Hi all,
got a controversial question: should one grease the freehub body before putting on the cassette? Specifically Shimano HG-L freehub body. I was thought no to do so, but an experienced mechanic in my shop stands by it, saying it prevents dirt ingress and stops/delays the bite marks from the cassette digging into the freehub body.
With sram’s XDR freehub body i give it a good smear of motorex 2000 and am quite happy with the results.
Thoughts?
I don’t think it would harm anything, but I see no real benefit.
I don’t see how it would stop dirt ingress. The cassette fitment to the freehub is not exactly a snug fit. Dirt is getting in. That said, dirt between the cassette and freehub doesn’t really affect anything either. Certain cassettes are a bit noise prone, so that’s one reason. I’d probably coat the freehub if I lived by the ocean too. Otherwise, it’s just making things messy upon removal.
I also don’t see how grease would help resist freehub notching. If anything, it would make it worse.
But again, unless you live by the ocean, there’s little trade-off one way or the other.
I don’t really see the benefit either. The cassette isn’t supposed to move on the freehub, so grease doesn’t really have a role in reducing friction. You put grease on bolts to stop galvanic corrosion, but I don’t think that’s an issue with cassettes. Isn’t the grease likely to attract dirt?
The reason Shimano says not to grease it is because it creates a tiny bit of extra movement ability that can lead to notching happening faster.
Also, excess grease will do the opposite of what the guy at your shop says and will ATTRACT grit into the interface, causing a sandpaper effect. A thin layer could theoretically help with future removal but that shouldn’t be an issue in most cases
There are pretty rare exceptions that a company like Shimano doesn’t have a reason behind their instructions.
It won’t be the end of the world if you choose to put grease on but I think it’s pretty unnecessary and it’s 50/50 as to if it hurts or helps.
I couldn’t get my cassette off of a hub a while back. Almost destroyed it trying to get it off. Anyway, I greased the hub before I put it back on, very risky, and it came off super easy the next time. So I’m in favour now !
It depends.
For use in anything but winter weather (salt on roads) and at or near the beach (salt again), I wouldn’t recommend to put grease on the freehub body. Indentation is promoted by reducing friction, I would expect.
It can be hard to remove a cassette after some time in salty conditions due to corrosion, so on my commuter and winter bike setup:
Yes grease!
I’ve always applied a very light coating of grease (Motorex White) on all the freehubs I work on. I’ve come across some freehubs where the surface has become corroded so that is why I apply grease.
From what I am aware, greasing FHB splines originated from a bygone era where it was quite common for both the cassette, and freehub body, to be steel; this practice was commonly employed to avoid the two components from rusting together, and aid in servicing. It was not uncommon to have issues when removing a cassette from a FHB because of corrosion on many of the 90s era bikes that I worked when I worked at a shop in the Northeastern USA.
On modern bikes I do not use grease on freehub body splines, only the threaded portion of the lockring, or the threaded portion of an XDR FHB.
My feeling was that notching and the need to eventually replace freehub bodies was just the deal, like other wear components. Do many people not have notching occur?
I’ve had it on pretty much all my bikes eventually, greased or ungreased…
I always put a thin amount of grease on the free hub body, I’ve never had a stuck cassette or to much notching.
Notching occurs more on aluminium freehubs. If you have a steel one it won’t notch as much, but you know, gainz..
As someone who wrenches for a living, we always apply a small dab of grease before installing the cassette at the shop. Coming from rainy, cold and gritty Denmark, we prefer to stay on the safe side, especially with XD bodies (can’t say why, but whenever we had a pesky cassette refusing to be removed from the freehub body, it was always XD).
As a mechanic in Victoria, Australia, I never grease Shimano HG cassette interfaces. They also don’t come greased on new bikes. And I’ve never have one creak other than those Dura Ace ones, which you can warranty. In my experience, grease only attracts dirt, and freehubs are a real pain to clean.
I have never experienced a stuck cassette, except when an aluminium freehub has notched, in which case grease won’t help you. Tightening your lockring to 40Nm will. But use a torque wrench because you can relatively easily strip the aluminium thread on the freehub.
To remove a stuck notched cassette, get yourself two chain whips (or similar tools). Remove as many of the smaller sprockets as you can by hand. The smallest sprockets are much less likely to be notched. Once you get to a sprocket you can’t remove by hand, hold the back sprockets with one whip and turn the other sprocket in the non drive direction to remove it from it’s notch. They come off easily enough if you do then one at a time.
SRAM xd drivers work differently. I do grease them.
