Hey all. I took my Moonlander out of the shed (the spare room) for the summer and have given it a ride, but theres 's absurd amount of self-steer which wasn't there before. The last time I used it was in Weymouth by the beach (rust?) and I assembled it when I got back, but hadn't used it since.
I took apart the headset and regressed it and everything. It's a Chris King one, the bearings aren't too bad, but it is missing one O-Ring, the one labelled J in the diagram:
I took apart the hub, a Hope Pro 2 Evo Fatso, and the bearings are pretty bad, noticeably worse on one side than the other. Regreased it anyway.
The pressure of the tyres isn't too low, and it was never like this before. Nothing close to it. I've done a fair few road rides on it no problem. I took it down to my LBS and they said it's fine, but obviously they won't know how it normally rides. The tyres are Surly Big Fat Larrys.
I'm honestly not sure what to do, does anyone think the above problems could be causing it? I'm at a bit of a loss honestly. Would really appreciate some advice please!
I find it needs just a miniscule amount of stiffness in the headset for that to happen.
Tyre pressure at usual level?
With sealed bearings there's no real point adding some grease, just get them replaced. As above, it doesn't take much wrong at the headset to cause that notchy, "three-penny bit" effect*
* time this was brought up to date?
tbh i found my old 100mm rims had rediculous self steer from the gyro effect
most noticable after id been riding any other normal bike for an length of time then jumped back on the sandman.
once you got used to it again you didnt notice it
I'm going to go with it having always been there and you had just forgotten what it's like. Try taking it for a long ride and you'll probably get used to it.
My Moonlander feels very weird to steer - at low speeds you're fighting the grip of the front tyre, and at higher speeds you're fighting the gyroscopic effect of the heavy front wheel.
IM(limited)E at 7.5 psi my fatty self steers really badly - at 8 psi its fine - so I would go with tyre pressures
might be riding it faster, since it's dry and you're not on a beach ?
(I have no idea how this might affect things)
(i.e. what somebody just said up there - I wonder why I can't just read through a thread before posting 🙄 )
tyre pressure does this on my fatbike
Thanks for the responses everyone, but it definitely isn't normal. The tyre pressures are not low, probably at about 10 psi with a bit of give, but not that much. So I don't think it's the tyres.
In that case it's probably the headset? What in the headset could possibly be causing it? When I took it to LBS they added a bigger head tube spacer and tightened it up harder, which helped a little bit, but it was still there. Took it home, checked everything, regreased it completely, put it back together only for it to be even worse, back to how it was before I took it to LBS.
I'm not too sure what you mean by minuscule amount of stiffness, sorry. I am missing one o-ring, which is the only incongruence I can notice in the headset, the one marked J in the diagram. Or it could be the bearings? The bearings don't seem that bad, not perfect, but not awful.
But then could it be the hub bearings? urgh!
I said already - putting grease into a headset with sealed bearings isn't doing anything. Tightening up the headset when the bearings are damaged will only make it worse.
I'd get some new headset bearings, fit them and see what it's like. It is very, very unlikely to be anything to do with the hubs.
With fatbikes, highish pressure can be an issue too, I had terrible selfsteer with my Bud until I dropped pressures lower.
I reckon 99% chance that it's the headset or tyre pressure. (How old is the headset? There's an "upgrade" or rather fix for the older shit ones that they made badly to get around paying aheadset licence fees. They'll sell you the parts that they should have sold you in the first place now to get the headset to work as well as a £20 FSA and to avoid the risk of it eating your fork steerer)
10psi on a Moonie is rock hard isn't it? I run 5-6psi on mine.
It's definitely not the tyre pressure, it's not high nor low, just in the middle, it has a small amount of give.
Scotroutes, I'll try sorting the headset out then. I've been researching bearings for CK headsets but they don't seem to be available, though there seem to be plenty of people saying to open up the seals and clean up and regrease the inside of the cartridge.
Thanks for the response Northwind, what is that upgrade you're referring to? I'm not sure if it is the older ones, I'll have a look when I get home? It's anodised racing green, and doesn't look that old though I could be wrong.
agreed with the above - my old fatbike was a little pressure-sensitive, but mostly I just wasn't used to the selfsteeryness of it when I hadn't ridden it for a while. I can't think of any possible reason a headset would have anything to do with this as long as it's not physically loose - its simply a characteristic of the bike
On any of my bikes I find that unless the headset is completely free of friction, roughness, resistance or whatever, I don't ride in a perfectly straight line, I just meander slightly from side to side. Given that on my fat bike I don't think I actually "steer" at all (if I want to go left, I lean slightly left, if I want to go right.......), anyway, any stiffness in the headset can only exaggerate the effect.
Now, please OP, go and fit some new bearings and come back to tell us the result 🙂
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"It’s definitely not the tyre pressure, it’s not high nor low, just in the middle, it has a small amount of give."
All about definitions this but generally I'd say mine are much too hard if they had a small amount of give.
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The King thing is what they call "griplock", and it's literally just the little split wedge that all quality headsets have always had. Check it out here:
It definitely isn't the tyre pressure, 100%.
On any of my bikes I find that unless the headset is completely free of friction, roughness, resistance or whatever, I don’t ride in a perfectly straight line, I just meander slightly from side to side. Given that on my fat bike I don’t think I actually “steer” at all (if I want to go left, I lean slightly left, if I want to go right…….), anyway, any stiffness in the headset can only exaggerate the effect.
Now, please OP, go and fit some new bearings and come back to tell us the result
That sounds like what's happening! Weirdly, I can't seem to find CK bearings anywhere, so going to have take it down to my LBS again, sigh. But seeing as CK seem to have a 10 year warranty, I wonder if it's worth giving them a shout.
The King thing is what they call “griplock”, and it’s literally just the little split wedge that all quality headsets have always had. Check it out here.
Thanks for the heads up! I can't seem to tell if I have it or not, do you know if there's a way to tell? I have a Stealth NoThreadset?
Haven't all King headsets come as standard with the Griplock thing for at least the last 5 years?
You need to take the stem off and pull the topcap up on the headset to tell if it's Griplock or not.
If the wedge is attached to the topcap it's a Griplock.
