Rear Freehubs, OLD & Dishing?

[MacB]

There are several frames around with 132.5mm rear spacing, so that you can choose to run road or MTB hubs. If you have a bike setup for touring with 135mm 9 speed rear wheel and triple chainset. The rear wheel gets borked but you have a spare which is identical but on a 130mm road hub. What needs to happen to get the spare wheel running in the frame?

I've read some stuff about redishing of wheels but not sure if that would apply when the rear triangle itself is being moved in, or out, to accomodate the differing OLD.

I can see that the cassette would now be positioned differently but can't quite work out whether that would be by 2.5 or 5mm. If the splines bit is the same length on each hub then that would indicate to me that the freehub itself, ie flange to flange, differs by 5mm and all other bits are the same. If this is the case then it would mean that all would work but the cassette would be 5mm inboard of the ideal chainline.

Would this still work, maybe on a limited gear range?

 

[PpPete]

Assuming drops-outs move symmetrically to take up the different OLD, then surely the cassette is only going to be 2.5mm further inboard? That's significantly less than 1 sprocket + it's spacer (4.34mm for 9 speed Shimano per Sheldon)
Minor adjustment to RD limit screws and you're away.

If your 130mm hub was one of that has 2 washers between cone & locknut on the drive side, I suppose you could take one of them out and put it NDS, then redish the wheel, but I don't know that I'd bother for 2.5 mm unless I was right on the limit for the RD limit screws.

 

[MacB]

thanks Pete, it's one of those mental aberration thing I just can't seem to get my head round whether it would be a 2.5 or 5mm difference. I've even drawn full scale diagrams of two hubs and am still registering a total fail. Dropouts do move symetrically but in both directions, out for the 135 and in for the 130. That's why I thought the chainline would be 5mm different. I can understand redishing if you're putting a 130 in 135 dropouts via spacers. as you'll then be moving the centre line of the wheel. But via movebale dropouts the centreline of the 130 wheel should remain in place.

Really just wanted to know if it could be done without redishing. Chainline would be altered but the RD would still operate fine as it's linked to the dropout. So cassette to RD relationship wouldn't be altered. It should just be cassette to chainrings that alters.

I think I need to go and get out on the bike

 

[mercurykev]

Three of my bikes have 132.5mm dropouts and you can swap road and mountain bike hubbed wheels between them without having to make any adjustments at all. No redishing, no reindexing the rear mech, no adjusting the H & L screws on rear mech. They just work.

 

[MacB]

Three of my bikes have 132.5mm dropouts and you can swap road and mountain bike hubbed wheels between them without having to make any adjustments at all. No redishing, no reindexing the rear mech, no adjusting the H & L screws on rear mech. They just work.

Mercurykev, I think I love you, in a totally manly sort of way just what I wanted to hear....thanks

 

[PpPete]

Huh! You're not only one with mental aberation....s'obvious you don't need to play with limit screws when you think about it.
Definitely needed my ride this afternoon!

 

[andrew_s]

There are no adjustments required because the adjustment depends on the distance between the RH locknut and the small sprocket.
You may have to reindex if the two hubs are of different brands - eg one Shimano and one Hope.
What would change is the chainline, but that would only be of interest if you were running two fixed wheels.