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Where is info on Isolastic Featherbeds?

Re: Where is info on Isolastic Featherbeds?

Postby frankdamp » Sun Apr 13, 2014 9:57 pm

The factory sure didn't make any Featherbeds with Isolastics. The engine suspension system was unique to the Commando.. The F/B was out of production before the isolastic system was released. Any "Isolastic Featherbed " is a bitsa.

The prime driving force behind the isolastic system was the horrible vibration level of the Atlas. We reckoned that a headlamp bulb would fail a 5000 iles even if it was never turned on. The vibration shook the filament off its posts.

200 miles on one of those suckers and your hands and feet were numb! The P-11 was tha same - I put a lot of miles on a P-11 prorotype. Vibration was manageable on the 500 and 600 Dommies, marginally acceptable on the 650SS, but the Atlas was awful.

I don't think the F/B frame could be adapted to isolastics. It's structurally so different.
Frank Damp
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Develpment & Competition Department
1967-68

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Re: Where is info on Isolastic Featherbeds?

Postby Rohan » Mon Apr 14, 2014 2:02 am

Frank, google on 'featherlastic'
Those folks in Tucson have built quite a few of them - they were all the rage at one stage.
Even have their own website http://www.featherlastic.com/
They even show an undertank view of the headsteady - but how that works with a flexy engine is anyones guess ?
Quite a smart looking special.

BTW, you seem to have forgotten about the Mercury. ?
This was essentially a single carb blue 650SS in a featherbed frame, built and sold at the same time as the 1969 and thereabouts Commandos....

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Re: Where is info on Isolastic Featherbeds?

Postby ashman » Mon Apr 14, 2014 4:05 pm

Yes they do look good and these poeple have gone to a lot of troubles making a product that they hope to sell, I still would like to ride one to see if they do handle well, some poeple would ride them but have never experanced riding a Featherbed frame bike before and would say they handle well, but put someone on the bike that has many months of riding a true Featherbed frame and see how they realy handle, you just can't hop on a Featherbed and ride it without getting use to them first.

When I first rode my 850 Featherbed my mate was on his Commando and telling me to push it throught the corners hard, was easy to say but in real life you need to ride it and get use to the way it rides and handle, but after a few weeks of riding it , it just got better and the more I rode it the more I pushed it and the more I loved it, you need to learn to slow the bike before the corners then while in the corners just open it up and let the Featherbed do its job, I push mine very hard and just love tight mountain roads with a few long, fast straights to wind up my hot motor, my 850 has a lot of power and is perfect in the Featherbed frame, it is a lot lighter and has brakes and suspenstion that work well, I also push my tyres to the edge of their limits, you need good rubber.

This is only my throughts, but I still reacon a Isolastic Featherbed will not handle as well as a trues Featherbed with hard mount engines, they are just changing the complete bike and I think I have the experance to know as I have been riding my 850 Featherbed for over 33 years now and it was a everday ride till last year when I brought my new Thruxton.

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Re: Where is info on Isolastic Featherbeds?

Postby acotrel » Thu Apr 17, 2014 1:06 pm

I've seen a period 3 historic race bike which was a featherbed 850. It gets passed off as a 750cc Atlas, however I believe it would be an excellent race bike - it would scare the shit out of the Triumph riding opposition. The Commando engine would be better than the 650 engines in that frame, the forward leaning motor would help the weight distribution, so the handling would inspire more confidence.
I have a problem with historic race rules which inhibit building such bikes. I feel we should be able to pursue the development of that basic technology
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Re: Where is info on Isolastic Featherbeds?

Postby Rohan » Thu Apr 17, 2014 3:45 pm

ashman wrote: built my stock cam up to a SS profile


This is where the story gets a little murky, Ashley. ?
The stock cam in a Commando IS the SS cam profile from the earlier dommies...

??

P.S. Featherlastics were a (passing) fad ??

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Re: Where is info on Isolastic Featherbeds?

Postby ashman » Thu Apr 17, 2014 4:00 pm

Well all I can say Rohan is my cam has been built up and has a bigger lobe profile than the standard Commando cam and it works very well in my motor :D .

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Re: Where is info on Isolastic Featherbeds?

Postby ashman » Fri Apr 18, 2014 6:15 am

Rohan I have a brand new Dommie SS cam sitting on my bench for my project bike and I used my veniers to messure the lobs on it and I also have a standard Commando cam on my bench at the moment as I am rebuilding a Commando motor for a friend and the Dommie SS cam lobs are a lot bigger than the Commando, so I have to disagree with what you say.

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Re: Where is info on Isolastic Featherbeds?

Postby acotrel » Fri Apr 18, 2014 2:51 pm

Rohan is never wrong !
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Re: Where is info on Isolastic Featherbeds?

Postby Rohan » Fri Apr 18, 2014 3:18 pm

And anything you say needs to be checked... !

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Re: Where is info on Isolastic Featherbeds?

Postby Rohan » Fri Apr 18, 2014 3:21 pm

ashman wrote:Rohan I have a brand new Dommie SS cam sitting on my bench for my project bike and I used my veniers to messure the lobs on it and I also have a standard Commando cam on my bench at the moment as I am rebuilding a Commando motor for a friend and the Dommie SS cam lobs are a lot bigger than the Commando, so I have to disagree with what you say.

Ashley


This is an original SS cam, or someones newly ground version of an SS cam ??
And the Commando cam, what year is it ?

The base circles are the same ?
Wasn't the rocker ratio changed, so the cams would measure different but be the same/equivalent grind...

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Re: Where is info on Isolastic Featherbeds?

Postby ashman » Fri Apr 18, 2014 6:00 pm

The Commando the cam is out of is a 73.
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