Featherbed verses commando frame

Ok I know this stirs a lot of emotional worms in a great big can so my question is quite precise
"In racing has a featherbed frame fitted with an Atlas or commando engine beaten a commando framed bike on the race track?"
And if so is this a regular thing?
I'm not looking for opinions, don't want to know about other frames etc
I have often heard commando verses featherbed frame comments, I once built a wideline framed 750 commando myself
But in racing did the featherbed beat the commando frame

It would depend on the kind of racing. In current classic racing it probably depends on the rider more than the frame.
I do remember seeing various Commando framed bikes weaving their way around Brands Hatch in the 80s. The featherbed framed bikes seemed more stable.
My opinion is that the Commamdo engine has to sit too high in a featherbed as the lower rails are too close together for a twin.

Baz, the answer to your question is yes, featherbed framed bikes have definitely beaten Commando framed bikes on the track.

But... Commando framed bikes have also beaten featherbeds!

It would certainly come down to rider ability and / or bike set up IMHO.

I’ve ridden both on the track, but the bikes were too different in too many ways, and I’m not a good enough rider to see through that.

What we really need is feedback from a good rider who has ridden good examples of both, fitted with the same powertrain...

Yes I can see what you mean about rider ability being the major factor
I have only ever ridden a featherbed commando engined bike on the road
I just wondered if there was any history

I talked with John McDougall about this some years ago.
John held the lap record at Westwood BC for some time and he also raced at Daytona. His racebike consisted of a lightweight Manx featherbed rolling chassis with a race tuned Atlas engine fitted.
When the Commando came along in the late sixties, British Motorcycles sponsored him to race at Westwood on one of their new Commandos that had been tuned for racing.
He told me that the Commando was a far easier bike to race than his featherbed Atlas.
I was quite surprised at his statement and asked what he meant.
His response " The Commando is easier to go fast on"
I never really did get a clear idea of what he meant, and it's too late now, he died a few years ago.
I suspect the vibrations made by a highly tuned Atlas motor in a solid frame vs a smooth Commando may have been part of the picture.

Glen

It's like Fast Eddie says, there have been plenty of cases of featherbeds beating Commandos, and vice versa. I raced on both for 20 years in local, national, and vintage events, and as others have said, on most tracks it is usually decided by rider skill, not who has the trickest bike. FWIW, I preferred the featherbed with a 750 engine, and the Commando PR with a 920 engine.

Ken

Ken, did you find the vibration of the 750 in the solid frame to be an issue?
I rode 2 stroke racebikes when I was young and never noticed any vibration.
I got back on one of them a couple of years ago and, my God it was awful.
Nothing changed with the bike, it had always vibrated horribly at high rpm, however youth and adrenalin seemed to make me immune to it.

Glen

I can't remember where I read it now, but someone pointed out at the time, once Commando race bikes came 'on stream', featherbed race bikes started disappearing of the tracks quite quickly.
Apart from everything else, featherbeds seem to weigh a ton!
Not including Manx featherbeds, incidentally...

In 1973 I periodically raced my 72 Combat on tracks in the PNW. Tight spokes, tight isolastics, different rear shocks, different front fork springs and oil. It was as well set up as this 20 year old college student could do. A friend and competitor had a Combat spec motor in a Featherbed frame. We would sometime trade off during the much more liberal practice sessions. I found my bike easier and faster on the larger tracks. His seemed more nimble on the shorter circuits. We knew nothing about such crazy things as rake, trail, and wheelbase. Old memories

worntorn said:

I talked with John McDougall about this some years ago.
John held the lap record at Westwood BC for some time and he also raced at Daytona. His racebike consisted of a lightweight Manx featherbed rolling chassis with a race tuned Atlas engine fitted.
When the Commando came along in the late sixties, British Motorcycles sponsored him to race at Westwood on one of their new Commandos that had been tuned for racing.
He told me that the Commando was a far easier bike to race than his featherbed Atlas.
I was quite surprised at his statement and asked what he meant.
His response " The Commando is easier to go fast on"
I never really did get a clear idea of what he meant, and it's too late now, he died a few years ago.
I suspect the vibrations made by a highly tuned Atlas motor in a solid frame vs a smooth Commando may have been part of the picture.

Glen

Click to expand...

http://www.bikeexif.com/vintage-yamaha-race-bike

“For anyone who’s ever ridden an XS, they can tell you about the extraordinary vibration this motor throws at you. The solid mounted XS race engines create a vibration so extreme, they actually make the bike a challenge to handle, and in the end will rob you of speed through cornering and straight acceleration. And all the while, you’re losing feeling in your hands going down the track.

This problem only gets worse when the XS engines are modified to create more horsepower which of course equals more vibrations. So much so, it’s very common for XS engines to literally shake the bike apart, even through your lock wire and gallons of Loctite.”

Click to expand...

baz said:

Yes I can see what you mean about rider ability being the major factor
I have only ever ridden a featherbed commando engined bike on the road
I just wondered if there was any history

Click to expand...

rohan posted some history/info ..finding the post tho

he was responding/countering the general position ~ "no way does rubber mount outhandle solid"

You get a 850 Commando motor set up in a Featherbed frame and have it set up right with a rider who knows how to ride a well set up Featherbed with the crank balanced right for the Featherbed I am sure the Featherbed will out handle the Commando, but like what other have said its up to the riders skill that win races plus a well set up bike.
As most know I convered my 850 Commando to a Wideline Featherbed in the early 80s and still love riding it so I have owned both, I also have rebuilt a few Commandos for mates as well a few other people, I alway get to ride them after the rebuilds and I still perfer my 850 Featherbed, I can also say that my 850 Featherbed is so much lighter than a Commando, yes the Featherbed frame is a bit heavier than a Commando frame, but you save weight everywhere else, one day I am going to get my hot Featherbed weighted but I am sure I have cut almost 100 lbs off my Featherbed compared to the Commando, but off course you can also get the weight off a Commando, all race bikes are set up for lightness, the less weight its carring the better chances of winning.
I have ridden with a few Commando riders over the years on my Featherbed and once we get into the twisties and I can tell you I leave them for dead, but I also know how to ride and push my Featherbed.
You can't just get on a Featherbed and expect it to out handle a Commando, you have to take your time to learn how to ride a well set up Featherbed and how to push them in the tight corners, you ride a featherbed differently to a Commando each bike has its own ways of riding them, but once you ridden a well set up Featherbed for a few weeks and you master their handling you will never look back, unless you want to see everyone behind you lol.
I have my Featherbed set up for high speeds, lightness and handling, but of course you can also do that with a Commando, but you ask anyone who has owned a well set up Commando/Featherbed bike and they will know what I am talking about, but remember every bike is different, it all about how it been built and set up, the riders skills etc etc it all plays a part in riding any bike and how far you are willing to push them and I push my Commando/Featherbed pretty hard and have done so for over 38 year now, its also has shown up a few modren bikes over the years.
The few trusted mates that have rode my Featherbed have always come back with a huge grin on their face and are blown away how well it goes and handles, the mates that have rode it have all owned British bikes for most of their lives.

Ashley

B+Bogus said:

I can't remember where I read it now, but someone pointed out at the time, once Commando race bikes came 'on stream', featherbed race bikes started disappearing of the tracks quite quickly.
Apart from everything else, featherbeds seem to weigh a ton!
Not including Manx featherbeds, incidentally...

Click to expand...

This is the sort of thing I was wondering
In the commandos early days it must have come up against featherbed Norton twins in proddie racing
I only know about road bikes
I wasn't very happy with the way my 850 mk2a handled but at the time I had an oif bonnie, and an 860 Ducati to compare it with
So I bought a wideline Triton chassis with a tickle front brake and fitted a 750 tuned commando motor
It was ported and had a lightened re balanced crank 3s cam etc
It handled well and went well but nothing outstanding
I don't think my 850 was ever set up right because when I rode my mates combat It was way better than my 850 and better than my featherbed
So I was wondering which one faired the best in racing
Cheers

I can contribute some data points for talking about weight comparison. I eventually managed to get my wideline featherbed race bike with 750 Commando engine down to exactly 300 lbs. with oil and a little fuel. That was with a lot of lightening in different places, single disks front and rear, titanium fasteners everywhere I could manage (axles, transmission mounting studs, swing arm pivot, mounting bolts, etc.), alloy tanks, and so on. I was never able to get the Commando Production Racer anywhere near that weight. Somewhere around 375 lbs. was as good as I ever managed.

Ken

Ken, was that with the thin wall Manx fbed frame or the heavier roadgoing featherbed?

Glen

worntorn said:

I talked with John McDougall about this some years ago.
John held the lap record at Westwood BC for some time and he also raced at Daytona. His racebike consisted of a lightweight Manx featherbed rolling chassis with a race tuned Atlas engine fitted.
When the Commando came along in the late sixties, British Motorcycles sponsored him to race at Westwood on one of their new Commandos that had been tuned for racing.
He told me that the Commando was a far easier bike to race than his featherbed Atlas.
I was quite surprised at his statement and asked what he meant.
His response " The Commando is easier to go fast on"
I never really did get a clear idea of what he meant, and it's too late now, he died a few years ago.
I suspect the vibrations made by a highly tuned Atlas motor in a solid frame vs a smooth Commando may have been part of the picture.

Glen

Click to expand...

A Commando has 27 degrees rake on the steering head. Most featherbeds these days use 18 inch wheels with a steering hear with 24.5 degree rake, so you can end up always dragging them away from the outside edge of the bitumen. A featherbed with 26 degree rake and 18 inch wheels is better. They handle like Suzukis. Vibration is not the issue - with a feather bed the crank needs to be rebalanced to a factor of 72. Personally I would use a remanufactured featherbed, long before I would use a Commando frame.

worntorn said:

Ken, was that with the thin wall Manx fbed frame or the heavier roadgoing featherbed?

Glen

Click to expand...

The bike has a heavier roadgoing wideline frame, from a '59 Model 99SS, with a Mick Hemming swinging arm. Picture here from 2007.



Ken

I wonder where the 75 pounds is.
The frame weights, according to member Lance are:

Commando – Some sort of 750, I think. No IDBare Frame: 28.5lbsFrame and Swingarm: 36.5lbsFrame, Swingarm and Isolastic Plates: 49.0lbs

Featherbed – 1955Bare Frame: 32.5lbsFrame and Swingarm: 40.0lbsFrame, Swingarm and Engine Plates: 43.0 lbs.


So just six pounds more for the Commando setup with Isos, a little less than I would have guessed.

Glen

didn't have a close up look at a fb swingarm until recently & was surprised to not see any re-enforcing like on the cmdo that was even progressive

baz said:

"In racing has a featherbed frame fitted with an Atlas or commando engine beaten a commando framed bike on the race track?"

Click to expand...

Yes indeed