A Shimano M730/32XT hubs question. 6spd or 7spd on a 130mm rear spacing?

[boy"O"boy]

A question for the collective.

Based around my Ridgeback 604 SIS build here - https://www.retrobike.co.uk/threads/boy-o-boys-1989-ridgeback-604-sis.476550/

The rear is an unmolested 130mm rear axle spacing. The Catalogue spec says this is a 7spd rear. I'm looking to rebuild the Mavic M7CD rims on the correct hubs.

I was always under the impression that a 130mm rear hub was for 6spd rear cassettes and 135mm was the 7spd version.

Could you get a 130mm 7spd version in the early days of these Shimano M730/32 XT hubs?

Want to make sure I'm buying the correct hubs for the 130mm rear.

All advice options welcome before I purchase from overseas.

Cheers
boy"O"boy

 

[Once A Hero]

I looked into this a little bit a long time ago, and established as you have done that the 130mm was specifically for the 6spd, and 135mm was specifically for the 7speed. I didn't however investigate if I could apply a 7speed cassette to a 130mm hub/axle. Instead I just had the frame cold set to suit the 135mm axle hub that I was using.

Hopefully someone with some specific knowledge will turn up and answer your question!

 

[bikeworkshop]

The xt m730 was available in 130 with a 6 speed fhb, or 135 with a 7 speed fhb, up to 88. Both with the smallest sprocket screwing on to the fhb to hold the cassette on.


https://velobase.com/ViewComponent.aspx?ID=3eeb73a2-62d9-45ae-bf03-10180114bcd6&Enum=110
I think the alloy hub was the same casting, so the difference in width was made by the axle and fhb, meaning you couldn't fit a 7 speed cassette (and correct fhb) onto a 130 hub without some bodgery and compromise.
In 1989, the xt hub was now the m732 in 135/7 only.

So the frame should be 135 (if the catalogue states 7 speed) meaning:
Either someone's run it with a 130 hub and it's bent the stays in.
Its much more common the other way round for us where a 126 racing frame has had a 130 wheel fitted, or god forbid even a 135 (cheap and wrong amazon rubbish), and the frame takes, or is given a set.
Or it was an earlier production frame and the jig was still set for the 130 (6 speed) but built up for 1989, and either nobody noticed, or it was a factory 2nd stuck in a store room for a decade or 2, which might explain the great paint condition.

You can't fit a 7 speed cassette on a 130mm xt hub, and it seems unlikely the bike went out 6 speed - too many components wouldn't be right.

 

[27motorhead]

@Tootyred should be able to help out. Check out this page and the following regarding a similar topic:
https://www.retrobike.co.uk/threads/92-team-marin-well-almost.473250/page-5

 

[Dr Dremel]

The 732 hub was available in 130 or 135 rear spacing. The hub body of the former is about 3-5mm (can´t remember exactly) narrower, but you can run it in a 135mm configuration with a longer axle and additional spacers if needs must (I did this with a black hub for a while until I found a matching 135mm).

However I can´t confirm if the 730 rear hub was available in 135mm spacing.

So no need to modify the frame if you can find a 130mm 732 hub. Should not be too difficult.

 

[raidan73]

I believe the M730 rear hub (87/8 was available in 126 and 130mm spacing, for 6 speed (because that was the best you could get at that time), and the M732 (89 onwards) was available in 130 and 135mm and was 6 and 7 speed compatible. Don't take that as gospel in any way though

 

[hamster]

The cassette body is the same as 6-speed was 5.5mm spacing whereas 7s is 5.0. You can fit an HG 7s on to it provided the smallest sprocket is 12T or larger. 11T needs a different detail on the freehub body.

As said above, there is nothing to stop you doing an axle swap, adding some spacers (B&Q washers do fine) and then redishing the wheel (its about 3/4 to 1 turn off/on the spokes. I've done it plenty of times. If you really want to stress about hub flange distances, they are the same as later 8/9/10 speed for the 'wrong' hub core.

 

[Dr Dremel]

You can fit an HG 7s on to it provided the smallest sprocket is 12T or larger. 11T needs a different detail on the freehub body.

As said above, there is nothing to stop you doing an axle swap, adding some spacers (B&Q washers do fine) and then redishing the wheel (its about 3/4 to 1 turn off/on the spokes. I've done it plenty of times. If you really want to stress about hub flange distances, they are the same as later 8/9/10 speed for the 'wrong' hub core.

Just to be clear, you can not fit a 7sp HG cassette on a 730 (6sp) hub without modification. The freewheel may have the same width, but Shimano made one of the alignment teeth a little bit wider to make sure the older hub is not compatible with the newer HG cassette. Of course you can file the alignment teeth of the HG sprockets, but it´s a real pain.

 

[Tootyred]

M730 are uniglide.....m732 are hyperlide with uniglide backwards compatibility.

M730 is 6 speed....screw on cogs at end (uniglide) in 126 and 130

M732 is 7 speed......lock ring at end (hyperglide), but accepts 6 speed hyperglide or unglide cassettes (hence the threaded end) M732 came in 130 and 135.

Hyperglide cassettes don't fit on uniglide hubs.....no wide spline....but Uniglide cassettes do fit on hyperglide with the threaded end. The threaded end was dropped later on as the uniglide standard died out.

Original M732 freehubs will not accept 11 tooth as they have no spline cutaway round the end. More modern replacements made for m732 in 7 speed and used on lx etc do as the last 2mm of spline is shaved off all round.

M732 internals ( except spindle) are identical in both 130 and 135. The difference is the 5mm extra body length on 135.

130 to 135 is perfectly do-able with just an additional 5mm non drive spacer and a longer spindle (146mm over 141mm)

Running 130 bodies as 135 actually decreases the dish and therefore the percentage tension difference between drive non drive, by effectively moving the non drive inboard 5mm, giving a stronger wheel build. This is however at the expense on 5mm more un supported axle, which effectively weakens the hub. Hence the move to narrow hub bodies and the adoption of paralax design to push the bearing out solving the issue.

I think .....

 

[Guinessisgoodforyou]

I put a 7 speed HG freehub on a 6 speed UG 105 hub. Bit of a bummer you can't do that with XT.