I mostly only use the front big chainring. Looking to convert the triple cranset to a single chanring. How to do this? Do I only need spacers/washers after removing the 2 chainrings or do I need a whole new crank/spindle? What kind of spacers or spindle would I need. Can I completely remove the front derailleur when only using a single chainring? I think they are STX BB and White Industries crank (or so I was told). Any help/advise greatly appreciated. Thanks in advance.........

Are you looking to save weight big-time? If not, just remove the front derailleur, hang the chain on the big chainring, and Bob's your uncle. At least you have the option of stopping and hanging the chain on the other chainrings when circumstances might call for it. Otherwise, I'm not sure if the nuts will bottom out properly when you thread the bolts just thru the spider and one chainring. Your best bet is just to try it.

There should be no problem, though, with just removing the front derailleur. It has no effect on chain tension or length the way the rear derailleur does.

You can either get shorter chainring bolts, or put a spacer the same thickness as the chainring behind the spider, where the middle ring would usually be.

Don't people usually use something to keep the chain on, then?

I don't see why. The front derailleur doesn't do anything to keep the chain on. It's kept on by the tension maintained by the rear derailleur. The bike becomes essentially a rear-only-shifted rig, like the original 5-speeds, and some current 7- and 8-speeds. There's nothing on such bikes needed to keep the chain on the chainring.

Get a set of BMX chainring bolts. And since you'll be using the entire range of your rear cassette, mount the big chainring where the middle one used to be so your chainline won't be too extreme when using your largest rear cog.

George

The prologue to the 2003 Tour de France was lost because a chain jumped off the chainring while using a single-ring setup with no front derailler. If you're going to use a single-ring setup, keep the derailler on. It won't look as pretty, but it'll keep your chain from jumping.

And with a front derailleur in place, the chain would probably have jammed between the cage and the chainring, instead of just falling off.

I agree with The Fixer... the big-ring chainline is biased toward the small cogs in the regular position. Move it to the middle.

I agree with madpogue re just removing the front derailleur. When I built up my bike I didn't bother with it or the granny ring and frankly don't miss them 99% of the time. If you do go for a single ring then mounting in the middle as fixer suggested sounds like a smart move

That's a good point. Generally the middle chainring lines up straight in front of the middle cog(s). 'Course, if you gravitate toward the smaller cogs, there may be some argument to leave the big chainring in its native position. At that point, though, it almost becomes a matter of splitting hairs.

Fore-

99.99999% people are NOT racing in the prologue of the Tour de France.

I ride without a front derailleur and it is not a single speed. I have a 6 spd in the rear and I haven't had any problems with the chain coming off. I do ride with the granny gear instead of the big chainring, I don't know if that has anything to do with the chain staying on.

Still, front derailleur does not keep the chain on the rings, it just "derailleurs it"

Miyataphile

If any of you are worried about the chain popping off, add chainguards that are commonly used in single-speed and cyclocross applications.

George

Modern chains are quite flexible side-to-side. Ive used a 1x5 setup and had to fit an old front mech to act as a chain-keeper. It stops the chain bouncing from side to side, and falling off the ring.
Mount the single ring in the position of the middle ring. This will give the best chainline, but the downside is that your pedals are father apart than they need to be. The pedal-to-pedal distance (sometimes called Q), should be a narrow as you can comfortably ride, to make your position much more aerodynamic.
When it is time to replace your bottom bracket unit, consider fitting a shorter spindle, and put the ring in the outer position.