Thorn Cycles Forum
Community => Rohloff Internal Hub Gears => Topic started by: Michael Falk on September 04, 2012, 10:42:49 AM
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I've put together a spare axle ring assembly closely following the Rohloff guidebook. After getting each end of the cable coming out of its exit it was necessary to cut each cable, after pulling each out as far as possible, to 165mm. Then the black concertina tubes were attached & then the male bayonet connectors.
I then compared my "finished" spare ring assembly to what I have on my bike. It was clear that my spare axle ring was not going to do the job since since its cables were too short! On my bike in 1st or 14th gear my longer concertined cable from the hub was out over 175mm. So, the screw adjustments near my rear brakes were not going to suffice if I was to use my "spare" ring assembly.
The ring assembly on my bike was put together by the only shop that deals with Rohloff here (Melbourne), did they simply not follow the manual? Is it necessary to follow the manual in this case or should I just estimate the lengths (& ignore the 165mm instruction) to cut the cable from the axle ring so that it meets the cables from the shifter?
I hope this makes sense to somebody!
Michael.
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Michael
When I have changed the cable on mine I have followed Rohloff’s instructions and it worked well for me. When I held up my replacement next to the one on the bike it certainly looked like it would fit and it did when I put it in. While they don’t have to be the exact measurement specified by Rohloff, there are limits. If they are too long then the black concertina tubes would be stretched beyond capacity in gear 1 or 14. Or the female bayonet connector could hit up against the mounting on the break. If they are too short then as you change into gear 1 (or 14) the bayonet connector on the short end would either hit up against the axel ring assembly or reach the limit of how much the black concertina tubes can be compressed, preventing you from getting into those gears. I suspect the available screw adjustment on the break mounting would be more limiting than these other two constraints. It certainly seems to be on my Raven Tour.
I just ducked down to the basement where my bike is parked and made some measurements. These were made with an old plastic ruler in low light, without glasses and with everything still on the bike. So be warned, they could easily be out by several mm! When I have my cables even the distance from the centre of the axel to the tip of the two male bayonet connector is ~155 mm. When I go into gear 1 or 14 the distance from the axel centre to the tip of the longer male bayonet connector is ~ 208 mm.
So to answer your question, I don’t think they have to be exactly 165 mm but you only have a few mm tolerance to work within.
If you could post some photos of your existing axel ring assembly and its replacement we may be able to offer more help.
Peter