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CC12345678910

Cassette lockring thread size

8 posts in this topic

Anyone know the thread specs for the lockring on a standardised shimano HG spline freehub/driver body, in this case a hope pro2 old? It seems to be a cards-close-to-chest secret if google is owt to go by.

Diameter? Pitch? Thread standard - american, english (24 or 26tpi cycle thread maybe), metric, other?

Dia. can be in fractional or decimal. I'll convert and work it all out in the end.

I've an alu 9spd freehub body coming from ebay but it's got a stripped cassette lockring thread so whilst I do intend to raid it for parts i'm curious to see if I could shorten everything to an 8 or 7spd and cut a new lockring thread. Seeing as by that point it's a pen holder anyway I see nothing to lose and something to gain.

Thanks in advance.

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1.37“ 24tpi British cycle thread rings a bell? Or is that bottom bracket?

Shouldn't be too hard to measure the pitch and if you can grind a suitable tip on a boring bar then bob's your aunties live in lover :)

Failing that, phone up hope, I'm sure they'll be able to tell you.

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1 hour ago, forteh said:

1.37“ 24tpi British cycle thread rings a bell? Or is that bottom bracket?

Yeah that's BB. Think the cassette is smaller diameter.

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8 speed is the same width as 9 speed, so you will only be able to shorten for 7 speed

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@forteh as said, 1.37 x 24tpi is BSA BB's and screw on cassette/freewheel thread.

@monkeyseemonkeydo is correct in saying that a cassette lockring dia. is a larl bit smaller.

@CurtisRider I had forgotten that. Still, the point of the exercise is to attempt to repair something that is otherwise shelf art, so a 7spd (or even smaller maybe) would be just fine.

FWIW I checked a cassette lockring with a thread guage which said 1mm pitch. So I double checked by nestling a m6x1 bolt into the freehub body i already have (the one that is going to get the salvaged parts from the fecked pro2 driver that's on the way) and that [the bolt] fits like a glove.

Just need to get the diameter sussed now.

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13 minutes ago, CC12345678910 said:

Just need to get the diameter sussed now.

|_____________|

'bout that.

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7 hours ago, monkeyseemonkeydo said:

Aye I found that already bud, but when using this (fairly comprehesive) tap chart http://www.custompartnet.com/tap-size-chart I couldn't make head nor tail. There doesn't seem to be (at least to me) a size that correlates to what those peeps quoted - If the dia. sounds right then the approximate TPI seems off or vice versa.  I've had the freehubs apart tonight to make up the 1 good from 2 bad so I've had the calipers out, taken (mildly!) informed guess' as to what size I'm after and ordered up a small selection of bolts and nuts in those sizes to see if a lockring threads into them.

I can only be wrong and it's cost about £4.90something to find out.

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