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Rockman 144.12


trialsmax04

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Please note that this freewheel MUST be bedded in with 'normal' riding before trials use, Rockman recommend around 5-6 rides. We also recommend thinning out the grease inside this freewheel after the bedding in period, since the sealed bearings will expel any excess grease when new and this will enter the pawl mechanism.

(Y)

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If you suspend the outer over a vice and put a BB tool into the interface, tapping the BB tool will press the bearing out. They are kinda tricky to get back together again though with all those pawls, so I would recommend removing both the seals from the bearings instead (prise them out carefully with a sharp object) and spraying thin lube in through the bearings instead. Give the freewheel a spin as you do it and this should thin out the grease.

Yeah, the bearings are press fit.

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They're quite a tight fit too, so I can't really see them just falling apart or anything. You'd have to basically somehow slide one of the bearings off/out of the shell which I can't really see happening from how tight they are to get in/out.

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With no circlip or anything? Seems a little brave!

That was my thinking, of course its got a way to fall out before it causes issues but I would much rather have seen a retaining lip on the core to stop the inboard bearing moving!

No real axial loads on it though, so should be alright. Just keep half an eye on it from time to time :P

And for the people who dont keep an eye on it from time to time? :P

Im guessing with the steel centre it will have better longevity over a number of dissassemblies but still, its going to wear and the bearings will eventually become loose.

Probably be absolutely fine but looking at it in a worst case scenario its bad engineering imho.

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is this every one that needs bedding in or does it just happen to some.

Mainly this freewheel.

I would much rather have seen a retaining lip on the core to stop the inboard bearing moving!

If you mean what I think you mean, that'd be impossible as you wouldn't be able to put the bearing in or out. The shell's got the ratchet in the middle, of if you put a lip on the outside it stops the bearing from being able to move in either direction at all.

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If you mean what I think you mean, that'd be impossible as you wouldn't be able to put the bearing in or out. The shell's got the ratchet in the middle, of if you put a lip on the outside it stops the bearing from being able to move in either direction at all.

An external lip on the core (same side as the extractor spline), assembly would be be: -

fit inboard bearing onto core - fit and retain pawls - fit ratchet ring - fit outboard bearing

The outboard bearing would be retained in use by the crank/bashguard and the inboard by the lip on the core. I wouldnt suggest it if it couldnt be done, its what I get paid for :)

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You might struggle to get the bearing past the pawl seats :P

Ideally a circlip on one side and a lip on the other, but that would add 2-3mm to the width of the freewheel... The bearings have already been custom modified (width reduced) to make the freewheel slim enough.

The fit on the bearings is pretty good, falls within H7/p6 spec.

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You might struggle to get the bearing past the pawl seats :P

Ideally a circlip on one side and a lip on the other, but that would add 2-3mm to the width of the freewheel... The bearings have already been custom modified to fit.

What about a couple of tiny grub screws into a small slot/hole in the bearing?

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Need to make em smaller then :P

Struggling to work out how that would be possible... (Unless that's internet sarcasm I've missed!)

What about a couple of tiny grub screws into a small slot/hole in the bearing?

Trials riders + anything that needs a 2.5mm allen key or smaller = fail :P But yeah, that would probably do it! Not very 'standard practice' but don't see any reason why it wouldn't work...

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Struggling to work out how that would be possible... (Unless that's internet sarcasm I've missed!)

A bit tongue in cheek, it would need a major redesign in order to accomodate what I suggested. You could use a needle roller for the inboard bearing, that way you could keep the pawl root diameter roughly the same size and use a conventional deep groove ball for the outboard.

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Yeah, would need a taper needle to keep it all together I think? Starting to sound expensive :P

Checked the tolerances on the bearing fit and they are good (H7/p6 - see above). I was editing that post when you posted so may not have seen it...

Well I never mentioned cost, proper engineering costs :D

Yeah I did see it, my main concern was once its been taken apart a few times the bearing tolerances will start to slacken as the surfaces wear, admittedly during the life of the freewheel it probably wont be an issue.

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