ISO Hubs / Bolt on cogs

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  • For anybody considering following me down the 15mm through-axle route, bike-discount have M758 hubs going cheap­ano-xt-front-hub-hb-m758-6-hole-e-thru-1­5mm-36h-680784

  • Could you elaborate please? Bolted thru?

  • Could you elaborate please?

    See up thread, my simple conversion and a few posts later @BobsHaeroIT did a conversion using top-hat bushes and a standard 10mm threaded axle. There's also a #tartmode conversion on my 464

  • I want to build a fixed gear stumpjumper '91.

    I found very old posts (10 years old or so) not only here but on other forums as well about disc mounted cogs.

    People in those posts wonder if they are safe to use. i wonder, 10 years after, if those are still around (being used by people) and people still going on them, as I found some online still up for sale.

    (for people that are not sure what Im talking about, these are cogs used to convert a disc brake wheels into fixed gear)


  • Never tried it myself although I do like the sound of it.
    Velosolo sell a bunch of stuff for it­

  •­29/?offset=75#comment14629815 here you have all the info.
    Running a disc cog myself and it's been flawless.

  • these are cogs used to convert a disc brake wheels into fixed gear

    Not really. Although some* people on here have had adapters custom-made to convert a factory wheel, the usual set-up is a Velosolo-converted front hub that you'd have to build into a wheel.


  • oh really? wait im confused now, the Velosolo (which is the one I was looking at) should work the way I stated no? from their website:

    "Converts a mountain-bike to fixed in the easiest possible way. Flip the wheel round, bolt on our cog and ride. No other expense involved and reversible in a couple of minutes."

  • yeah that s the one I was looking at, cheers anyway ;)

  • For a mountain bike rear wheel, yes (although even in that case I'd check the chainline first).

    For a 120 OLN track or 130 OLN road frame then it's a little more complicated than that.

  • ok cool,, thanks

  • Or go upmarket.

    HubJub sell them.

  • @mdcc_tester please make adapters available for the masses, so we can all buy cheap Mavic Boost front wheels for conversion. Don't forget to make a 130mm version.

  • we can all buy cheap Mavic Boost front wheels for conversion

    Boost is for use with the outer ring position on road cranks, for track cranks you want regular 100×15 wheels.

    For a plug-and-play 15mm conversion kit to cover 100 and 110 hubs in 120 or 130 frames, with a "shift the hub sideways" option on the 100 to allow for road cranks, it would need a kit containing two reducer bushings, lock nuts and and a stack of spacers to assemble onto the Velosolo straight M10×1.0 axle and ordinary track nuts. Since the reducer bushings are the only special part, this seems like something Velosolo should be doing, not me. Nobody in his right mind is going to want to pay for the kind of #tartmode conversion I did for my 464.

    For my next trick, I'll be converting a hub for my T3 where the shop sales literature specifically says " Quick-Release only. These are not convertible to Thru-axle" 🙂

    EDIT: @BobsHaeroIT is already pretty close to the same solution. It looks like it's intended only to do 100 to 120 for track chainline, although it would obviously also do Boost110 to 130 for road chainline since it just adds 10mm per side and leaves the hub in the middle

  • Merged

  • Some of use would like a road crank for their fixed wheel! I know that the market would be tiny so I can appreciate that even if you have a friendly CNC workshop you can go to this might not be very viable.
    I have a 130OLN frame on its way and I've been considering going for a Velosolo dingle plus road double (41 and 46mm chainlines, right?), but that's for another day...

  • 41 and 46mm chainlines, right?

    More like 40 and 48. If you're going for that, a 100mm hub as a starting point plus a 5mm spacer between sprockets gives you 41.5 and 49.5 chainline at the wheel end with 3mm thick sprockets, so if you want to be exact you actually need to move the hub to the left by 1.5mm. That adds dish, but still not as much as a road hub.

  • Hmm, I was merely quoting the Velosolo suggestion. Easy enough at the hub end but if it doesn't match at the front it sounds a bit like a faff.

  • I was merely quoting the Velosolo

    Their numbers are a bit off. 4mm spacing between two 2mm thick 3/32" sprockets gives 41 and 47 on a 100mm hub run centrally between dropouts. If you're using bushingless 3/32" chain, that's plenty close enough to 40/48 to be acceptable, not many frames are actually tracked so accurately that you'd even know without measuring whether you were out by 1mm on both combinations or zero and 2mm either way. I'm pretty sure all my fixei bieks are out by at least 1mm and even the ones with ridiculously inflexible 1R8 chain run fine.

  • It's easy to over-think chainline matching. Given that frames are rarely straight, BB shells get faced to <68mm, spiders are milled after forging/moulding to get the chainring mounting faces flat, parallel and square to the spindle axis but positioned where there's material to do it given the variable amount the material moves after coming out of the mould and any of a dozen component tolerances on the BB and hub bearing registers and spacers either stack up or cancel out, you'd need to stick the bike on a CMM after assembly to know how co-planar the chainring and sprocket really are.

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ISO Hubs / Bolt on cogs

Posted by Avatar for spotter @spotter