Feel rhythmic rubbing when driving slow

**tony_b** · 7th May 2011, 17:50

ok, 2 weeks ago I got the front tyres changed and afterwards (maybe by coincidence) I noticed what feels like a gentle rhythmic/pulsing rubbing or vibration on the peddles when driving slow (below 20mph). It reminds me of when I had a buckled wheel on my old BMX as a kid and the brakes kept rubbing on the ben part of the wheel. With that in mind I checked the front brakes and found the pads were low and the discs were a mess with a big lip so figured maybe it was that.

So today I have replaced the front discs and pads with help from the very good how2 section by Gary. Thought that would have solved the problem but nope!

Anyone got any ideas on this? Its driving me (excuse the pun) nuts.

**m8internet** · 7th May 2011, 19:05

When you changed the front tyres, what exactly did you do?

On my last tyre renewal I swapped the rears to the front and had a dreadul noise between 20mph and 40mph, plus vibration on braking
On closer inspection of the front nearside tyre I found the tread depth varied quite significantly
This was due to the nearside rear shock absorber having failed, wearing the tyre unevenly around its circumference, leading to the noise and vibration

**tony_b** · 7th May 2011, 19:10

I never changed the tyres myself, I had them done at a tyre place that fits 'nearly' new tyres taken from salvaged cars. The tread seems fine on them but I'll have a closer look tomorrow. Could uneven tread cause an on/off vibration though?

**Derek Mc** · 7th May 2011, 20:32

Sounds suspicious as though the carcase of the tyre may be unsound and it is to blame

**tony_b** · 8th May 2011, 15:55

is there a way to check this without buying new tyres? I rally can't afford a new set unless I really have to.

**TimTay** · 8th May 2011, 16:02

Does sound like the tyre could be out of shape.

**alcutler** · 8th May 2011, 16:34

Originally Posted by tony_b

is there a way to check this without buying new tyres? I rally can't afford a new set unless I really have to.

Jack up each wheel and put a fixed point - almost touching the tread of the tyre - revolve it slowly by hand and you should be able to see any noticeable variation as the wheel goes round. If one is running out take it back to where you bought it from and ask for an exchange tyre - even though a used tyre I think they still have to comply with the sale of goods act, if they are operating as a business!

**TimTay** · 8th May 2011, 16:52

Just be carefull when spinning as an out of shape tyre can mean. Broken steel cords sticking out the tyre. Very nasty if you don't notice spin the tyre and put your hand on it! Speaking from experience. Ouch doesent seem to cover it!

**tony_b** · 8th May 2011, 17:10

Thanks guys, I'll try the 'spin' test. I hope it is just the tyre as at least thats not gonna be too costly.

**m8internet** · 8th May 2011, 18:39

Don't use your hand, use a tool of kinds fixed or supported in place
Your hands are then free to rotate the wheel
Whenever handling wheels always use gloves

I would also suggest taking tread depth measurements
Take them at three positions across the tread - inner, centre, outer
Take them at four corners of the tyres - 12, 3, 6, and 9 o'clock
Then compare
Ideally they should be identical
However what you might end up with is :
5.5 5.5 4.5
5.5 5.5 5.0
5.5 5.5 4.5
4.5 4.5 3.5
This is a tyre excessively worn at the 9 o'clock position and with a slight variation on the outside edge