzocchi forks.

Lots of solidly mounted brackets still going strong. They do need to be fitted absolutely tension-free though. The brackets fracture if they are bent (crash damage, etc.) and focibly fitted, or stressed through bent stanchions, causing the sliders to travel in different directions, ie, not parallel. If stanchions and axle are straight and the sliders don't show excessive slop, there's no real reason to go to the trouble of fitting the silly grommets and the totally inadequate spacers that go with them. The function of a fork "brace" is also lost with the rubber mounting.

Worn swingarm bushes are the norm, lubrication was mostly neglected. The slop will not decrease by tightening the nuts further, new bearings are needed. As the spindle for the bushes is the part that is usually worn, and is no longer available, a swap to needle bearings is a viable option.

piet
 
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There are two types of bracket. The earlier one is rigidly mounted, the later one has enlarged mounting holes allowing a rubber grommet with a bush in the middle to mount in the hole, effectively rubber mounting the bracket.
As for the swing arm, don't bother about torque. Tighten firmly to take up all lateral slop, if there's still movement when grabbing the rear wheel, the bronze bushes are shot.
Paul
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Only the later triple brackets were altered for rubber mounts, before the switch to Marzocchi forks.

Lots of solidly mounted brackets still going strong. They do need to be fitted absolutely tension-free though. The brackets fracture if they are bent (crash damage, etc.), or stressed through bent stanchions, causing the sliders to travel in different directions, ie, not parallel. If stanchions and axle are straight and the sliders don't show excessive slop, there's no real reason to go to the trouble of fitting the silly grommets and the totally inadequate spacers that go with them. The function of a fork "brace" is also lost with the rubber mounting.

Worn swingarm bushes are the norm, lubrication was mostly neglected. The slop will not decrease by tightening the nuts further, new bearings are needed. As the spindle for the bushes is the part that is usually worn, and is no longer available, a swap to needle bearings is a viable option.

piet
There is however the photo in the Green Book of Tim Parkers 3 day old SF2 with a broken bracket.
Paul
 
Thanks guys- I've got the Green Book but hard to decipher the exploded diagram. I might put some rubber washers to cushion the bracket somewhat. I understand that uneven movement of the fork legs might put stress on the brackets. The slop in the swingarm is probably minor but I'll consider new bushings down the road once it's running again.
 
Thanks guys- I've got the Green Book but hard to decipher the exploded diagram. I might put some rubber washers to cushion the bracket somewhat. I understand that uneven movement of the fork legs might put stress on the brackets. The slop in the swingarm is probably minor but I'll consider new bushings down the road once it's running again.
Just putting rubber between the bracket and fork leg would not be advisable as you cannot then positively tighten the bolts. The factory rubber mounts had grommets fitted to the bracket and spacers (as Piet mentions) through them for the bolts to tighten up to.
If the swing arm bushes, spindle etc has been thoroughly cleaned and is dry a scrap of play wouldn't concern me, but if it is greased and there is evident play I would replace it.
 
Working out the length required for those steel sleeves through the rubber grommets so you end up with the guard mounting solidly enough to nip the bolts and not crush the grommet isn't as easy as it sounds. Add to that they must be hex head bolts, you cannot get an alan key into that space if the wheel is fitted, and you can only get a 90-degree turn on those hex heads anyway so mucking with all 8 bolts fast becomes a painful little job, and after its all done check you haven't fitted the guard back to front as well. Wait 20 years and those grommets will rot out and you can do it all again.
 
Working out the length required for those steel sleeves through the rubber grommets so you end up with the guard mounting solidly enough to nip the bolts and not crush the grommet isn't as easy as it sounds. Add to that they must be hex head bolts, you cannot get an alan key into that space if the wheel is fitted, and you can only get a 90-degree turn on those hex heads anyway so mucking with all 8 bolts fast becomes a painful little job, and after its all done check you haven't fitted the guard back to front as well. Wait 20 years and those grommets will rot out and you can do it all again.
You fit the guard before putting the wheel in.
Otherwise, you can mount the bracket without the mudguard blade, it'll give you easier access.
Brass insert is roughly 8mm long.
Paul
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those bronze swingarm bushes wore out within 15,000 miles on my bought new SF, it was well greased, strangely the slop was only end float, not on the spindle or sleeve, to replace, a hydraulic press is realy usefull, unless you want to cook it and burn the paint off, removal can be done by cutting a slot in the bush with a dremmel, and then simply knocking them out after the compression has been released, to fit new, you realy do need a press, I tried to do mine with studding and some plate washers, but they only went in so far, which made a trip to a mates workshop the only way to complete it. as Piet says go for needle rollers, when I built my SF into an Egli (at 36,000 miles) I worked it to have taper rollers for the swingarm (I got a part finished swing arm in the incomplete kit from Graham Binnion), and made my own, hence the taper rollers and eccentric bushed chain tensioners.
CLEM
 
Thanks once again guys- I will enlarge the holes per Paul's example and put in the grometts and spacers. For now, I'm leaving the swing arm alone and will revisit that once the bike is running again- the slop is minimal and I'm probably making a big deal out of nothing
 
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