DIY Rear wheel alignment tool

Homemade, custom and specialized tools that help make things easier
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Brian UK
Lookin' Around
Lookin' Around
Posts: 62
Joined: Thu Feb 06, 2014 2:15 pm
Location: Worthing Sussex uK

This is copied from another area of the BB but I think this is the appropriate place for it

This may be 'over engineering' the answer to the problem but it is quite adjustable and quite cheap and should work.

This works on the basis that the four tips of the bolts should be in a straight line and will show that the sprockets are both straight and in line with each other. It assumes that the sprockets are straight and in good order and that the front sprocket is in the correct position. The length of bolts is to avoid footrest brackets etc.

Materials:
length of aluminum angle
4 x 4in M8 bolts (5 in may be better if you can get them - I couldn't)
4 x M8 nuts
8 x penny washers (don't know what they're called in US but large washers to fit the M8 bolts

Total cost in UK about £10 (That would be about $16 but costs may be different in US)

Process:
1, Cut a piece of aluminum angle to cover the distance between the front of front sprocket to the rear of the rear sprocket plus an inch or two. (If you have enough angle to cut two pieces this length that is good and miss steps 2 and 3.)
2. Cut a piece of aluminum angle to cover the width of the rear sprocket plus an inch or two.
3. Cut a piece of aluminum angle to cover the width of the front sprocket plus an inch or two.
4. Put two washers and a nut on each of the four bolts.
5. Clamp a piece of angle each side of a bolt, loosely between the two washers of each bolt, so that the angle parallel with the four bolts clamped between them.
6. Adjust the space between the bolts so that bolt 1 and bolt 2 are just inside the width of the rear sprocket, then bolts 3 and 4 are just inside the width of the front sprocket and the distance between bolts 2 and 3 is from 1/2 inch before the front of the rear sprocket to just inside the back of the front sprocket.
7. Tighten the nuts a bit so nothing slips.
8. If your worried check on a flat surface that the tips of the bolts are all in a straight line

This may seem a lot of work but you now have a tool which will show your sprockets are in line with each other and that the rear sprocket, and wheel, are aligned with the bike. It should also be adjustable to fit any other bike.

To use you need to remove the front sprocket cover. Place bolts 3 and 4 on the front sprocket and bolts 1 and 2 on the rear sprocket. If they are ALL touching everything is OK. If bolts 1 or 2 are not touching then the rear wheel needs adjustment so they both touch. If this cannot be achieved and either both bolts don't touch the rear sprocket OR both bolts don't touch the front sprocket, it is an issue with the spacing of the rear wheel i.e the rear wheel is NOT centered correctly.


Pictures:

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