Topic: CB750K Wheel Rebuild - Rim Offset

[joerinnis]

I'm rebuilding a set of wheels for my 77 CB750K.  I neglected to measure the rim offset before I removed all the rusty spokes.  Can someone tell me the offset for both the front and rear wheels.  It appears the rim is centered over the hub in front, but not sure on the rear.
Thanks

[evanphi]

I've only heard of the front wheel being offset from factory, but not the rear. Everyone should put the front to center, though.

[DH]

I've only heard of the front wheel being offset from factory, but not the rear. Everyone should put the front to center, though.

How do you determine when hub is centered in wheel? measurements?
I am lost when it comes to wheel truing. Please elaborate. I can build a spoked
wheel, but damned if I can true it.

[Bodi]

Stretch a string across the rim, measure to the hub flanges. Centered=equal measurements.

[BomberMann650]

A wheel dishing tool.

This fellow crafted his own beautiful example of one.

[evanphi]

put a straight-edge along the hub flanges up to the rim. measure from straight-edge to rim (once you have it true, of course).

Here's that trick to see how much offset your wheel has without removing the tire/tube/rim-strip. It'll be about 5mm, this was standard from factory... but this will also help you get it well centered.

I'm silly. Don't use string hanging over a tire. That'll just be inaccurate. Use a straight edge on the hub about a foot long, and then measure to the lip on the rim. The rest is the same:

Measure the closer side

Zero your caliper

Measure the further side

And there's your offset!

Now you can center your wheel. The distance should be the same on both sides.

If you have a dial gauge, you would set it on one side, then adjust the wheel over towards center HALF the value you got for offset. If you don't have a dial gauge, you'll have to re-measure using the above method.

[joerinnis]

Thanks for all the quick and helpful responses.  I just read the note on the search function not working. Tried the Google advanced search and found several posts on the same subject including a nice tutorial on lacing and truing.

http://forums.sohc4.net/index.php?topic=84746.0

With all the great advice I'm good to go now.  So glad I found this forum.
Thanks
 

[kerryb]

I seem to remember a great explanation of this in hondsman's book.  He gave the history of wheel offset to accommodate using dual front brakes for racing, which mentioned the wheel was offset from the factory by what I remember as 4mm.  Then he explains that re-centering the wheel ( move it over 4mm)  would help solve the problem of front end wobble on deceleration.  No I haven't done it to my k8 and I still have a little wobble on deceleration, but I do plan it sometime soon.  I really like that homemade measuring tool, I should try to make one of those.

[Old Moe Toe]

The front wheel should be a no brainer.
Once you have the spokes all in the right holes you should be able to bolt the front wheel in the forks while bike is on the center stand so that the wheel rotates.Then tighten up the spokes so that you get the wheel running as true as possible AND each side of the rim being equidistant from the fork tubes. You can use a cable tie attached to a fork tube as a guide to get the wheel to run true and by working on the spokes you will find you can get it centered to just about perfect.