single ring
 

if i want to run a single ring up front, what's the best way to make sure that sucker doesn't fall off - bashguard (or two)? front derailleur (will this induce lots of bad rubbing and sounds)? single speed specific ring? inquiring minds want to know!

Just curious... does running a single chainring without a front derailer really allow the chain to fall off more easily in bumpy situations? I've never noticed the derailer keeping the chain on currently with the triple. I'd imagine if the chain did attempt to fall off, I'd feel the chain re-engage in my pedal stroke if the derailer kept it from falling off, but I don't.

Look at what the downhill guys use...they only use one front chainring, so start there.

I'd never take a cross bike down the gnarly stuff real downhillers ride. I'm talking about the normal cyclocross type terrain.

the downhillers have all kind of funky (i.e. heavy) stuff to keep their chains on - bash guards, chain guides, etc. i've been told you gotta have something, though like blastradius i've never noticed my chain falling off the front ring (except for when my front derailleur needs a little tweakin'). might just try running it free and clear and see how that goes.

Report back once you've tried it. :)

I used an old front mech to keep a chain on my single ring. Modern chain are quite flexy, so you do need something, even on the road.
Specialities-TA used to do some swish Al bash guards for CX.

"old front mech"? What's that?

The chain will absolutly definatly come off with out some sort of set up. Unless your running a fixie or at least true single speed w/ no rear derailure so you can pull the chain tight. I run a single 42 and lower the deraillure rite over the ring and it never comes off now. Some people will use the 3rd eye chain watcher and the large 53 ring on so it doesnt come off on the out side, 3rd eye only protects the inside and they have there problems like for example sometimes you can jam the chain under the 3rd eye b/c it's only plastic and can bend to allow the chain under it with some force and then you will never get it out with out taking it off, ie you lose the race.

Best solution is a ring guard set up. check out cyclocrossworld.com. It is a single 42 with two larger carbon or some other material rings on either side and apparently are flawless but run about 100 bucks too. I am definatly gonna run one next season...

as am i, just suggesting to look at the equipment they use, i.e: one front chainring system. their stuff is durable and reliable, because the last thing you want is to have a chain fall off during a 50+ mph downhill

Good to know. So I take it you've tried it without any sort of guide.
Looks like the old front derailer is a cheap alternative to the single purpose guides.

Yeah, the downhill stuff looks good and works well, even if a bit heavy.

You might need special munts on the BB for some of the downhill chain guides. If I were doing this (which hopefully I will be soon), I'd go for a bash ring on the outside and something like a Third Eye, but metal.

Yes I did try it out once. I have an old Nashbar tour XC that had a triple that I converted to a single. I was surprised at how much of a weight difference there was removing the two rings and shifter derallure cable ect.. I test road it before a race twice with no problems. But on race day things go a lot harder and I lost my chain 3 times! it was a bummer to see the whole field fly by while trying to get my chain on ;)

i was just poking around on Sheldon Browns website and found exactly what you are looking for. Its ment for single front rings and derailluers in the rear. Looks lighter than the gigantic bash gurads on the DH bikes.

http://www.sheldonbrown.com/harris/chainrings.html

you'll need two of em, to go on both sides of the chainring

Why all the talk about the stuff downhill racers use? Why don't use two single speed protection rings like all the pros do? Like those made by Spooky and Specialite? I use the carbon ones from Specialite and they work great at minimum weight (18 gr. per ring)

boomforeal, do you have a rear derailler? If so the tension of the drailler keeps the chain on.
I run a single front with a ho-made bashring outer and no problems.
I will probably order a single unit like above for inner after I do several more pressing upgrades (it's never gonna end :rolleyes: )
If you are playing with a triple spyder the bolts for large, mid will fit the 2 plates, no bolts needed.

Note that you'll need to use a 118mm BB normally used for a triple crankset. This will give a better chainline.

those cf and aluminium rings look pretty sweet. i've got an xt 8 speed in the back, and was worried that if i used a maxed out front derailleur to keep the chain on (besides it being kinda ugly) i'd get chain rub. . . but i think i'm going to try it, and if need be just widen the cage, as the rings are kinda spendy. thanks for all the advice!

Can you take a file to a large worn-out chainring and make your own lightweight "bash" guard?

I agree with JW; Its not gonna fall off (at least not on the roads) if you have a deraileur. I been running a single ring on my racing bike for 6 (?) years. Never had the chain fall off.

Mine fell off 3 times in one race last year with no bash rings and an xt rear deraillure. I put my Suntour xc front back on and spread the cage and it still tries to come off but so far it has not. btw I run an 8 speed and have no chain rub on the front... Next year I am definatly getting the rings.

Did you see how Miller lost the prologue of the TdF last year?

Single blade combined with the cobblestone Champs Elysee and no rings to prevent the chain from coming off.

yup it's a bummer to work so hard only to watch the field pass you by as your on the side putting your chain on!