Topic: Wheel alignment (offset from each other) question

[Yamahawk]

I guess it liked it in there!!
Charlie

[DaveBarbier]

It also didn't "break" loose at any point when it finally spun out. I was holding the tire with my left hand and pulling on the vise grips with my right very hard until right at the end. It wasn't cross threaded but I wonder if the threads in the stud were damaged. Either way, I chased them with a tap and all's good.

[DaveBarbier]

Getting back to this thread I started earlier this winter.

I added the spacer I made from a sprocket and it centered the wheels a bit but it’s far from perfectly inline with the front and noticeably off center if you look at the rear tire from the back of the bike. Because I was more curious I decided to see what the vertical levality was to the wheels. I held a level against the tires vertically and they’re not the same. Rear is almost perfectly level and the front is off a few degrees. This would, of course, affect the alignment as the bottom of the tires could be off while the tops of the tires (can’t measure that) are good. Both wheels spin true.

Can anyone else check this on their bike? Keep in mind the front forks have to be perfectly straight or else it’ll angle itself. I measured from the center of the axle to a motor mount bolt.

Thoughts? My frame bent (steering neck)? Is this just how they come from the factory? Seems like the bike has always been like this and I couldn’t tell if there was an issue so I’ll probably remove the spacer and put it all back to normal.

Front

Rear


Yes, I could strip the bike and put the frame in a jig to check and alter it but I’m not going to do that. Maybe get a new donor frame and check that one...not really against that. Maybe a project for next winter.

[DaveBarbier]

Interesting ‘suspended’ frame jig, I’ll try that maybe next weekend.

The forks aren’t plumb either. Both forks have the same angle as the tire. Forks aren’t bent, I rolled the tubes on my bench before I swapped them (talking about the R6 front end swap I did this winter) and they’re the same length.

[DaveBarbier]

Oh I see, the tops of the fork tubes are exactly the same height off the top clamp. The forks are within 1mm off the ground on a level smooth portion of my floor.

And to answer your other question, I’m measuring from the outside of each tire for alignment with string and, to double check, with a straight 2x4.

Unless I’m just look for a problem, I think I can see my steering neck seam (when I look from the front of the bike behind the headlight) a hair crooked. I could be seeing things, though, haha.

[DaveBarbier]

Also, put a level on the tops of the brake rotors and a level on the top triple clamp. Also, the fork tubes are square to the clamps. Meaning the clamps aren’t cocked or improperly machined.

[Don R]

https://www.ebay.com/itm/Motorcycle-Frame-Jig-Neck-Cones-1018-Mild-Steel-2-O-D-Chopper-Harley/122868277667?hash=item1c9b8521a3:g:7fwAAOSwg3FUg1m1&vxp=mtr

 You could jig up the chassis and get a set of these cones with a pointer rod on a flat table. I got a free 75F once with no engine and began to reassemble it. it for sure had a twist. Probably why the engine was pulled out of it. There weren't any damaged parts on it so it must have been wrecked and repaired with bolt on parts.

[Don R]

 Or get a 2 or 3 foot piece of straight tubing that fits the front axle clamps and one that fits the swingarm. Make one end level and compare to the other. 

[Yamahawk]

...but it's consistently not level...
Charlie

[DaveBarbier]

And to answer your other question, I’m measuring from the outside of each tire for alignment with string and, to double check, with a straight 2x4.

Wood? Ain't straight. Use 1/4"x2" steel flat stock, or better yet, 1" square tubing. Even a flat 36" metal ruler.

But I see your level is not... 

Yes, but taught string is straight . That’s how I’m measuring, running string from the rear tire to the front. I’m just using the 2x4 for quick checks as I move the tire around.

[DaveBarbier]

...but it's consistently not level...
Charlie

It’s consistently not level in the front, but as I move to the back of the bike it becomes more level.

Can one of you guys check out one of your bikes?

[DaveBarbier]

https://www.ebay.com/itm/Motorcycle-Frame-Jig-Neck-Cones-1018-Mild-Steel-2-O-D-Chopper-Harley/122868277667?hash=item1c9b8521a3:g:7fwAAOSwg3FUg1m1&vxp=mtr

 You could jig up the chassis and get a set of these cones with a pointer rod on a flat table. I got a free 75F once with no engine and began to reassemble it. it for sure had a twist. Probably why the engine was pulled out of it. There weren't any damaged parts on it so it must have been wrecked and repaired with bolt on parts.

Thanks for the replies Don, I’ll definitely check this out if I end up going the jig route. I do like the simplicity of the strings as Cal suggested, though.

[jgger]

I would think that when checking the front wheel that rake and trail play a huge part. If the front wheel isn't pointed axactlly straight then any plumb measurements will be inaccurate.

[DaveBarbier]

If your top clamp is not level, then how are you forks plumb? From the top clamp angle, that would translate to the axle/rotors and the forks and wheel. Any change your steering stem is bent? Does the top clamp change its slant when moved side-to-side?

I'd like to see you remove the front wheel, and check the internal components carefully, maybe the rim is laced up out of whack too? Have you checked it for true recently? CT has some pretty harsh roads and bomb-straifed roads from winters 

I never checked the alignment with the original forks and wheel. This winter I did an R6 fork swap and laced up a new wheel with new spokes. Wheel is true and spins nicely.

My forks aren’t plumb, they have the same angle to them the tire does. It IS as if the steering neck is angled. That would explain everything but that’s not really easy to measure unless things are disassembled, which I’m prepared to do. I will remove the wheel and check if the axle is level. I bet it’s at the same angle as the top clamp.

I’ll check the slant of the stem. A level won’t really work for that so I’ll probably use my phone’s level which will give me degrees of pitch.

I’m using a custom top and bottom triple clamp from Cognito Moto. It does have an aluminum stem (solid, not hollow) instead of steel. When I was lifting the fork assembly into the neck to assemble it it does flex. I have to lightly hammer the top triple on. Hard to explain, maybe when/if I remove the forks I’ll take pictures. On the bench, the top clamp slides on the forks smoothly. When it’s assembled, the weight of the front end flexes the stem enough where I need to coax the top clamp on. Normal?

[DaveBarbier]

I would think that when checking the front wheel that rake and trail play a huge part. If the front wheel isn't pointed axactlly straight then any plumb measurements will be inaccurate.

You think right

[Yamahawk]

Really Dave, the only way to check it is to take off the forks and triple tree and check the neck for plumb. that's the key. If the steering neck is plumb, then your forks will be also, if the front R6 triple tree and stem hasn't been tweaked from an accident. Start at square one, and go from there.
Charlie

[Yamahawk]

Just thinking... did you replace the stem in the R6 forks with one from a CB750? THAT could be out... as Cal stated, the stem may not be square with the triple tree, and if the R6 stem has been replaced, that would be a likely culprit.
Charlie

[DaveBarbier]

I agree Charlie, I see disassembly in my future, haha. I welcome it with open arms.

I’m not using the R6 triples. I’m using custom ones from Cognito Moto. Billet aluminum with aluminum stem.

[DaveBarbier]

If you remove the front end, place the triple tree on a flat, level surface. Verify the stems plumb. Assemble top clamp, check for level. Its possible that the stem is not plumb and that in turn is translating down the forks to render the wheel and axles out. It would need to be off pretty far because the neck bearings should rectify that much bend out. Could still be off enough to create the problem you're seeing.

It's also very possible the wheel is not fully seated in the axle clamps, flush and flat. Before you tear everything apart, you might just dismount the wheel from the forks, and reinstall and see if that brings the axle around to level. That won't address the top clamp though.

I’ll check the triple clamps thoroughly but I’m almost certain they’re machined accurately and the stem pressed in straight.

The axle can’t really be ‘not fully seated in the axle clamps’. These forks have a hole bored in them which the axle slides through. Not like the SOHC4 forks where the axle is hep up into them via a holder clamp. But I will remove the wheel first and make sure it’s all good.

[DaveBarbier]

You know Devin and I are very good friends. And I never badmouth people who make every effort to do the right thing, but, I am aware of a couple of custom trees he made that the stem pressed in off-kilter. He remade them twice, but the tolerances were so tight that the stem called as he pressed it and it was askew by a few degrees. Not saying that happened here, but small variances translate over length to larger more measurable amounts.

Devin’s a great guy, was talking on the phone with him about my swap for half an hour. I’ll check the clamps. I would feel better if the stem were stainless but I’m sure aircraft grade aluminum is fine too, haha.

[bwaller]

I saw your pic with the level across the tops of the rotors, it's telling. Check the steering stem first because it's easy. Since the front is now off...

If your frame steering head is out Don's suggestion with the cones and a long straight rod through them will answer a lot. Remove the tank & seat and level across the frame. Even a piece of long straight threaded rod with nuts top & bottom of the cones will give you the answer.



 

[DaveBarbier]

Yeah, the whole front end is angled. I’m really hoping it’s the stem...I think. Not actually sure what would be the easiest fix. I guess getting another lower triple. Bent neck doesn’t seem fun, but if that’s the case I’ve been riding like that for like 5 years, haha.

This weekend will be fun filled for sure.

[DaveBarbier]

And yes, I may buy those cones. I could machine my own but honestly it’ll be faster to have them here for the weekend.

[DaveBarbier]

Ok, so I took apart the front end. I think I found the culprit. But first I’ll just say that I’m visually looking at the neck and it all seems straight. I bought those neck cones (thanks Don) and will head down to the local machine shop to get a straight piece of 3/4” round bar to be able to extrapolate the neck angle to be doubly sure.

I first removed the wheel and reinstalled it three times and I kept getting the same angle on the tire, so I’m confident that’s not the problem.

I removed the forks and I rechecked that the forks are straight. Held a straight edge along each fork tube and they‘re perfect.

I checked the bearing races in the neck in case I put them in cockeyed, but nope, perfect.

The triples seem to be the issue...hopefully, as this means just replacing the triples will get me back in alignment.

Some pictures of the triple on the bike. Notice when the steering stem is in the triple as well as one fork leg, the other fork leg isn’t lined up properly. I have to force the fork into the triple. It‘s like this would twist the forks, and the direction it would twist is the direction which would make my wheel angled.

Forks off the bike.


Left fork leg lined up with the hole in the triple.


Right fork leg isn’t lined up. You can see the crescent shaped gap on the bottom. I can get the fork into the triple, but I have to tweak it. Yes, it’s not really significant, but it’s not lined up perfectly. With a CNC mill, it should be perfect, no?


Thoughts?

[Yamahawk]

Bing Bing Bing... you hit the jackpot there, the triple trees should line up perfectly, UNLESS one of the tubes is tweaked... If one is slightly bent, then you will have that angle also. Have you tried rotating that tube, or the other one, to see if that gap changes with the rotation... i.e. does it follow the tube around the triple tree hole. You would have to try one tube, then insert it and try the other tube to see if either tube is tweaked. It is either the tubes or the tree... leave the lower triple loose enough that you can rotate the tube that looks out, if the gap doesn't clock around the upper triple tree hole, the remove the other tube, lock the one you just tested into the lower tree and the upper, and rotate the other one too see if the gap is there and clocks around the top hole.
Another consideration is if the stem is out, and then neither tube should fit if it was centered.
Charlie