Security Bolts Rim Locks And Tyre Creep

[hencam]

Evening all,

My father and I run a number of Bultacos, 250s mostly, in club trials in the Wiltshire, Somerset and Devon area , I tend to ride a little more often than him and in a few larger events such as the Exmoor 2 day etc. I am just trying to build the picture here. Bikes are pretty standard, Bulto wheels and Akront rims 1.85" width. we have run IRCs and Michelins on the rear and generally prefer the Mich. we do not skimp on items that matter such as tyres, tubes and security bolts, we run two security bolts as is the norm, the problem is rear tyre creep. I have tried most makes available on the market, some billet types from well known sprocket manufacturers to those available from dealers in general. After any wet trial the tyre will have crept round to the point it needs pushing off the rim and pulling back round. I am 15 stone (most of that is riding gear honest ) and run between 3 and 4 psi. Dad is a little heavier and runs 4 - 5 psi, is this problem the norm, or am i missing something, not doing them up tight enough etc. we have been riding for a few years and just don't recall ever having to do it so regularly.

any help advice as always is gratefully received

[woody]

If you're using tubeless tyres they will creep a bit because the bead is different where it seats on the rim. You can trim them to the same shape as a tube type with a blade, that may stop them creeping as much (not done this myself and never compared the two, so can't explain how it's done)

I'm assuming you're using tubeless as Michelin don't do a tube tyre any more

As for the security bolts, I've used 'normal' cheap ones without any problem in the past, so can't imagine which you use will make any difference.

[hencam]

Hi Woody,

thanks for the rapid reply, yes using the Michelin tubeless, I have already seen the many posts on IRC, we had used them in the past and were always happy until we fell victim to the inconsistencies, when your spending £70 - £80 you can't take the chance.

It had also not occurred to me that part of the problem may be that new tyres grip so much better than 20 years ago so therefore more torque is transmitted through the tyre exacerbating the problem.

looks like i am not alone, so will get on and accept and make the best of it.

[twinnshock]

I also had a problem. Back in the day it was quite common to drill the rim at the security bolt position and screw self tapping screws into the bead. Obviously not to long! 3 each side at each security bolt position total 12 off. I have done this to My model 80 and I no longer have a problem.

My 1978 Frontera had this mod when I bought it.

Stuart

[big_red_bike]

Hi i had the same problem on my fantic . I tried different rim locks but no improvement . I then marked the tyre and rim with a marker pen and found it was not the tyre that was moving.It was the tube moving inside the tyre.The cause was the heavy duty tube fitted,when running with low psi the tube came away from the tyre.I fitted a normal tube and have had no problems in over a year .

[htrdoug]

Nuetech TUbliss will solve your problems.

[topcat]

Hi i had the same problem on my fantic . I tried different rim locks but no improvement . I then marked the tyre and rim with a marker pen and found it was not the tyre that was moving.It was the tube moving inside the tyre.The cause was the heavy duty tube fitted,when running with low psi the tube came away from the tyre.I fitted a normal tube and have had no problems in over a year .

I was going to suggest the same thing, normally not actually the tyre moving but the tube

[b40rt]

So, what's moving the tube, but not the tyre ?

[dadof2]

Thoroughly degrease the rim and the tyre bead then paint evostick contact adhesive all round the rim and bead after fitting the tyre, leave 5 minutes then inflate and leave overnight before using

http://www.henrygallacher.co.uk/ do a special adhesive for sticking neoprene (a type of rubber) to metal, this bonds stronger than evostick, so strong it may tear fragments out of your tyre when you need to remove it so only glue one bead or you cant fix a puncture easily.