I'm finishing up my new city bike, and have just realized that FD I had earmarked for it won't fit; it's for a narrower seat tube. Crankset is Deore LX triple, I think 28-38-48. I took the bike for a spin, and it dawned on me that I really don't need all three chainrings - it's completely flat around here, and I won't be doing any long trips on it. My question is: is it possible to take off two chainrings and leave only the middle one? If so - what would it involve? Would I need to get shorter bolts for example? Or is there a chainguard (cheap if possible I could install in place of the outer ring?

Riding a triple sans FD seems just wrong to me, although I'd do it if other options were expensive / difficult =).

TIA

you can grind the teeth off of old chainring to make cheap chain guard You also might need a chain keeper for the front when in your biggest gear in back.

+1

If you need a chainkeeper, it's less than 10$. If you file teeth down, you're out time and about 8$ for a 1x9 conversion.

Thanks for the ideas. Now that I know the alternative, I think I'll slap FD on the bike. Grinding teeth off the chainring sounds like a lot of work .

And they would fold easier too.

If you're not bouncing off logs just get some of the short chain bolts used on the the inner rings and hacksaw adn file down the long outside nuts to size. Or get some track bike chain bolts.

In case anyone's interested.

I told friend of mine about my 'problem', and he got a chainkeeper for free from a bike shop he was buying a new bike from. I installed it, and it doesn't work at all - my BB spindle is too wide. The gizmo would keep chain from falling off granny chainring, but not the middle one. Back to buying FD...

Or, leave the three rings on without a derailer. You can allways move the chain to the other rings by hand if you need them. (just don't try while moving)

i did it to a mountain bike. used a 105 double crank with a 42t ring. just get some single stack bolts. its been working fine for me. thought i might need a bash guard or a salsa crossing guard, but haven't had any problems with the chain jumping off the ring. and i hop up curbs and run into some bumpy roads around here. just make sure the ring is lined up with the middle/middle cog of the cassette and it should be good.

and if you're looking for some type of bashguard, look at the BBG ones on ebay. 10 bucks & 4 bucks shipping.

This is a city bike. There's probably no need for a bashguard. There's probably no need for a chain keeper either--the only time I've had a chain fall onto my bottom bracket was from shifting from the middle ring to the inner ring on my mountain bike with a misadjusted front derailleur. None of my bikes' chains have ever just fallen off a chainring while not shifting. My advice: get some short BMX/track bolts and ride the damn thing.

City bike? No problem. Just run the single chainring. LOT'S of us are running 1x8's 1x9's or 1x whatevers with no FD and don't have any issues. Just mount it on the inner side where the middle ring would go normally so it's more or less centered to the rear cassette.