520 vs. 530 Chain

[lakeview]

On my '77 "cafe" project, the P. O. had comissioned a fancy braced swing arm. I decided to use it and all was fine on the right side as to clearances, until I went to the chain side. Using standard 530 Chain, there is significant interference front the swing arm rubbing on the chain. Everything is tightened up and axle is equally adjusted both sides.
In my view switching to a 520 chain, only 1/8th inch narrower would not provide the clearance needed, plus switching sprockets and chain are not really in this bike's budget and I have a stock swing arm to use anyway.
Anybody see any easy way of getting another quarter inch of clearance other than grinding down the inside of the brace?

 

[5twins]

I think the only fix is to re-work the brace, move it out farther on that side. An obvious fabrication FUBAR, lol. You would think that should be a very important dimension to check/verify during fabrication.

 

[mrtwowheel]

In the 530 size chain, different brands/models are different widths, same for the 520. You could shop around for the thinnest width chain. Non-Oring chains are usually thinner than Oring chains. I don't think that difference is gonna help you. But then, maybe the builder had a specific chain planned for that swingarm.

Scott

 

[delagem]

If it were mine, I'd put a honkin' big screwdriver in there, and pry that brace away about 1/4". I'd put a piece of cut pipe or something to pry against, to prevent flattening/damaging the swingarm or brace. And put a block on the other side while prying, to keep the entire brace on the far side from shifting/bending in while prying. And frankly, I'd bet that's what my welding shop would do, too, if I brought it to them.

But I'm an admitted hack.

Kewl looking brace!

 

[MaxPete]

What about using a smaller rear sprocket....?

 

[TwoManyXS1Bs]

I'd remove the rear wheel, bolt in a pipe/spacer to maintain axle plate width and alignment. Then use my porta-power to spread the offending tube.


Typical frame straightening routine...

 

[mrtwowheel]

I'd remove the rear wheel, bolt in a pipe/spacer to maintain axle plate width and alignment. Then use my porta-power to spread the offending tube.
View attachment 146136

Typical frame straightening routine...

I used a porta-power in the body shop when I was a young'un. You can move anything with one of those. The auto stores should, but don't, offer them in their loan-a-tool programs.

Scott

 

[Jim]

I'd remove the rear wheel, bolt in a pipe/spacer to maintain axle plate width and alignment. Then use my porta-power to spread the offending tube.
View attachment 146136

Typical frame straightening routine...

Yeah... what 2M said. 'Cept you don't need all that fancy equipment. Got a 1 ton hydraulic jack?

 

[lakeview]

I first "dressed" the weld that seemed a bit bulky with a grinder and cleared up about a quarter inch. Refitted, a bit better but not right.
Next, my bottle jack was 9 inches tall and too big for this job, so went to the scissor jack. This effort got a bit more clearance but still no joy.

I had this ready for my stalled '74 rebuild, had already wrestled fresh bushings into it and added the 5Twins recommended grease fitting so I will expect I will switch over to it in the morning.
There will be cooler days when the flies aren't biting to fix the other guy's mod.

 

[lakeview]

And thanks for the interest and replies. I had been doing well without resorting to brute force that I almost forgot I have big hammers and prybars.
Sprockets now are 17/34 and don't really want to go to the 32 sitting on the bench and don't think its smaller diameter will quite carry the day.

 

[Mailman]

Oh dang it! I missed the party. What the heck , I’m putting this here anyways!

 

[MaxPete]

Oh dang it! I missed the party. What the heck , I’m putting this here anyways!

View attachment 146157

If in doubt...hit it again, and with feeling this time!

Pete

 

[halfmile]

The swingarm brace is not as easy as it looks. The first one I built the main loop was too long and too narrow. With the suspension fully extended the front of the loop would hit the lower cross member. Bent up another loop and shortened the front and vertical braces 1/2". The rear of the loop had to follow the outside edges of the swingarm. The left side middle vertical brace had to curve out from the swingarm to the loop. Long story short a 20 foot stick will make one usable 42" loop and braces eventually. The last pics are of the mono shock conversion and the loop had to be that short to clear the dog bone. Good luck with your build.

 

[lakeview]

Half mile, thanks for showing a usable braced swing arm. The P O said he had paid $400.00 for the one pictured, too bad it was wrong. Comparing this one to your pics, the error is clear.
Just finished installing a stock one with new bushings, through bolt and pivot tube.
Onward!

 

[MaxPete]

View attachment 146207
Half mile, thanks for showing a usable braced swing arm. The P O said he had paid $400.00 for the one pictured, too bad it was wrong. Comparing this one to your pics, the error is clear.
Just finished installing a stock one with new bushings, through bolt and pivot tube.
Onward!

Too bad - that bike swing arm really work on that bike IMO - at least aesthetically...

 

[fredintoon]

View attachment 146132
View attachment 146133
On my '77 "cafe" project, the P. O. had comissioned a fancy braced swing arm. I decided to use it and all was fine on the right side as to clearances, until I went to the chain side. Using standard 530 Chain, there is significant interference front the swing arm rubbing on the chain. Everything is tightened up and axle is equally adjusted both sides.
In my view switching to a 520 chain, only 1/8th inch narrower would not provide the clearance needed, plus switching sprockets and chain are not really in this bike's budget and I have a stock swing arm to use anyway.
Anybody see any easy way of getting another quarter inch of clearance other than grinding down the inside of the brace?

Hi lakeview,
Chop out the short vertical tube and replace it with a piece of flat bar.

 

[gggGary]

Joe Wise Guy sells braced arms welded or prebent kits. stock length or extended, just adding it here for future reference He tends to sell on fleabay. He's been doing this for a LONG time.
https://www.ebay.com/itm/XS650-xs-6...121269?hash=item3d82c78e75:g:Iy4AAOSwkI5ZeifU

 

[flyerdon]

Swingarm length and attitude are critical to the handling and stability of the motorcycle and manufacturers try a lot of dimensions before they finalize any critical component. Changing the wheelbase (because the swingarm has been shortened or lengthened) by even 1/2 inch can have quite an effect on the bike's handling so I'd be careful when making changes to it.

 

[lakeview]

Cue pic of 'Busa with extended s/a.
lol

 

[gggGary]

This do?