Top cap tightening

[MattDB]

Just unboxed my MTB and not much to do to set it up. My first worry is getting the top cap tightness wrong - It's easy to feel play on my road bike with it being rigid but on the MTB there's slight play/rattle in the suspension when I do the usual 'front brake on push back and forwards' to feel for play. I can feel the play in headset when the top cap is REALLY loose but it's not obvious to me at the moment when this has gone.

Any tips?

 

[Deleted member 23692]

Put your finger on the join between the bottom of the head tube and top of the fork crown when rocking it forwards and backwards (with the brake on). If you can feel any movement then it needs nipping up a tad more

 

[MattDB]

Cheers - It does feel like there's a little bit of movement when I rock it firmly - but it also feels like I've tightened it more than I should have - i.e. the instructions that came with the bike suggested 'finger tight' - unless my fingers are particularly weak.

 

[Smokin Joe]

With integrated headsets containing sealed cartridge bearings you do not have to be precise with tightening. My method is to take up the play then give another 1/4 - 1/3 of a turn to settle the cartridge against the taper in the head tube. They still turn freely and last for years (Seven in the case of the bike I sold three years ago with the headset still as good as new) without further adjustment or issues.

 

[jonny jeez]

Cheers - It does feel like there's a little bit of movement when I rock it firmly - but it also feels like I've tightened it more than I should have - i.e. the instructions that came with the bike suggested 'finger tight' - unless my fingers are particularly weak.

Do you need to also loosen the headset bolts...like you do in a road bike.

Sorry if this is obvious but I didn't once and could not figure out why The play was still there.

It was late in my defence and I was tired.

 

[Citius]

Tightening the top cap screw is pointless unless you first loosen the stem bolts on the steerer clamp..

 

[Smurfy]

I wouldn't worry about getting this precisely right initially. On one of my new bikes I managed only a few hundred yards before I could detect slight play in the headset. Clearly the head set cups had not been fully pressed into the head tube during the bike build, so after a few hundred yards and a couple of bumps the headset had settled a fraction of a mm and was slightly loose. I quickly hopped off, adjusted it and have never had to touch it since. So my advice is to nip it up, then go for a quick ride to settle things, then check again.

 

[MattDB]

Thanks for those suggestions. Yes definitely loosened the stem bolts first. I guess I'm just struggling to identify what is play vs what is the slight movement/noise of the suspension fork.

 

[lpretro1]

If it is too loose you'll get judder under braking. Do it up until it feels snug and with front wheel off floor turn the bars slowly left & right - should be smooth and easy.

 

[summerdays]

I've put the front wheel at 90 degrees when checking for movement, then the finger on the actual joints if I'm still not sure.

 

[MattDB]

I've put the front wheel at 90 degrees when checking for movement, then the finger on the actual joints if I'm still not sure.

Thank you - so should be no movement at all forwards and backwards?

 

[summerdays]

Thank you - so should be no movement at all forwards and backwards?

I wouldn't say no movement but it seems to reduce the amount of movement from the forks by having the wheel that way (or seems to do for me).

 

[Cubist]

Occasionally you can get play in the forks anyway, where the stanchions slide into bushings in the lowers, and on some budget forks there will always be play. You can isolate which is which by holding the crown where it meets the bottom of the head tube and rock the bike forwards on the brakes. Any movement at all will be obvious.

 

[MattDB]

Thanks very much everyone for your advice - think I've cracked it!

 

[Sharky]

- think I've cracked it!

You must have over tightened it, time for n+1