Wibbly wobbly weirdness
lost_in_thought
Posts: 10,563
OK, so.
On the tifosi, when cornering, I keep getting the slightly perturbing feeling that the bike is just about to disappear from underneath me and head off sliding down the road.
It actually feels like the rear tyre is rolling off and the rim is hitting the road.
Now, I thought that the problem might be low tyre pressure, so pumped the tyres up to 120PSI (max on the side wall is 130) and still had the same problem.
I also checked the wheel (to the extent of my minimal knowledge) and no loose spokes, no irregularities that I could find.
Any suggestions? The wheels are Khamsins, the tyres are 'Vredestein Ricorso 700x23c'...
On the tifosi, when cornering, I keep getting the slightly perturbing feeling that the bike is just about to disappear from underneath me and head off sliding down the road.
It actually feels like the rear tyre is rolling off and the rim is hitting the road.
Now, I thought that the problem might be low tyre pressure, so pumped the tyres up to 120PSI (max on the side wall is 130) and still had the same problem.
I also checked the wheel (to the extent of my minimal knowledge) and no loose spokes, no irregularities that I could find.
Any suggestions? The wheels are Khamsins, the tyres are 'Vredestein Ricorso 700x23c'...
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Check the wheel nuts.0
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Is the feeling from the front or back?
If it is front - check the fork for stiffness, especially carbon forks....no cracks and so on. Make sure any QR skewers are well done up and the wheel is lokcing place - spin the wheel and see in the bearings grind or the wheel moves about wheilst locked in place.
For the back end. Check for craks in the frame welds/joins. Check the QR skewer is well done up and clamping the wheel in place. Check wheel bearings as with front.
Check you seatpost and seat are fixed on nice and tight (has happened to me before now that I though the bike was "vague" - turned out I had a loose seat!
Check your clamp bolts on the stem and bars too! Nice and tight!
Get the wheels trued - or just checkl the run straight'ish by eyesight.
Ummmmm......errr....0 -
Remove all the spokey dokeys.0
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have a look at the hub. some of the nuts in the assembly may have come loose over time or may not have be tightened correctlyThe doctor said I needed to start drinking more whiskey. Also, I’m calling myself ‘the doctor’ now0
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don't ride while pissed<a>road</a>0
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From the back...
The wheel appears to be true, checked the skewer was holding it in place, will check the seat...
No idea how to check the bearings though, and don't really know what a cone is!0 -
If it's a carbon check it over carefully especially around the BB area.0
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lost_in_thought wrote:From the back...
The wheel appears to be true, checked the skewer was holding it in place, will check the seat...
No idea how to check the bearings though, and don't really know what a cone is!
Cones just hold the bearings in the hub. There'll be a 15mm locknut outside of them0 -
Are you pedalling when this happens or in extreme cornering mode with the outside foot planted at the bottom of the stroke?Short hairy legged roadie FCN 4 or 5 in my baggies.
Felt F55 - 2007
Specialized Singlecross - 2008
Marin Rift Zone - 1998
Peugeot Tourmalet - 1983 - taken more hits than Mohammed Ali0 -
Think JonGinge is on the money as this is what I had recently. It felt just as Lit describes.0
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Feltup wrote:Are you pedalling when this happens or in extreme cornering mode with the outside foot planted at the bottom of the stroke?
Both - I tried pedalling and the other method to see if it made a difference...0 -
Does it feel a bit 'gyroscopic'? I had that on one of my bikes after I put a new set of tyres on it.
IIRC it was on the front though.0 -
Crap tyres probably..........0
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simple_salmon wrote:Does it feel a bit 'gyroscopic'? I had that on one of my bikes after I put a new set of tyres on it.
IIRC it was on the front though.
Not really... just slippy and unstable...0 -
fossyant wrote:Crap tyres probably..........
Hmmm, I did wonder...0 -
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It may be play in the spokes allowing for the lateral pressures to deform the wheel shape and give you the wobbles.
I had this with some Bontagers paired spoke jobbies that I binned for some Mavics.
I reckon your spoke tensions off and you need to get them tightened.
or some new mavics.
NEW STUFF!!!!Fixed gear for wet weather / hairy roadie for posing in the sun.
What would Thora Hurd do?0 -
Greg T wrote:It may be play in the spokes allowing for the lateral pressures to deform the wheel shape and give you the wobbles.
I had this with some Bontagers paired spoke jobbies that I binned for some Mavics.
I reckon your spoke tensions off and you need to get them tightened.
or some new mavics.
NEW STUFF!!!!
+1 All the best SCRer's use em...........;-)0 -
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Bassjunkieuk wrote:Greg T wrote:It may be play in the spokes allowing for the lateral pressures to deform the wheel shape and give you the wobbles.
I had this with some Bontagers paired spoke jobbies that I binned for some Mavics.
I reckon your spoke tensions off and you need to get them tightened.
or some new mavics.
NEW STUFF!!!!
+1 All the best SCRer's use em...........;-)
There's a pair sitting in my local sorting depot with my name on them
Saying that my Bontrager Racc X lites haven't missed a beat in the last year and about 8000 miles. On the other hand the set of Bonty's that came on the Mad one have lasted less than 1000 miles :evil: :evil:pain is temporary, the glory of beating your mates to the top of the hill lasts forever.....................
Revised FCN - 20 -
Thanks all, I've got lots of checks to do this evening!
I do have an unused (by me) pair of Rolf Primas under my bed... maybe I should just change the Khamsins for them!0 -
I put some cheap slicks on my fixie CX and they are very squirmy even compared to the orignal CX tyres with nobbles. It will be interesting to see if the Rolfs cure the problem.Short hairy legged roadie FCN 4 or 5 in my baggies.
Felt F55 - 2007
Specialized Singlecross - 2008
Marin Rift Zone - 1998
Peugeot Tourmalet - 1983 - taken more hits than Mohammed Ali0 -
lost_in_thought wrote:Thanks all, I've got lots of checks to do this evening!
I do have an unused (by me) pair of Rolf Primas under my bed... maybe I should just change the Khamsins for them!
Under bed, in kitchen draw...anywhere else you keep cycle stuff?! I get a hissy fit if it comes near the house, hence, warehouse shed!0 -
JonGinge wrote:lost_in_thought wrote:From the back...
The wheel appears to be true, checked the skewer was holding it in place, will check the seat...
No idea how to check the bearings though, and don't really know what a cone is!
Cones just hold the bearings in the hub. There'll be a 15mm locknut outside of them
+1 on that. The bearings/rear hub is a bit loose on my Focus at the moment but the idiot at Wiggle who set the bike up has overtightened the cassette on so I need to get a chain whip to get it off to check what's going on, but sometimes it feels like there's some wobble in the rear.... If it is the hub/cones, don't overtighten them though.Do not write below this line. Office use only.0 -
check the tyres first are they seated properly
grab the front tyre /back tyre and shake side to side if there is play its the bearings
or cones .0 -
Headhuunter wrote:JonGinge wrote:lost_in_thought wrote:From the back...
The wheel appears to be true, checked the skewer was holding it in place, will check the seat...
No idea how to check the bearings though, and don't really know what a cone is!
Cones just hold the bearings in the hub. There'll be a 15mm locknut outside of them
+1 on that. The bearings/rear hub is a bit loose on my Focus at the moment but the idiot at Wiggle who set the bike up has overtightened the cassette on so I need to get a chain whip to get it off to check what's going on, but sometimes it feels like there's some wobble in the rear.... If it is the hub/cones, don't overtighten them though.0