I've acquired a pair of old Alexrims DC 4.5 Disc 26" MTB wheels with Formula hubs, but the rear wheel is missing the axle. I've been reading various posts about how to measure / replace the axle, but haven't found anything that makes me confident enough yet to buy a replacement. Is there an easy way to tell what size / type I need?

I initially presumed I would just need a standard axle for 5mm QR skewers, but when I measured the internal diameter of the hub it was 12mm. So is this hub actually designed for a 12mm bolt thru axle?

Any advice or pointing in the right direction would be greatly appreciated!

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  • 1
    Please add a picture of the hub, this will allow conformation of what type it is. May 1, 2020 at 12:08

2 Answers 2


If the hub has a smooth, straight-walled 12mm diameter hole through it, yes it's for a 12mm through axle. (A 'through axle' isn't really the axle of course, it's a fastener that goes through the hollow axle in the hub.)

If this is the case, there are through-axle to quick release adapters available that you can use.

BTW, have you checked that the hub width is correct for your frame?

UPDATE: Nope not through-axle. Just missing axle and bearings.

  • The front and rear dropouts are both 10mm. The front hub has an axle for 5mm QR skewers, which is ideally what I would want on the rear as well
    – MarkyMark
    May 1, 2020 at 12:27
  • @MarkyMark I mean dropout spacing, 135mm is standard for QR, 142mm or more for TA on the rear. However, your pics show you do not have a TA hub May 1, 2020 at 12:30
  • The distance between the rear dropouts is 135mm. So does that mean I am looking for a 135x5mm rear axle and not 135x12mm?
    – MarkyMark
    May 1, 2020 at 12:37
  • You want a QR axle of the correct length for a 135mm hub (145mm). Rear axles are 10mm x 1mm thread pitch. Then of course you need matching cones, spacers, nuts and bearings. Have you ever rebuilt a hub before? May 1, 2020 at 14:06
  • No this will be my first attempt. Are there any particular brands you'd recommend looking at?
    – MarkyMark
    May 1, 2020 at 14:44

It's likely not going to be practical to fix this.

The axle is the easy part. It's a standard axle hub. You need any 146mm M10 quick release repair type axle.

The cones and seals are the problem. They have to be right for the hub. The main conceivable way of getting what you need is finding another of the same hub in a big nasty box at a used parts oriented shop. With some time and hassle, cones might be obtainable new or cannibalized if you both looked hard enough and were willing to do the work of obtaining and testing them, i.e. assembling the hub with them and seeing how you feel about where the ball track is falling. That still leaves seals. They're only going to come from a donor hub.

You need to look for explanations why it got parted from its guts to begin with. Are the cups in good enough shape to warrant messing with? Is the freehub working right?

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