Damaged freehub body

fernholt

I have been changing and fitting my Ultegra cassette for a while, using a torque wrench at 40 Nm and I didn't seem to have a problem. However, I have noticed that recently the cassette cogs have been eating into the hub. It's a bit of a worry. Am I doing something wrong I wonder. I have recently put a new cassette on to a slightly damaged hub as the other wore out, but I think this has damaged the hub more.
Does anyone have any ideas?
Am I doing something stupid?
Is there some trick of the trade.
The cassette is always on tight and doesn't rattle about or anything.

Unfortunately the hub is on a Powertap so a bit exepensive to replace :roll:

thanks

Weejie54

I would reckon that you have an alloy freehub:

Some "premium" off-brand hubs use aluminum bodies to save weight. This is a Bad Idea because the standard Shimano spline pattern is not designed for this material. The steel sprockets are liable to cut notches into the edges of the splines, which can make it very difficult if not impossible to remove the cassette from the damaged body.

http://www.sheldonbrown.com/k7.html

fernholt

Yes it soudns like the alloy freehub.
I found this in another thread.

"It has to be the Cycleops freehub body. Yes the Shimano alloy versions do get chewed up by the sprockets. The Campag ones very rarely do. The older powertap pro used a Shimano freehub body but they new hubs have totally different internals. There is a steel freehub body which comes with the 2008 Pro model and the 2009 Elite+ model which wont get damaged by the sprockets but it is much heavier. "

That's not ideal. But such is life.

john

fnegroni

And, let me guess, it is a Shimano/SRAM compatible freehub body, which means it has shallow splines?

If that's the case, I have exactly the same problem.

After some research, I have established that Shimano intends for its cassettes to be mounted on tall splines. In fact, each cog only makes contact onto 3 or 4 splines at a time and if the splines are shallow, they get eaten into.

SRAM on the other hand makes their cogs unload the force onto all the splines, so even if shallow, they don't get eaten into so easily.

My plan is to put a SRAM 1070 cassette and keep the current freehub on my wheels, or upgrade to a Shimano 10sp specific freehub body and stick with Shimano, or even better fit a SRAM Red cassette and freehub body.