[mtnb1kr]

How close should the rear derailleur be to the spokes with the American Classic coversion cassette? I am using a set of Alex A-Class ALX400's. When the deralleur is shifted to the largest cog it misses the spokes but just barely. Any little flex in the wheel and it would be rubbing the spokes. The way the cassette is made the large cog sets closer to the spokes than a regular cassette but this seams too close.

 

[Mel Erickson]

As long as it doesn't hit the spokes it's ok. Wheel flex could cause enough deflection to allow the derailleur to hit the spokes if it was really close. Could you put a spacer behind the cassette and still get the lock ring tight?

 

[Mark McM]

Conversion cassette/spoke clearance

How close should the rear derailleur be to the spokes with the American Classic coversion cassette? I am using a set of Alex A-Class ALX400's. When the deralleur is shifted to the largest cog it misses the spokes but just barely. Any little flex in the wheel and it would be rubbing the spokes. The way the cassette is made the large cog sets closer to the spokes than a regular cassette but this seams too close.

The absolute answer depends on the wheel (and the cassette size), but the derailleur will always be closer to the spokes with a Campy/Shimano conversion cassette - sometimes too close, depending on the brand of hub.

Campagnolo cassettes are wider than Shimano cassettes. Consequently, Campagnolo (and Campagnolo compatible) wheels are built with more dish - the drive side spokes are more inboard to make room for the wider cassette. Since Shimano cassettes are narrower, wheels with Shimano compatible hubs frequently use hubs with flanges slightly more outboard, to reduce dish.

A Campagnolo/Shimano conversion cassette is designed to have Shimano splines, but Campagnolo spacing, so it is wider than a Shimano cassette. Fitting this wider cassette onto the space where a Shimano cassette is intended to be sometimes takes a shoe horn - the result is that there is often less clearance between the derailleur and spokes. In some instances, the derailleur becomes too close, and some wheels are not compatible with C/S conversion cassettes at all.

 

[The Flash]

that's the truth....

The absolute answer depends on the wheel (and the cassette size), but the derailleur will always be closer to the spokes with a Campy/Shimano conversion cassette - sometimes too close, depending on the brand of hub.

Campagnolo cassettes are wider than Shimano cassettes. Consequently, Campagnolo (and Campagnolo compatible) wheels are built with more dish - the drive side spokes are more inboard to make room for the wider cassette. Since Shimano cassettes are narrower, wheels with Shimano compatible hubs frequently use hubs with flanges slightly more outboard, to reduce dish.

A Campagnolo/Shimano conversion cassette is designed to have Shimano splines, but Campagnolo spacing, so it is wider than a Shimano cassette. Fitting this wider cassette onto the space where a Shimano cassette is intended to be sometimes takes a shoe horn - the result is that there is often less clearance between the derailleur and spokes. In some instances, the derailleur becomes too close, and some wheels are not compatible with C/S conversion cassettes at all.

Mark hit it spot on....the dish would be a little different due to freehub size which affects the spoke angle on the drive size. I'd recommend using it with any kind of Mavic K's as the derailleur will hit the spokes.

The only thing that I would check is to see if you can use a thin cassette spacer to move it over a bit if you still have enough spline left.

The Flash