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jrahm
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68 Posts
Discussion Starter · #1 ·
Maiden voyage on my Mono 9, and I dropped the chain clattering downhill through a rock garden. Small cog apparently does not leave enough tension in the derailleur to keep the chain on the ring in rough terrain at speed. I think it is the derailleur jumping around that threw the chain. I could lose a couple of links, but I'm not sure that will do it.

Did a forum search, no real help. Chainstay type hanging roller tensioner, or...? Anyone had this problem? I was surprised there was no bash ring/chain guard on the bike stock.

thanks in advance

John
 

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My Mono9 chain was slapping the frame the other day but I'm mostly on the street, maybe one of those stick on frame guards would do the trick.

Have you ever noticed how many bash guards/rings are on the market? a zillion of them, some being plastic and others metal. I chose a nice black smooth metal one and it works fine with my long pants, never a problem there.

By the way.........nice bike:D
 

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Wrecker V2 / Nimble9
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1,197 Posts
I was suffering from major chain drop all the time when I first got my El Mar, even with a guide & bashgard.

The chainguide above looks nice. I have only a 1 sided guide and it pops off still, now only once in awhile since I took out as many chain links as possible.
 

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Derailleurless
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9,122 Posts
Three questions:

What derailleur cage length? Shorter cages holds the most tension; XTR supposedly has greater relative spring tension than XT.

Which chain ring? SS-specific, with longer, non-profiled teeth, is preferrable to a profiled shifty-type chainring.

How short is your chain? Using Shimano & SRAM's big-big method as a starting point, I'd add just one extra pair of links into the equation.
 

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95 Posts
solutions for a 1X9

1) Bash ring - to help from slipping off the outside of the front ring
2) N-Gear Jump Stop - to help from slipping off the inside of the front ring
3) Non-ramped and pinned chain ring
4) Use a short cage (or medium cage) rear derailleur

the N-Gear Jump Stop is a much cheaper option than the rohloff

http://www.gvtc.com/~ngear/

 

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the original big ring
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241 Posts
Yep, same problem here when I set up my Niner MCR (love this bike!) as a 1x9. Drove me nuts when it started happening. It began with the chain falling off on the inside - used a jump stop and that fixed it. I've got a buddy who uses a 'third eye' and it works for him.
Then the chain was falling off to the outside. Solution was running a light chain-guard/bash guard. I'm using a Salsa Ring Dinger with my Middleburn cranks and it works great!
Good luck!
 

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DSC00335.JPG

I have used this cheap solution on a couple of different bikes. PVC end plug and a zip tie with an outer ring. Simple and effective.
 

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That is pretty normal really, just because of the low chain tension while using the small ring and not pedaling. I just shift into the middle ring before a rough downhill and problem solved. It totally sucks dropping your chain during a race.
 

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jrahm
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68 Posts
Discussion Starter · #13 · (Edited)
next step

Looks like problem solved...I will get my hands on the Rohloff, which looks like the most elegant and failproof solution...actually caps the chain over the ring so that it cannot bounce off. Unfortunately they are backordered @ Speedgoat. I also e-mailed Redline, and will post their response FYI.

thanks again guys...

John

p.s./edit Got a jump stop and a Salsa bash ring/chain guard @ Webcyclery this afternoon (local shop), looks a lot like the fix photoed by tozover comment #22 below. Set the Ngear jump stop as close to the chain as possible without it making noise in the big cog. Should do the trick, now boxed in on both sides and has worked for others. Must say the Rohloff still looks like the cleanest option, what can I say, I'm impatient.
 

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Birthday Collector
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jrahm, the simplest thing to try (and the cheapest) is to remove enough links so that the rear derailleur will still shift comfortably to the large cog, but not have any real extra slack in the chain. That will keep the R.Der from being at low tension when in the 11 or 12 or whatever you run. Most of the time you are probably in the middle of the cassette anyway - right? So the chain will be even a bit tighter. If this cures the problem, then it cost you only the time to cut the chain down! If not, then you know you need another fix.
I'll vouch for the cool chain guide jeffh has - it is a nice-looking piece of hardware, and I haven't seen his chain come off with it on... An old front Der that is locked in place may work for you too, depending on your chainline. Good luck!
 

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ATBScott said:
An old front Der that is locked in place may work for you too, depending on your chainline. Good luck!
I've been using the front derailleur locked in place on my 1x9 with fairly good results. However my chain still falls off - probably 1-2x during a 3-4 hour ride. I don't use a bashring, and I don't really want to. The Rennen chainguide would probably be idea, but the price seems a little bit rediculous to me.

Edit: I forgot to say that most of my derailments seem to occur when I'm coming to a stop and back pedal a little bit. Very rarely does it derail going through choppy stuff at speed.
 

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local trails rider
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Something like this with a bashguard should work well, also preventing the chain from falling off at the bottom:
http://www.blackspire.com/chain-guards/blackguard

I converted to bashguards after destroying just one big ring on rocks and stuff.
 

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<----N-gear jump stop, bash ring, SS salsa chain ring, med cage rear derailleur, and properly sized chain and I don't have any chain dropping problems at all. Even on the rocky stuff going quickly dowhill.

Make sure the N-gear is fairly close to the chain. I think the directions call for 1mm. At first I had the stop a little further away and the chain dropped occasionaly. So I followed the directions and moved it closer and haven't had a problem since.:thumbsup: (and that was with the ramped chainring)
 

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Let's ride
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7,125 Posts
Universal had my Rohloff in the mail in 1 day, last week.

Don't think it is a small CR issue. I drop my chain on my 1x9 CX bike all the time. It has a 39t CR.
 
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