V-Twins in Featherbeds

acotrel · Aug 31, 2018

The front cylinder head and exhaust pipe on the bike in the photo, stop the motor from being two inches further forward because of the frame tubes. A Mk3 Seeley frame might be better handling than a featherbed, with that motor. Whichever frame is used, two front heads would be good. A single carb on a Harley motor in either frame would be like a racing car with a log manifold.

Petersen · Sep 9, 2018

I spotted this Danish Ducton (or Norcati) at the Rockers vs Mods in Malmö, Sweden in 2016. Ducati Monster engine, I believe.

Fast Eddie · Sep 9, 2018

So...

Has he improved an old Norton...

Or ruined a perfectly good Ducati...?!?

acotrel · Sep 9, 2018

It depends on where the weight distribution ends up. A featherbed frame bike which is light in the front, can destroy the riders' confidence. The bike can feel very vague in the middle of corners. With a Manx motor, the weight is well forward an down low in the featherbed frame - so the handling is always positive and the bike tightens it's line slightly when coming out of corners.

Fast Eddie · Sep 10, 2018

Indeed Al, and with that horizontal front cylinder, it’s difficult to see how he cudda got the mass of the engine far enough forward to get remotely close to any stock Norton set up...

Petersen · Sep 10, 2018

I found some more pictures of the Ducton here:

https://www.motorcykelgalleri.dk/galleri/billeder/norton-ducton-800/56309

Weight distribution/handling issues aside, it's an interesting build. From an aestethic point of view though, it doesn't quite do it for me.

Fast Eddie · Sep 10, 2018

Petersen said:
From an aestethic point of view though, it doesn't quite do it for me.

I think you’re being rather polite...

And I agree !

acotrel · Sep 15, 2018

With the featherbed frame, when fitting any motor other than a big single, you always have the problem of something hitting the front frame tubes when you try to get the motor far enough forward and down. 'Fitting the best motor in the best frame gives you the best bike' is great in theory, but in practice it is often not so easy. The Mk3 Seeley frame is very good in this respect - the open front usually allows the motor to be where it needs to be to get decent handling. I like featherbed frames - the best Period 3 historic bike, is the two-valve JAWA engine in a featherbed - cheap and effective.

Bernhard · Nov 22, 2018

Went thro the internet, when I came across this;

Index of V-Twin Specials;

http://www.diagnosis2012.co.uk/vtwinspecialindex.html

Denis J · Aug 30, 2019

ashman said:
Over the years I brought a brand new 91 1200 Sportster , but only had it for 3 years, I liked the power of the 1200 but a HD was just not my bike, but the last year or so I have been thinking about what it would be like to put a 1200 Evo motor in a Featherbed, be a lot lighter than a cast iron motor, I have a spare Slimline Featherbed all I need is to find a cheap 1200 Evo motor :roll:

Ashley

Ironhead engine is 21 lbs lighter that the Evo. FYI

ashman · Aug 30, 2019

Denis J said:
Ironhead engine is 21 lbs lighter that the Evo. FYI

Not sure how a heavy iron head sportster engine can be lighter than a alloy sportster engine, iron is way heavier than alloy, as well I am doing up a 79 Super Glide and I can tell you that motor is heavier than my mate's Evo motor when I helped him put it in.

Ashley

Denis J · Aug 31, 2019

ashman said:
Not sure how a heavy iron head sportster engine can be lighter than a alloy sportster engine, iron is way heavier than alloy, as well I am doing up a 79 Super Glide and I can tell you that motor is heavier than my mate's Evo motor when I helped him put it in.

Ashley

Its not common sense
But I found out why
The transmission and flywheel and rod kit is very heavy on an ally sporty. It was a hot debate in the XL forum. I weighed both. All the versions of iron motor were lighter. Partly why an evo bike is overall heavier too. My 70 XLH is 448 dry on my scale. My 03 is 503 dry. Buddies 04 1200 is 538 dry..another example of factory specs being off the mark.

Bernhard · Sep 26, 2019

Ogri's V-twin was never lie this-amazing what a bit of elbow grease can do;

https://en.wikipedia.org/wiki/Ogri

norton bob · Oct 6, 2019

A pal of mine has built a Norcati with an 860 GTS motor. It looks very ungainly but apparently rides ok. Cannot see how it improves on the Ducati frame. Pointless.

Fast Eddie · Oct 7, 2019

norton bob said:
A pal of mine has built a Norcati with an 860 GTS motor. It looks very ungainly but apparently rides ok. Cannot see how it improves on the Ducati frame. Pointless.

Ex-bloody-actly !

Onder · Oct 10, 2019

Yes but. If you build a custom bike one of the reasons is to have a bike nobody else has. It is just for the fun of doing it.

Fast Eddie · Oct 10, 2019

Onder said:
Yes but. If you build a custom bike one of the reasons is to have a bike nobody else has. It is just for the fun of doing it.

That’s all true if building a pure ‘custom’ ie no functional intent behind it. Just art for arts sake.

If wanting to claim it’s a ‘special’ there has to be some kind of reason / excuse behind the engineering.

But generally speaking, any ‘special’ that uses a modern sporty bike engine inserted into an old chassis as a way of ‘tuning’ the old bike is a fail, cos almost always the real result will simply be a de-tuning of the modern donor bikes handling and braking potential !

acotrel · Oct 14, 2019

I think the Hedlon looks marvellous, and so do the Norvins. There are a couple of Norvins racing in historic classes in Australia, one has a well-known Superbike rider as it's pilot. A good guy on a Manx will beat any of them. Function beats beauty any day.
I was talking to a guy who works on one of the Norvins. He boasted that it has 50% weight distribution - obviously thought that was good. The problem is that when any of us get on a race bike, we tend to ride around it's handling defects. Will-power can help you go faster. But a good bike makes a good rider.
If I was serious about historic racing, I would buy a Ken McIntosh Manx from New Zealand - one with 19 inch wheels and original geometry, but also the Molnar motor. That is what he had Cameron Donald riding at Phillip Island.

gortnipper · Oct 14, 2019

Fast Eddie said:
But generally speaking, any ‘special’ that uses a modern sporty bike engine inserted into an old chassis as a way of ‘tuning’ the old bike is a fail, cos almost always the real result will simply be a de-tuning of the modern donor bikes handling and braking potential !

But, there are is a glut of modern engines off of cosmetically or fork/frame totaled modern bikes while the donor frame may have had a lump. So, in these cases the 'special' may handle better!

Al's#5 · Feb 9, 2020

Bernhard said:
With humble apologies if this has been posted before;

http://www.diagnosis2012.co.uk/featherbeds.html

V-Twin-Obsession

http://www.diagnosis2012.co.uk/vtwinobsession.html

As a new member browsing the site, this post recalled the time I came across a Norvin in a trials bike shop near me in the late 70's, priced at a grand it nearly caused an early divorce. Similar situations later in life with a Lotus 7 and later a DBS. 3 misses down to the missus but can't complain, still enjoying my present vehicles.

V-Twins in Featherbeds

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