How do I tighten the chain?

[takeonafrica]

Hi,
I'm currently on tour with a rohloff - raven tour... I've been tightening the chain periodically by adjusting the bottom bracket. But now the chain is loose and I have reached the limit with the EBB. I tried taking out a link but then the chain was too short to reattach...

So for now I'm making do with a loose chain but it keeps coming off on bumpy roads - and there's a lot of those here. It has also slipped a few times today although it stopped once i cleaned the dirt off the chain.

There must be something I'm missing! Can someone help me?!

Should I be able to remove a link? I don't have a half link with me.
Or do I need to get a replacement chain and reverse the sprocket? If so, is reversing the sprocket easy?

I'm in the middle of Benin at the moment and they're not big into bicycles here - motorbikes and their repair shops there are plenty of though but no cycle repair places that i've seen.

So if I can fix it myself I'd rather. Next big town will be Abuja but that's about 10 days ride away on possibly rough wet muddy roads...

Advice on what to do much appreciated!!
Oh - I've done about 15,000km on the current set-up so I guess the loosening chain is par for the course.

Thanks, Helen

[expr]

Helen, you should be able to take out a link when the ebb has been used up plus a little, especially as you say its falling off now now and again.

reversing the sprocket is easy when at home with a nice cup of tea and a large vice as a friend, unfortunately on-road can change the goal posts radically without the right tools etc.

As an emergency take back out the link and try putting the chain on the front chainring while the ebb is just out of the frame and then try to push the ebb back in.

Dave.

[julk]

Helen,
I have just measured my eccentric and from the thinnest bit being at the front (fully tightened chain) to the thinnest bit being at the back (least tightened or new chain) is about 14mm of adjustment. This adjustment takes effect on both the upper and lower chain runs and adds up to 28mm.

Taking a full link out removes about 26mm, so in theory you should have been able to remove a full  link and turn the eccentric from the fully forward to the fully back position and reattach the chain.

What did you you do when to tried taking a link out? Did the eccentric adjust right back to the starting position?

15,000 kms is a very good life for a chain, especially over rough roads!
Julian.

[takeonafrica]

Hi - thanks for the help.
I tried removing the link again and have fitted the chain back fine. Not sure why had trouble before.
So for now I'm hoping it'll be ok.

If the chain keeps slipping then I presume I'll need a new chain and reverse the sprocket. If I'm going to get a chain sent out, is there any tool I need aswell to do the work (besides a large vice)? And perhaps some information on how to actually do it 

I'm not very good with the repair stuff but I'm learning as I go!

Thanks, Helen

[julk]

Helen,
Glad to hear it all went back together ok with the chain shortened.
Now you have the chain back on and it is tighter, there should be no problems just riding with it, but if there are then....

If you are going to reverse the sprocket you will need a
'Rohloff Sprocket Removal Tool for Rohloff Speedhub 500/14 - 8501', a strong chain whip and a big vice or 24mm spanner to hold the sprocket removal tool (and gearbox) together and still whilst you unscrew the sprocket with the chain whip.

The Thorn website says
The sprocket of the Rohloff SPEEDHUB 500/14 is secured to the gearbox over a six start thread. To remove the sprocket with a chain-whip, the driver must be firmly held in place. This is the job of the sprocket tool. It is placed over the driver, secured by a quick release lever (CC versions) or axle nut (TS versions) and can then be held firmly in position with a 24mm wrench.

There is a good sprocket removal description with pictures here.

The sprocket will be on tight as the action of cycling tightens it up on its threads. You will probably need some upper body strength and/or a helping hand. Once you get the sprocket off, grease or copperslip the threads before refitting the sprocket. Whilst the sprocket is off the oil can leak out, so either refit the sprocket soon after removal or leave the wheel sprocket side up to keep the oil in.

If you are doing all this plus a new chain then the Thorn chainring can also be reversed at the same time for some more life. I am assuming you have a chain tool as you have removed a link already from the old chain - the new chain will need shortening to fit, probably leaving about 100 links in use.

Best of luck with your adventure.
Julian.

[geocycle]

Julk has it about right.  You can reverse the sprocket but i think i would completely replace it to avoid any need to do it later in your journey (they are not expensive and you's will have had a hard life!) and you'll need to order the sprocket tool.  I'd also reverse the chain ring as the new chain might not sit well on one that has done your kind of mileage.

I'm really enjoying dipping into your blog -good luck

[Paulson]

I'm really enjoying dipping into your blog -good luck

What's the url - can't seem to find the blog??

Thanks

[geocycle]

http://takeonafrica.com/