Tandem Tom

As I start a bit of maintenance on my touring bike getting ready for our next tour I was curious about replacing the above. Wondering how to choose a new one? Are they specific to the hub? Are there " better" grades?
Thanks!

Tandem Tom

It is a Shimano hub 9 speed.

Amt0571

They're specific for the hub. For some hubs you can choose some variants eg: Shimano HG, Microspline, xD, and sometimes the same variant may be available in aluminium or steel. I think that's all.

I wouldn't replace the freehub unless it's broken IMHO. You should make sure to lubricate it though. Normally you should lubricate it with a thin oil if it has pawls, or with a thin grease if it has ratchet mechanism,

HillRider

For Shimano hubs the freehub bodies have some interchangeability within series. For example an 8/9/10-speed 105 hub can take a similar vintage Ultegra freehub body. Just be sure to have matching seals to accompany the replacement body.

Andrew R Stewart 

Generally one first tries the OEM spec replacement to eliminate the "oops I got the wrong one" moment after the bike is already taken apart. As said there can be some options to materials made in compatible freehubs but not all manufacturers (as opposed to the branded name on the hub) make the same fit in differing versions. Shimano has had compatibility charts available over the years in their tech docs. Accessing these docs can be a challenge and I don't have the magic link for your specific hub. I never suggest subbing an Al splined version for a steel as the Al splines will get dinged by the cogs over time, few people will also change their cassette to a version that has as many cogs on carriers to reduce this notching of the freehub body (and then also replace the chain to go with that new cassette)

Generally the bearing and ratchet (ring types and pawl types are both ratchets BTW) remain the same regardless of the splined outer body material. So the "upgrade" is more about weight loss VS shorter term spline life.

Shimano freehub bodies are quite easily serviced with the common flushing out of old grit/lube and replenishing lube with a medium weight oil dripped through the body. I would suggest doing this every time one overhauls the axle bearings, about once a year or three, use dependent. Andy

HillRider

+1 Aluminum freehub bodies are generally a poor idea unless specifically designed to tolerate the cog's wear pattern. Campy makes suitably resistant aluminum freehub bodies as did Shimano with their short-lived 10-speed only 7800 series hubs and contemporary Dura Ace and Ultegra wheelsets by making the splines taller and the notches in the cogs deeper to distribute the loads better. Other than that, Shimano freehub bodies are steel for most groups and Ti for Dura Ace (and XTR?).

70sSanO

There used to be a .pdf online of shimano freehub body interchangeability by hub and shimano freehub body P/N. If you have a specific hub, I can look it up and give you other hubs where the body was used. Just an example the freehub body on the DX FH-M650 is the same as the 105 FH-1055.

Over the past year I have swapped out 4/5 non-officially-compatible freehub bodies. Much of it depends on the freehub body shoulder (deep or shallow) and the diameter of the freehub body seal. But there are a few of the newer ones that won't work; in addition to the 74xx freehub bodies.

I would think that the bearing surfaces (freehub body cup) on the higher end Dura Ace/Ultegra and XT/XTR are of better quality and will spin smoother. Wheels Mfg makes aftermarket cones that seem to be well made. If you do find a suitable replacement freehub body, try to get the complete hub, especially if it is the same model as what you currently have. This way you will have replacement cones and seals.

John

Edit Added: You can also remove a working Shimano freehub body off an unlaced hub by mounting a 28t or so on the hub and filling the rest of the body with spacers or small cogs. make a cut-out on a board for the hub to go through and and hold the 28t cog to the board with a couple of lag screws. Generally a 10mm allen wrench in a breaker bar makes short work of it.

KCT1986

Much of it depends on the freehub body shoulder (deep or shallow).

Think that this what 70sSanO is referring to. Note the difference in how far the rear of the body would be in the hub shell.

Seen listings on many online vendor web sites that have the wrong photo. Beware!