Heinz Kegler Clamps

I would not think aluminium would be strong enough to hold the pivot pin securely as intended under the loads put upon it by the swinging arm

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Almost 20 years ago I was over at Heinz Kegler's home in Albuquerque visiting and as usual talking Nortons when he asked me if I would volunteer my 73 850 for an experiment he wanted to pursue. Being very much a featherbed frame man and openly critical of the Commando's rubber mounted swing arm Heinz felt loose ISOS were very dangerous, he had an idea and asked me to come over the next week. When I came back he showed me a set of aluminum rings he had machined that were halved to go around the swing arm cradle and each ring had a bolt with nut. He drilled my cradle with two holes and fitted his rings, perfect fit immediately, explaining to me that my bike was, once again, his test mule and that I should ride it a lot for a month and report back. When I came back over and told him that slight wallowing in the rear end was completely gone he checked the tightness of the bolts pushing the spindle forward, nothing had moved.

Heinz set about making more of his rings and started advertising in Norton News, and the rest is history.

I still have his prototype rings on my 850, strong and doing their job along with one of the very first sets of Brian Tyree's threaded adjustable pre Mark3 ISOS.
Brian lives here in the Albuquerque, New Mexico area and came up with the idea of adjustable ISOS while riding home from the Norton National in Torrey, Utah.
Once again my bike was the test mule as Heinz modified one of Brian's early sets to have a larger allen bolt to bear down and better stay in place without ISO loosening.
Brian patented his threaded ISO adjusters and met with Mick Hemmings to arrange for Mick to act as his distribution source.

Can you post any pics of them?

To; 1up3down, Thank you for taking the time to answer my question about trying the Kegler Clamp in aluminum . Your answer was a breath of fresh air. It was based on actual experience instead of ego inflated opinion. I've also been contacted by a very well known and respected Norton race shop that sells an aluminum version of the Kegler Clamp. I think that after hearing from you and them I will be giving it a try in aluminum. Have a great New Year!

Thanks for sharing the source for the aluminum clamps!

I've decided to order an aluminum Kegler Clamp kit from NYC Norton next week when they reopen after their holiday closure. I hope to post pictures of the install.

I ordered these from Mcmaster-Carr: http://www.mcmaster.com/#6436k19/=10hgkld

They are black oxide steel. I drilled the set screw hole and threaded it, then I ground a flat spot for a lock nut on the top of the collar where I drilled the hole. Later on I didn't bother to use a locknut. I just blue locktited the set screw into the collar's threads.

The reason I used steel collars is 2 fold.

1) I have an enormous ego

2) The swingarm is long and has a lot of leverage. After I torqued the set screws, I even wondered if the threads on the steel collars were going to strip out on the very first ride. So far they've held up, and really tightened up my handling quite a lot.

What's the advantage of using aluminum collars? rust resistant? lighter weight?... Is aluminum the obvious choice for people who's ego is in check??...

No big deal. The reason I raised the question is I saw on here somewhere that Heinz Kegler's original clamps were made out of aluminum. He was the person who invented the fix in the first place.

The McMaster Carr clamp can be bought in Aluminum or Stainless also.
Not sure what grade aluminum, might buy one to find out.

They also have one with the flat side machined in already:

http://www.mcmaster.com/#split-shaft-collars/=10hnkvd

Just ordered a set in aluminum from NYC Norton. Seems that they have installed close to a hundred of the aluminum Kegler clamps with ZERO problems. The reason that I bought from him instead of making up my own kit is that I like to support the few guys that are still left in the business. I live in the Seattle are and have seen more and more of the local guys retiring with no one in the area taking their place. Old Britts gets most of my business, but how much longer is Fred going to continue? He's already cut back on service and days of operation. Same with Cisco in Tacoma. I'm sure that this scenario is true nationwide.

Seems to me the aluminum vs steel conversation is a bit overstated. Neither is necessarily better. In general, steel is stronger than aluminum but you can achieve the same strength if you use a thicker aluminum or more exotic alloys. My guess is the main reason commercial manufacturers use aluminum is they can crank them out faster and they don't have to bother with providing corrosion protection. If I was to make my own, my preference would be stainless.

Stephen Hill

My understanding is they are not there to stop the turning of the spindle so much in the cradle, Although that would be bad. But to stop the rocking that takes place when the cradle starts to wear. On my rebuild I checked it with a brand new spindle and the center nut tight, and I could detect a slight rocking. After installing the clamps it was as solid as could be. So aluminum should be fine if it stays nice and tight. Correct me if I am wrong. :wink:

eskasteve said:

Just ordered a set in aluminum from NYC Norton.

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Have you received them yet? I looked on their website but did not see them.

Just bought a set of the zinc plated steel clamps from McMaster Carr. Very nice.
Steel is real. Besides they'll be covered in oily grime on no time at all.

The aluminum clamps have arrived and they are installed. I can tell the difference when I grab the rear wheel and move it side to side. Much stiffer. The weather here on Whidbey Island has sucked ever since the install so I haven't been able to try it out on my 10 mile stretch of windy test road. NYC Norton has a fine photo of the clamps on their website under the "Products" heading. As for if aluminum is the proper material for this application , my thought process is that if Heinz Kegler made them originally in aluminum and if one of the premier Norton race teams feels that aluminum is the proper material , then case closed for me.