1974 Commando swinging arm rebuild question ( Complete engine rebuild happening as well )

[Jonez69]

I purchased a tired 74' Commando from the original owner this past summer. It has several issues that need addressed. The engine ran nicely when I purchased it and the bike has 32,400 miles on the clock. The gentleman I purchased the bike from is in his mid seventies and was just not interested in putting any more $$ into the bike, so he sold it. The bike had vibration issues when I got it caused by worn out isolastics and a missing cradle bolt. I replaced the missing cradle bolt and the front Iso and rode the bike a few times, taking 25 mile drives and averaging about 40 mph. The vibration problem was gone, but the swinging arm had play, so I knew it must be addressed ASAP. Also, the front left cylinder base stud snapped off! I know it was there when I bought the bike from pictures I took. So, I parked it and committed to a complete rebuild and repair of all the problems. We all need a winter project, right?! My question today is concerning the swinging arm replacement parts. I have seen a sealed bearing retro-fit kit out there and wondered if anyone is a believer in these kits or is it better to stay with OEM parts. Here are a few pics for your viewing enjoyment and thanks in advance for the replies!

 

[kommando]

Stay OEM and fit the Kiegler clamps at the same time, as long as you add oil every 6 months it will last as long as a set of sealed bearings.

S

Thread 'Heinz Kegler Clamps'

Jan 19, 2014

does anyone know where I can by a set of these?

• Skelly
• Replies: 52
• Forum: Norton Commando Forum

 

[ludwig]

Check the swing arm for parallelism.
Many are warped from new.

 

[batrider]

Swingarm is my winter project... My bike has never ever had the wheels in the same plane. Time to fix it.

 

[johnm]

Check the swing arm for parallelism.
Many are warped from new.

Most.

 

[Torontonian]

Most.

How to ?

 

[johnm]

How to ?

Test if they are twisted?

Fit a shaft through the swinging arm bushes and the rear axle slot. Sit on a level table on V blocks. Any twist will be obvious.

 

[YING]

Test if they are twisted?

Fit a shaft through the swinging arm bushes and the rear axle slot. Sit on a level table on V blocks. Any twist will be obvious.

Okay. So if you find it is warped,how would you go about fixing the problem?
Thanks,Mike

 

[concours]

Okay. So if you find it is warped,how would you go about fixing the problem?
Thanks,Mike

Contact a talented, EXPERIENCED metal fabrication professional.

 

[ludwig]

Firmly clamp the front part of the swing arm. With a suitable lever the legs will bend surprisingly easy. Whatever you do, always keep the spindle in place and check frequently that it is not binding.
But if you don't have the tools, follow Concours advise and leave it to a pro.

 

[franko]

I don't know when the gussets were added to the swing arm. If you take to someone for straightening or you are a competent welder, these might be of help: https://andover-norton.co.uk/en/sho...cement-gusset-for-swing-arm-welding-required-

 

[L.A.B.]

I don't know when the gussets were added to the swing arm.

From serial 300003. The swinging arm then becoming part 064539.

 

[Rockithound]

Warning: welding the gussets into a swing arm can permanently warp it beyond usability. Extreme care & welding knowledge is necessary for this "upgrade"...