Rohloff dropout question for Andy

[Sweptwind]

Hello Andy, and all here. I'm curious as to why Thorn didn't stick with Rohloff's standard dropouts. They seem to have all options covered, ie. disc brake tab, rack mounts, and mech tab if you ever wanted to go back to it.

Personally, I've got to have a disc brake tab, so the standard dropouts seem ideal for what I'd be looking for.

Cheers

[Andrew]

quote:Originally posted by Sweptwind

Hello Andy, and all here. I'm curious as to why Thorn didn't stick with Rohloff's standard dropouts. They seem to have all options covered, ie. disc brake tab, rack mounts, and mech tab if you ever wanted to go back to it.

Personally, I've got to have a disc brake tab, so the standard dropouts seem ideal for what I'd be looking for.

Cheers

Hi here's Andy's reply:

"The method which we have chosen to use to adjust the chain tension (by
means of an eccentric)is fully approved by Rohloff.

We believe that our method is superior to sliding dropouts.

Dropout failure is, as we state in our literature, not an unknown phenomenon
and we believe that having our own custom, vertical, socketed stainless
steel dropouts produced for us is the most reliable method of adjusting the
chain tension. It is not an option that we undertook lightly...the moulds
for these dropouts cost us $10,000! Obviously this would not be an option
for a smaller builder, hence the widespread use of sliding dropouts."


Cheers,
AB

[eblair]

Any engineering decision involves tradeoffs. I don't have a Thorn with the eccentric BB, but I do have a bike with a Rohloff hub and the Rohloff sliding dropouts. They work very well and so far have been quite reliable.

They have several very minor drawbacks, however: first, any time you move the sliders (to adjust chain tension) you have to align the rear wheel, and second, any adjustment can also make minor changes to the rear brake pad location. Because of the geometry of the sliders this latter is very minor and usually requires no changes to the brakes, but the effect is there. Finally, if you have, as I do, mudguards that are closely fitted, then when you adjust the chain you slightly change the spacing between the mudguard and tire.

The eccentric BB that Thorn uses means that adjusting chain length has no effect on the rear wheel alignment or the brake pad position. But it does have some (presumably tiny) effect on the effective seat-tube angle and can change minutely the height of the pedal crank above the ground.

You pays your money and you takes your choice. For what it's worth, if I were to get a new Rohloff bike I'd go for the Thorn approach. And not for any of the reasons I've mentions but purely for aesthetics: the Rohloff dropouts are, in my opinion, a not terribly attractive.