Sprocket and Groupset Compatibility

My hubs have a 6 speed Shimano Uniglide Sprocket. I would like to use a Shimano 600 Ultegra groupset on my bike but as I understand, this groupset does not come in a 6 speed edition. Would I be able to fit a 7 speed cassette on the hub? Or just use a 6 speed cassette with the Shimano 600 components as 7 speed and 6 speed spacings are similar? I read Sheldon Brown's page on 'speeds' but I'm still confused.
Thanks for any help.

Derailleurs are (with a couple of obscure exceptions) "dumb": they do what the shifters tell them to do. So unless you're using indexed shifters, whether the freewheels have different spacing is irrelevant.

tl/dr
Yes, a seven speed freewheel will fit fine.

It's you again! Thanks for all your help :)
So I could in theory put a 7 speed freewheel on and use the SL-6400 shifters which are 7 speed and I will be fine?

I'm afraid so; I'd wait to see if it works before you thank me...

Yes, 7 speed freewheels (almost) all have the same centre-to-centre spacing: http://sheldonbrown.com/cribsheet-spacing.html

I'm still pretty confused about the best course of action in my situation. My frame has a rear spacing of 126mm and my hubs are 126mm width Shimano 6 speed Uniglide 36/36. I would like to use as much of the Shimano 600 Ultegra "tricolour" groupset as possible and I'm not sure whether this will be possible with a 6 speed hub as the 6400 Derailleur is 7 speed (velobase.com/ViewComponent.aspx?I­D=c7069264-613f-48e1-8112-d3236e2fd096&E­num=108). However this build (the same frame as mine) vitus979.com/my-vitus-979/ seems to have used that derailleur on a 126mm width hub.

126mm OLD is the standard for 5 to 7 speed. OLD increased to 130mm with the introduction of 8 speed.

Hubs for screw-on freewheels aren't speed/gear specific in the same way that freehubs for cassettes are (8 speed and above): the threaded part of the hub that the freewheel screws onto is the same.

Your current hubs will happily accept freewheels from 5 to 7 speeds.

Have a browse through Sheldon's glossary if any of the terms aren't familiar to you.

The op says he has 6 speed uni glide. Silly suffolk has assumed that the op has a 6 speed freewheel which maybe correct but maybe not. The op may have a 6 speed uni glide cassette in which case finding a 7 speed cassette is hard has they are almost extinct.

If the op use friction shifter and does fit a 7 speed cassette or freewheel then fiction shifters don't care what your sprocket spacing is. Down tube shifters should be friction

All shimano road mech until the new 11 speed ones have the same parallelogram design meaning they are interchangeable. A 10 speed mech can be used on 6 speed and visa versa.

The VeloBase page for the SL-6400 shifters say they are indexed (http://velobase.com/ViewComponent.aspx?ID=75c91ac5-4408-49e5-a9f1-d6581e1be9d5&Enum=104) I was under the impression that this meant they were not friction shifters but would be happy to be told I'm wrong :)

EDIT: I uploaded a picture of my rear wheel to make things easier

1 Attachment

As I understand it, this means I can use a RD-6401 even though it is supposedly 8-Speed, with a 7 speed setup?
Thanks for your help!

Apart from early Dura-ace, Shimano road mechs up to 10-speed and MTB mechs up to 9-speed have the same cable pull ratio. That means that, for a given amount of cable pulled by the shifter, they'll move the same amount.

So, with a 7-speed shifter, they'll move the distance between 7-speed sprockets, while with a 10-speed shifter they'll move the (smaller) distance between 10-speed sprockets.

It's the shifter that controls the indexing, not the mech.

Silly suffolk has assumed that the op has a 6 speed freewheel which maybe correct but maybe not. The op may have a 6 speed uni glide cassette...

"Silly" indeed: what's that about never assuming anything?

I uploaded a picture of my rear wheel to make things easier

That's a freehub for a cassette, rather than a screw-on freewheel.

From what's been said above, you'll struggle to find a 7 speed cassette.

However, according to VB your shifters can be run either indexed or friction, so you could still use them with your 6 speed cassette.

Thanks everyone for your help! I'll use my 6 speed cassette for now and keep a look out for a 7 speed one :)

7 speed ug cassettes are available look on ebay or post wanted adds in forums. I got one for a customer that way new as well for a chap in Finland.

Shimano RSX 100 7 speed STIs are afaik the only 7 speed STI set up that will run in a 126mm set up. I've used them previously on a Vitus frameset.

I've got a nice clean set knocking about if you're interested running 7 speed ergos'

That sounds good, I'll message you.

Any shimano 7 speed shifter will index a 7 speed cassette in a 126mm frame. 7 speed spacing is just that and it does not matter the width of the dropout.

I am making my Cross Check into a 1x10. I have Deore 10speed cassette, derailer and chain all good - drive train is fine. I was trying to re-use the Duraace 1o speed bar end shifter I had from a road group. However it is not compatible. Googling indicates that is true.

Can someone recommend a bar end shifter I can get that works with a 10speed MTB rear derailer? Or do I have to get a thumb shifter or downtube shifter? Is there some magic cable or gizmo that cures this issue?

@edscoble please chime in with your wisdom

10 speed MTB derailleur won't work but a 8/9 speed one will (same cable pull).

Just get the cheapest 9 speed MTB derailleur and wack a 11-34 (or 36) cassette on and bob your uncle.

Here's something to read;

http://rivbike.tumblr.com/post/125363801684/fun-wfriction-and-scroll-down-one-post-for-the

Thanks @edscoble - I read the 9sp compat info after I got the 10sp bits. My Duraace shifter is old which made me think it would be ok. The incompatibility was introduced in 2013, no?

I just looked at the shimano data sheet it also says both Road and MTB, me so confused now. I think I need a 2 year+ old 10 speed derailer.

It's the MTB derailleur that's incompatible, unless you got the early one that have the same cable pull as the lower tier one.

@edscoble - So if I go get a Deore 9spd instead of the 10speed my problem goes away. What about the cassette?
I am being told that the 10speed Deore cassette needs to be swapped to a road cassette, because of the very slight difference in spacing they introduced.

So I am back to the road gearing I had before, since it was a Tiagra 10 Speed cassette previously.

Hey all,

I realize that this is a long shot but does anyone know if a Rolf Vector Pro wheel set, which I understand is Shimano 8/9/10 compatible, takes a 7 speed rear cassette. I am trying to get a second wheel set for my vintage cross bike and the seller is not sure.
Cheerio