Who can skim my wheel in So. California - recommend plse

I had my T140 front wheel rebuilt (by Buchanan's, so not by cowboys). Now, when mounted in my bike, the disc runout seems out of spec. The manual gives a 0.0035" tolerance and I am measuring about 0.012". It's a brand new disk, that the manufacturer states has less than 0.001" deviation. So, I suspect that the mating face is not to true, probably as a result of the rebuild (maybe the two hub halves were moved relative to each other).

So, I am seeking a shop that can skim the face, preferably someone in the Southern California area. Does any member know of, or can recommend a shop that has the capability to skim the face of a complete wheel?

Thanks,
Peter

I would check the disk first before doing anything else. Once I had a brake job done on my car, new disks put on and the mechanic said no need to turn them, at the first application of the brakes, it was obvious something was wrong so after some head scratching, he turned the new disks and after all was fine.

In these days of CNC automatic machines you expect everything to be perfectly identical and perfect, if that was true, everyone would be out of work because machines would do everything better... not quite there yet :!:

Jean

Corona850 said:

I had my T140 front wheel rebuilt (by Buchanan's, so not by cowboys). Now, when mounted in my bike, the disc runout seems out of spec. The manual gives a 0.0035" tolerance and I am measuring about 0.012". It's a brand new disk, that the manufacturer states has less than 0.001" deviation. So, I suspect that the mating face is not to true, probably as a result of the rebuild (maybe the two hub halves were moved relative to each other).

So, I am seeking a shop that can skim the face, preferably someone in the Southern California area. Does any member know of, or can recommend a shop that has the capability to skim the face of a complete wheel?

Thanks,
Peter

Click to expand...

Have you checked the rim for "runout"........ Also take the disc off and check the hub for run out before you "slash and burn".... Is the axle straight with no obvious wear........ If you "know" the hub and rim prior to rebuild and it was OK check and recheck......... Veeeeeeeery unlikey the hub is at fault. IMO....

olChris said:

Have you checked the rim for "runout"........ Also take the disc off and check the hub for run out before you "slash and burn".... Is the axle straight with no obvious wear........ If you "know" the hub and rim prior to rebuild and it was OK check and recheck......... Veeeeeeeery unlikey the hub is at fault. IMO....

Click to expand...

Yes. Checked the hub and found about 0.005" runout at the edge of the flange (I did that after my original question was posted). If you do the math, that gives about the 0.012" at the disk edge that I found.
I do not "know" the hub. It was an eBay buy. The wheel seemed original, but rusty. The axle did not appear bent. It is pretty stout. It would take a pretty substantial front-end whack to bend it, and the wheel was rusty (which is why I had it rebuilt) but not bent.

On Triumphrat a couple of people have also doubted that the hub could be at fault, but I am not so sure. It might never have been right. In the mid 70s Triumph was a struggling company with clapped-out machine tools, so there QA/QC might not have been top notch. The manual says to keep moving the disk around trying the four possible positions to see if the runout can be improved. That is obviously a way to manipulate the tolerances until the end result is acceptable. If all the parts were within spec that approach would not really be necessary or effective.

Anyway, Sunday afternoon with a dial indicator and a whet-stone has improved the situation.

BTW I have seen a few posts about people mounting a 2nd disc on T140 and T150s etc. with no mention of checking the runout. The disk I bought warns that the "non disk" side of the hub probably was not trued at manufacture. I think it is something to think about if one is upgrading the front brake.