Unrideable steering driving me up the wall...

[xtaffa]

... Or into ditches.

Never known anything like it; last 4 or so rides the bike has been fine up to a point, usually furthest from home, when it develops this weird cyclical tug to the steering/wobble which is practically unrideable. Last two times it's come on after the same long, rubbly uphill slog. Have tried three different front wheels, two different (modern) tyres so pretty confident is not front wheel. Threadless headset has been apart and adjusted. Rear wheel showing no signs of funkiness/ misalignment; no gear problems or rubbing.

Having come back just now from another abortive, sweary ride, I'm a bit at the end of my tether... Dark thoughts about frame fatigue and misalignment on b@stad stiff, 26 year old aluminium crowding in...

Any thoughts appreciated; it's a '96 M2 Stumpjumper with a rigid spesh fork.

 

[DrGooGoo]

Maybe its the road/trail itself?
I thought I had a flat spot on one of my front rims the other day, but it turned out to only be bike path I was riding.

 

[tintin40]

what tire pressures you using? Or take the frame to a frame builder and check its all correct?

 

[foz]

Have you checked the frame and fork for cracks?

 

[thekingofming]

If you have another bike (I know, it's a luxury we don't all have the option of) can you try doing the same rides using that. It might rule in/out the route or something happening with you.

Is it all offroad routes? What if you do the same length ride on road?

 

[xtaffa]

Maybe its the road/trail itself?
I thought I had a flat spot on one of my front rims the other day, but it turned out to only be bike path I was riding.

what tire pressures you using? Or take the frame to a frame builder and check its all correct?

Have you checked the frame and fork for cracks?

Hi guys,

Thanks for these; different bits of trail/road but always after a rough/offroad section, not trail itself; started when running looow pressure on knobblies, but still there running high pressure on the intermediates I've swapped in and done more fireroad/road since the trails started getting chewed up... No visible cracks in either frame or fork; quite a tasty additional creak to the usual, associated with bumps, has come in though. Is there a DIY alignment check before scouting out a frame builder who isn't booked up until 2030? We can't be talking thousandths of an inch here given the warpy feeling I'm getting.

 

[xtaffa]

If you have another bike (I know, it's a luxury we don't all have the option of) can you try doing the same rides using that. It might rule in/out the route or something happening with you.

Is it all offroad routes? What if you do the same length ride on road?

Cheers mate,

Could borrow wife's bike and try as you suggest. It's mixed riding; 4-5 miles of tarmac to bridle way/trails and fireroad with bits in between; since the recent deluge, more on firm stuff to save the trails. Last two rides after first bit of dirt, some after 15 miles and a range of surfaces...

 

[Stressed]

Steerer tube loosening at the crown slightly?

 

[xtaffa]

Steerer tube loosening at the crown slightly?

I think in calmer light of day, fork/headtube area has become my focus; will check this cheers mate. Also got a set of Rond bouncers I will swap in to see if it goes away.

 

[hamster]

If you have the front dismantled, try removing the lower headset cup and re-installing it 90 degrees rotated. It might be slightly distorted in the front-rear axis, alternatively there may be slight dimples in the races (brinnelling) caused by wear. Anyway, it will reduce the headset's wish to return to a particular position which really makes handling feel terrible.