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or, at least, it is to my brain.
I'm wresting back my venerable Hope Pro II hubs from the offspring's bike and fitting these to my Roadrat. And needing to go from bolt-through to QR for the front hub.
I think I have all the original bits from the conversion in the other direction (QR to bolt-through), but the QR adaptor is very slightly too big to slot into the middle of the bearings. Yes, I've attempted grease and brute force, but not even this will make the adaptors slot in.
And this would make me think I have the wrong size adaptors. But I'm quite sure* that these are the ones that came from the hub originally - and besides they neatly fit into the other Hope Pro II hub I have on my FS bike.
Are all Pro II front hubs exactly the same - or maybe the bearings that are fitted vary a bit over time? I dont think either hub is an EVO version.
* - really, really, but not quite 100%
Yeah same adaptors on the front for Pro2/Evo and Pro4.
I might have a set of you need a second lot to try
Hmm. Spacers are more missing than misaligned. Will hunt for them in parts box. But this probably doesn't explain it, unless I am misunderstanding how this works.
Thanks R3G. The bit I get stuck on is that these adaptors must have originally come from the same hubs. But, this could have been almost two decades ago - and 30 yo me was not super organised with how he stored stuff like this.
To expand on GFJ's post. There is a spacer tube between the bearings that 'connects' the inner races. It's 20mm ID. When running 20mm it is right next to the axle. When running 15mm there is a gap. With QR the adapter pushes through the bearing into this spacer. I'd it is not perfectly aligned then the adapters will bottom out on it. You should be able to reposition it worth your fingers.
I think the pro2 is similar to the pro2 Evo, couldn't find a diagram for the non Evo. The spacer sits between the bearings and is centralised by an o-ring. If you take the o-ring off the QR endcaps, the endcaps should slide into the bearing and spacer easily.
Thanks Nixie - the inner spacer looks like it is aligned well. But I don't think the adapters are actually getting through the bearing into the spacer. Maybe not even getting 1mm into the bearing. There is a superficial about of corrosion to the inner surface of the bearing. Do you think the tolerances are that high that this would make the difference?
Thanks GFJ - you are bang on. I took the o-ring off and then tried again. I may have tried a gentle tap with a hammer, and it finally slots in. I might back it out again and try removing the corrosion so that it will go in without force.
I guess, the time in the school bike racks with a 15mm axle allowed the corrosion to build up. And the tolerances are that fine.
Thanks folks. These 20 yo hubs live on!
Corrosion would not help as it effectively reduces the ID.
The bore on an SKF 20mm bearing is +/- 0.008mm. so even if that was the slackest hearing possible, adding more than 0.016mm of rust would make it too tight.