NEED HELP!

AvalancheGT

Hi guys, I'm new here.

I'm looking at converting my GT avalanche elite to 1 x 10, the crank set is All-Terra T-651 which for the time being I'm willing to keep using, only issue I have is I don't know the BCD/PCD of the crank and what size bolts I'd require to fit a RF NW chainring.

Any able to assist or know what the BCD/PCD of the Crank.

Thanks

larkim

First things first - are the chain rings on that crank removable? In the past I can recall posters wanting to go 1x and then finding that they can't actually remove the necessary chain rings to facilitate it.

If you can remove them, then the BCD is simply a measurement of the bolt holes which a simple ruler will get you a good enough measurement (I think) - 94, 96 or 104 are common, you just need to do your best measurement of centre of bolt hole to centre of bolt hole, and assuming you can measure to within 2mm you'll have the answer you need.

Also, NW rings are relatively cheap, so if you're not sure between 94 and 96mm it's not too unreasonable to buy both and return the one that does fit.

See also viewtopic.php?t=13093090

AvalancheGT

I can remove the chainrings, is it possible if I get the shorter bolts to use the middle chain ring that's on there at the minute? Or would I end up dropping my chain more often than not?

billycool

Your current chain ring is not `narrow wide` and not designed for 1x.

It may drop the chain. You can get chain guides to help with that though. There is mention of that on the other discussion that Larkim posted. If the chain ring is worn, It's not really worth it and NW is the preferred option.

You can get a new NW chain ring for about £20-£25 and shorter bolts for about £5.

AvalancheGT

Ah thankyou for your help.

larkim

You can simply remove the derailleur (or use the limit screws to force it into a permanent position over the middle cog) and try out the middle cog to see if the ratios are to your liking. If you've got a 32 on there currently, you might find you want to go 30 or 34 based on your experience. Leaving the mech in place but unused adds something of a chain retention to the setup, but clearly isn't ideal as a long term solution.