Headset DIY SOS

kingofthetailwind

So I've had a rattle at the front of my TCR for a few weeks, and wondered if it was coming from the headset. So I removed the top cap, and noticed there was a second bolt underneath. Thought I'd remove that too, only to realise that the star nut was attached to the other end. The star nut has now fallen down inside the steering tube and I can't get it out!

Have I turned this into an LBS job? Need the bike for the morning!

sungod

the complete assembly is a steerer bung/expander

you may be able to slide out the bung, you need a tough hook/similar to insert and use to to push up from the underside of the bung

then it's simple to get the nut out, re-assemble and re-fit

but they can be quite tight even when the expander bolt+nut have been removed, the outer face is often milled so that it 'bites' the inside of the steerer

if you can't shift the bung, invert the bike so that the steerer is vertical, then use a bit of wire to jiggle the nut into the correct position (and the right way up!), gently insert the bolt while turning until the thread engages - i've done this in the past, it's fiddly

Monty Dog

You should be able to pull the top parts of the fork expander out and the remove the bottom bit, re-assemble and retighten. it'll probably be easier if you unbolt the brake caliper and remove the fork entirely - you can clean and grease the headset whilst you're there ;-)

kingofthetailwind

sungod wrote:

invert the bike so that the steerer is vertical, then use a bit of wire to jiggle the nut into the correct position (and the right way up!), gently insert the bolt while turning until the thread engages - i've done this in the past, it's fiddly

Worked! Glad it did as the bung was going nowhere. I hope my bike forgives me for turning it upside down. Thanks very much. Wet weather bike on my club's sportive tomorrow avoided.

So when you're tightening the bolt into the star nut it just needs to be snug, right? Then tighten the top cap bolt until there's no movement in the forks?

Still no wiser as to what was causing the rattle though. :?

sungod

there's usually a specific torque for the inner bolt, but it's no big deal, as long as the bung doesn't slip while adjusting preload it'll be ok

fit top cap, stem bolts loose

tighten top cap bolt until just barely snug

a) tighten stem bolts

b) straddle bike, hold front brake on hard, push/pull on bars and feel for any play in the headset, if there's some, loosen stem bolts, tighten top cap bolt a smidge more and return to a)

kingofthetailwind

Yeah, seems good to go.

Thanks for your help. Much appreciated.