8ounce

I am looking to buy a compact crank and I currently have a 9 speed system. I was thinking of buying a 10 speed crank for 2 reasons, 1: I can get better deals on them, 2: I may upgrade to 10 speed in the future. I know this has been spoken about before and this setup can work, but is there a possibility of having issues. I would hate to spend money on an upgrade that would give me inferior shifting.
Also what would be recommended, a 9 speed chain or 10 speed.

Once again, I know this topic has already been discussed, but I guess I am looking for some reassurance or forewarning before pulling the trigger.

Thanks

RT

This is a question best posed in the Mechanics forum, or better yet, a search in the Mechanics forum.

Needless to say, when you use 9 speed stuff with 10 speed stuff, you are asking for incompatibility. I learned the hard way with a 10 speed 105 crankset with 9 speed everything else. Front derailleurs matter, chain matters, and if you get a 10 speed chain for your crank, your 9 speed cassette may have a little bit of difficulty shifting, but nothing tragic. A 9 speed chain with a 10 speed crank will invite rubbing as the rings are spaced a little differently, and 10 speed chains are narrower to match.

But do go consult the Mechanics forum. Better answers over there.

himespau 

Sheldon Brown didn't seem to think it was a problem.

paulkal

It will be ok.
I am using a 10 speed crankset with 8 speed without any problems for about 6 years now.

8ounce

You are right wrong forums, my bad.
Thanks for input

motobecane69

um, you must not adjust stuff very well. fact is when it comes to cranksets, in many cases they are listed as 9/10. I run a 10 speed ultegra crank with 9speed casette. regarding chains, it's important that the chain match the cassette that you are using so 9 speed casette, 9 speed chain.

foresthill

10 sp crank will work fine with asp everything else. I know a number of people running this with no problem.

RT

No need to condescend with your 'um' I see many 10 speed cranks, not a lot of 9/10. I do see a lot of 8/9 though. A quick Google search supports my position - lots of rings available, but the rings differ in width by a very small amount. From what I can tell, the spiders are the same. At least with the 105 crank I had, the rub was difficult to adjust out. There seems to be a difference between 5700 and its predecessors, and that is the only crank I saw on the first few pages of a search.

The catch-22 is that if you use a 9 speed chain to match the cassette, the marginally thicker chain width is what causes the rubbing on the rings when you even get close to crosschaining. If you use a 10 speed chain to try and moderate the rub up front, you end up with minor shifting inconsistencies in the rear.

At least I'm not going to go all badbikemechanic on you

ericm979

You may need to trim the front a bit more often than if you had a "9sp" crank. But other than that it will work fine. 10sp chain has the same width rollers as 9sp but the side plates are slightly narrower. It's a small difference.

(this is on Shimano, I have no idea about 9sp vs 10sp Campy).

8ounce

thank you all for advice. just pulled the trigger on this:
https://www.chainreactioncycles.com/M...?ModelID=41435

And just one question on the above quote, what do you mean by trim the front?

ericm979

https://www.sheldonbrown.com/derailer-adjustment.html

BTW, the best ISIS BB I have used is the FSA Platinum Ti. The non-Ti version should also be good, just a bit heavier. The ISIS design leaves little room for bearings. Single row ball bearings just don't have the load capacity. FSA Platinums use dual-row bearings.

Make sure to torque the crank on to spec, and check it periodically.

tagaproject6

You'll be fine. Use a 9 speed chain if you are going to retain the 9 speed cassette.