850 in a 1962 featherbed frame?

Jim mine runs pretty smooth and don't vibrate and I don't have light weight pistons or rods, I have only lost a top gearbox nut and one muffler bolt in 34 years in the Featherbed frame, but the top gearbox nut was my mistake as forgot to tighten it up tight, I do get a little bit vibration in my handle bars at serten revs but have fixed that now with thicker rental bars and now have no vibrations at all but the vibes I did have where ever so slite and only at serten revs ranges.

Ashley

The only problem with the full fairing it hides a beautyfull motor, it takes alot from your bike, but everyone has their own ideas, I like your Featherbed without the fairing, but what ever its a nice looking bike, I just love any Featherbeds.

Ashley

ashman said:

Jim mine runs pretty smooth and don't vibrate and I don't have light weight pistons or rods, I have only lost a top gearbox nut and one muffler bolt in 34 years in the Featherbed frame, but the top gearbox nut was my mistake as forgot to tighten it up tight, I do get a little bit vibration in my handle bars at serten revs but have fixed that now with thicker rental bars and now have no vibrations at all but the vibes I did have where ever so slite and only at serten revs ranges.

Ashley

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I'll take your word for that and you may have something special. But my experience was different and its been 30 years on featherbeds. I tried a bunch of balance factors. The filiments in my light bulbs would break when I revved it out at night leaving me to drive home in the dark. I went through a lot of headlamps. I lost a foot peg rubber, an airfilter, a rearview mirror, wires breaking. None of that happens anymore. My 73mm bare pistons are down to 170 grams with the Ultralight machining. Its like night and day.

The featherbed is a wonderful frame. And there's nothing like a good running Nort. But smoother is always better in my book. Forgive me if I'm trying to spread the word.

ashman said:

Jim mine runs pretty smooth and don't vibrate and I don't have light weight pistons or rods, I have only lost a top gearbox nut and one muffler bolt in 34 years in the Featherbed frame, but the top gearbox nut was my mistake as forgot to tighten it up tight, I do get a little bit vibration in my handle bars at serten revs but have fixed that now with thicker rental bars and now have no vibrations at all but the vibes I did have where ever so slite and only at serten revs ranges.

Ashley

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It's a 360deg parallel twin with approx. 2lb total reciprocating weight - it will vibrate, physics dictates it will vibrate, you'd have to be dead not to notice vibration. You'd think if one person working from home could get a parallel twin to run smoothly by changing the handlebars then the whole motorbike world would be running parallel 360deg twins. It's why Norton ditched the featherbed - because of transmitted vibrations from a 360deg parallel 750cc twin. If yours dosen't vibrate I'm amazed you've not been nominated for a Nobel Peace Prize for eliminating vibration from 360deg parallel twins.

I really don't know why people who haven't got a Commando bother harping on about how great their non-Commando bike is and how much better it is than a Commando on a Commando forum. The difference between a Norton Atlas and a Norton 750 Commando is the frame. You might want to stick your posts in the other motorcycle section or get a Commando. I'm a bit pissed off at the moment, so nothing personal - spares related delay on the rebuild.

Al-otment said:

ashman said:

Jim mine runs pretty smooth and don't vibrate...

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It's why Norton ditched the featherbed - because of transmitted vibrations from a 360deg parallel 750cc twin. If yours dosen't vibrate I'm amazed you've not been nominated for a Nobel Peace Prize for eliminating vibration from 360deg parallel twins.

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I think what's happening in this conversation is probably related to the aspect of all things being relative.

Ride a classic (pre-70) big-inch Harley around for a morning, then jump on your Atlas and take it out for a relatively smooth ride all afternoon!

I have 3 bikes with 360° twin engines in rigid frames (Laverda 750 SF, Triumph T120RV and the above Norton), they behave totally differently, yet are all perfectly usable. Yes, they all vibrate somewhat, but each in its own way...the T120rV has a strong vibration at around 4200rpm, but virtually nothin either side of it; the Laverda vibrates above 6000rpm but is very smooth under...and the Norton...well, I am still running the engine in but it is very very smooth under 4500rpm (I'll have to wait a bit to find out what it does above that) :mrgreen:

I also ride a flat twin from the same period (75/5 from 1971) and frankly, even though it is a perfectly balanced engine i can't say that it vibrates much less than any of the other 3 at high revs...

These comments to say that if we didn't want to feel 'some' vibration when riding our bikes we would all be riding 2014 plastic Japanese 4 cylinder bikes.

BUT WE DON'T.
:mrgreen:

You can say what ever about my Norton Featherbed, it does have some slite vibrations all bikes do, but mine is as smooth as it gets and one thing my bike is mostly all Commando, just a better frame annd Commando running gear and noway a Atlas.

[quote="Al-otmen

It's a 360deg parallel twin with approx. 2lb total reciprocating weight - it will vibrate, physics dictates it will vibrate, you'd have to be dead not to notice vibration. You'd think if one person working from home could get a parallel twin to run smoothly by changing the handlebars then the whole motorbike world would be running parallel 360deg twins. It's why Norton ditched the featherbed - because of transmitted vibrations from a 360deg parallel 750cc twin. If yours dosen't vibrate I'm amazed you've not been nominated for a Nobel Peace Prize for eliminating vibration from 360deg parallel twins.

I really don't know why people who haven't got a Commando bother harping on about how great their non-Commando bike is and how much better it is than a Commando on a Commando forum. The difference between a Norton Atlas and a Norton 750 Commando is the frame. You might want to stick your posts in the other motorcycle section or get a Commando. I'm a bit pissed off at the moment, so nothing personal - spares related delay on the rebuild.[/quote]


My crank wasn't balanced in my back yard shed, the old English gentleman that did the balancing knew what he was doing and for some unknown reason my motor runs pretty smooth, I can ride it all day long and not have any pain or soreness, it will never be as smooth as my Triumph Thruxton but is pretty close to it, we all have our own ideas and build our bikes the way we want them, all I know is I have had a love affair with Nortons since a very young age and brought my 74 850 new when I was 17 years old, it was my first road bike and slowly over the years I have looked after it, care for it and keep the maintenance up to it and it has given me reliable service ever since to this day, yes it has changed over them years but the most important thing is I LOVE NORTONS.

Ashley

Al-otment said:

.....I really don't know why people who haven't got a Commando bother harping on about how great their non-Commando bike is and how much better it is than a Commando on a Commando forum. The difference between a Norton Atlas and a Norton 750 Commando is the frame. You might want to stick your posts in the other motorcycle section or get a Commando....

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Wow Al, you might want to check the title of this thread, then skip over it and open a different one & save yourself a bit of heartache. I've been curious about the commando drive-train transplant into a slimline for quite a while, so I've enjoyed this thread. I'll not chime in again as I don't want to get off topic any further.

cjandme said:

Al-otment said:

.....I really don't know why people who haven't got a Commando bother harping on about how great their non-Commando bike is and how much better it is than a Commando on a Commando forum. The difference between a Norton Atlas and a Norton 750 Commando is the frame. You might want to stick your posts in the other motorcycle section or get a Commando....

Click to expand...

Wow Al, you might want to check the title of this thread, then skip over it and open a different one & save yourself a bit of heartache. I've been curious about the commando drive-train transplant into a slimline for quite a while, so I've enjoyed this thread. I'll not chime in again as I don't want to get off topic any further.

Click to expand...

cj, as we're getting a bit pedantic you might want to check the sub-section this post has been put in.

To get back on topic (albeit in the wrong section) - will an 850 engine work in a slime line frame? Well, as the main difference between the 850 and 750 is the bore size, then I would say yes it will work if what you mean by work is that the engine will fit and start.

Something similar to this was done back in the 1960's by a company called Norton and they named the bike the Atlas. But they found the vibration (something to do with reciprocating mass) caused parts to fracture and fall off the motorcycle. There seemed to be a shortage of old English gentleman in the factory at the time and they didn't fit the proper handlebars. And so they made a bike called the Commando which had a different frame to the Atlas.

ashman said:

I have had my 850 Commando motor in a 1957 Wideline Featherbed for 33 years now and it works very well, as the ad says it has a balanced motor which has to be done to run solid mounts for smooth running, so this set up should run sweet and handle great and the price for a good Norton these days are high so I think if everything has been rebuild its a good price, but thats my opinion as I just love Featherbed framed Commando motors combintions.

Ashley

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Please show us a photo of the other side of your bike.

Something similar to this was done back in the 1960's by a company called Norton and they named the bike the Atlas. But they found the vibration (something to do with reciprocating mass) caused parts to fracture and fall off the motorcycle. There seemed to be a shortage of old English gentleman in the factory at the time and they didn't fit the proper handlebars. And so they made a bike called the Commando which had a different frame to the Atlas.

I have heard this said many times, and each time I wonder "Do I have a very special one off Atlas?"

My first Atlas was a '62, bought with less than 2K miles on it with the admonition from all my BSA and Bonnie buddies that Nortons shook and parts fell off. First off I noticed it did not vibrate any worse than the BSA's and Triumphs of my friends. It was my Bonnie 650 buddies weekly routine to go around the bike tightening everything up, something I never had to do. The 62 was a dog as far as performance, and when the 63 came out with 8 more advertised HP, I bought a new 63 Atlas (still have it).

I have heard lamp filaments broke off....I replaced the Brit bulbs upon burnout with US made and have never had to replace them any more frequently than one would expect.

Parts fracture and fall off? The only part to have ever fractured (and many times) is the spider in the clutch center, due to it being a 500 cc design that was pushed beyond its limits, rather than from vibration.

Parts loosen up? I rode the Atlas transcontinental round trip. Nothing loosened up except the chains.

At 70 mph. the vibration in the handlebar grips is intolerable on a long cruise. I found however, cruising at 60 mph was more sensible because:

1) holding on against the wind riding bolt upright is less tiring
2) vibration in the grips is acceptable
3) fuel economy is much improved, there are less fuel stops, and at the end of the day, I found I put as many miles behind me as at 70, and I was not as beat.

Putting a 750 Cdo engine in an Atlas or other FB frame should be doable with no more vibration than I have with my Atlas. The installation has to use the engine as part of the frame, as it was originally designed to be. Pushing it up to an 850? Well, maybe.....better to use the light weight pistons and con rods.

Sure...I would love to have my Atlas be as smooth as the Cdos. If I was 20 years younger, I would put in JSEng pistons and rods. It would be smoother, not as a Cdo, but then Cdo's are not Featherbeds either.

Slick

PS: I will admit to one vibration quirk that has come up after 85K miles. At some elevated RPM (not sure what, but near top end), the 5th digit (the 10K one) vibrates backwards. I now have only 5K miles on the chronometric. If I keep rev'ing it up, I'll have a new bike, right?

Chris said:

Hi

Nice bike.
Pipes are just plain wrong.
Slimline frames are much more comfortable to ride.
IF & it is a big IF
You can tell the difference between a wideline & a slimline you must be a top top pilot.
However after 6 laps & the wideline chaffing your thighs you might change your mind.

Chris

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When I was racing my wideline Triton it always felt big, and it always seemed to be knocking my corners off. However that's what you get with those old style bike. My Seeley 850 feels like a 350cc British bike. When I rode the Z900 Kawasaki, I was surprised how small it felt. If I was buying a café racer, I would still prefer the wideline - I know what those bikes were in the era - I think you buy that sort of bike for the nostalgia kick.

Here is a pic of the other side of my bike, not the best one



Here is another one just after the rebuild and those handle bars didn't stay on.



By the way I am still running my orginal headlight bulb and I have done over 130,000 miles while this motor has been in the Featherbed frame and its been in that for 34 years, plus I had done 15,000 miles after I brought it new while in the Commando frame.

Ashley

ashman said:

Here is a pic of the other side of my bike, not the best one

Here is another one just after the rebuild and those handle bars didn't stay on.

By the way I am still running my orginal headlight bulb and I have done over 130,000 miles while this motor has been in the Featherbed frame and its been in that for 34 years, plus I had done 15,000 miles after I brought it new while in the Commando frame.

Ashley

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How many miles do you get from a motor before cylinder wear causes smoking, blowby etc?

I have only done one rebore 40+, but when I did it we only went 002" clearance on the final hone and did the first 100 miles on a very cold night, that was many years ago and my mortor is still tight and does not blow any smoke at all.

This rebore has about 60,000 miles on it but just over 4 years ago I had to replace the crank cases, so when I put it together I just put new rings with a light hone, the bores where still in good nick as well as the pistons (oginal Hepolite pistons)

Ashley

Quote " 1.Added the end weights to either end of the handlebar to damp vibration by moving the bars' resonant frequency away from that generated by the engine
2.Help to protect the rod and handle & reduce damage while wresting.
3.Enhance the comfort & smooth of riding
4.Easy installation without any modification required. "

:?

Guzzi fit /s handle bar weights ( end plugs ) as dampers / harmonic balancers .

As did some pre war automobiles in the curled ends of the front sping steel bumper blade , to stop Axle Tramp . Thus if yr bars are blurred , the balance could be altered with bar end weights .

They all said the Atlas Bars buzzed at 90 . to test this , remove the bar end weights from a Guzzi , and follow itr to see if the rider looks puzzled . :lol:

ashman said:

.........By the way I am still running my orginal headlight bulb .......Ashley

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Wow that's one heck of a light bulb Ashman !! The bike that's attached to it ain't bad either I especially like that style of gas tank that came on some of the featherbed models, and if I recall from earlier posts you said that your new seat is sold for an Interstate commando model, any difficulty fitting it to your wideline ?? Cj

Hi CJ

The seat mounts had to be moved is all I did, not a hard job but have to take the seat cover off as well as the foam, I cut the oginal mounts off and made new ones then welded then in place where they had to go, it was only out by a 1" or 2", I have two seats for it one dual and one solo, but now its only registed for solo which saves about $200 a year, a big saving when you have another bike as well 2 cars on the road, but the Innerstate seats are so comfrotable when riding all day.

The dual seat I got a new cover for it so had to be pulled apart anyway and the Innerseat with the hump was brought new from Burtons British Bikes in England, Danny the owner is very good to deal with and only took 3 working days to come from England to Australia, better than Aus Post.

Ashley

I was looking at that Burtons solo seat for my ride, how comfy is it?