Broken spindle
 

My son was riding his Gitane TDF last night, and had the BB spindle snap on him. Fortunately, he was just starting out from a stop sign, so didn't crash and wasn't hurt at all. The crankset/BB is an Ofmega Mistral. The spindle is marked Ofmega 68C, and total length is 115mm. I'm not sure why this happened. Perhaps we had tightened the crank bolts too much? At any rate, I'll be looking for a BB or spindle for this. I think the crank arm is fine, but I posted some pics. More available here: https://flic.kr/s/aHsmRjeYdy

If I can't find an Ofmega spindle or BB, any thoughts on replacements that might work? It is an assymetric spindle, much like Campy. I'll have to measure between the lands and the end lengths, but possible a thin-cup Campy Record spindle might work? At one time I had one, I'll have to look. I presume something like a Shimano UN55 would not work.

Thanks for any thoughts/advice on this.

https://cimg1.ibsrv.net/gimg/bikefor...0f798ba6aa.jpg
https://cimg2.ibsrv.net/gimg/bikefor...a17e764aa4.jpg
https://cimg3.ibsrv.net/gimg/bikefor...25ec3c1a21.jpg
https://cimg5.ibsrv.net/gimg/bikefor...6558eda923.jpg

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here is a pre-owned example listed as 116mm in TL -

https://www.ebay.it/itm/Vintage-Ofme...0AAOSwoGdemy~L

also you can post in the ISO thread (stickies) and in the C&V for sale forum

tip - some taper experts have written that OFMEGA is unique and does not interchange well with others.

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Thanks, but that one is marked 70P, so is Italian, as are those on US Ebay (including the one that says it is English).

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my apologies

after posting enlarged image and was able to read the 70C marking

letter is C for "corsa" indicating a two plateau intended usage


https://cimg2.ibsrv.net/gimg/bikefor...cbbc22c89d.jpg


checked ebay.it, ebay.com and subito.it without finding any good candidates :(

btw -

you might wish to check with Palo Alto Bicycles ("PAB") regarding spares availability. they are the creators of the Avocet badge. owner of shop was a part owner of OFMEGA.

https://www.paloaltobicycles.com

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:(That has been ready to go for a long time, those dark spots have been that way for a while.

Glad the kid is ok.

Guess we should check spindles closely more often. :foo:

Somewhere I have an English spec Ofmega BB which I prob won't ever need to use, and I'm guessing might have a suitable spindle for you. will check for length and revert...

Update: Asymmetric spindle is marked 68c and measures 118mm in overall length. markings on cup seem identical to yours: 34.8 x 24 f.s.

Also, in case it's helpful, the Ofmega cranks that matched this BB have been mounted on a regular cartridge BB (prob Shimano) for quite some time: although they have never been really stressed they've done a few thousand miles now without any signs of rejecting the spindle.

That is absolutely gnarly dude! I wonder if it made any creaking noises before it just snapped off? To me it looks like the failure was due to some impurities in the steel alloy or in other words a "bad part". I snapped a pedal off a bike once. But, it had already bent a little first. So, I should have known it was about to go.

I had this one partially fail while riding, had to soft-pedal back to the ride start after the crankarm started hitting the chainstay.

It's just a cheap JIS spindle.

https://cimg4.ibsrv.net/gimg/bikefor...5d30956772.jpg

Just an update: I found the thin-cup Campy Record spindle, and it matches up pretty nicely. It measures 114.7mm vs. the 115.5mm of the Ofmega, the tapers seem very similar. I'll have to remeasure them, but both the end and the thickest parts seemed almost the same. The taper on the Ofmega is just slightly longer. The crank seems to sit on the Campy spindle just slightly less deep, but I'll measure that as well. The spindle fits fine in the BB cups; adj. cup is out just slightly from with the Ofmega spindle.

If this doesn't work, I have a Campy Racing T crank with correct BB I can toss on here for a bit.

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...the Ofmega spindles where the taper is problematic are the earliest ones. The socket and spindle end on those are very obviously much smaller than standard tapers of all other makers. It's impossible to mount one of those cranks on a standard spindle, if that helps any.

Even though that is ~2mm longer, that might be of interest. Let me know what you would want for that, shipped to 60504.

Yes, that is helpful.. thanks! The crank arms do not seat as far on the Campy spindle as they do on the Ofmega. I was measuring about 0.7mm less (distance from spindle end to flat where the crank bolt washer seats.) I think they are on far enough, but it makes me slightly nervous. Chain line seems fine. Might go ahead and try it... I can always switch cranksets.

can you clarify which dark spots are the issue? There are two photos and both have dark areas. Do you mean the first photo?

The darker side actually looks to have a bit of rust tinge to it and would have shown up with Magnaflux or maybe prussian blue, the lighter side is the side that was still hanging on, till it didn't. :(

Both pics show dark where it was cracking, the the grey/silver with clean dark accents is what was hanging on I believe. ;)

Thanks.
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so where do you get magnaflux testing done? I have a frame that some suggested I get fluxed, due to possible cracking.

Most any possible cracking on a frame can be sussed out by close inspection from an astute eyeball. ;)

Its kind of an old school thing, you can call around to automotive machine and cylinder head shops but they will probably not want to do something out of their wheelhouse.

I think you can buy kits but its a skill that can be tricky.

A framebuilder is who you should try to consult.

Do you have pics of the area in question, is the paint stripped, can you see any wrinkles, distortion, cracking paint, etc. ?

I will send pics at a later date. Frame is stashed away at this point. It’s a 72 Colgano. On its last ride, the steerer tube broke. When I pulled what remained of the fork, I saw some damage to the paint on the down tube. As the bike in question had been ridden hard and often stored outside, albeit in a dry climate, I chalked up the paint issue to cracks. A car guy I know suggested Magnafluxing. Having only a passing idea of the process, I never followed up on his suggestion. I figured I would look at the frame again if a replacement fork of the right type ever materialized. Still waiting for the fork, but curious about the viability of the frame.

IME a placeholder fork would be the first thing to do, almost every cool bike, part frame, etc I have has come after I got something for the meantime.

Could be nice, fancy or just ok but I find that once you take some of the pressure off, the right thing often comes along sooner rather than later. ;)

I know it sounds like a load of crap but has worked for me more than a few times and several times in fine fashion. :crash:

Ok. You convinced me, guess it’s time to pull that frame out of the rafters.