WM3 Rim Lock on WM2 Rear Wheel.

Fast Eddie · Jun 29, 2025

Valsp said:
Having just suffered a rear blow out at 60mph on my N15CS when the tyre turned on the rim I would urge anyone to fit them on similar machines. The original bike had them but I did not have them fitted to my new rims as I didn't think they would be needed if not riding off road. However I failed to take into account that the N15 being geared down produces a lot of torque when accelerating even fairly normally.

My understanding is that old tyres needed them due to their rigid structure and hard rubber.

I had the rear tyre turn on the rim on my Tiger Cub years ago, the tyre on that thing was of unknown age as tyres just didn’t seem to wear out then … but I don’t have any rim locks fitted to any of my current fleet… all of which (I would hope) significantly out power and out torque that ole Cub !

kommando · Jun 29, 2025

If you look at modern alloy rims then on the inside where the bead sits they are knurled, compare that with the slippery chrome smooth surface on the old Dunlop rims. What compounded it was also the stiff side walls of the older tyres which then ran lower PSI. Even with an alloy rim and a high PSI modern tyre if you get a slow puncture and fail to notice then the tyre will creep and pull the valve off, just a lot less likely than with a slippy chrome rim with old stiff tyres running lower pressures.

concours · Jun 29, 2025

Gordoninnc said:
Off road motorcycle tires benefit from rim locks because of the low pressures used.

BUT.......comparing vintage WM rims with modern rims. With our older type rims (on the highway) there's no "safety lip" (look it up) In short, there's nothing (except the rim lock) keeping the bead from falling into the rim's well if pressure is lost. IF it does.....the tire can actually come off the rim. Some of you have already heard my "story"........so I'll not bore the rest of you with it. Do a little research on rim profiles.......you'll see it.

I watched it from the front row.
Ho
Lee
Shat
!!

Gorden speaks the truth.

WM3 Rim Lock on WM2 Rear Wheel.

Fast Eddie

kommando

concours

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