Wobbly headset.. Help!

AliShah2020

Active Member
Dear fellow cyclists,

I've replaced an OEM 60MM STEM for a shorter one (35MM) and realised my front headset was a bit wobbly. I've tightened it up now by hand using an Allen key, and realised I might need to purchase a torque wrench.

I have a hard tail MTB with front suspension locked out and it's difficult to tell if after tightening by hand whether the headset is loose or the bike is simply moving a few mm on the front suspension when rocking it back and forth.

I'm a bit paronoid of the head set being too loose or too tight and damaging it by accidentally.

Can I please ask what the torque should be on tightening the bolt at the top of the headset? Please see photo.

I'm considering purchasing a torque wrench to do this upgrade for peace of mind.
 

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figbat

Slippery scientist
OK, so what have you tightened and how?

To remove headset slack you need to loosen the two rear stem mounting bolts, then tighten the top cap bolt until the slack is gone but the steering isn't stiff - this takes a bit of feel and may require a couple of goes. Once you are happy that the slack is gone and the headset isn't too tight then retighten the stem bolts. It is these bolts that hold it all together in tension - at this point you could completely remove the top cap and bolt and it should stay tight (don't actually do this, but you could theoretically).
 

figbat

Slippery scientist
Also you need to be sure it is headset slack you are feeling and nothing to do with the brakes. You can test this by turning the steering 90° then rocking the bike back and forwards - if it still knocks it's probably the headset (assuming the fork lowers aren't loose and the wheel axle is tight).
 

cyberknight

As long as I breathe, I attack.
OK, so what have you tightened and how?

To remove headset slack you need to loosen the two rear stem mounting bolts, then tighten the top cap bolt until the slack is gone but the steering isn't stiff - this takes a bit of feel and may require a couple of goes. Once you are happy that the slack is gone and the headset isn't too tight then retighten the stem bolts. It is these bolts that hold it all together in tension - at this point you could completely remove the top cap and bolt and it should stay tight (don't actually do this, but you could theoretically).
im having trouble with my old bike simarly if i have it loose enough to steer easily the headset rocks , tight enough not to rock then its stiff steering and theres no inbetween
 
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AliShah2020

AliShah2020

Active Member
Hi @figbat

Thanks very much for your comment. That was mega helpful. I followed your directions and I have fixed it now. I used a T Shaped Hex Allen Key on the top cap and clamp bolts. The headset was wobbly before when rocking the bike back and forth. I was extremely apprehensive of overtightening the top cap bolt and instead I left it loose. It just needed approx 1/2 a turn and boom sorted. I did it by "feel" and turned the T shaped Hex Allen key with just forefinger and thumb with an open hand grip.

There is no more wobbliness. I checked the bike, it steers left and right normally without being stiff.

I am a bit OCD. Can over tightening the the top cap bolt result in damage or does it merely just make the steering stiff? How tight should you go? Do you do it by "feel" always or do you use a torque wrench?

Thanks again 🍻:okay:

P.S I'm a newbie so lots to learn but getting there.
 

Andy_R

Hard of hearing..I said Herd of Herring..oh FFS..
Location
County Durham
Hi @figbat

Thanks very much for your comment. That was mega helpful. I followed your directions and I have fixed it now. I used a T Shaped Hex Allen Key on the top cap and clamp bolts. The headset was wobbly before when rocking the bike back and forth. I was extremely apprehensive of overtightening the top cap bolt and instead I left it loose. It just needed approx 1/2 a turn and boom sorted. I did it by "feel" and turned the T shaped Hex Allen key with just forefinger and thumb with an open hand grip.

There is no more wobbliness. I checked the bike, it steers left and right normally without being stiff.

I am a bit OCD. Can over tightening the the top cap bolt result in damage or does it merely just make the steering stiff? How tight should you go? Do you do it by "feel" always or do you use a torque wrench?

Thanks again 🍻:okay:

P.S I'm a newbie so lots to learn but getting there.
If you overtighten the top cap the steering will stiffen, which in turn will cause excesive wear on the headset bearings over time. When you do up the top cap bolt you aren't trying to "tighten" it, you're aiming to remove any slack.
 
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AliShah2020

AliShah2020

Active Member
@Andy_R

"When you do up the top cap bolt you aren't trying to "tighten" it, you're aiming to remove any slack. "

Wow. That is described perfectly to a layman like me. Thank you very much. Can I please ask, can the headset get loose over time (six months) through general cycling, hitting road bumps etc? Are there parts of a bicycle need tightening up again over time?

Thanks for your time.
 

Ajax Bay

Veteran
Location
East Devon
can the headset get loose over time (six months) through general cycling, hitting road bumps etc? Are there parts of a bicycle need tightening up again over time?
Not normally.
Mudguard stay fixing bolts (at the mudguard end), perhaps. Some bolts/screws are worth fitting with some threadlock: chainring bolts, bottle cage screws, mudguard stay screws (at the dropout end). And maybe stem bolts (bar end of stem).
I would periodically remove, clean, regrease and refit a seatpost and its clamp (maybe every 3 months) (alloy seatpost into steel frame).
 
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AliShah2020

AliShah2020

Active Member
@Ajax Bay thanks very much for this. I just realised it would be good to see if there is a basic maintenance book I can buy on amazon. I've spent a fair bit of time collating YouTube videos for a "MTB Maintenance" playlist I've made.

I've got a stealth dropper post (overkill for the urban city roads). I applied some SRAM butter to the post and make sure the seals stay clean. I imagine taking it apart is going to be difficult lol. I'll cross that bridge when I come to it...but hopefully not too soon!!
 
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cyberknight

As long as I breathe, I attack.
Are they sitting square in place? The symptom you describe sounds like the bearings might be out of alignment.
afaik the cartridge bearings sit directly into the frame with no races so i cant see how they would not sit flush but its worth a look at the weekend , got to fix the mudgaurds on the commuter too :sad:
 
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