Tyre S O S!!!

[west bay]

Right heres the problem, brought a new Raleigh Pursuit 2010 edition yesterday and put it all together and at first everything seemed fine, however after takin it for a spin i felt myself bouncing up and down as if i was riding on square wheels. On closer inspection it seems as if the tyres are shot to pieces, when spinning wheels in hand the back tyre seems to jump up and down and snake from side to side in places and the front one isnt much better. Ive tried everything i can think of to sort problem out, but to no avail, rims look perfectly true so it must be the tyres. Is there anything else i could try? I used to work in a cycle shop many moons ago, but lot of the parts on this bike are totally new to me so i feel a bit lost. Doing London to Brighton on Sunday so havent really got much time to play about with.

 

[OldGoat]

I'd run it down to your LBS and have them check it out.

 

[Akadat]

Deflate the tyres to about 5 psi or soft enough to squish them around the rim by hand. Seat the beads the same depth all round on both sides. There is usually a line in the rubber or some texture to use as a guide. If the tyre is deeper on one segment it will be higher in the opposite segment. Massage the tyre until the seating is visually equal all round on both sides. Pinch an push the high spots in, and pull at the low spots, plus a little side to side wiggling where necessary. It doesn't take long to get it quite accurate, then pump up to the recommended pressure and they should be good.

The valve stem should be vertical. If it leans forward or backward then this can be corrected by deflating the tyre completely, massaging the tyre and tube around the rim until the stem is vertical, then proceed as above to seat the tyre nice and concentric.