Help Needed From MTBers On The Forum

[msl819]

I have a SRAM/Truvativ Noir Crankset on my Cielo mtb that is in need of new chainrings. I have never had to replace the rings on a set of cranks before. They are 104 BCD and it is a 3x9 set up. I would think I could buy a set of rings from SRAM as a replacement but have not found such a set. Do I need to go back with what came stock? Should I look to other aftermarket marker (if so who are they)? Can you guys help point me in the right direction?

[vqdriver]

I'm running an XT set on a race face 104/64 crankset. Fit pretty well

[Peter P.]

You probably can't find rings for your SRAM/Truvativ crank because you're either looking exclusively on-line or you're looking for SRAM rings.

Your local shop can order OEM rings under the Truvativ brand from QBP. They list the Trushift, X.0 and X.9 10 speed, and 8/9 speed rings.

I see no reason to experiment with other brands' rings as the Truvativ rings already have the ramps and pins necessary to work with your shifting system.

[msl819]

You probably can't find rings for your SRAM/Truvativ crank because you're either looking exclusively on-line or you're looking for SRAM rings.

Your local shop can order OEM rings under the Truvativ brand from QBP. They list the Trushift, X.0 and X.9 10 speed, and 8/9 speed rings.

I see no reason to experiment with other brands' rings as the Truvativ rings already have the ramps and pins necessary to work with your shifting system.

Thanks... that is what I needed to know. I was trying to look online to get an idea of how much it would cost to replace the rings. I will swing by my lbs today and see what they tell me about replacement rings from QBP. It is primarily my middle ring that is is shot. My other two are not skipping. When replacing rings should you always replace all three together to keep wear even or just the ring that needs replacing?

[cmbicycles]

It depends on how worn the other rings are. Often the middle ring is the most heavily used and the first one worn out. If you are just doing one ring, then stick with the brand of the other two rings for the best compatability, otherwise the shift ramps/pins may be slightly less than optimal.

Just to cover the bases, usually chain wears out first, then cassette, then chainring(s) so you may have other wear issues you need to address at the same time. If you haven't already, it would be worth checking your chain and cassette to make sure you don't need to replace them as well.

If you have a good LBS, then just take it in and ask one of the mechanics to look at it. They may have a tool for chain wear, possibly one for cassette wear, but chainrings measured via visual inspection. (IME good mechanics can tell everything visually w/o gauges, but the gauges make it a little less subjective... as long as they are still accurately calibrated and haven't been dropped). So as long as you trust your lbs, have them take a look at it.

[msl819]

I replaced my chain and rear cassette and on the first ride started having skipping issues. A first I thought it was my rear derailleur but upon further inspection my middle ring is visibly worn and the new chain is not mating as it should. I know I need to replace the middle, and it does get the lions share of the work on that crankset, but the outer and inner, is it the norm to replace as a set or just as needed?

[dustyrider]

Some say replace as a set; others say replace as needed.
I've found chain and cassette as a set, and chain rings as needed seems to work best for me.
I'd imagine that your little ring and middle ring on a MTB would get more use overall. It may be worth your while to get a granny gear since everything else is new.