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Freehub not engaging in the cold? (files.catbox.moe)

submitted 7 hours ago* (last edited 6 hours ago) by [email protected] to c/[email protected]

8 comments fedilink hide all child comments

Edit: Thanks for support! Right now my plan is to try and replace the grease in the hub with something known to work in low temperatures.

So I got some new wheels for my commuter and on my first ride, after ~3 miles it feels like I'm getting some chain skipping - I wasn't - then soon after the hub completely stops engaging and I walk home.

Never had that happen before. Thought it might be a cold temperature issue but bringing the bike indoors overnight didn't seem to resolve it right away, but eventually something did. A short test ride later and the hub froze up again.

They're Hunt wheels, I reached out and they said it's unexpected but probably not because of the cold temperatures (about 20F). They sent a new set and the exact same thing happened on the first ride, about the same distance.

I'm leaning toward it being a temperature thing, and they just have too thick of a grease in the freehub that is getting thicker in the cold? If this is the case, would it be simple to pull apart, clean, and replace with a different grease?

I hate driving to work, so I'm tempted to try and pick up a hub locally this weekend to swap (if that's possible, I've never tried and haven't looked into standards or anything).

If it is a temperature thing, it can get to -40F here, and I (usually) still bike to work in those temps, so let me know if there's anything I should "shop for" in a replacement.

If anyone has any other ideas what could cause this, let me know! I'm worried I used the wrong cassette or something dumb that I don't know about (Hunt support didn't seem to think so). I suppose there is the chance that I just got 2 bad sets in a row.

More info:

HUNT 4 Season Gravel wheelset
- Shimano/SRAM HG Splined
Cassette: Shimano CS-LG300 CUES LINKGLIDE HG 9sp Cassette 11-41t
The wheel's freehub came with a spacer for compatibility with different cassette types and I am not using the spacer: A guide on when to use the spacer

For what it's worth, Hunt has been great to work with

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[–] [email protected] 3 points 3 hours ago* (last edited 3 hours ago) (1 children)

Do you store the bike inside in warm? I'm guessing condensation could play tricks with you here and pawls freezing on spot even with very small amount of humidity there and not enough of grease.

Another option is what people have said, too thick grease for the temperature .

Either case, this might even be amplified if you have aluminium freehub body and steel pawls, with aluminium shrinking more than steel when it gets cold and the tolerance being tight.

You can try swapping from vaseline to oil where the pawls are, but just know that this will massively shorten the service intervals. Also this may be obvious, but don't replace vaseline with oil in the bearings:)

[–] [email protected] 2 points 3 hours ago (1 children)

The bike is in my garage normally which is usually quite a bit warmer than outside, but by no means heated. I kinda doubt condensation or water are what's happening just because in both cases the rear wheel was unboxed, installed, and taken for a ride and failed on that first ride.

I don't really know the basics of oil vs gease but will be doing more research before changing anything :)

[–] [email protected] 2 points 3 hours ago* (last edited 3 hours ago)

I don't really know the basics of oil vs gease but will be doing more research before changing anything :)

Grease is thicker and stickier, lasts a lot longer but also offers weaker lubrication than oil. Both of them thicken in cold temperatures, but since grease is more viscous in equal temperature, it also becomes too viscous in warmer temperatures than oil. They don't have a strict freezing point like water, but slowly get more viscous as temperature goes down

That's very generalized, there's both oils and greases that can take very extreme temperatures

[–] [email protected] 7 points 7 hours ago* (last edited 7 hours ago) (1 children)

Your analysis sounds correct. Replace the lubricant with light oil, not grease, for a test. If they still seize up, then it is likely material+tolerance (some parts are too close together and get pressed against each other due to differences in contraction with temperature decrease) that makes them seize and not the lubricant. If they don't seize with the light oil, figure out what grease works in the cold.

How's the Cues BTW?

[–] [email protected] 3 points 7 hours ago (1 children)

Thanks, I'll do some testing this weekend!

And Cues is great so far (9 months) - but for a commuter bike in a flat area I wonder if I should have gone with fewer gears to have a wider chain for longevity reasons. Not much chain wear yet, I just wonder.

[–] [email protected] 3 points 7 hours ago

I doubt longevity would be a problem. LinkGlide is supposed to be so much chunkier than Hyperglide that it should be incredibly durable. After all one of the purposes for it is to withstand electric mid drive torque. Those put torque similar to standing pedaling through the drivetrain on a regular basis.

[–] [email protected] 7 points 7 hours ago (1 children)

Hunt hubs are easy to take apart and grease. Seems worth a shot if you can find a lighter grease that's better in the cold.

[–] [email protected] 1 points 7 hours ago

Great to hear, I'll do some research and give it a try this weekend. Thanks!