26” Coversion to 1 x 9 - Chain falling off

[wilhelm-S]

I converted my old 26” MTB hardtail to a 1 x 9 spd setup. I basically removed the inner and outer chain rings and middle ring serves as the ‘1 x “. My problem is that the chain continously derails. Obviously the front deraileur that used to keep the chain ‘ in line’ has been removed in the conversion. How do I keep the chain on? Any tips ?

[Chavo]

Use a narrow-wide ring specific for purpose since the stock chainring that you have left in the middle is designed to allow the chain to be moved off it by the front derailleur.

 

Your rear derailleur likely also doesn't have a clutch mechanism which means the chain moves more freely when encountering trail/road obstacles and thus exacerbates chain movement leading to it falling off. Otherwise buy a chain guide that essentially replaces your front derailleur and you can probably keep the standard ring for a bit (but that is an imperfect system - just get a narrow-wide ring).

[Baster_Klong]

Chain guide or "Narrow/Wide" - "Thick/Thin" chainring should solve your problem.

[wilhelm-S]

I guess the trick would be to make sure the N/W chain ring fits onto the middle-ring holes? Specifically referring to the fixtures, threads and spacers.

[David Marshall]

It could also be that the chain ring is worn.  The FD does not hold the chain in place so it shouldn't fall.

[Martin PJ]

The FD performs a good job as a chain guide. So agreed, without narrow wide front chain ring it won't work. I have been this route before. Ideally your rear derailleur should be a clutch derailleur, but they don't come in 9 speed. But a 1x9 with narrow wide can work well if the derailleur spring is not tired. In muddy conditions you will get chain suck though.

[Martin PJ]

Something else which is not always common knowledge is that it is possible to tighten the spring on many of the Shimano derailleurs, road and MTB, check YouTube for how to, takes 5 to 10 minutes to do it.

[paarlmtb]

I have been running a 1x9 for many years now, in all that time have had maybe 4 or 5 chain drops.

 

I run a Rapide narrow wide oval ring which is cool as it has built in spacer so no need for shorter bolts and chainline is also improved.

 

I have a sunrace 11-40 cassette. I have a sram X0 derailleur.

 

I don't do gravel grinding, I ride Paarl mountain, Rhebokskloof, Banhoek, Boschendal so it gets a good beating 

 

My advice is to google correct chainlength which is determined by the angle of the derailleur.

[Chavo]

I guess the trick would be to make sure the N/W chain ring fits onto the middle-ring holes? Specifically referring to the fixtures, threads and spacers.

If you have an older crank it's most likely a 104BCD. If you're unsure, post a pic of the crank for more accurate input

[Karman de Lange]

Install a inner and outer chain ring at front. problem solved

[wilhelm-S]

Something else which is not always common knowledge is that it is possible to tighten the spring on many of the Shimano derailleurs, road and MTB, check YouTube for how to, takes 5 to 10 minutes to do it.

 

I have a XT RD, I will go see if I can adjust the spring...

[Headshot]

This is useless without pics!

[pista]

1X conversions are for 29ers only.

[wilhelm-S]

 

Pic # 1:

I think it is a 104 BCD. I had to install 4 x washers to make the crank-bolts fit. With the outer ring missing the bolts are too long (didn't have short bolts).

[wilhelm-S]

 

Pic #2:

 

Definitely not a N/W chain ring, so that's the first thing I will change.

[wilhelm-S]

I have a XT RD, I will go see if I can adjust the spring...

 

 

Not sure if this RD is adjustable... will have to search...