Hello,

I wish to convert my standard Cub swinging arm, so that it is suitable for a 4.00 rear trials tyre.

I have been told that I need to lenghten the arm by one inch, and widen it by one inch.

I need to know how and where to cut, and how to weld it all back up.

Has anyone got pictures, etc, of the details ?

Thanks in advance.

Hi Guy's

Hi TCM.

I made mine one inch longer by lenghening the back fork slot by the inch and then filling in the front of the slot with a slug of steel and drilling it for a snail cam bolt. I made it one inch wider by heating the right hand leg casting at the front to red and gently leavering the leg out to the shape of the left hand side, then let it cool and again heat the tube and bend so that the shape matches the left hand leg. set it on a flat serfice and make shure both legs lie without rocking.Any small difference can be adjusted by cold setting.Hope this helps.

Regards Charlie.

Many thanks for taking the time to reply,

Thats just the information I was after.

Regards, Jon

Hi Guy's

Hi TCM.

I made mine one inch longer by lenghening the back fork slot by the inch and then filling in the front of the slot with a slug of steel and drilling it for a snail cam bolt. I made it one inch wider by heating the right hand leg casting at the front to red and gently leavering the leg out to the shape of the left hand side, then let it cool and again heat the tube and bend so that the shape matches the left hand leg. set it on a flat serfice and make shure both legs lie without rocking.Any small difference can be adjusted by cold setting.Hope this helps.

Regards Charlie.

Hi Charlie,

What model/year was your swinging arm off? I understand some are kinked one side and some both as standard?

I presume later models were kinked both sides for more clearamce, although still not enough for trials tyres.

Steve.

Hi Guy's.

Hi Steve.

Yes I think you are right mate, The later one must have been the ones with double kinks.

The one I used came from a 1958 frame so had the straight right leg. I have heard of using Bantam and C15 arms but I feel they still need modification.

Regard's Charlie