Odd steering feeling

so...
took headset apart, ran biro over cups no pitting, regreased everything. reassembled (that was fun). tightened. i think. no play. no binding when turning bars.
bike now veers left.

it's time to start all over again isn't it?

looked at this again earlier. there is binding. at around 11o'clock (so to speak). hence why it veers off to the left. yet the bars move freely to the right, i think there's a dead spot at 11.
if anyone's got any answers before i throw in a new headset when the bike might be fucked, i'd be grateful.

Is this a threaded or threadless headset?

threaded.

Ok. I'm not going to be off any help but... on some threadless stems if they're not perfectly square to the stem, when you tighten up the top cap it can compress stem onto a part of the headset, causing it to stick slightly. If this is the case trying flipping the stem over, or try a different stem.

Which is of no use to you. But someone else might find it useful.

that's cool. more help to everyone.

Ok. I'm not going to be off any help but... on some threadless stems if they're not perfectly square to the stem, when you tighten up the top cap it can compress stem onto a part of the headset, causing it to stick slightly. If this is the case trying flipping the stem over, or try a different stem.

Which is of no use to you. But someone else might find it useful.

You should always use a spacer or two, even if very thin ones. It tidies up this interface.
The top cap should only be tightened enough to remove play, then loosened back slightly after stem bolts are done up.

I must say, I've fitted hundreds of Ahead stems and never seen that to be a problem.

solved. took to shop. dead spot explained as "dead bearing". so. should anyone experience anything similar, look to some of the first shouts (prav i think) of change bearings.

done a search but not seen this exact topic covered before...

On my pompino I've noticed the steering feels less predictable, comfortable than my road bike. I'm wondering if this is to do with fork rake or trail. It feels somewhat like a wheelbarrow (this is the best analogy I can come up with), and I feel distinctly lacking in confidence during some turns etc, especially on off-camber descents but often during fairly normal riding. I'm finding that even when coasting at slow speed I often prefer just to lean into the corner than attempt to steer normally.

what length stem are you using? sounds like it could too short / long?

Go to
http://issuu.com/mark77a/docs/masters__thesis_june_1985_-_strida/18
for a primer on bicycle steering geometry.

Thanks for that link mdcc, I have a frame with mismatched forks, so this could be very useful.

James, might be worth measuring the two bikes to see what the difference is?
Straight edge from headtube to floor, plumb line from axle to floor to get distance between.

Hi

Basically what happens in that i can't keep the handle bars straight, they like to veer to the left, this got progressively worse, i should say that a year ago i had an altercation with a car, not a massive crash but the forks/ bars went out of alignment, had everything readjusted and everything was fine, then i started to notice a very subtle veering to the left, not very noticeable at all at first but now it's very pronounced, when i life the bike off the ground the bars immediately snap to the left.

Now i googled and looked around forums and stuff and it sounds like it's either a headset/ fork/ or frame issue. I wanted further advice so i thought i'd consult the beautiful LFGSS hivemind.

Incidently, i just had another encounter with a car last week, this time pretty big, got cut off so it was head on (exploded inner tube, forks/ handlebars gone out of alignment etc etc) so i guess major overhaul is needed. what do you guys advise?

Hi

Basically what happens in that i can't keep the handle bars straight, they like to veer to the left, this got progressively worse, i should say that a year ago i had an altercation with a car, not a massive crash but the forks/ bars went out of alignment, had everything readjusted and everything was fine, then i started to notice a very subtle veering to the left, not very noticeable at all at first but now it's very pronounced, when i life the bike off the ground the bars immediately snap to the left.

Now i googled and looked around forums and stuff and it sounds like it's either a headset/ fork/ or frame issue. I wanted further advice so i thought i'd consult the beautiful LFGSS hivemind.

Incidently, i just had another encounter with a car last week, this time pretty big, got cut off so it was head on (exploded inner tube, forks/ handlebars gone out of alignment etc etc) so i guess major overhaul is needed. what do you guys advise?

Sounds like the frame or forks have been damaged in one of the two accidents. I'd get a proper mechanic to check the frame over, but if it is likely to be terminal for the frame.

Yeah the problem will likely be far worse after the most recent crash, the bike is just sat there now, haven't checked it out properly. The the crash from last year wasn't so bad, not head on anyway, more like being shunted and chucked onto the pavement and the bike ended up on top of me! But that still knocked the bars/ forks out of alignment.

Some ideas here - https://www.lfgss.com/thread40070-2.html

take to LBS for alignment test.

Yeah, what they said.

If the fork or steerer-tube is bent to one side even slightly, then it'll be all over the shop.

on another note. I have two sets of forks where the bottom crown race is loose on the fork stem. 1" threaded steerer, vintage Stronglight head set, 531 British and Italian columbus forks.
I thought that 1" steerers would all have the same shoulder for the crown race.

ideas on a post

Ta.
edit: Sheldon has saved me again.
http://www.sheldonbrown.com/headsets.html

used the fucking search dot com

Cheers everyone :D

Yeah, what they said.

If the fork or steerer-tube is bent to one side even slightly, then it'll be all over the shop.

This is the correct analysis, replace those forks asap before the odd strain it puts on bearings damages your headset as well.

I'm dredging, but would like some confirmation of my suspicions.

Built up a beater for a friend. Frame and forks look straight, wheels sit straight in the frame.
Headset is not perfect but i've used worse. 1" threaded. Alignment was confirmed with the Park alignment tool.

Bike has a weird gyroscopic steering feel. i.e. it likes to wander and wants to pull left or right - feels exactly like trying to turn a spinning wheel off balance when you're holding the axles.

There's no play in the steering and no binding of the headset. The lower race is flush against the fork crown seat.

The problem made the bike nearly unrideable when i had a 60mm stem and risers on, I switched to a 100mm stem and it's better, but still there in the background.

I suspect the fork steerer is not dead straight or the crown race is actually warped.
Also I think the geo of the frame is quite steep at the front potentially making it twitchy?

The lower race is flush against the fork crown seat.

It's probably pressing on it once the bike is loaded, so the steering will feel free in the workshop but will bind on the road.