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What rear cluster should I use?(11 posts)

What rear cluster should I use?maxr
Sep 26, 2002 6:39 PM
I have a background in recreational mountain biking. 10 months ago I had a big crash and ruptured medial and cruciate ligamnets in my knee. I had knee reconstruction surgery, and am still rehabilitating. I had a lot of muscle waste on the damaged leg, and it is still 2 inches smaller in circumference at mid thigh than my good leg. To help with the rehab. I bought a road bike ( 2 chain rings) as I figured the more 'steady' pedalling in road riding would be better than the short bursts that are generally the norm in mountain biking. Anyway, my problem is that my damaged leg (along with the 18 pounds I put on by doing nothing for 4 months!!) mean that I can't really grunt up hills. The residual damage is such that as yet I can't stand up and pedal as my bad knee just collapses.Also, I'm used to having the granny gears of a mountain bike to crawl up hills. My question is what sort of rear cluster should I use? I have stalled on some hills with the standard cluster ( no gear low enough). What would be ideal is a cluster with much bigger gears for the lowest 2 or 3, and relatively standard cogs for the higher gears. Does such athing exist? Whats the biggest low gear I can get?
Thanks in anticipation.
re: What rear cluster should I use?look271
Sep 26, 2002 7:26 PM
I'll do this again. Aaaaarrrrggghhh!look271
Sep 26, 2002 7:32 PM
I just did a reply to you and the text evaporated! Oh well, here we go again; If you have Shimano you are limited to a 12-27 or a 13-26; that's the lowwest gearing available. However, if you have your mtb cassette and rear derailer and it is 9 speed, you can swap put it on the road bike and that will give you a 39t front with whatever cassette you use on the mtb, probably a 32t?. If it's Campy, you can get a 29t rear, but it requires a different rear changer, I think.
Would agree, but.......RickC5
Sep 27, 2002 5:09 AM
if you have Shimano, you CAN swap the casette, rear derailluer and chain for mtn bike stuff (XT for example), and get a 11-34 casette. I just did this on my wife's Trek 5500, as she really needed lower gears (like this gentleman) and I didn't want to spend the bucks to convert to a triple crank set-up.
Uh, didn't I say that?! (nm)look271
Sep 27, 2002 8:32 AM
Swap the chain?TheKid
Sep 27, 2002 10:53 AM
Under what circumstances do you need to swap the chain. My current cassette has a 25 tooth sprocket. If I swap to a MTB cassette with a 32t, do I need to change the chain?
Lengthen the chainKerry
Sep 27, 2002 4:28 PM
For every 4 additional teeth on the cassette or chainring (combined) you need to add two links (1") to the chain, assuming everything was the right length to begin with. So in going to 32 from 25, consider adding 4 links (2") otherwise you run the risk of trashing the derailleur in the biggest cog (when on the large ring). Standard (though not only) method for chain length determination is to put the chain on the big-big combo, and add 1". Assuming you have a long cage rear derailleur, you should have no problem with chain droop in the small ring/smaller cogs.
re: What rear cluster should I use?desmo
Sep 26, 2002 7:44 PM
the Campy 10 speed 13-29 is really nice as it's mostly "straight block" except for the 26, 29 low gears. fairly affordable in the Centaur group. or you may want to get a triple. you can also make up all kinds of huge combos with a mountain der. if you have some of that stuff around from your other bike. or you could put slicks on your mtb! that's what I rode on the road last time I was "recouperating". good luck with that knee.
re: What rear cluster should I use?Spunout
Sep 27, 2002 3:21 AM
Agreed, the campy 13-29 is a good setup.

But if your new bike is a shimano 9 speed, just swap your MTB rear mech and cogs to your road bike, it will shift fine. Might need a longer chain, but check that anyways.
Agree, in principle.MXL02
Sep 27, 2002 4:21 AM
I did not know this could be done, but we just bought a Santana tandem which has ultegra up front and XTR in the rear...seems to work just fine.
re: What rear cluster should I use?NJRoad
Sep 27, 2002 3:57 AM
You could try a custom cogset from Harris Cyclery. It's not cheap but the extra $15-$20 you pay for the custom setup is almost like paying your physical therapist.