Ultra Torque Pista Campagnolo Ultratorque Track crank conversion

Mega dredge

Part Deux...

As mentioned above, the Ultra Torque cranksets use proprietary chainring bolts. Are the holes in the chainrings the 'normal' diameter though? Or will the Gebhardt 135 BCD track chainring have appropriately sized bolt holes for Camgagnolos weird bolts?

In other words, will this chainring fit the cranksetbelow?

Yes, it will fit.
I just used standard bolts without problems.
The proprietarity is probably the hidden long bolt plus spacer that is needed for a geared setup. That can be replaced by a normal bolt and no spacer needed as only one ring.

Edit: don’t listen to me.

will the Gebhardt 135 BCD track chainring have appropriately sized bolt holes for Camgagnolos weird bolts?

Normal rings have 10mm holes, the Campag bolts for carbon cranks are 8mm. You can use normal rings with Campag bolts, but not vice versa, they will be loose in the through holes but the heads fit and the ring is retained by clamping pressure anyway. You will want some backing plates to replace the inner ring, using thin spacers as you would with metal cranks risks applying excessive pressure to the spider tabs. I keep thinking I should make a product to solve this, as I have some Fulcrum RS cranks awaiting conversion

Or go dingle-speed with two chainrings!

You can't usually get a chainring much bigger than a regular road inner to clear the stays 🙂

does there exist an actual description of what this mod is anymore? feel like I've asked this before

does there exist an actual description of what this mod is anymore?

No, because my blog needed upgrading to php7 and I couldn't be arsed.
The basic feature of the original mod to aluminium UT cranks was milling a bit off the mounting face at the back of the crank to allow thicker track rings to fit, and taking the locating lugs off the back of the spider arms since there was no inner ring to locate on them.
There are no new UT 5-bolt cranks and haven't been for some time. I did this a decade ago because the Mirage and Veloce UT cranks were being sold off cheap (i.e. £25) as end of line product, which made it worth investing in the machining.

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Got 48t on my inner ring, from memory. 50t on the outer.

Further to the discussion on Campag carbon cranks and their 8mm bolt holes, here's the nice way to solve it. Record/SR inner rings are threaded M8×0.75 for the corresponding FC-SR200 bolts, and don't use nuts. This leads to the obvious conclusion that M8×0.75 flange nuts big enough to replicate the loading would be perfect. An absolute stickler for zero axial runout would mill a relief where the ring mates with the back of the crank, as the Campag rings are 3.6mm thick and most track rings are 4mm. The original UltraTorque spec allows for shims, but not negative ones, so if you use a thinner ring you can make up the difference in 0.2mm increments. 5^th bolt is just a generic chainring bolt from the parts bin rather than the long bolt in the Campag double kit.

These nuts will be taking a trip to the anodiser, after which there will a couple of sets spare.

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couple of sets spare

The timing couldn't be more perfect for me. I'd like to purchase a set if possible.

I'd love a set too please

Was there any actual progess on a final version of the campag set ? Would love to see them on a bike !

The aluminium (Mirage, Veloce) ones have been seen on various of my bikes at different times, the Mirage ones have been passed on, the Veloce are still on my Hirame.
The carbon Fulcrum ones will be going on my 464, so follow that thread if you want to see them installed, or just look at the first page to see it with Mirage UT cranks

Mistakes were made 🙂

The SRP bolt didn't like full torque with inadequate head support (8mm bolt in a 10mm hole). In theory, this is exactly the condition it's designed for. I've broken those SRP ones before, so I suspect a manufacturing fault, either on that batch or more generally. They are long since out of business, so it's a moot point. Previous installs with steel bolts have been fine.
Anyway, onwards and upwards, using the long bolt from the FC-SR200 set just needed a couple of M8 washers to take up the space and meant all five bolts use the same T30 tool. Of course, it's not pretty, so some nice one-piece spacers will be made. The Gebhardt track ring is a very close thickness match for the original Fulcrum/Campag road outer.

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Final piece of the puzzle

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@psg1ben and @gdm you have provisional dibs on the two spare sets, £25 for four nuts and one spacer, FC-SR200 bolts not included

Did wonder if this would pop up. Just in time for me actually. You'll have a PM this evening. Thanks! 😊

Ok, bringing this thread back from the dead, but if anyone is interested im building a 1x campy group.
Started with a chorus ct crankset.
Even though the crank bolt is slightly offset this hope keeper chainring in 110 bcd fits perfectly.
Using just a standard chainring bolt for the crank side.

I am waiting for my campy specific 6mm chainring bolts to arrive but other wise we're looking good.

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There's still one set of my special nuts available if you want to replicate the method I used on the Fulcrum cranks above.

Ah thats an interesting prospect !
How have they been holding up over time ? They still solid on your build ?

Thanks for those nuts!
They gave life to my 1x minivelo with a Sram chainring.

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still solid on your build ?

All my 2022 road time trials were done on that bike, zero issues.

Nice ! I'll send you a dm ;)

@psg1ben now thats a funky bike 👌