126mm Hubs freehub transplant

[on-my-p7]

Has anyone managed to transplant a 7 speed freehub body on a newer 8-10 speed hub shell ?
I have already sprung the frame from 118mm to 126mm so cant risk spreading further to 130mm; I need to downsize 130mm hub to 126mm.

So my plan is to buy new hiubs Shimano 105 fh-5700, frmove the freehub and fit a 7 speed freehub so that I can build it at 126mm.

From what I can tell the splines are the same and it looks as if the mating shape of the freehub body is the same on the 10spd 5700 as the older 7spd stock one (fits STX and A410). But I'm a bit nervous of buying these new hubs if it doesn't work. Also I think I'd have to lace the hub into a rim to be able to unscrew the freehub from the new 5700.

Has anyone done this 7spd down size ?
What combos work ?

many thanks

 

[mattsccm]

I'll be honest I never take the slightest notice of what size the width was meant to be. I build 8-9-10 speed hubs as 7 speed and 'tother way round. I just play with the spacers.
Never crossed my mind to worry about it to be honest There is usually so much in the way of spacer etc. on the left that you can take hell of a lot out.

 

[on-my-p7]

Many thanks, so you have found that the 7spd freehub body fits, may be with a spacer, onto a 10spd hub ?
I tried the 7spd freehub body on an Ultegra hub I have and because that hub has a recessed face the 7spd freehub body sits too close, and the cassette fouls the spokes !
I guess a 2-3mm spacer between the hub and freehub body would solve that. Also the cone and seal washer on the right are different size.

Is it just trial and error to find the cone, spacers and seal ?

 

[TheShipwright]

Re:

Sheldon says you can upgrade from a 7 to and 8/9 so I guess you can go back the way as we'll.

 

[glpinxit]

2 things: have you tried the 8 speed wheel in your frame with a washer removed from the axle, it may fit with adequate clearance both sides? I assume you are planning to use a hyperglide cassette with one cog removed as 7sp is most likely uniglide which is unobtainable now (freewheel or cassette).

Read Sheldon Brown, as above. I did and just went from 7 to 8 (purely to get a lower bottom gear) so I now have a nearly new UG cassette and freewheel I might be parted from (13 to 21 teeth though).

 

[bikenrrd]

Re:

My wife's bike runs 7 speed Shimano on a freehub designed for 8/9/10 speed.
A couple of points:
1. You need a spacer between the cassette and the spoke side of the freehub, i.e. before the largest sprocket. 7 speed cassettes are narrower than 8/9/10 speed and so you need the spacer to get the lock ring to tighten. Having the spacer against the spoke removes the problem of the cassette fouling the spokes.

2. Hyperglide cassettes are still available in 7 speed but they are at the lower end of the quality spectrum. You might be able to find something better NOS on eBay or similar.

I managed to get some NOS RSX (IIRC) hubs on eBay just over a year ago that were made around the switch from 126 to 130mm spacing. They have a 4mm spacer to remove from the axle to get to 126mm. You might still be able to find something similar.

 

[on-my-p7]

Re: Re:

Sheldon says you can upgrade from a 7 to and 8/9 so I guess you can go back the way as we'll.

Thanks, I did read through that a few weeks ago. I dont have spares that I can try the fit and cobble together, I'll have to buy stuff and so need to know they are compatible from the off or I'll end up spending pots of money.

 

[on-my-p7]

2 things: have you tried the 8 speed wheel in your frame with a washer removed from the axle, it may fit with adequate clearance both sides? I assume you are planning to use a hyperglide cassette with one cog removed as 7sp is most likely uniglide which is unobtainable now (freewheel or cassette).

Read Sheldon Brown, as above. I did and just went from 7 to 8 (purely to get a lower bottom gear) so I now have a nearly new UG cassette and freewheel I might be parted from (13 to 21 teeth though).

thanks, This is what I am trying to do but dont have a spare 8-10 spd hub, I have to buy one. the thing is having removed the 4mm axle spacer the freehub body (8-10) spd will foul the frame and so need to fit the 7spd freehub body which is narrower. What I need to know is will the 7 spd freehub body mate properly with the 8-10spd hub shell ?

re Hyperglide yes that is what I will use, there are still plenty of 7spd HG50 cassettes available here.

 

[on-my-p7]

Re: Re:

My wife's bike runs 7 speed Shimano on a freehub designed for 8/9/10 speed.
A couple of points:
1. You need a spacer between the cassette and the spoke side of the freehub, i.e. before the largest sprocket. 7 speed cassettes are narrower than 8/9/10 speed and so you need the spacer to get the lock ring to tighten. Having the spacer against the spoke removes the problem of the cassette fouling the spokes.

2. Hyperglide cassettes are still available in 7 speed but they are at the lower end of the quality spectrum. You might be able to find something better NOS on eBay or similar.

I managed to get some NOS RSX (IIRC) hubs on eBay just over a year ago that were made around the switch from 126 to 130mm spacing. They have a 4mm spacer to remove from the axle to get to 126mm. You might still be able to find something similar.

Many thanks:
re 1) i have also done this on my wifes bike but I cannot fit a 130mm wide hub in the frame of the bike I'm doing up; you cannot fit wider than 7spd cassette on a 126mm OLN without making the wheel weak from too much dish. So i need a 7spd freehub fitted as well as the 7spd cassette.

re 2)I can get hg50 7 spd here, that will be good enough.
thanks

 

[bikenrrd]

On the hubs I have the 4mm spacer is removed from the non-drive side, so I can't see how that would cause the freehub or cassette to foul the frame. If the smallest sprocket is fouling the frame, you might be limited to a larger small sprocket. I like 13->26 as a cassette anyway.