Rim locks

The question on repairing a tube got me to thinking. What does the rim lock actually do? Keep the tire from sliding on the rim or keep it from coming off the rim in case of a flat?
And why isn't there one on the front rim? It can't be because on the rear you get all of the acceleration force, when on the front you get most of the braking force which hopefully matches or surpasses the acceleration force on the rear.
Thanks,
Ride safe

Well this search helped but as always, everyone has their own opinion.

this search

Post edited by: The Milkman, at: 2007/08/25 21:21

Post edited by: The Milkman, at: 2007/08/25 21:22

I've always thought it was to keep the tire from slipping on the rim
Mark

The Milkman wrote:

...And why isn't there one on the front rim? It can't be because on the rear you get all of the acceleration force, when on the front you get most of the braking force which hopefully matches or surpasses the acceleration force on the rear....

That's a good question. My off-the-cuff wild guess would be that downward pressure on front wheel during front wheel braking provides sufficient pressure to hold the tire pressed tightly against the wheel without needing rim locks.

Am wondering if ultra-low pressure dirt-bike or trial-bike front tires use rim locks. :huh:

Post edited by: loudhvx, at: 2007/08/25 21:47

short sheetmetal screws about 4-5 in each side of rear rim srewed into bead of tire work as well and are a lot lighter and easier to change tire.its usually needed when you run real low air pressure in rear tire and are launching it really hard,the tire will hook up and the rim will spin inside cutting off valve stem

From what I've heard is that the fisrt Z1's needed the rear rim locks because the amounts of power they made would spin the rim inside the tire on hard launches. This would tear the valve stem off like Plummen said.

I took them out when a put a Kenda Challenger on my 1000 when I had the stock rims. I never had a problem with the rim spinning in the tire.

later, Doug

Patton wrote:

Am wondering if ultra-low pressure dirt-bike or trial-bike front tires use rim locks. :huh:

My KTM dirt bike has one rim-lock on the front and two on the back.
Mark

Years ago I owned a BSA on which I put a factory race engine. As a result of a violent upshift I spun the rear wheel inside the tire and sheared off the tube's valve stem. POOOOF, instant flat at about 50MPH with traffic coming up behind me (and one fool blowing the horn) as the back of the bike swung back and forth in wide arcs. After changing my pants, I spoke to an old veteran racer who told me about using short screws through the lip of the rim to hold the tire. This solved the problem on that BSA. The rim locks on the Kawasakis are just a more elegant way of doing this, although a pain when mounting tires. Ed

So, it sounds like these rimlocks were put on really high powered bikes. Why on earth did they put these things on an primitive emmission controled, lean jetted 750CSR twin? BTW, mine were not given back to me by the mechanics at the kawi dealer, I took my bike to, in order to remove the rear tire from my wheel. At the time I didn't know what they were and couldn't figure out how to get the tire off the wheel. I didn't notice they were gone, until some time later when I found out what they were and put 2 & 2 together.

Heck, my 650C2 has TWO locks on the back and one on the front. That's serious overkill, IMO.
I think the Big K got very conservative with the designs of their later bikes after learning a whole bunch of stuff with the Z1.
All my enduro bikes had two locks on the rear and one on the front. I never ran any more than 15PSI in either wheel and sometimes as low as 8PSI in the rear, depending on the terrain.

My KL250 has rim locks both front and rear and the 650B has none on the front and two on the rear. When I picked up the 650 rear wheel from the shop after getting a new tire on, he commented about it being street wheel with rim locks. He put them back in!

But, why only on the spoke wheels and not the cast wheels?

My 650 C1 with cast wheels has 2 locks on the back tire.