Old yarn - friction?

[Staticam]

I was gassing with my father the other day, motorbikes came into the conversation... he told me of a friend of his, 20 (probably 30+) years ago, who had Kawasaki something or other. Anyway he was at the lights lining up the car in the next lane. Green, nailed it but just sat there. Apparently sheared the valve and just span the rim in the tyre!

Anybody know if that's possible, confirmed, plausible or busted?

[Ocean1]

Have you never heard of rim locks?

[Staticam]

Nope, not till just before, I have heard of bead locks though (car nut by default). Tried looking up rim/wheel spin ... spinners for bikes, haven't seen those before thankfully. I think I've seen what wiki describes, only on old bikes?

[Katman]

Not that rim locks are used on road bikes.

The wheel would be impossible to balance.

[cs363]

Not that rim locks are used on road bikes.

The wheel would be impossible to balance.

KB is no place for facts Steve, you of all people should know that! :)

[Kickaha]

The wheel would be impossible to balance.
.

I would say difficult, but not impossible

Cost you a fortune in weights though

[Staticam]

KB is no place for facts Steve, you of all people should know that! :)
Weren't any facts, impossible is just an opinion.

[NordieBoy]

I would say difficult, but not impossible

Cost you a fortune in weights though

2 opposing rim locks...

[BMWST?]

tyre must have been pretty soft and he used too much lube in mounting the tyre

[pete376403]

pretty doubtful that the skinny tyres of 20 -30 years ago could generate enough friction froa small contact patch on the road to overcome the friction of the tyre bead/rim interface (18" diameter x 2 beads at normal road tyre pressure. Add to that the internal friction of the tube against the tyre (he did say it sheared the valve, which would only happen with a tube)

Add to that the normally fairly oily, smooth road surface found at most intersections wouldn't have much grip at the best of times .

I'd say busted, but its a good story, and it's good to be able to yarn with your dad about bikes.

[Ocean1]

Not that rim locks are used on road bikes.

The wheel would be impossible to balance.

An XL500's not a road bike?

I knew I wern't doin' it right...


2 opposing rim locks...

I've spun a 510 Michelin with two. Was the old rubber ones, though, and there wasn't much air in there.

[Katman]

An XL500's not a road bike?





For solely road usage the tire pressure should be high enough that it would negate the need for a rim lock.

A dual purpose bike obviously has to be a compromise between both worlds.

[NordieBoy]

I've spun a 510 Michelin with two. Was the old rubber ones, though, and there wasn't much air in there.

Torpedo7 do some really cheap copies of billet Talon ones that work quite nicely.

[Paul in NZ]

Kinda 'depends'. I grew up with 50's bikes (yes yes I know, 12 bhp and I'm boring) but the more powerful ones and many of our dirt bikes would have one or two rimlocks on the rear. Remember that we didn't have that much choice in tyres, they all ran tubes and they would be left on as long as they could pass a wof. To be honest some of them were pretty hideous and the local shop would sell you old tyres for $5 if that was what your budget demanded - god knows how old some of them were. We would run old avon SM's that were like concrete .....

I ran 2 rimlocks on my 500cc Norton engined dirt bike running old Avon Gripsters or else the tyre would creep around the rim and eventually tear out the valve stem and used then on the grass track bike too.

Early Japanese bikes often ran horrible tyres with way too much nylon in them so if it was under inflated it might be possible

[Jantar]

I saw something similar happen at a standing 1/4 event in School Rd, Mosgiel, in 1973. A kwaka 500 tripple, and the rider lowered the tyre pressure to try and get more grip. Yep, he pulled the valve clean out of the tube.

[Richard Mc F]

Not that rim locks are used on road bikes.

The wheel would be impossible to balance.

As I recall my 1972 bonniville had them

[MSTRS]

I used rimlocks on a TS125, after tearing one tube valve off.
I guess that no matter the air pressure in there, the grip a tyre bead has against the rim is very low compared to a tubeless tyre. Otherwise, why is a tube necessary? (yes, I know, spoke holes...)

[unstuck]

Only ever seen it on a tractor, not the hardly davidson type either.:yes:

[Paul in NZ]

Only ever seen it on a tractor, not the hardly davidson type either.:yes:


If you look at the typical 'Trade Dunlop' WM3 on the back of a US spec pom bomb you will usually notice it has 40 spoke holes, 1 valve hole and 2 rim lock holes.... It was reasonably typical....

[Katman]

Hey listen, bikes didn't exist before 1980. Ok?

[Paul in NZ]

Hey listen, bike's didn't exist before 1980. Ok?

Quite correct - they only had 'motor cycles' back then, you know, real things made of iron n steel n aluminium n stuff. No 'bikes' which are all plastic n horrible with too many cylinders and too many camshafts all in the wrong places... Bah!

[Grumph]

You forgot....they weren't "designed" or "styled" by a bunch of poncy Europeans either...they were just as the engineers thought they should be.

Early Jap chrome rim with no serrations round the bead - hell yes - a very possible scenario,

As for rim locks - even Manx nortons came with them - eff'n hard dunlop triangulars could and did move on the rim without them.

[Taz]

That always happened when the bikers of old fitted 18" tyres onto 17" rims to save a few quid :lol:

[NordieBoy]

That always happened when the bikers of old fitted 18" tyres onto 17" rims to save a few quid :lol:

Or with motards when 16.5" rims came out and the magazine testers thought it was a bit easy putting a new 17" tyre on for some reason...