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Re: Expresso front wheel rebuild
Posted: Sat Mar 10, 2012 6:56 pm
by Mal S7
004 by
mal_hutch, on Flickr
... and fast forward to today, the relaced wheel with ss spokes and my precision truing jig. So much for expresso! Does anyone know where my dial indicator has gone?
005 by
mal_hutch, on Flickr
Trueing it radially was straight forward, I just screwed in the nipples til the thread just disappeared, and it was pretty damn close, then screwed them in 1/8 turn at a time. Sideways run-out is proving challenging, I've got it to within about 1.5 mm but now seem to be chasing my tail grrrr. The rim has taken some big potholes over the years so its a bit hard to pick the out-of-true from the out-of-shape.
I could really do with my dial indicator that seems to be lost in the never never of my messy shed. I know you can eyeball these things to near enough, but the dial is invaluable to show the rim moving as the spokes are tightened.
Oh well... sigh ... Its a beautiful autumn day to sit in the shed and listen to the radio and test my patients (sic)
Re: Expresso front wheel rebuild
Posted: Sat Mar 10, 2012 6:59 pm
by dougie
You're getting there.
Repeat after me - "Dial indicators are for unimaginative people."

Re: Expresso front wheel rebuild
Posted: Sat Mar 10, 2012 7:09 pm
by Duane Ausherman
Dial indicators are for people who want to just dial it in directly to a good number and be done with it.
Don't forget to release pressure from the spokes that you need before tightening up those that you are moving. You must loosen just as much as you tighten.
I have done many of them and once you get the hang of it, it goes quickly. To turn 1/8th of a turn is only for the first round, as later it is way too much. You will be chasing your tail all over the place.
Re: Expresso front wheel rebuild
Posted: Sun Mar 11, 2012 12:48 am
by Chuey
Dial indicators, unless they are special ones with an appropriate scale (most are too fine in increments), will not get you anywhere you need to go. If you are 1.5mm within true, you probably are as close as you can get on these wheels of ours. In other words, the rims are not laser accurate. The width varies some. They are formed, not lathe turned.
It sounds like you are on the right track. Your eyes can see a gap of light between the feeler and the rim. As mentioned above, that is more accurate than the forming of the rim. Add to that, the fact that they are used rims and you are doing very well to get it as accurate as you have. On the Weinmann rims I've worked on, the weld area deviates quite a bit.
Spokes should not be too loose. If they are, they will loosen more over time. I do not know how to convey how you would make sure they are not too loose.
Chuey
Re: Expresso front wheel rebuild
Posted: Sun Mar 11, 2012 12:51 am
by Chuey
Duane Ausherman wrote:What kinds of things to you talk about with your patience?
I don't know about Shell'be but I try to avoid talking with my impatience because I always get in trouble when I do that!
Chuey
Re: Expresso front wheel rebuild
Posted: Sun Mar 11, 2012 3:24 am
by Mal S7
Thanks for the encouragement and tips fellas.
I think,.. aside from the odd pothole wallop,.. its within about 1.0mm of lateral true now, depends on how and where you take a reading aghhh! Probably a good thing I don't have a dial indicator or I would never sleep again. Thanks Chuey for the reality check!
I moved on from that. Took the wheel off and threw it on the grass. Popped the fork lowers off... pheweee that fork oil is steenky and black, and I can no longer ignore that blown fork seal. Oh well its an opportunity to finally do the twin-disc conversion.
Re: Expresso front wheel rebuild
Posted: Sun Mar 11, 2012 3:39 am
by Duane Ausherman
Chuey knows about bicycle wheels and I only know about BMW motorcycle wheels. The big error is where the rim is welded and that can be up to 1/2 mm in error. Just ignore that spot and true it up. If the rim has dents in it, then all bets are off. Aside from the welded area I would never be happy with any error over .010" or 1/4 of a mm.
The place to "follow" with either a pointer or dial is on the inside of the rim, just where the bead is controlled. You will notice all of those tiny dents that are to hold the tire from slipping on the rim. They will cause a chatter on the dial indicator, so just ignore them as they are only .001" in height. They can be worn down to almost nothing on an old rim.
The rim and wheel assembly at the BMW factory in Berlin didn't use a dial indicator. This guy was fast and good at it, but that was all that he did. I could see that he got them all to less than 1/2 mm.
To judge the tightness of the spokes, just get them to a musical note. I never used a spoke wrench, just a modified screwdriver. It is ground to fit exactly into the slot and has a cutout for the spoke.
This is truly a simple job and it only requires some patience. Not everyone has it, but if you can pay atttention, then do your own trueing of the wheels.
Re: Expresso front wheel rebuild
Posted: Sun Mar 11, 2012 3:42 am
by Mal S7
This btw is my spoke spanner I made from an old wheel bearing. Works well.
007 by
mal_hutch
Re: Expresso front wheel rebuild
Posted: Sun Mar 11, 2012 3:49 am
by Mal S7
Duane Ausherman wrote: The place to "follow" with either a pointer or dial is on the inside of the rim, just where the bead is controlled.
Hi Duane, yep, that's where I ended up taking my reading. After I get my forks back together I will try to scrounge up some more patience and see how close I can get. If I spin the wheel real fast and hold an angle grinder nice and steady won't that bring it in??

Re: Expresso front wheel rebuild
Posted: Sun Mar 11, 2012 6:23 am
by DucatiPete
Mal S7 wrote:Don'tcha just love sandblasting
001 by
mal_hutch, on Flickr
Sure do! lookin good mal... & lookin forward to seeing the results in the flesh (as it were)...
I soda blasted fivey's hubs - w elcheapo hand held blaster (cost maybe $25?)... cleaned 'em up ok, but i didn't strip the spokes so some are goin green near the hub - suspect it's the copper under the plating oxidising. Theyre still looking alright too - for a dodgy 2 year old job. IIRC the soda cost almost as much as the gun... and that shite goes EVERYWHERE, including your eyes, no matter the protection used... stings like crazy!! I did mine at a mate's place - now that's a real mate!
