Chain jumping

[rickster]

I have had my hub for 1 year of off road riding I managed to re-cable the hub using advice from this forum [XTR cables ] and for the first time its shifting sweetly .BUT after installing a new 9sp chain on the bike its is jumping every link and the bike is unridable I have installed new jockey wheels and the chain line is perfect the sproket is showing some signs of wear but nothing too bad .I reinstalled my old 9sp chain [SRAM PC59] and it jumps much less but still does[ middleburn ss crank ,nicolai helius,32 sproket,chain tensioner,]has anyone got any ideas I running out of patience with this setup it was supposed to be trouble free and has been anything but ! People thinking of purchase please note !!

[stutho]

Hi rickster,

Don't despair yet!  In nearly 8000 (road) mile I have only managed to get the chain to jump once - and that was my fault, the chain was very loose.  However the big difference is that I don’t have rear suspension or a chain tensioner.

The first thing to note is that there are two versions of the Chain Tensioner,  part number 8250 is the ‘normal’ model while part number 8245 is the ‘Downhill’ version.  Rohloff also recommend when using full suspension that a ‘downhill’ chain guide (for the) hub is used part number 8291.  Rohloff do a Downhill kit Part no 8293 that include #8245+ #8291.

Just to muddy the water a bit more I think that Rohloff at some point revised the spring tensions in one or both chain tensioners – I am unclear if it possible to fit the new spring to the old tensioner.   

 The deep prongs on the hub sprocket should help the chain stay in place.  I don’t know what model of chain ring you are using.  If it is a single speed chain ring (again with deep prongs) then all is well.  However if it is a standard chain ring then you may either want to swap it out or fit a chain guide for the chain ring – Rohloff (and other) make these Part number 8290.

I have to admit I am a bit out of my element with all of the above as I have never even ridden a full suspension!  Maybe someone with more experience would like to comment.  (You may have a little more luck on another forum as I don’t think to many people on this list are riding full sus)

All the best

Stuart    

[stutho]

Just had another thought – What sprocket size are you using on the Rohloff.  The 13-tooth sprocket would not be a good idea as there is less sprocket for the chain to hold.  The 13-tooth sprocket is also incompatible with the Downhill kit mentioned above.

The reason I ask this is because if you are using anything other than the 13 tooth sprocket that your chain ring is outside the permitted range  -but maybe you already know this ;-)

Just for the record the minimum’s are 40/17,  38/16,  36/15 and  32/13.

Stuart

[stutho]

Sorry for the triple post!!!

I just re-read the OP

quote:BUT after installing a new 9sp chain

Big mistake you need to use a 3/32" chain i.e. An 8 speed chain.  This is probably where most of your problems are coming from.  The only 9-speed chain that is permitted is Rohloff own model. Using a 9 speed will also prematurely ware the jockey wheel, sprocket gear and (probably) the chain ring.

In short change to a 8 speed chain and reverse the sprocket (if a 15,16, 17) and the chain ring

Stuart

[rickster]

Thank for the interest in my problem I am running the wrong rear sproket 16 standard I should be using 13 with my Middleburn uno 32 but that aside I have an internal hub problem there is nothing els it can be ! I have swapped out the chain tensioner for an XT mech now running an 8 sp chain what I really need is a dealer in the north west or Northern England who can put on a 13 sproket and I can fault find again all this stems from my dealer supplying a hub with no knowledge of the pitfalls involved. I am now looking at a very expensive repair and a lot of downtime on my bike exactly what I bought the hub to avoid please note if you dont live near a Rohloff dealer be warned  I have just missed my favourite time of the year to cycle and very dissapointed with Rohloffs tech response which is 'Return it to Germany'

[stutho]

Hi rickster,

I have had no direct experience with returning things to Rohloff in Germany but on this list you will find that people have had VERY quick turnarounds from them.  I seam to remember someone saying that there bike was idle for less than one week!!   Sorry you have had so many problems.  I am guessing you fitted the hub yourself and had no help?  Unfortunately there are several important differences in the way you set up a Rohloff compared to a derailer some of which are not immediately apparent.

Most people on this list will be using the Rohloff hub in a bike frame designed specifically for its use – it makes things a lot easier to maintain and very reliable package.    

With respect to your gearing in your last post I would recommend sticking with the 16 sprocket but increasing the Chainring to a 38 tooth.  The 13 sprocket is not reversible and will ware quicker and uses a different chain line.

[rickster]

SJS are saying the sproket won't matter tehy overgear tandems all the time! and it is likely to be a worn sproket or a faulty hub causing the problem. The annoying thing is that there is no one who can help in the North The Nicolai Helius and indeed all Nicolai's come with Rff ready dropouts and has worked a treat so far will have to get a sproket tool and bite the bullet.I wonder how there new lighter speedhub will hold up on the trails or will it ony be sold to Roadies?  thanks for your comments.

[Andy Blance]

quote:Originally posted by rickster

I have had my hub for 1 year of off road riding I managed to re-cable the hub using advice from this forum [XTR cables ] and for the first time its shifting sweetly .BUT after installing a new 9sp chain on the bike its is jumping every link and the bike is unridable I have installed new jockey wheels and the chain line is perfect the sproket is showing some signs of wear but nothing too bad .I reinstalled my old 9sp chain [SRAM PC59] and it jumps much less but still does[ middleburn ss crank ,nicolai helius,32 sproket,chain tensioner,]has anyone got any ideas I running out of patience with this setup it was supposed to be trouble free and has been anything but ! People thinking of purchase please note !!

Hi Rickster,
I am sorry to hear that you have been having problems with the chain jumping on your Rohloff hub WITH CHAIN TENSIONER…I’m sorry but hardly surprised!
When I designed our Rohloff bikes, I was determined not to use a chain tensioner…I’d had enough of chain suck with derailleur bikes and I didn’t want it with Rohloff too! I expect your Chainring is not made of high enough quality alloy…we use 7075 for our chainrings, and I expect that the teeth have “belled out” and  that the chain is jamming on the ring. You could try one of our rings, you could also try 8sp chain…the extra width between the plates should diminish the problem.
Regards,
Andy B.