ian0789

So I was looking to upgrade a few parts for my 2nd bike. I was looking at nashbar and came up with a few ideas but in the end I found that 8speed group sets are not as easy as to find when trying to upgrade a triple. I was looking at a chainring/crank combo and it was about a second away from buying it. I found out its a 10 speed crank but from what I gathered the difference would be nothing if I used it on my 8speed set up.

I also noticed people used 10 speed FD and RD on 6,7,8,9 speed set ups. So what is the bottom line when it comes to swaping out parts? I know I need to keep my cassette 8 speed as I am not changing out my shifters (Triple / Eight) or chain. But as for Chainring/crank and FD/RD does it really make a big difference and if it does are we talking chain slip / miss shifting or just a bit of noise?

ronp6

The rings on a ten speed crank are closer together than they are on an 8 speed. The chain for an 8 speed setup is wider and may rub on the rings. I have used a 9 speed chain and gotten away with it. You could try that if your chain is too wide. A 10 speed chain is too narrow for an 8 speed cassette since the cogs are thicker. You could also make shims to space out the rings to open up the distance.

hockeyteeth

^^^

Yup. I have 9spd rings with my 7spd chain and had to use some chainring spacers to keep the chain from rubbing.

FastJake

In all the ratios or just the small/small combos?

ronp6

The problem is on the smaller rings other than the 2 or 3 smallest cogs; the big ring is fine unless you have a problem with the narrow front derailleur. Spacers are an easy solution and they could be shirt cardboard or thin washers with one edge flattened off with a file. They will be sandwiched between the ring and the crank so it doesn't have to be fancy.

ian0789

Well thank you for the info, I found some conflicting posts that said it will work while others said spacers. I think I will just build up set slowly during the winter and make my end choice on cranks once I find a good deal on shifters.

dsbrantjr

Commercially manufactured chainring spacers are readily available in numerous thicknesses, no need to kludge something up.