10sp rear mech on 7sp?

pbracing

Can I fit a 105 10sp rear mech on my 7sp Pinarello? I've already got it lying around. Also, on the same theme, I've got a 105 Hollowtech 2 10sp crankset, will that work? I know they're for narrow chains, and you couldn't run a10sp chain on 7sp bits, but what about the other way round? :?

Meanwhile the bike's upside down in the kitchen and the wife gets home at 4.30. It's like an episode of 24, nearly

NaB

pbracing wrote:

Can I fit a 105 10sp rear mech on my 7sp Pinarello? I've already got it lying around. Also, on the same theme, I've got a 105 Hollowtech 2 10sp crankset, will that work? I know they're for narrow chains, and you couldn't run a10sp chain on 7sp bits, but what about the other way round? :?

Meanwhile the bike's upside down in the kitchen and the wife gets home at 4.30. It's like an episode of 24, nearly

Why not switch to a 10 speed cassette....surely the easiest option i you've got a 10 speed rear mech . i know there's stuff on Sheldon Brown about mixing 7/8/9/10 groupsets but I can't see the point in trying myself :? I would have thought that given the spacing difference between 10 and 7 speed the rear mech won't shift very smoothly...but then this isn't something I've tried so I could be wrong.....

Monty Dog

A 7-speed chain wouldn't run on 10 speed components smoothly, particularly the rear mech cage and jockey wheels would be narrow and it might be pretty noisy if it works at all. Likewise, you may get chain rub on the inside of the large chainring. To run a 10 speed cassette you'll need to change the rear hub. Suggest you do a bit more research - more details of what components you have would help too i.e. hub type i.e. cassette or freewheel, shifters etc.

pbracing

Thanks chaps. I have got a 10sp cassette, the trouble is I've only got 7 sp shifters, so it'd be pointless.
Damn, it's only the shifters stopping me converting it to 10sp, and till now thought I was happy with it being 7sp.

:idea: I know if I put the 105 shifters on from my Trek (to make a complete 105 groupset), I'd have to replace those with some new DA. ha ha

NaB

Can't see much point in shelling out for shifters if its a hack bike...

maddog 2

it all depends on whether the 7spd chain will:

- run through the rear mech cage without rubbing, and
- rub the chainrings on the 10spd chainset (and front mech cage for that matter)

7spd chain is the same as a 8spd. Both are externally wider than a 9spd chain, and wider still than a 10spd. However, internally they are all the same width. So the 7spd chain will run on a 10spd chainring (or jockeys) no problem.

The issue is the external width of the chain - it might not fit through the cage of the mech without rubbing, and it might rub the chanirings on extreme gears, such as small-small.

Never tried it myself but there's definitely a chance it might work

If it doesn't quite work you could consider a 9spd chain - that should be fine on you 7spd cassette and is narrower than the 7/8spd chain

[now it's time for lunch.... 8) ]

andy_wrx

I run a 10sp 105 rear mech, 9sp Ultegra front mech and 9sp 105 chainset on my 8sp TT bike (8sp chain [SRAM I think], cassette & barcons) - it works for me...

If you have the bits, the bikes upside down in the kitchen and you have nothing else to do all afternoon, why not try it - what do you have to lose ?

Monty Dog

I agree if his transmission was 8 speed - 8/9/10 speed chains all accommodate the same thickness of sprocket whereas a 7 speed sprocket is thicker and therein lies the problem - even if it was a cassette hub (which it might not be) you could fit narrower spacers to between the existing sprockets to make it 10 speed compatible - but he doesn't have the shifters either so it all becomes a bit hypothetical and pointless....

djb1971

I'm also running a 10sp 105 rear and front and a hollowtech 10sp chainset on a 7 speed chain and cassette on downtube shifters and it runs very smoothly. It's on one of my old raleigh hacks

markos1963

djb1971 wrote:

I'm also running a 10sp 105 rear and front and a hollowtech 10sp chainset on a 7 speed chain and cassette on downtube shifters and it runs very smoothly. It's on one of my old raleigh hacks

Ah! I was hoping that someone would come up with this. I too run a 7 speed set up on my hack bike and the rear mech is on its way out. I was going to get a campag one off ebay but 80's kit is selling for silly money so I was thinking of using a 10 speed Veloce. Thanks for posting you have given me the confidence to give it a try.

NaB

Obviously you can run anything with friction shifters its just sti/ergos that pose a problem...

pbracing

:shock: :shock: NaB, a hack bike?! Haven't you seen the pictures? How very dare you

Thanks Dogs, Monty and Mad, I didn't know about the chains. I think as was said, as it's stripped down i might as well try it. I'll know straight away if it doesn't work.
You can see the difference in jockey wheel thickness between the 7sp and 10sp.

Not going back to downtube levers, no way. Bar sti shifters are the best thing since sliced bread.

andrew_s

It should all run fine if you use a 10-speed chain. Like Maddog said, the chains are all the same internally, so the 10-speed chain will fit onto the 7-speed cogs OK.
It may be that a 7-speed chain will work, or it may rub. That's a matter of try it and see.

itboffin

I'm running a 10 speed campy crankset with 8 speed chain, 7 speed cassette and down tube indexed shifters on a 5 speed suntour derailleurs, runs like a dream in fact I'm so impressed I'm considering switching a couple of my bikes to down shifters

pbracing

andrew_s wrote:

It should all run fine if you use a 10-speed chain. Like Maddog said, the chains are all the same internally, so the 10-speed chain will fit onto the 7-speed cogs OK.

I thought Monty Dog said 8,9,10sp were the same, but 7sp cogs were thicker and the chain was wider. I concluded from that that only a 7sp chain would run smoothly on 7sp cogs. I'm confused again now.
Does anyone know of a decent quality 7sp rear mech? I've found these 2 at £10. What do you think?

NaB

itboffin wrote:

I'm running a 10 speed campy crankset with 8 speed chain, 7 speed cassette and down tube indexed shifters on a 5 speed suntour derailleurs, runs like a dream in fact I'm so impressed I'm considering switching a couple of my bikes to down shifters

Nice I like the silver bar tape...but the cable is a bit slack no?

pbracing

Think of the wind drag off those cables, and how do you see through them.

I noticed your bars have a deep drop. I've got these which are 40cm c-c. I don't want anything for them, if you put a few quid in a charity box to offset the postage. They've got the same silver tape

http://i396.photobucket.com/albums/pp47 ... its005.jpg

itboffin

I never travel fast enough to notice, yes I'm a big fan of that brand of tape.

Thanks for the offer but I have more bike parts than is healthy or normal.

Accept for my bike carrier which I just reversed over - doh!