Offset Rear Rims

[bobscott]

Why have offset rear rims not been more universally embraced? It certainly helps balance the spoke tension and should lead to a more durable and potentially lighter wheel.

Is there a tubular version available from anyone?

[ergott]

Why have offset rear rims not been more universally embraced? It certainly helps balance the spoke tension and should lead to a more durable and potentially lighter wheel.

Is there a tubular version available from anyone?

No tubular. It is one my first recommendations.

[Kirk Pacenti]

It has to do with some patent issues. We were working an O.C. rim at Bontrager in the mid 90's. Unfortunately Ritchey beat us to the punch and patented the ideal position of the offset (3mm off center). We ended up getting around it by going 2.5mm off center, if memory serves.

My guess is that the further away from the 3mm O.C. position, [closer to center] the less reason there is to bother doing it at all. It's been a long time...some of the facts and details are pretty fuzzy to me now...

[Brons2]

It has to do with some patent issues. We were working an O.C. rim at Bontrager in the mid 90's. Unfortunately Ritchey beat us to the punch and patented the ideal position of the offset (3mm off center). We ended up getting around it by going 2.5mm off center, if memory serves.

My guess is that the further away from the 3mm O.C. position, [closer to center] the less reason there is to bother doing it at all. It's been a long time...some of the facts and details are pretty fuzzy to me now...

If you were working on it before Ritchey's patent, you should sue to have the patent invalidated under the theory of "prior art".

[Kirk Pacenti]

If you were working on it before Ritchey's patent, you should sue to have the patent invalidated under the theory of "prior art".

True, but this was going on before the Trek buy-out. I think KB couldn't fight it for lack of $$$. It may have been a case of "the one with the biggest checkbook wins"!

I honestly don't remember. I do recall that we settled on a 2.5mm O.C. rim.

[Brons2]

How about 2.99 or 3.01 mm? :D:D

[bobscott]

I wonder what Campy's off set is?
Or how did they get around the Ritchey and Bontrager patents?

[ergott]

It has to do with some patent issues. We were working an O.C. rim at Bontrager in the mid 90's. Unfortunately Ritchey beat us to the punch and patented the ideal position of the offset (3mm off center). We ended up getting around it by going 2.5mm off center, if memory serves.

My guess is that the further away from the 3mm O.C. position, [closer to center] the less reason there is to bother doing it at all. It's been a long time...some of the facts and details are pretty fuzzy to me now...

Wouldn't ideal offset be influenced by the rim depth? Velocity Aerohead OC offset if 4mm. I know it was a while ago, but I would think that more is better to the point of decreasing rim durability. You don't want the spoke hole too close to the sidewall of the rim making a weak point. The V shape of the Aerohead must make the design work better because you are still drilling the holes at the thickest point of the rim bed. Using a 20mm rim vs. 19mm rim would also be a factor.

[Kirk Pacenti]

Wouldn't ideal offset be influenced by the rim depth? Velocity Aerohead OC offset if 4mm. I know it was a while ago, but I would think that more is better to the point of decreasing rim durability. You don't want the spoke hole too close to the sidewall of the rim making a weak point. The V shape of the Aerohead must make the design work better because you are still drilling the holes at the thickest point of the rim bed. Using a 20mm rim vs. 19mm rim would also be a factor.

My point of reference is MTB rims that were roughly 22 wide by 19 deep. Road rims likely have a completely different "ideal" offset. It's not immediately obvious to me how rim depth would have that effect, but I am sure you'd know more about the depth affecting the offset than I would. I've hardly built any wheels....