How do I know whem sprocket needs changing ?

[swayzak]

Hi

I've had my Sterling since 2009 and had several chain changes.

I read on here about issues around reversing the rear sprocket.

At what point should I do this ? Does the bike shop need a special tool from Rohloff to do so ?

Thanks

[il padrone]

There is no measuring gauge that I'm aware of. Definitely change it when it gets to look like this:




Generally a good indication would be when you fit a new chain and when riding under load it skips teeth on the sprocket, or it is really very noisy. Otherwise the appearance of the teeth of a badly worn sprocket takes on a 'shark-fin' profile. This says "change me".

[swayzak]

Thanks

Looks quite dramatic - won't the reversed sprocket be a bit dodgy too ?

And will my LBS need a special tool from Rohloff for this ?

[JenM]

To reverse the sprocket you will need a sprocket removal tool (see below), a chain whip and a large adjustable spanner. I reversed mine without too much difficulty.

http://www.sjscycles.co.uk/rohloff-sprocket-removal-tool-for-rohloff-speedhub-500-14-8501-prod10359/

There is also a video which I played a few times before attempting it.

http://www.youtube.com/watch?v=TqpgkyQ5tkI

Good luck

[geocycle]

I run mine until they get pointy ie a bit more than the second larger picture in il padrone's post.  This is a good example from Pete Gos http://petergostelow.com/thebigafricacycle/general-posts/a-well-worn-weapon/

I tend to leave mine too long to reverse without the chain skipping so I've put a new one on each 9-10,000 miles. Now just started on the third.  Wear rates depend on your riding and especially how much off-tarmac,

[Matt2matt2002]

To reverse the sprocket you will need a sprocket removal tool (see below), a chain whip and a large adjustable spanner. I reversed mine without too much difficulty.

http://www.sjscycles.co.uk/rohloff-sprocket-removal-tool-for-rohloff-speedhub-500-14-8501-prod10359/

There is also a video which I played a few times before attempting it.

http://www.youtube.com/watch?v=TqpgkyQ5tkI

Good luck

Here is the SJS quote for the item
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.

What is a CC or TS version? And do I need to buy a quicke release leaver and / or axle nut?

Thanks
Matt

[geocycle]

Matt, if your wheel is held in place with a quick release or security skewer the chances are you have the CC verison.  Basically, take the wheel out, remove the skewer completely, put the rohloff removal tool in place, replace the skewer to hold it in place.  Then put your biggest spanner on the rohloff removal tool, a chainwhip on the sprocket and undo in anticlockwise fashion.  Best to remove wife and kids as language can get colourful when you hiy your knuckles on the sprocket!  The first time I did it was a pain and had to get a neighbour to help, last time was easy and I did it on my own.  Think sudden shock not gradual pressure.

[JimK]

Here is a photo of my sprocket removal set-up. I hold the wheel up against my legs and push down with my weight on the spanner and chain-whip handles during the actual operation.

You can see I have a bit of rubber band to hold the chain on the chain-whip to the sprocket all around.

Andre will be happy to see... well, not exactly a Persian rug I suppose, but at the very least Persian-style!

The bare feet help because when you lose a little part on the rug it is impossible to see, but then you step on it and ah! you've found it!

You just need to clamp the Rohloff sprocket remove tool with your quick release skewer for the first eighth of a turn, just to get it started. From there you can remove the skewer and unthread the sprocket with your fingers, using the removal tool very lightly so the rotation unthreads the sprocket rather than spinning the freewheel!

[Andre Jute]

Thanks for the photo, Jim. Very helpful. Love your Persian, and the tip about working with bare feet...

[Matt2matt2002]

Hi folks.
I had my first rear flat today. A small thorn in a well worn Schwalbe Marathon.
Fitted a new Scwalbe inner tube and will patch up punctured tube tonight.

Had a chance to check out rear sprocket and thought I would post a picture for comments.



Think I have the original chain. Rohloff hub could be from 2008!
Bike is third hand, at least.

Any comments on state of rear cog, appreciated.

Not sure of tooth count on front cog but bike came with a larger cog in case I fancied a change. Quite happy with present set up but may play about with things and fit larger front cog since I believe its quite easy to do.
Am I correct in thinking Thorn recommend even numbers of cogs on front and rear?
If so, what cog count will be compatible with my 16 rear?

Thanks folks

Matt

[geocycle]

That sprocket has had very little use. I'd expect it to do another 8000 or so Miles. 

You can use any combination of chainring.  Most folk use 38, 40,  42, or 44 with a 16.  Check the gear tables in the thorn PDFs.

[Andre Jute]

Had a chance to check out rear sprocket and thought I would post a picture for comments.



Think I have the original chain. Rohloff hub could be from 2008!
Bike is third hand, at least.

Any comments on state of rear cog, appreciated.

Don't you ride your bike, Matt? That cog looks pretty new for a "third hand bike". Or maybe the two previous owners sold it because they weren't using it, in which case whatever you paid less than the ex-Bridgewater price is a bargain, because somebody else took the hit of the initial capital depreciation.

[Matt2matt2002]

Thanks Andre,
                     because somebody else took the hit of the initial capital depreciation.
Music to my ears. I like that. I'll hold that thought.

Yes indeed, I do ride my Raven. 40 mile trips x4 or more times a week. Last month I had a PB of 800 miles.

If only bikes could talk. With a hub from 2008 it could have had many adventures.
However, the chain is one fitted at time of sale,,I believe.
Can't quite recall the chain make and code but it is German and no longer made.
I will dig out the details.

Do Thorn help out with bike history? I could supply hub and frame details.
Year of sale would be nice to know. Further details could have security consequences so wouldn't expect to learn much more.

Matt - who is suddenly feeling richer for some reason.

[Danneaux]

Hi Matt!

Your "Old Bird" is a lovely ride, and all the better for being "experienced".

As for stories...

My first "real" touring bike was purchased from the shop where it was stolen, then recovered. The thief managed to saw through the cable holding it at the end of a string of display bikes on the sidewalk out front, then rode off...right past a passing police officer who saw the shop owner chasing after. The officer bumped the bike's rear wheel, spilling the rider, who was taken into custody. The bike went along in the car trunk (boot) as evidence and then was returned to the shop where it couldn't be sold as new, so I got a nice 25% discount for some scratches on the top tube and a really interesting back-story. I sold that bike to my father with 22,000mi on it, then he rode it another 13,000mi before buying another. Neither of us could bear to part with it, so it stays on, a proud member of the fleet. Nothing fancy on paper (high-carbon plain-gauge tubing, but one of the sweetest-riding bikes I've tried. It still rides very ncely).

Yes, if only bikes could talk!

Unfortunately, the back-story on many of the touring Thorns I see on eBay is often like this: "Bought in anticipation of Really Big Tour that now won't happen, so this is surplus to requirements and up for bid". I always find that sad; dreams deferred or derailed and the bike of a lifetime left untested in battle, so to speak. I believe they always find their rightful owners in the end, however, and I think the Old Bird has found a home -- and some real Adventure ahead -- with you, Matt. May you have many happy journeys together.

Best,

Dan.

[il padrone]

If only bikes could talk. With a hub from 2008 it could have had many adventures.
However, the chain is one fitted at time of sale,,I believe.
Can't quite recall the chain make and code but it is German and no longer made.
I will dig out the details.

With that sprocket wear I would suggest that your bike has led a very cossetted life - probably a total mileage of less than 10,000kms, especially if the chain is the original. Most chains are stretched out to more than 12 & 1/8" after about 6-7,000kms and then the sprocket will be much more worn than yours is - basically a new chain would require a new sprocket.

My sprocket is worn, nearly as bad as the second photo I posted above. It has done 18,000kms and I have rotated three chains on it - one chain has been binned, the second is on its second rotation and nearly toast, one more to have its second rotation. So each chain has lasted about 7,000kms.