Commando motor in solid frame

Brooking 850 · Sep 6, 2016

deleted

Brooking 850 · Sep 6, 2016

Alan, it may pay to read about Keith Corish's NORVIN he built in the 1950"s
Classic Bike Guide, June 2016 (the one with the new Norton Dominator on the cover) Page 19
Quote " that didn't stop Corish's Norvin becoming the most successful bike in Australia's racing history"
Not crap by any means!!!
Regards Mike

Jagbruno · Sep 7, 2016

Brooking 850 said:
Alan, it may pay to read about Keith Corish's NORVIN he built in the 1950"s
Classic Bike Guide, June 2016 (the one with the new Norton Dominator on the cover) Page 19
Quote " that didn't stop Corish's Norvin becoming the most successful bike in Australia's racing history"
Not crap by any means!!!
Regards Mike

As I am in the process of building a Norvin in a "Low Boy" replica frame (alleviating the CG height problem common to all Norvin AND Egli Vincent!), I would be really interested to read this article. Unfortunately CBG is not available in Belgium...

Rohan · Sep 7, 2016

A lot has been written about the Corish Norvin, and several later copies.
Some of it possibly online, I'll have a look.
I've seen one of them ( can't remember which one) seriously in action - it was wickedly fast, on a very tight little track too - blew everything into the weeds. (they were all 500 and 650 though).

http://www.antiquesreporter.com.au/inde ... imms-vinc/
Can't see much, its all too black !

We seem to have diverged from Commando motors, somewhat....

Bernhard · Sep 7, 2016

As I am in the process of building a Norvin in a "Low Boy" replica frame (alleviating the CG height problem common to all Norvin AND Egli Vincent!), I would be really interested to read this article. Unfortunately CBG is not available in Belgium...[/quote]

Unfortunately this is a load of b**********
What’s wrong with Flea Bay :?: :?

Bernhard · Sep 7, 2016

Rohan said:
Something else to consider is what tyres/tires Alan was using in all these sagas. ?

Something I heard a good while back may have some bearing on this.
A work colleague mentioned he had had new XXXXXXX tires fitted, by the importer, who said "try these".
(This is a road bike.) Owner said these tyres were like nothing he had ever seen, "you could lean the bike over until it was 90 degrees off vertical, and they still hung on". (bit of an exaggeration, but you get the picture.)

Apparently they were proddy racing specials = a really sticky compound.
Nothing on the sidewalls to indicate they were different, in the slightest.
Said they were a bit of a waste on a road bike, and they only lasted about 3000 km.
But were fun while they lasted. There are tyres, and there are tyres ?

Race compound put into road tyre moulds is an old trick, I believe Dunlop used to make a batch of TT100 like this, but I could never obtain any, I do know that Metzeler tyres used to make a front ME33 with their race compound to match the rear ME1 motorcycle tyre at about 33% extra, (the ME1 appears to be no longer available) I used to buy one for the winter to prevent myself getting into front wheel slides.
There is also the problem of damp on the braking area, spilt Castrol R veg oil which the slugs gang love, which then leave a lot of their slime on the tarmac :shock:

Bernhard · Sep 7, 2016

Delete

Jagbruno · Sep 7, 2016

Bernhard said:
As I am in the process of building a Norvin in a "Low Boy" replica frame (alleviating the CG height problem common to all Norvin AND Egli Vincent!), I would be really interested to read this article. Unfortunately CBG is not available in Belgium...

Unfortunately this is a load of b**********
What’s wrong with Flea Bay :?: :?[/quote]

I am not sure I understand your post correctly. Please elaborate.

Dances with Shrapnel · Sep 7, 2016

Brooking 850 said:
Hey Dances , I need to do this, what do you think the ideal balance should be with a standard Commando frame with an 850 motor?
I weigh 82 kg/s
Regards Mike

I don't know what an ideal balance should be, especially for a specific bike but I do know what I was working with on my Commando in a Seeley Mk2. This is a race bike with Steve Maney barrels, lightweight billet crankshaft, TTI magnesium gearbox, lightweight wheels and other lightweight stuff. This bike weighs in at 285 lbs with lube and w/o fuel.

Percentage distribution from recollection as I don't have my notes available:
Unladen - about 50/50 F/R
Ladened tucked rider position - about 55/45 F/R - maybe closer to 52/48 F/R

The above bike and configuration runs like a dream on the track at speed. I believe that you need to look at the whole bike - suspension, wheels/tires, squat/anti-squat configuration, sprung to unsprung mass ratio, and ladened weight distribution.

As for a Commando 850, I would only be making an educated guess as to what the weight distribution is or should be. I had campaigned an 850 Mk3 sleeved to 750 cc and always felt like I was fighting to get further forward (more weight forward) in the turns. The Mk3 had the greater rake angle and I was using relatively wide AVON Super Venoms front and rear. The steering was heavy; heavier than a stock Commando with 19" Dunlop K81s.

The Featherbed with a Commando engine is a pretty good package; that is why I was asking what the ladened weight distribution is. I would say that it would be a good starting point for a Commando 850.

acotrel · Sep 7, 2016

I was extremely disappointed when I respoked the wheels of my Triton to 18 inch to fit decent rubber. The bike became less nimble and was exhausting to race. The problem was there was no cheap way back and in any case, at the time you could not buy decent 19 inch tyres. I believe the Domiracer that Phillis rode had 18 inch wheels. Makes me wonder about it's steering geometry.

Brooking 850 · Sep 7, 2016

Thanks Dances, I will get it weighed up prior to my next race meeting end of October, I'm away from home at present.
Yes you are right I seem to feel my Commando frame requires me to be mounted further forward on the bike, I am using a café racer style tank that I got off madass, it could well be shorter for racing for sure.
Regards Mike

Dances with Shrapnel · Sep 7, 2016

Mike,

I was using a Dunstall (box looking) fiberglass fuel tank (weighed a ton) and a Corbin Gunfighter seat - probably not the best combination for a Commando race bike, so perhaps it was that combination that was giving me the "feel" that more weight was needed on the front.

Bernhard · Sep 8, 2016

Jagbruno said:
Bernhard said:

As I am in the process of building a Norvin in a "Low Boy" replica frame (alleviating the CG height problem common to all Norvin AND Egli Vincent!), I would be really interested to read this article. Unfortunately CBG is not available in Belgium...

Click to expand...

Unfortunately this is a load of b**********
What’s wrong with Flea Bay :?: :?

I am not sure I understand your post correctly. Please elaborate.[/quote]

your quote; "Unfortunately CBG is not available in Belgium...[/...[/quote]

Then, what did you really mean :?:

the back copies of CBG can be obtained on flea bay;

http://www.ebay.co.uk/sch/i.html?_nkw=c ... bike+guide

L.A.B. · Sep 8, 2016

Or: http://www.classicmagazines.co.uk/issue/CBG

Commando motor in solid frame

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