Dropping the large chainring

[lifternick]

Hi,
I ride a 2007 Cannondale Rush and have done quite a few mods and upgrades. I am now finding that I have damaged the large chainring a few times and considering how little I use the large ring on the trails am considering removing it, increasing the size of my middle ring from a 32t to a 36t o 38t (granny is a 22t) and installing a Cycle Logic chainguide with bashring, BB mount, adjustable for 36-38t chainring with an MRP roller. My current ringset is Truvativ Trushift and I am thinking of buying the Blackspire Superpro Middle Ramped 36t. Does anyone see any reason why I shouldn't do this and any issues I might face with the upgrade to a bigger middle ring without changing the granny ring size? Also is there anything I need to do to compensate for the missing large ring? Cheers

[Nobody]

You might get more replies if you put this in "MTB". I can't see any obvious problems with what you are going to do.

[il padrone]

You'll probably want to shorten the chain a few links.

[thomas_cho]

You'll probably want to shorten the chain a few links.

Why would you want to do that? The function of the rear derailleur is to take up chain slack and move the chain at the rear. There is no need to shorten the chain in this case.

Back to the OP, seeing that the large chainring is already damaged, why dont you use it as a chainguard by leaving it there? Limit your FD movement to the middle, and small. You will have to adjust your Hight FD limit guards in anycase.

[trailgumby]

Sounds like a good idea. I don't think you'll have too many issues going to a 36T middle ring but I wouldn't go any higher than that without going up a little on the granny.

I'd also second shortening your chain a few link pairs if you drop the big ring. You don't need the chain to be as long, as your biggest diameter front and back drops from 44T and 34T to 36T and 34T. Assuming it's not too long to start with (always the case fresh out of the bike shop, for some reason ) then you could drop 4 link pairs. A shorter chain increases the tension that can be applied by the RD, whihc reduces chainslap and the likelihood of dropping your chain over rough terrain.

On rough fast descents I will often change to the big ring even though I'm nowhere near needing it for pedalling, just to make sure the chain doesn't jump off. Reduces how often it bites into the inner-tube protector on the chainstay as well.

A mate of mine has a Rush. Nice bikes. My Jekyll is probably due for trading in, but it rides so nice I'm having trouble parting with it.

[il padrone]

You'll probably want to shorten the chain a few links.

Why would you want to do that?

Just because it's no longer needed so long. Depending on the old big ring size, maybe as many as 5 links. Less chain to slap around on the rough rocks, better tension on the derailleur and drive.

[lifternick]

thanks for all your comments. Will give it a go and post my success or failure.