Dura-Ace 7700 Freehub Body compatibility?
 

I've noticed that every so often the freehub on my Dura Ace rear hub will skip, nothing major but a bit disconcerting to say the least. I have been a long time user of the Morningstar Freehub Buddy on this hub, and usually give it a gear oil flush every year or so as part of routine maintenance. I remove the freehub body to do this, so I can let the excess oil drain out of the unit (versus all over my hub/spokes or into the greased bearings on the drive side).

Anyway, I was going to try and do a solvent flush followed by one or more lubricant flushes over a period of a couple days to see if that helps. Everything I read on the internet (including Sheldon Brown) said that Shimano 9-speed stuff was interchangeable, so I ordered a Tiagra 4500 9-speed freehub body to put on the wheel for interim use while I worked on the 7700 body. However, when I went to install it, it didn't fit as it seems to be a bit shorter than the 7700 body. It sits too much inboard, and as a result the cassette can't fully seat as it hits the spokes before it goes to the bottom of the splines. Also, the shortness of the body was apparent when I installed the axle and had a bunch of extra length on the NDS end.

There was a thin shim with the replacement body, perhaps I will re-try with that but I was under the impression that this was to replace the existing shim/washer around the hub splines (which fits into a recess in the hub), not sit on top of it as a spacer. Plus, it didn't seem thick enough to resolve the problem I had. Hmmm...

I probably won't ride for the next few days, so I likely will service the 7700 body this weekend so no big deal. While I have it off, I may retry the 4500 body with the shim and see if it works better that way, at least to satisfy my curiosity. If it does fit that way, I will come back and update the post, if for nothing else to help someone else who may be searching about this.

They all use different part numbers, Tiagra through DA, FWIW. I too would have thought there was some interchangeability but maybe not.:foo:

I don't know the compatibility range for the 7700 hub. To fit into my Cannondale 126mm dropouts I used a body from an XT-732 on my 7700 and it worked great. But, you don't want a 7 speed freehub body.

I'm "thinking" a body from an XTR-950 might work, but I have not tried it. If that works I have read that the body from an XTR-950, or 910, will fit on an XT-737. One of these days I try it. So if a 950 works a 737 should fit, but I can't verify that.

The trend here is pretty obvious in that compatibility with other 1990's hubs will probably give you a better chance. I'm sure someone has done a swap with a non-ti freehub body.

Whatever comes about from this thread I will file away.

John

Worked on the 7700 freehub today, gave it a good solvent flush and got all the old lubricant out (and a bunch of other crud). Re-lubricated using the freehub buddy, and a light bead of Teflon grease around the rear-side bearings. Running smoothly, we will see how it performs on the road.

I didn't care for my freehub body on that hub so I replaced it with an Ultera freehub body. Works fine.

Do you know if it was from a 6500 or 6600 freehub?

Thanks!

John

I think either will work.