strange wedge type thing in trials bike rim any ideas?

[guest668]

ok my son is restoring a suzuki ts125 ( i know its not a thumper but thought someone might be able to help)...we were taking the old tyres off the rims and found the wedge type thing in the pic between rim and inner tube (connected to rim by nut and bolt)...we are wondering if its to stop inner tube slipping........anyone got any ideas or thoughts many thanks!!



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[Mark]

A rim lock, locks the tyre to the rim, it prevents the tyre/tube slipping and ripping the valve out.

Only used on off road bikes because of the lower pressures used and more traction given.

[steveD]

It is designed to clamp the tyre to the rim when tyre pressure is low.
The inner tube should sit over it.
Real pain if you really do not need it!

[guest668]

many thanksfor the responses cheers!!!!!!!!

[Smithy]

Very useful in winter as you can run your tyre pressures lower and get more grip. On my old trail bikes I used to go to about 15psi on road in winter and about 5psi off road. Of course you need knobblies for it to make sense.

[SteveC#222]

I once spent 5 minutes watching a young sprog with an air hose clamped to one wondering why his tyre wasn't blowing up!  ...I told him in the end...   We use to fit 1  front wheel and 2 in the back then run 5-10 psi off road.