Seven speed cluster on six speed hub?

[80sDave]

I am thninking of upgrading from a mid 80's shimano 600 (6200) SIS six speed to a late 80's 600 Ultegra (6400) SIS 7 speed. I would like to use the exsiting six speed hubs. Can I fit the 7 speed cluster to the six speed hub without too many problems. I plan to use all the seven speed components but just re use the six speed hubs. I checked out Sheldon Brown's site but I am still unclear as to how difficult this will be.

Any advice appreciated?

[531db]

I am thninking of upgrading from a mid 80's shimano 600 (6200) SIS six speed to a late 80's 600 Ultegra (6400) SIS 7 speed. I would like to use the exsiting six speed hubs. Can I fit the 7 speed cluster to the six speed hub without too many problems. I plan to use all the seven speed components but just re use the six speed hubs. I checked out Sheldon Brown's site but I am still unclear as to how difficult this will be.

Any advice appreciated?

Firstly we are talking about screw on freewheels (clusters) and hubs - yes?

This is because a 7 speed cassette will not fit on a 6 speed cassette hub.

So ok if it's freewheel hubs we are talking about, both "normal" 6 and 7 speed hubs are fitted with a 126mm spaced axle (OLN).

But 7 speed hubs have a couple of extra mm of space on the right (freewheel) side and less on the left, to account for the slightly greater width of a 7 speed freewheel. You often can screw a 7 speed freewheel onto a 6 speed hub and fit it in the frame ok without the smallest cog fouling the frame, but putting the chain on the smallest cog will foul the frame.

What you have to do is this: Remove sufficient (usually about 3 or 4 mm) of spacers from the left hand side of the axle and put them on the right to provide cog clearance. This will also move the rim to the left, so the wheel will require redishing and truing as well.

[rogerrabbit]

You could always put a Suntour 7 speed freewheel on, which takes the same space as other 6-spped freewheels. No mucking around with hub spacing and re-dishing of wheels then. Only trouble is that you will need to go to friction shifting (not indexed), which is good for the soul anyway!

[80sDave]

531db - I have probably used the wrong terminology. The seven speed is not a screw on, it is individual cogs (cassette) and I assume the 6 speed is the same. I have a perferctly good Shimano 600 6200 series groupset but I was just getting greedy. I am trying to sell the 600 Ultegra 7 speed groupset but thought that I might upgrade to that if it doesn't sell.

Rogerrabbit - I have one Campag seven speed friction shifter already on my McLachlan (Reynold 708) and will soon have another when I update my Mercian (Reynolds 531c) to Campag Record/Super Record and so was looking for the convenience of the SIS on what will be my training bike (Peugeot Galibier Reynolds 531).

[familyguy]

Unlikely that the 6 will be a cassette. The 6261 rear hub listed at VeloBase.com is a 6 speed cassette. You might have to take the cogs off and see what you've got, cause the rear hub 600EX that I have is screw on (and is also not listed at VeloBase).

Jim

[80sDave]

familyguy - thanks for that. I will need to check.

[il padrone]

I am thninking of upgrading from a mid 80's shimano 600 (6200) SIS six speed to a late 80's 600 Ultegra (6400) SIS 7 speed. I would like to use the exsiting six speed hubs. Can I fit the 7 speed cluster to the six speed hub without too many problems. I plan to use all the seven speed components but just re use the six speed hubs. I checked out Sheldon Brown's site but I am still unclear as to how difficult this will be.

Any advice appreciated?

Firstly we are talking about screw on freewheels (clusters) and hubs - yes?

Shimano introduced cassettes in 1979-80. Within a couple of years most of their higher end components (600, Dura-ace) were all cassetttes.

This is because a 7 speed cassette will not fit on a 6 speed cassette hub.

So just change the cassette body. It can be done relatively easily - pull the hub bearings down, remove axle, use 10mm (?) hex key inside freehub to remove it. The main question is can you still buy 7 speed cassette bodies?

I'd suggest you try Loose Screws

[531db]

I am thninking of upgrading from a mid 80's shimano 600 (6200) SIS six speed to a late 80's 600 Ultegra (6400) SIS 7 speed. I would like to use the exsiting six speed hubs. Can I fit the 7 speed cluster to the six speed hub without too many problems. I plan to use all the seven speed components but just re use the six speed hubs. I checked out Sheldon Brown's site but I am still unclear as to how difficult this will be.

Any advice appreciated?

This is because a 7 speed cassette will not fit on a 6 speed cassette hub.

So just change the cassette body. It can be done relatively easily - pull the hub bearings down, remove axle, use 10mm (?) hex key inside freehub to remove it. The main question is can you still buy 7 speed cassette bodies?

I'd suggest you try Loose Screws

Easier to get a 7 speed cassette hub then......

[il padrone]

Yes, it may be. But not if he has to build it into a new wheel.

[80sDave]

il padrone & 531db - I have a set of 600 Ultegra 7 speed Hubs that I will pull apart to see if I can re-use cassette hub/body. The Sheldon Brown site made more sense when I got into the sections in more detail.

Thanks for your help.

[531db]

il padrone & 531db - I have a set of 600 Ultegra 7 speed Hubs that I will pull apart to see if I can re-use cassette hub/body. The Sheldon Brown site made more sense when I got into the sections in more detail.

Thanks for your help.

Just watch out for Uniglide/Hyperglide compatability issues. Your 6 speed is undoubtably Uniglide, your 7 speed ????

[80sDave]

Thanks 531db. I will check it out and let you know.