What size rim locks/ bead locks do i need for a 1968 Cota 247

I have akront rims and will run 2.75x21 front and 4.00x18 rear.

 

Thanks

 

 The rim should have the size stamped in it. I does not go by tire size.

They should be marked wm1and wm2 or wm3 on the rear.

2.75 x 21 is a WM1 rim, 4.00 x 18 is a WM2 rim. Rim locks are identified as for WM1, WM2, WM3,etc. rims.

A 247 rear will probably be wm3. 4.0 x18 can be either 2 or 3.

 

 

Edited October 27, 20214 yr by b40rt

Rim info FYI. Rim lock needs to be suitable for size of rim and 21" rims are not always the same WM number - I know that from experience Hondas have used both 1.6 and 1.85 (WM1 and 2) on trials bikes.

rims.pdf

The tyre clamp size is the distance between the flanges in inches. 1.85 clamp fits rim with 1.85 inches between the flanges

14 hours ago, nh014 said:

2.75 x 21 is a WM1 rim, 4.00 x 18 is a WM2 rim. Rim locks are identified as for WM1, WM2, WM3,etc. rims.

so 1.60 for the front and a 1.85 for the rear?

 

Read the f**ken answers ....

So I took the old tires off and measured the front 21" and rear 18" rim. They are both 1.60 +/-

These are akront rims and i believe them to be original to this bike, (1968/1969 year) 21M00389

 

Edited October 28, 20214 yr by 1968Cota247

On 10/26/2021 at 4:50 PM, lineaway said:

 The rim should have the size stamped in it. I does not go by tire size.

Only stamp on rim is on WP

Unusual to have such a narrow rim on the rear I would have thought, but the caliper doesn't lie. I would think that you will need two at 1.60" or WM1...............

 

On 10/28/2021 at 12:50 PM, 1968Cota247 said:

So I took the old tires off and measured the front 21" and rear 18" rim. They are both 1.60 +/-

These are akront rims and i believe them to be original to this bike, (1968/1969 year) 21M00389

 

I've got a 1960's rear rim that width taken from a Bultaco so I'm not surprised to see that your old Cota has one too.