Gearing Question 32 tooth
 

I have a Lemond Sarthe (Campy Veloce) with a stock triple chain ring, Currently I am running a 13 - 29 cassette on the back. I bought a 32 toothe cog for the back, as I am a below knee amputee and could use a little more help up the steep hills around here! I removed the 16 tooth cog, as instructed, and used the spacer to install the new 32. Everything works fine, except that there is no way that I can shift to the 32 while in the big chain ring (52) in front. I physically will not go over. I know that I should never be in this configuration because of the dramatic cross chain thing, but am I just wishing for something that can't be, or does anyone have any suggestions?

Thanks

Hi,
you don't want to even try, it's damaging. ALso, you can duplicate that gearing without twisting the chain.

What could I change to copy that type of gearing? Perhaps a smaller front chainring?

Like late said, use your small chain ring. A 42T chain ring and 26T cog (42/26) will give you the same gear ratio, as will 39/24 or 36/22.

If you leave it like that sooner or later you'll forget, try to force it in and it will snap off the rear derailleur.

I suggest you take the bike into a shop and have them set it up properly. They'll probably replace the chain and they may have to replace the rear derailleur if it doesn't physically have enough chain wrap.

If you're doing this yourself you'll need a chain breaker. These are cheap but the better one's work easier and wear slower.

First you need to determine if the rear derailleur is correct. Break the chain either at the master link if your chain has one (this is a REAL pain in the butt because they're invariably jammed - but working it will eventually free it up) or with a chain breaker if it doesn't. This chain will probably be a throw away anyway so it's no big deal and you can use it to learn.

Now that the rear derailleur isn't being limited by the chain shift it into low gear. You may have to rotate the rear derailleur back to clear the 32 with the jockey wheel.

If the rear derailleur will not clear the 32 (as it probably won't unless you have some sort of super touring rear derailleur or a mountain bike rear derailleur) you'll need to buy a new rear derailleur. I ASSUME that the Campy long arm rear derailleur will JUST shift a 32 but that depends on some variables such as the derailleur mount and the dropout type.

Anyway, knowing that the derailleur WILL shift the 32 you then shift it into the big ring and the big cog. Then thread your new Sachs chain through the rear derailleur properly (Over the top jockey and under the bottom making sure you're under the guides) then over the large cog and over the big ring.

You then have the two ends of the chain hanging off the front ring and the rear derailleur. Pull these together until the rear derailleur is stretch ALMOST to it's limit but not quite. Hold the ends of the chain together and see how many links you have to remove - COUNT THEM. The Sachs master link is a outside link so you have to break the chain leaving an inside link.

You need to break the chain at the right length. Remember that you're right on the limits of what the derailleurs will handle so if you cut it too long it will sag in the low-low combinations and if you cut it too short you're right back where you started.

Now, none of this is very hard and if you're mechanically inclined you'll probably have no trouble at all completing it in 30 minutes.

Though it is a handfull of writing.

A better way would be to change the Campy uses a 30 tooth small ring down to as small as a 24.

I would suggest you go to the smallest available. You'll have to ask at your bike shop. This is a MUCH better idea than the 32 and if you can't climb in a 24/29 you won't be able to climb anyway.

Problems? The rear derailleur may not have sufficient wrap and you'll only be able to use the largest cogs in the triple. But you do that anyway.

http://www.sheldonbrown.com/gears/

find you gear inch on the 30 or 42...

http://www.bikeforums.net/showthread.php?t=158001

don't cross...basic rule

the big ring should only be used with the first half of you cog set...
the middle should reach most of your cog set...
the granny should reach the easy upper half of your cog set...



oh ya...did you add a link or two to the chain? I tight chain will not shift as it should...