Road Cycling - cogs

my bike route is mostly going uphill... so i figure, why don't i use mtb cogs?

why shoudn't i? what are the disadvantages of this crazy plan of mine(i won't use the mega range mtb cogs though)?

just another crazy thought.... what do you think?

Why do you think you have a crazy thought? Up here in new england many of us ride wide range cassettes, I run an XTR 12-34 in the rear with an XTR rear deraillure and a D. A. 30-39-53 up front on my touring bike, An ultegra 39-53 front and a 12-27 D.A. rear on my road bike. On occasion, when I race the road bike I install a 11-21, but only for race day. The wide range gearing I normally ride makes hilly riding more enjoyable and it shifts and works fine.

Yea, XTR and DuraAce cassettes are the same, so it shouldnt be weird.

You may not need mountain bike cogs.
At the beginning of the riding season when I'm not in shape I swap my Ultegra 11-23 for an Ultegra 12-27. It's amazing what the 25 and 27 tooth cogs can get me through until I'm in better shape.

"MTB cogs" is only a label, not really a different type of equipment. It's just a question of what your derailleur can handle. If you have a short-cage road rear, you might need to replace it to use anything much over a 27-tooth cog. With a long-cage RD, you can go up to a 30 or 32 easily.

Two of my bikes have road triples and MTB RDs with 12-32 or 12-34 cassettes.

RichC

so it isn't crazy then... im going to install 12-34 Deore Lx cogs. i have 11-21 on my road... but i have 105 cassettes, does the Deore or Deore LX cassette fit? all are 8 spd.

they will fit on the cassette body but you may use an MTB long cage deraillure. Like i said in an earlier post I ride a 30-39-53 front with a 12-34 rear, I use an XTR long cage derailure, It works well and shifting precision is right on the mark.

Originally posted by dexmax
so it isn't crazy then... im going to install 12-34 Deore Lx cogs. i have 11-21 on my road... but i have 105 cassettes, does the Deore or Deore LX cassette fit? all are 8 spd.

If you have a racing cassette like that it's a good bet you have a short-cage derailleur, and you will need to replace it. In terms of quality, the Deore LX is roughly equivalent to 105.

The cassette will fit the hub, that's not a problem. You will also need a new chain, your current one will be too short.

RichC

An XT or LX rear derailleur should work fine with your shifters and allow you to use cogs up to 34T if you want to.