Flummoxed! XS650SK Front Fork Alignment.

jetmechmarty

Project collector
Top Contributor
XS650.com Supporter
Messages
8,717
Reaction score
28,207
Points
688
Location
Coldwater, Mississippi
I will preface by saying that it has been about 20 years since I last wrecked this bike. In the course of the last three years I have had it all apart. It had complete fork and swingarm service including steering and swingarm removal.

Summer of 2022, I rode the bike to Eureka Springs, AR. I rode the bike approximately 1,000 miles on that trip. Along the way I noted that the bars were pointed to the right. The swingarm was what I last futzed with. So, at Eureka Springs, @JRP01 and another seasoned VJMC member thoroughly checked and aligned my swingarm and rear axle. Still pointing right. Since then, I've engaged in private conversations with @JRP01 and @gggGary. Both helpful, but....

I'm fresh at it today. My rear axle alignment is within one millimeter left to right. I'm confident it's good. Oh, tire wear is normal. I did another 500 mile trip on it in recent weeks. All good but the handlebar right. I can see the alignment mismatch on the bottom triple clamp when I ride. It's not the handlebar. The fender is also misaligned.

I did this procedure.
I cannot detect a bent tube.

I did this procedure.
Still no joy.

Here is how it sits.
IMG_3230.jpg


With only the top clamp on the fork tube tightened, I have forced it into alignment using the wheel clamp and handlebar. If that fails, what could it be and how? I'm not sure if I can finish. I have only two hours of daylight remaining. If I button it all up it's likely next weekend before my next opportunity to ride it.

Thanks in advance for your input.
 
Could be the lower triple is bent. It's easier to do than most would guess. Don't ask me how I know....
You must have another triple around there you can swap in? If not, I can send ya one?
 
I probably have a few of them. Once I determine that nothing else is likely I’ll buy all the stuff, namely new bearings. I don’t know how to get the lower bearing off without destroying it.

Is this the relevant check for the XS650?
 
Bent stanchion or tree. To check the stanchions, roll on a flat surface. To check the tree, assemble the stanchions in the tree and check they are level and on the same plain.
Unlikely to be the top tree as that will align itself with the lower tree when bolted up.
I would definitely check the stanchions, if they are bent, they may wear the lower fork legs, depending on where the bend is. Normally the bend is just below the lower tree. But you never know. If something is bent, when everything is bolted up, everything is working against each other and lower stanchion wear could still result.
The fact you can see the triples aren't aligned and the guard is off says something is bent.
 
Since you "know" your tubes are straight if you drop one out of the top triple (wheel and fender off. It should go right back up in the hole again if you have to struggle to get the tube in the hole that's the bent lower triple. At that point you want to be checking the neck too.
Sorry but I've had bikes with bent necks too.....
Is this the bike that breaks rear shocks?
The above is a @gggGary post on this issue I posted over a year ago. Yeah, the fork slides right in. I need to leave this issue a priority rather than jump one bike to the next as I have been doing. @Jim, thanks for revisiting this with me again.

My concern is I've done something stupid and missed something simple.
 
Bent stanchion or tree. To check the stanchions, roll on a flat surface. To check the tree, assemble the stanchions in the tree and check they are level and on the same plain.
Unlikely to be the top tree as that will align itself with the lower tree when bolted up.
I would definitely check the stanchions, if they are bent, they may wear the lower fork legs, depending on where the bend is. Normally the bend is just below the lower tree. But you never know. If something is bent, when everything is bolted up, everything is working against each other and lower stanchion wear could still result.
The fact you can see the triples aren't aligned and the guard is off says something is bent.
Thanks for that. I’m buttoning up. I’ll check it tomorrow or next week. If it still tracks as it did, I’ll have to break it down completely as you suggest.
 
Many times, the tubes just get twisted in the trees. To straighten it out, loosen the clamp bolts top and bottom so they're just snug, then roll the bike up to a garage door jamb and whack the side of the front wheel against it a couple times. Which door jamb and side of the wheel you do this to will depend on which way the wheel needs to be moved to align it. This will twist the tubes back to where they need to be in the triples, also straighten the wheel in relation to the fender.
 
Is this the relevant check for the XS650?
Kinda? That lower surface isn't machined so not easy to see if they are flat, but if you can see the top triple is twisted while riding it should be obvious.
you can put something flat across the fork tubes below the triple if it rocks the triple's bent. If you cant find anything, bottom of a machinist's vice is flat so are mirrors, pretty much any piece of glass is flat enough for this test.
Tougher to sus out a bent frame have you checked front to rear wheel alignment? strings, long levels flat straight 2x4.
 
Since you "know" your tubes are straight if you drop one out of the top triple (wheel and fender off. It should go right back up in the hole again if you have to struggle to get the tube in the hole that's the bent lower triple. At that point you want to be checking the neck too.
Sorry but I've had bikes with bent necks too.....
Is this the bike that breaks rear shocks?

Tougher to sus out a bent frame have you checked front to rear wheel alignment? strings, long levels flat straight 2x4.
Some time ago, I checked with long fluorescent tubes. I think if the frame was bent, I would have been bothered by this years ago.

If I’m going to take the entire front end apart, I may as well do a thorough check.

 
On an Evo when I had the forks apart and rolled the tubes on a platen one was straight and the other .040 bent in one more or less mid way. Marked the radial position with a punch at the top end. Put it all together with the tube oriented so that it pinched the axle, ie did not lead, and did not trail. It worked. Yeah, mickey mouse... I had a good complete wideglide front end that I had just given away... bummer. I wonder if your tubes are actually straight....in trouble shooting it's very easy to assume.
 
you can put something flat across the fork tubes below the triple if it rocks the triple's bent.
I used a carpenter's level. Fail. It's barely detectable, but fail, nonetheless. If I understand correctly, this proves the lower triple is bent. If that's the case, it's certainly cheaper than new fork tubes.
 
I used a carpenter's level. Fail. It's barely detectable, but fail, nonetheless. If I understand correctly, this proves the lower triple is bent. If that's the case, it's certainly cheaper than new fork tubes.
The other day I was lookin' at carpenters levels at Home Depot. Mine's so old it's hard to see the bubbles. Anyway....
Every damn one of 'em had a slight twist in the frame. Jus' sayin'.....
 
It is very awkward to do, but dropping the lowers and fitting the naked tubes gives a nice long place to used some plate glass, what 20 inches of exposed tube, maybe more. For myself, this skew in front end stuff calls for tooling and dial indicators and such. Of course once things are kosher, putting the lowers back on the tubes in situ is also awkward. I have done this once, it was a bitxch. Best of luck amigo...
 
It is very awkward to do, but dropping the lowers and fitting the naked tubes gives a nice long place to used some plate glass, what 20 inches of exposed tube, maybe more. For myself, this skew in front end stuff calls for tooling and dial indicators and such. Of course once things are kosher, putting the lowers back on the tubes in situ is also awkward. I have done this once, it was a bitxch. Best of luck amigo...
I'm very capable of doing this. I'm just busy or lazy. Both, actually.
 
Back
Top