rear wheel alignment

I use a trammel to measure my rear axle to the swing arm pivot on both sides and make them even on each side. This is one way to get the rear wheel straight. I just did this on a 07 yz250 and when the axle to swing arm pivot are equal on both sides the axle block marks are off by about 1/8th" as well as the amount of the axle adjust bolts and the tire is closer to one side of the swing arm. What else can I do to make sure the wheel is wear it should be and that the chassis is not out of whack?

The best way to align the rear wheel is to make sure that it is in line with the front wheel. This can be accomplished either with strings or visually.

I have a 2000 yz250. I adjusted my chain as you mentioned, measuring form the center of the rear axle to the center of the swingarm pivot bolt with a tape measure (don't have any precise measuring instruments that large). Well, my rear sprocket was wearing down on the inside.

I repeated the procedure and found the numbers were the same. I then measured from the center of the rear axle to the center of linkage bolts (through swingarm) and found the measurements off. I made the adjustments and it works well now.

The adjustment blocks, stamped line on them or the lines on the swingarm are off. I do not use those lines to make adjustments.

Spin the rear wheel and watch how the chain tracks along the rear sprocket. It is very subtle. You want the chain to ride the sprocket straight and even on both sides for the entire ~180 degrees they are in contact.

I have always used the string method as well. It makes a big difference when the marks are off.

Can someone explain the string method to me? Also how could you visually sight down the edge of the wheels when they are different widths?

Also how could you visually sight down the edge of the wheels when they are different widths?

This is actually quite easy to do and just about as accurate as the 'string method'.

The trick is to use the knobs like gun sights. First, align the front wheel from the front by sighting along the outside edges of appropriate knobs on the front tire and center the wheel with the rear tire. Then from the back, sight along appropriate knobs on the rear tire and move the adjusters until the rear tire is centered on the front. Since the rear wheel has been moved, recheck front to rear alignment again. This is much easier done than said and you only need to do it once after each tire change. For subsequent chain adjustments, simply adjust the chain by moving the adjuster nuts the same number of flats on each side.

Doesn't any one use a chain alignment tool or a straight edge/ ruler against the back sprocket? I use the tool and it works great.

Cheers

http://www.motionpro.com/motorcycle/partno/08-0048/

Edited by Subaru297
added link
Doesn't any one use a chain alignment tool or a straight edge/ ruler against the back sprocket? I use the tool and it works great.

Cheers

http://www.motionpro.com/motorcycle/partno/08-0048/

If you can assume that your swing arm is straight, the hub properly centered by the spacers used, and the engine is in the correct position (all things that should apply to most reasonably stock motorcycles that haven't been crashed hard) that's a very accurate way do check the veracity of the marks on your swing arm blocks, and I usually do it that way at least once on any given bike. After that, I just fudge whatever discrepancies I find into future adjustments.

But that method still depends on the bike's chassis being correctly oriented, and when scratch building or checking for bent frames, etc., more complete and elaborate jigs are needed.

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