Commando motors in Featherbed frames or other frames

ashman

ashman

VIP MEMBER
Joined
Jul 11, 2010
Messages
5,603
Country flag
As there has been a lot of talk about puting Commando motors in feathebed frames as well as other frames I throught I start this thread so we all can ask question or anything else to do with this subject, I won't go into the full history of my build over 33 years ago now as I have put it up before but if someone wants to know I will, all I say is this has been done over 33 years and in that time my bike gets better and better with over a 140,000 miles on it with a lot of new improvements over them years, a lot of up grades in that time, with improvements to the front end, carbies, ignition and anything else to make this bike better.

Some might not like what I have done, but hey its my bike and its built for me by me and I know how good it is to ride, smooth, light as a feather, handles like riding on rails and very powerfull, it is my HOTROD and its a one of a kind in my area, built my way.

Ashley
 
How about putting up a good side on shot of your bike.
Or a link to one.
I always thought a Commando-in-featherbed would make a good hotrod, and yours with front disk brake seems the perfect example.
I had a good look at one in the UK about 30 years ago, and bought a kit of engine plates etc to do it, but it never quite happened.
Finding /making exhaust pipes seems one challenge, and yours sounds to have perfected that too.

What did you do with the oil tank and the battery box - they std featherbed parts or other.
What about the engine breather pipe, which wouldn't be catered for on a featherbed oil tank. ?
Cheers.
 
Commando engines WITH the isolastics, in featherbed frames, are called "FeatherLastics" and there are numerous variations on that theme.

Why the heck not.
 
grandpaul said:
Commando engines WITH the isolastics, in featherbed frames, are called "FeatherLastics" and there are numerous variations on that theme.
Why the heck not.
Click to expand...

Indeed - why make it simple when it can be done in the most complicated fashion ?

They do seem to get good reports though.
But were a whim of fashion, is anyone still doing them ??
 
I'd certainly be interested in learning more about your bike. The obvious first question for me is why Commando motor versus Atlas motor if not iso mounted? Still trying to wrap my head around how long some of you have had your bikes. I mean, I was still in grade school. Anywho I'm all eyes and ears...
 
I still have the Featherbed oil tank and battery box will never get rid of them, I ran the bike for 30 years with them on, but the last rebuild when I had to replace my crank cases I went for a round alloy oil tank that sits under the seat tray which holds all my electrics and because I am now running a Joe Hunt maggie no need for a battery, I run my lights off my altennator with a battery elimator (sorry about the spelling) with minamal wiring (as long as the head light, tail/brake light works), I have shed a lot of weight off this bike compared to a Commando.

Commando motors in Featherbed frames or other frames


Commando motors in Featherbed frames or other frames


I am very happy with this set up now and think it will stay this way, I don't know about putting Isolastics on a Featherbed frame as they were designed for hard mounts and its been sometime since it was brought up so that tells me it might not have worked out as I think putting Isolistics in would change the handling side of the Feathebed frame.

As you can see in the bottom pic I run a catch bottle for my engine breather and have just fitted a XS650 reed valve into the breather line, the bottle is to catch any oil that blows out but only gets very little in the four years its been there.

Ashley
 
I brought my 850 Commando brand new in 1976 (17 years old) and converted it to the Featherbed in 1980 so I used what I had at the time, a lot of my mates throuht I was mad at the time but for me it was the best thing I have ever done to my Norton, handles so mush better, lot lighter and with the work done to the motor it has all the power I ever need, its such a good feeling to open the throttle half way through a tight corner and let the bike push itself out of it and steer where you steer it

Ashley
 
Ashley, that is a very lovely bike. I remember when the Atlas first arrived there was a problem with the barrel flange cracking, you obviously avoid that with the 850 motor. The angle of the motor in your bike must help the handling. I found that getting the weight well forward is essential for good handling with that frame. I've thought of building a similar bike for road use, however I think I would be back to the same vibration problems that Norton had, so went to isolastics. What balance factor do you use, and where in the rev range does it vibrate ?
 
Thanks Acotrel, its a great bike to ride, the crank was balanced at 72%, the slite vibrations I get stay right through the rev range, no diffrents at all, when I first built it I had it up to 125 MPH, but these days my high speed runs are a lot less, but I do take it over the ton very often and some more, the good thing about the work that has been done to the motor it get there realy quick, it surprises a lot of moden bike riders when we take off from the lights and I stick with them or sometime in front of them and on the highway it will cruise between 75 and 90 mph all day without any problems.

Ashley
 
Triton Thrasher said:
Snorton74 said:
The obvious first question for me is why Commando motor versus Atlas motor if not iso mounted? ...
Click to expand...

The obvious answer is more power.
Click to expand...

I'd never heard of an Atlas's problem being lack of power. I also wasn't aware that the original Commando motors were that much more powerful than an Atlas motor, thought the whole point was for vibration isolation to help extend the lifespan of an old engine design????
 
The main Commando frame is the lightest (over 500cc) I've ever dealt with, over 100 bikes apart to the bare frame. Now, I can't say that still holds true once you add in the isolastic cradle & swingarm...
 
It does make a nice combination. I've had mine since 1985. I bought it looking like this as a street bike.

Commando motors in Featherbed frames or other frames


Then converted it to a race bike for the AMA Battle of the Twins series (no pictures), and later for the AHRMA twins series in this configuration.

Commando motors in Featherbed frames or other frames


This was the final roadracing configuration back in 2007.

Commando motors in Featherbed frames or other frames


I've also run it a few times at Bonneville and El Mirage, looking like this.

Commando motors in Featherbed frames or other frames


and like this.

Commando motors in Featherbed frames or other frames


So far it has always had a 750 Commando engine, either standard or short stroke. I'm now setting it up with a 920 engine and nitrous for El Mirage in 2014, and also plan to run it with Steve Maney aboard with a 650 short stroke Commando engine at Bonneville.

When I'm all done with that, I plan to put it back to street trim and ride it. I think you could say that I've got good use out of the bike!

Ken
 
Hi Ken

I am not sure which version of the bike I like the most :D

Chris
 
Ken after you had all your fun on that bike it would be good for you to put it back on the road then you can have all the fun you need when you need it, take it out when the mood is right, I ride my new Thruxton most days but when I get the mood to ride fast around tight mountain roads and long and short straights before the next set of tight corners the Norton is the one I like to be on best, slowing down for the corner then just hit the throttle when in the corner and let the bike power through it is a great feeling, with the Flatslide carbies and the Joe Hunt maggie they work so well together and of course the SS cam helps, can't forget that :lol:

Ashley
 
ashman said:
and of course the SS cam helps, can't forget that
Click to expand...

This is where the story gets a little murkey ?
Commandos came with the SS cam, as stock.
Although repackaged to suit Commandos....

??
 
I don't like the way the Dommie and Atlas motors sat straight up, a Commando needs to be leaning into the wind, plus they look faster that way in my mind, so when I made my engine plates it had to lean forward (it has a catch me if you can look about it), when I first built this bike there were no shops around that you could buy engine plates and stuff to do the conversion so every thing had to be made, I was lucky that I worked at a TAFE college (trade college) for 31 years and was aT/A to a maintenance Fitter/Turner for 15 years while there so I had lots of machinery to use and play with, it was a lot of fun making things for my Norton and the tradesman (Steve) I worked with was such a good teacher to me, we had a Oxy cutting machine that had a lazer light so we copyed the patten with Indian ink set it up and the cutter followed the patten, cut the plates perfect, just had to grinde the sharp edges of the plates (5mm steel plates).

If I need to do major work on the motor I can undo 4 engine mount bolts and remove the head stay then just lift the whole engine, gearbox and primary out in one hit but a lot easyer with the carbies off of course and just put it up on the bench.

Ashley
 
My stardard cam was built up and reground by Ivan Tighe Cams in Brisbane over 33 years ago, they said they had the SS cam profle, who knows it maybe bigger than a SS cam, but all I know it works a lot better than the starndard cam, the power kicks in about 4,500 RPMs and just keeps reving, it revs very freely
and got to watch it you don't over do it.

My standard Commando engine use to only rev to 6,500 revs (116 mph) and wouldn't go no further, this engine has been over 125 mph, I know this to be true as thats the speed I went through the police radar at the time :roll: I was lucky that day as the old copper sitting at the radar machine was a old motorcycle copper and rode Triumphs so got off with a stern warning (but that was back in the early 80s)

Ashley
 
Surely there must be others that have gone down this road putting Commandos in Featherbed frames, when I brought my featherbed frame in 1979 my friend Don who got me into Nortons decided to build Tritons so he went down the road with Triumph engine Featherbeds, but I stuck with Nortons, Don still builds Triumphs and has admitted he should have stuck with the Nortons as most of his Triumph engines are running Norton cranks (he makes his own cranks) he always looks at mine and tells me I have been lucky with 37 trouble free years with my Norton.

Ashley
 
You must log in or register to reply here.
Back
Top