Bonneville America Forums Forums Technical Forums Custom Corner swingarm pivot width

Is anyone able to tell me the width of the swingarm at the pivot for both a Speedy and the Bonnie?

6.5 inches.

Thanks. I didn't think it would be the same for both

The Bonny swingarm is shorter in length and narrower at the axle, or so that I have been informed. Never actually measured one. I think a Bonny s chain is only 102 links and ours are 112, so I believe the shorter part to be a sure thing.

Lay down reach under your bike with a ruler it is accessible to you. I gave you the inside pivot width of a Bonneville according to a phone call to SC asking my brother to measure one. I didn't measure a America.

I am not following why you think you have to take your bike apart to get the Speedmaster/America measurement.

Are you thinking of shortening the wheelbase by 6+ inches on a Speedmaster taking all the distance reduction from the rear? If so you really need to think about sprung weight being redistributed as it pushes on the Speedmaster front end.

Actually, thinking about a new build on a Bonnie frame but using an SM swingarm. I see now that the Bonnie frame actually integrates the swingarm pivot into the foot peg brackets. This may lend the possibility of custom swingarm mounts that would accept a (presumably) wider SM swinger.

I'll do some measuring on my America tomorrow. The Bonnie frame just arrived tonight, but I do not have the peg brackets or a swingarm to compare -- I may need to buy one anyway.

i'm trying to visualize this.

It's been done, there is a guy on youtube with one. He was briefly a member here, but when we didn't fawn all over his bike properly, he posted some adverse BS and split. BTW, it was a cool scoot.

Who was that Ryk? I don't remember that.