Engine and Gearbox mounting plates for C'do engine in F'bed (2012)

Re: Engine and Gearbox mounting plates for C'do engine in F'

In 1980 when I first converted my Commando to the Featherbed I used my old Commando engine rear mounts with a few extenstions welded to them to fit the Featherbed rear mounts, then a few years later made new ones out of steel with less steel to make them lighter, then a few years later made a set out of Alloy but at the time I only had 6 mm alloy plate to use, you need to go 8 mm if you use alloy as I found the 6 mm alloy vibrated more, I ended going back to the steel plates (5mm thickness), with steel engine plates I find I get no vibrations at all, but I found there wasn't much weight diffrents to using steel plate to using the alloy ones.

Also you need to make a very strong head to frame top mount, if you don't the top of the head stay to frame will crack the frame tubes if its to weak, my motor is mounted with the same angle as a Commando and the motor sit forward as far as it can, I have also made it that by just removing the engine mount bolts to the frame then remove the head stay I can remove my whole motor, gear box, primary and engine plates out of the frame all together if I need to do any major work on the motor, I can lift the whole lot out within less than 1/2 hour work, I also put hollow steel tubes inbeteen the frame mounts and engine plates where the long bolts go through, so everything bolts up tight without bending any frame mounts when done up tight.



hope the pic helps.

Ashley

Re: Engine and Gearbox mounting plates for C'do engine in F'

I have set of plywood patterns for engine plates copied off a set of new Converta engine plates from Unity Equip if that is off any use.
I am in Sydney ,Australia, so no problem to send them across to WA.
Get back to me if interested
Brett

Re: Engine and Gearbox mounting plates for C'do engine in F'

If I was doing that these days, I'd buy some 5mm chrome moly steel plate off the hot-rod guys, and if they have laser cut facility - get them to shape it, then finish it off with an angle grinder. The advantage is removal of flex around the rear top mount near the pivot, which can cause the frame to crack. It is the reason I always use full circle rear engine plates. 8mm aluminium is easier and cheaper. Whichever way you go, you will need decent cardboard templates and drill your own holes so they are a neat fit.

Re: Engine and Gearbox mounting plates for C'do engine in F'

acotrel said:

If I was doing that these days, I'd buy some 5mm chrome moly steel plate off the hot-rod guys, and if they have laser cut facility - get them to shape it, then finish it off with an angle grinder. The advantage is removal of flex around the rear top mount near the pivot, which can cause the frame to crack. It is the reason I always use full circle rear engine plates. 8mm aluminium is easier and cheaper. Whichever way you go, you will need decent cardboard templates and drill your own holes so they are a neat fit.

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I don't get any flex whats so ever from my rear engine mounts but I also have tube steel between the mount brackets with the mounting bolts going through them which stops any flex at all, my first set of enging plates where completely round but the extra weight didn't help, but the way I have them set up now works the same as way, but its more important to have a very strong head stay.
So after running my Commando motor in the Featherbed now for 35 years I have never had any cracks at all in the frame.

Ashley

Re: Engine and Gearbox mounting plates for C'do engine in F'

I have a set of mounting plates that I'm using for patterns for my featherbed (Ref: Lumpy's Featherbed Commando) and I'm in Perth. Please contact me, if you would like to use them as patterns for your build.

Cheers,

Lance

Hi All.
Please, who supply the plates to mount a Commando engine into a featherbed frame?.
Thank you.
Piero

pierodn said:

Hi All.
Please, who supply the plates to mount a Commando engine into a featherbed frame?.
Thank you.
Piero

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RGM do. But I know someone who’s just done this with RGM plates and the front plates didn’t fit.

Andy Molnar does too.

Making the front plates is a soda, but the engine needs to be as far forward as possible. So if I was buying the rear plates, I'd be asking the question.

A bit depends on your intended use for your bike. For a road bike, it does not matter so much if your motor is an inch further back from the front frame mounts. When I first started racing my 500cc Triton, I could not get anything like a decent lap time , so I changed two things. I removed the separate pipes and megaphones and fitted a 2 into 1 exhaust - and I remade the engine plates and moved the motor forward that inch. I got a bit more torque and the bike handled better.
I have a friend whom I have raced against in about 20 road races at Winton. He has a 650cc Triton with separate pipes and reverse cone megaphones. He used an ordinary four speed Triumph gearbox where I used a close ratio four speed Triumph gearbox. Both of us were using methanol fuel. I could get around him and up alongside him in the straights. But I could never convincingly beat him. His bike was too fast. With a Commando engine in a featherbed frame, you have loads of torque, so the gearbox is not so important. But if you are racing, you need all the help you can get. If the motor is that inch further back, you won't feel so confident in tight corners when racing. I have ridden both of those Tritons. My friend's 650 would blitz anything down the straights but my 500 was better around the corners. So your choice of race circuit is important. On Winton, there was nothing in it. At Phillip Island he would make me look stupid, except that I would go into the corners faster. I once had four crashes in one day at Phillip Island. It is too fast for drum brakes.

ashman said:

So after running my Commando motor in the Featherbed now for 35 years I have never had any cracks at all in the frame.

Ashley

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I know you posted buying your Commando new but how did it come to have the Featherbed frame conversion ?

Time Warp said:

I know you posted buying your Commando new but how did it come to have the Featherbed frame conversion ?

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Before I brought my Norton new a good friend of mine had a very hot 750 Commando motor in a Featherbed frame but his motor sat straight up like the Dommies did I was 17 years old at the time and was riding a Honda TL250 trials bike my mate Don loved playing on it so one day we swapped bikes for the day, he rode the trials bike where we rode at a old rife range from the war days, lots of short hill climbs etc and I rode his Norton but I took it up the ranges where there was lots of twisty roads, thats how I fell in love with Nortons and two weeks later I brought my new Norton Commando.
But I just loved the way the Featherbed frame handled and in 1979 Don had a couple of Featherbed frames and he sold me the one I have for $400 with a roadholder front end but the front end was pretty well had it, In 1981 I started the converstion I was on the dole at the time so everything was done on a very tight budget, motor was stripped and cam sent to Ivan Tighe here in Brisbane to get the cam built up and grind to 2S, the crank was send down the road from him to get balanced for the Featherbed frame, the head was shaved and ported for the cam and while still building it in 1982 I got a job at a TAFE college (TEC College) not far from my place, thats where I cut all the engine mounts for it so the motor was on the right angle like the Commando, they had a Motorcycle section and two of the teachers one was a old school British biker and the other use to be pitt crew to a NZ Norton race team, so lots more work done with their help.
In 1983 the Featherbed was ready for the road and everything I did to it worked so well, it was so well balanced and so light and I can tell you it felt like riding on a featherbed the bike handled like it was on rails, but it took me about 2 months of riding to get to know how well it did handle.
I ended up working at the TAFE college for 31 years and most of that time was in the Maintenance Fitters workshop as a T/A to the fitters and over those years we did a lot more improvement to the Featerbed and just over 7 years ago a complete rebuild where I spent more money improving it to the way it is now, with better front brakes, Lansdown inturnals in the front end and rebuilt Koni shocks and some more work done to the motor but not much work, added the JH maggie, PWK carbies and a round alloy oil tank and got rid of the battery, the Featherbed shaved a few more pounds off it, this bike is such a pleasure to ride, its fast, it super light and it handles like its on rails, the harder you push it in the corners the better it handles, really its hard to explain how well it does handle.
Over 37 years in the Featherbed I have all the same engine mount bolts and in all those years I have only lose one muffler mount bolt and a top gear box nut, my exhaust pipes have never come lose in all that time, thats how smooth this bike is, this use to be my everyday ride till I took a redundancy from my job at TAFE 5 years ago and now its semi retired like its owner, I now have 2 Nortons and 2 modren Triumphs Thruxtons, but I still get a big smile on my face when I do take the hot 850 Featherbed out for the day, this bike has always been so reliable and only once in all those years it let me down when it threw a rear chain, that was about 5 years ago.

Ashley

pierodn said:

Hi All.
Please, who supply the plates to mount a Commando engine into a featherbed frame?.
Thank you.
Piero

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Piero the best way is to make them, set the motor in the frame where you want it make up cardboard temp plates and find a steel fabrication shop and they will cut them for you, I did mine in 5mm plate steel, or find someone who has a plasma cutter, its not that hard really.

Ashley

Tip: a bandsaw with a 1/4" carbide 8-10 TPI blade makes very short and accurate work of cutting alloy and most mild steel. Lower the blade speed and you can even cut harder steel. Scribe your lines and wipe the surface with WD before you cut.

ashman said:

Before I brought my Norton new a good friend of mine had a very hot 750 Commando motor in a Featherbed frame ...............
Ashley

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That is a great story
Around the same time you were on the TL250 I was at the local tracks on a RM125 S MXer I bought new in August 1976.
Those were the days, when I was doing the paperwork, the salesman asked if I had ridden a motorcycle, I said No.
He said something like... OK, good luck with that... I first rode a Commando in 1979 (iirc) a rebuilt black Combat (Not that I knew what a Combat was) It took a while to come back around to Nortons with it being Kawasaki Triples from 1977 on, first H2 in 1980.(Which I still have)

After the TL250 I had a RM125S as well in the first 10 years I had a few dirt bikes as well the Norton for road riding, at 60 now I still have a CRF450X a bit more power than the RMs of the days, never been without a dirt bike or road bike since the age of 15 when I left school and still riding with mates who started at the same time, my mate Don still has a old TL250 and a few Tritons, he went the Triton way when he sold me he Featherbed frame and I stuck with Norton's.

Ashley

The ones from Andy Molnar are the best quality and fit - by far. As detailed above, he is www.manx.co.uk

• NR206 Norton Commando Engine, tilted - Featherbed Frame

Andy supplies these to Norvil, so if you want a decent product with poor and rude customer service, that's always an option for you.

• NR206S PLATE SET - COMMANDO ENGINE INTO SLIMLINE FEATHERBED FRAME - DURAL

Bear in mind, Andy's plates are for the featherbed with front mounting for twins.
If your frame is for the single cylinder (ie you have the flattened top tube on the right side), the front mount is different, and will need modification.

The other consideration is that the Dural is thicker than the original plates, so you will need longer studs and bolts to mount.

Ashley, your comment : 'In 1983 the Featherbed was ready for the road and everything I did to it worked so well, it was so well balanced and so light and I can tell you it felt like riding on a featherbed the bike handled like it was on rails, but it took me about 2 months of riding to get to know how well it did handle.'

Bikes are very deceptive. If you never use them in anger, you probably never discover how good or bad they really are in the handling department. When I practice on a race circuit, I work progressively up into the corners braking as late as possible, and I work on getting on the gas earlier coming out of corners. Sometimes I might scare myself, but everything is still under control. That way when you actually race, you know how fast you can get around the corners. You know how any corner should look as you approach it at speed. I never liked my Triton after I changed the wheels from 19s to 18s - it became a pig. With road bikes, it is a different game - most of the time you have not been where you are going. So you act with more reserve. I don't ride on public roads and I stay away from big race circuits, where a get-off is usually too fast.

Al I ride my Norton pretty hard and push it to its limits when up in the tight twisties we have a lot of mountain ranges in the SE QLD with some long straights before the tight corners, I do know how to ride my Featherbed, I slow my speed down before the corners and once in the corners I open it up, the Featherbed set up right will push you through the corners and I can tell you mine grips the tar pretty good when powering through corners, I have been caught out on some corners that get tighter half way through but I never back off and have got around them but it had me sh.ting myself thinking to much speed but the Featherbed has made it look easy and has got me through, I have also past a lot of bikes on the inside of corners up in the ranges and with the torque of the hot 850 both motor and frame work so well together, the bike is so light and nimble and the best thing is I have rode these ranges for over 43 years and know these roads like the back of my hand and over that time the roads have been made even better, even my mates who ride sports bikes can't believe how good my Norton handles for a old bike, it shows up a lot of modren bikes, but I am a very silkfull rider and I get that from riding hi powered dirt bikes, at 60 now I still haven't slowed down, but I am more wiser and smarter in how I use that power and torque and a frame that handles it.

Ashley

By the way Al I learned a lot of my riding silks from riding around Lakeside Raceway back in my younger days, its a very tight track and is only 20minute ride from my place, its a historacial track now and was saved from the developers and still gets used today.

Ashley