chaadster

Folks,

I’m perplexed by this chain guide thingy which came on my bike. It seems like it cannot be positioned to really do anything, so I’m wondering if I cannot just pull it off without concern.

It’s a 1 x 10 setup, with a guarded 40t chainring and 11-42t cluster.

I have the guide/keeper positioned as close to the guard as I can get it, aligned so that it doesn’t rub in any gear, but the trailing end is dropped as low as it can go, in hopes it might catch some chain if it decides to come off and do something to retain it. Could it be installed improperly?

It strikes me as a really clunky piece of kit if not an utterly useless one; I’ve seen some pretty discreet chainkeepers— if that is, in fact, what this thing is— but this huge piece looks like a fixed derailleur. I tied to spice it up with some anodized bolts, but visually I’d rather be rid of it, so if it’s superfluous or there are better options, any insight would be appreciated.

As you can see in the pic, it’s well proud of the chain and not capturing it at all. The guide channel is not wide enough to overlap both the ring guard and chainring, so it cannot be lowered, and the guide plates are to thick to slip between the ring guard and chainring, so it cannot be lowered to capture more chain for that reason, too.

Really, I cannot get my mind around this piece; is it only effective when in the
40/42 combo? I don’t get it. Please help!

Thanks!

2_i 

The chain guide is likely there to prevent a dropped chain. When you shift in the rear, a wave propagates up to the front and may lift the chain off the ring.

LesterOfPuppets

If you don't have a clutch rear derailleur, you'll want to keep that on there or the chain will likely drop occasionally while shifting gears or riding on bumpy ground/pavement.

BCDrums

How'd you get your name onto the chain stay?

Amt0571

Unless you have a narrow-wide chainring and a clutch derailleur, you need some means to keep the chain on it.

If you don't like the guide, you could do something more discreet, like putting a chainguard on both sides of the ring. My Dahon folding bike has the chainring "sandwitched" between 2 chainguards and it works. Sometimes I hear a metal "clank" when shifting and it's the chain hitting the metal guard, so they seem to do their job.

chaadster

Is there any other reason for a chain guide?

I didn’t realize that simply shifting would cause chain drop. I thought it took bumps or shocks to do that, especially across the upper run, where the chain is under tension...or are you saying the wave travels backwards, across the bottom and lifts the chain from the underside of the chainring? Such a chainguide would seem to be in the wrong place for a mechanism like that.

chaadster

it’s a Deore Shadow Plus, so it is clutched; you think the guide is superfluous, then?

chaadster

I dunno if if the ring is “narrow-wide,” but the RD is clutched (Deore Shadow+).

I’ve payed attention to it but cannot hear any contact between chain and guide in any gear. It came preinstalled on the bike, and when going over it out of the box, it seemed positioned so high that there was no way it could have contacted the chain, so I brought down, in as close as I could to the chainring and without any rub in any gear.

This is my first 1x setup, so I’m not familiar with problems specific
to that kind of setup, but I see lots of 1x bikes without such a guide and wonder what the difference is that this bike needs one. Given it seems unlikely it could even do anything, I’d really prefer to remove it if it is indeed unnecessary.

chaadster

Oh, I get vinyl transfer decals made for most
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Here are a few of the others:

Amt0571

It's probably tehre because the chainring isn't narrow-wide. If you remove it it'll probably derail.
r

chaadster

thanks. I’ll see about fitting a “narrow-wide” chainring then.

Amt0571

You can try if it derails with the included chainring first though. My bet is that its going to work in normal conditions, and probably derrail if you shift over bumps.

chaadster

I looked up NW rings and went out to check the bike, and it does have one already. So this is perplexing, because it has a clutch RD and a NW ring, so why does it have that clunky guide on it??

I guess I'll just take it off and see how it goes.

Thanks for the help!

Amt0571

Take it off then. You shouldn't need it.

hokiefyd 

It costs you nothing to remove it and just how it works. I have a fatbike with a non-clutched rear derailler and a "poor man's" 1x drivetrain -- I took the large ring off the crankset and I'm using only the small ring. I removed the front derailleur entirely, I don't have a chain device, and the chain ring is not a narrow-wide design. Despite that, I haven't dropped a chain yet. I couldn't say that it'd never happen, but it's been fine so far. You could remove it and see how you make out. It'll cost you nothing but time...and perhaps some greasy fingers if you do drop the chain once or twice.

Amt0571

Well, if you drop the chain unexpectedly when sprinting, for example, it can cost you your teeth

2_i 

The wave along the bottom is dampened by the tensioner. It is the one going along the top that can cause the drop without provisions of one sort or another. On bikes with front derailleurs it is the derailleur cage that prevents the drop. The clutch that is on in a clutched rear derailleur reduces the wave on top.

Gresp15C

I was dropping the chain on my Diamondback 1x9 all the time. It had a chain guide too. Of course Murphy's Law dictated that it only happened at the most embarrassing moments. Switching to a narrow-wide ring was like night and day -- no drops since then.

Geepig

My 1974 Carlton never had one, but it was only 1x5, and the only time was when I did something stupid with a badly worn chain. My brother's 2x5 would, if the lever wasn't quite in place.

Canker

The chain guide isn't meant to work with that style of bash gaurd so you might remove one or the other. The chain guide is pointless as currently setup. If you don't have a narrow wide chainring I'd loose the bash and keep the chain guide, even on a gravel/road bike that could be useful. The bash is pointless unless you are actually mtn biking.

veganbikes

Take it or leave it probably not a bad thing but with a clutch and a NW you should be fine. Heck my NW with a non-clutched derailleur (old XT 8 speed) works just fine and dandy and I haven't yet dropped a chain (at least not that I can remember)

I do like the pink bolt on it so I would vote to keep but only for that bolt.

chaadster

That’s what I thought...it certainly does not appear to be able to do anything as-is. The bash guard, however, also protects the pants leg from brushing the chain, so I’m preferring to keep it for that. Ditching it, though, does open up the possibility of a fiting a tricked-out chainring! Bespoke Chainrings has a couple of dope ones in stock right now which would look so swass...