my new pr3 has a flat spot

[max]

Two weeks ago i installed the last pr3 in nz on my front wheel, took it to the testing station and it passed the warrant of fitness test.

Yesterday took it for a ride and noticed a distinct bounce in the bike which correlated with the tire rotation, worst at 50 km/h and also at 80 km/h but a bit less so at that speed; had to be the new front tire.

I looked at it and the small ridge close to the rim was uneven and closer to the rim where the valve was ( where the bead had popped on initially ).
Then i removed the wheel, checked for roundness and yes, there was a distinct low spot near the valve area.
Broke both beads, re-inflated the tire until both beads set and checked again; still there and in the same place!

Had a think for a while and broke the beads again but decided to put tire soap on the rim, the white stuff mixed with water especially made for this purpose and position the bead setting part of the bike opposite the valve area where it would pop on the rim as the pressure increased.
So the tire was nicely greased up and inflated again, this time the bead set with LESS pressure and the tire was now centered perfectly on the rim, balanced again and checked that it was now perfectly round as it should.

Moral of the story; i initially used a soapy spray bottle to seat the tire but the tire mounting lube ( the white stuff ) was a much better choice for the job since it allowed the bead to slap in place with a lot less friction due to the lube.

Thought i would let you know about my small saga and how to avoid it if it happened to you since the best way to learn is from someone else's mistakes, all the best for the season

[mvk24_imp]

Thanks for the heads up max

2014 CB1100, 1981 KZ440 LTD, 1993 Yamaha XJ600 Seca, 1994 Yamaha XJ600 Seca

[Cormanus]

Nice work, Max.

[GoldOxide_imp]

Thanks max. Tire mounting can sometimes be non-trivial, even for the seasoned installer.

[the Ferret]

interesting and glad you got it figured out

[Houtman_imp]

The right lubricant is SO important .....

[Sparky80_imp]

yes, the correct lube is important for ALL of lifes lessons.

I've probably installed close to 100 tires and use NoMar tire paste for every one. Never had any problems mounting them and getting the bead to set.

https://www.nomartirechanger.com/sp-lube-pint.html

[max]

Thanks Sparky, that's good info, i finally found some in this small island and here it is;



Same idea, seen it in tire workshops and now i know why the professionals uses it.
Mix with water and apply in the working area, job's a good'n.

Here's a shot of the tire going off and on the bike with the balancing in between;

https://www.youtube.com/watch?v=uEkR-vhL7xM





The trick is to rotate the rod so the inner races move and get rid of the friction, it also checks if the bearings are in good condition ( should move smoothly )

Thanks for all the replies

[dave]

A friend of mine uses WD-40 to mount tires. I found this odd, but he said he's been using WD-40 for years to mount tires with no negative affects. Any comments?

[pekingduck]

A friend of mine uses WD-40 to mount tires. I found this odd, but he said he's been using WD-40 for years to mount tires with no negative affects. Any comments?

I'm sure any liquid would work better than nothing, but a petroleum based solvent may harm the rubber. Even if it doesn't, it's no longer an inexpensive commodity compared to soap.