Adj. Monoshock Ride Height - Help me think....

[LeeGS550E]

I've been brainstorming ideas for making this linkage adjustable in length:



You can kind of see that I've added about 30 mm of length to it by cutting it and welding in a piece. It would be nice if we could come up with something that's adjustable on the bike. I wanted to pick up ground clearance (after going to 17" rims) and wanted to decrease the angle of the front forks.

So what do you think? Concentric holes in some kind of bushing? Incorporating a large bolt with a threaded portion instead of a piece of solid steel like it is now? Using notches instead of round holes for the top bolt? Let me know your ideas.

Thx,

Lee

[Billy Ricks]

It might be easier to do what you want to do from the bottom of the shock. Modern bikes have the fixed end at the top of the shock and those with ride height adjustment use a plate that can be moved up or down on the frame. With a little fabbing I think something could be done at the lower end of the shock. A T-shaped section of aluminum plate on each side of the swingarm with holes drilled about 1/2" apart.

The easiest way would be to buy a shock with ride height adjustment built in. Fox used to incorprate that into their Twin-Clickers.

[LeeGS550E]

Hrm - not getting your idea about the T shaped plate, Billy. But that's a good thought about doing it from the bottom. Hadn't thought of going that route.

What I have done is order (4) 12mm female thread heim joints, and 2 'jackscrews' that are 1/2 LH threads and 1/2 RH. So the heims go on the jackshafts, then on the bolt thru the swinger and bolt thru the linkage. I should be able to get 30mm of safe adjustment out of them, and I'll be able to cut the jackshafts down a little and it'll give the same ride height I'm at right now. Got this idea from a guy on the oldskoolsuzuki site.

I'm always keeping an eye out for a used fox, hagan, or works shock, but after 3 years, no such luck.

[salty_monk]

Lets have a pic when you get it mounted up

[madjack57754]

The "T" shaped links are called adjustable dogbones and they are avaliable for late model mono shock bikes like Bandits and 'Busa's.

[LeeGS550E]

The "T" shaped links are called adjustable dogbones and they are avaliable for late model mono shock bikes like Bandits and 'Busa's.

OH I see now. I thought you were talking about something that would work with the existing aluminum arms that are welded to the swingarm. So you guys are thinking of replacing that portion of the swingarm with dogbones like a more modern setup? That would work with some beefing up of the swingarm I suppose. Or I guess you could leave them in place and make extensions that changed the point where the shock mounts there.

[salty_monk]

I think he's talking about an adjustable link to replace the one that you have extended by welding a piece in.

Dan

[Billy Ricks]

My idea involved welding the T's above and across the swingarm where the shock lower mounts. The bottom of the T welded where the shock mounts with the top of the T welded across the sides of the V where the shock mounts. The top of the T would need to have some material bent at a right angle to meet the V and maintain a perpindicular attitude for the adjuster.

[LeeGS550E]

Well, I got the heim joints from Midwest Control Products tonight. Maybe I didn't do my math right, but putting the two heim joints on the jack screw makes for too long a linkage. Its about 130 mm tightened all the way down. I wanted 100 mm with them adjusted all the way out. The threads are also too course. I got 12x1.75 left and right thread heim joints, but the fit between jack screw and heim joint is too sloppy. So its back to the drawing board. Either I try different size heims or I go with something different entirely.



I did purchase another linkage from a guy parting a bike out, so I've now got a couple linkages to play with.

[LeeGS550E]

Here's a follow up with what I've now come up with (in case anyone has been watching):

Started with this idea:



Stole the bottom bearing and race from an extra 700 linkage, and the top yoke from a 550 linkage (I'm still using the 550 rocker arm with the 700 swingarm). The bolts are 10mm x 1.5 x 100mm. Got 'em all welded together, did some cleaning and trimming, and this is how it fits:



Tried a bit of adjusting. Seems I'm getting about a 1:1.5 ratio between change in linkage length and change in ride height. Not sure if I like the looks of it, but maybe I'll just use it to find the optimum length, and then redo the permanent one I'd built before.

And now its beer time. Cheers!

[salty_monk]

That makes me nervous... At the very least I'd put a plate half way up the thread to prevent the threaded stock deflecting outwards or inwards & failing that way but I'm not 100% I'd trust that.

Dan

[LeeGS550E]

That makes me nervous... At the very least I'd put a plate half way up the thread to prevent the threaded stock deflecting outwards or inwards & failing that way but I'm not 100% I'd trust that.

Dan

Hmmm, you think its enough compresson to buckle them, huh?

There's only straight compression on them - no moment.

[salty_monk]

Maybe... depends if they are 100% straight in every plane & 100% adjusted to exactly the same length! I very much doubt you could ever be that accurate.

Just my thoughts anyway - it's your bike.

I'd also have been happier with a plate welded right across the bottom race rather than those nut/bolt heads welded to each side like that too. That would have created other space issues I'm sure but should be able to overcome it someway.

I would use it for testing then weld up your other one to the length you want.

Interesting concept though for sure

[LeeGS550E]

Maybe... depends if they are 100% straight in every plane & 100% adjusted to exactly the same length! I very much doubt you could ever be that accurate.

Just my thoughts anyway - it's your bike.

I'd also have been happier with a plate welded right across the bottom race rather than those nut/bolt heads welded to each side like that too. That would have created other space issues I'm sure but should be able to overcome it someway.

I would use it for testing then weld up your other one to the length you want.

Interesting concept though for sure

I think I'll use it for finding the geometry I like, and then switch back to the solid piece.