Fastest Isle of Man Commando?
- Thread starter highdesert
- Start date
- Status
post132573.html?hilit=peter williams#p132573
ni na ni naa ni naa , 155 I think . :wink: Not Metric . :lol:
anything for a excuse ( for nice pictures . )
See below post . = They BANNED the SUPERCHARGED A.J.S.
Tecnically , Tuned Pipes on a 2 stroke is SUPERCHARGEING .
Therfore , for parity , Supercharged 4 strokes Vs 2 Stokes .
or NO Pipes .
Slick Tyres , and TRACK IMPROVEMENTS count for a good deal.
Whay , its sealed these days , and you dont have to stop and open Keppel Gate even .
ni na ni naa ni naa , 155 I think . :wink: Not Metric . :lol:
anything for a excuse ( for nice pictures . )
See below post . = They BANNED the SUPERCHARGED A.J.S.
Tecnically , Tuned Pipes on a 2 stroke is SUPERCHARGEING .
Therfore , for parity , Supercharged 4 strokes Vs 2 Stokes .
or NO Pipes .
Slick Tyres , and TRACK IMPROVEMENTS count for a good deal.
Whay , its sealed these days , and you dont have to stop and open Keppel Gate even .
Argh , here the garbage is . ( works F-750 tripe )
how-the-west-won-eventually-then-shut-shop-t11783.html
The determined rider was in hospital by this stage ,
The caption there is " Norton Triumph Raceing " . N V T . Norton Villiers Triumph .
http://en.wikipedia.org/wiki/Motorcycle ... eed_record
Therefore im disgusted the new Thunderbird wont take 80 % Nitro , and . . anyone got one lying around looking for a purpose in the grande scheme of things ?
Villiers ?
Non Supercharged .
how-the-west-won-eventually-then-shut-shop-t11783.html
The determined rider was in hospital by this stage ,
The caption there is " Norton Triumph Raceing " . N V T . Norton Villiers Triumph .
http://en.wikipedia.org/wiki/Motorcycle ... eed_record
Therefore im disgusted the new Thunderbird wont take 80 % Nitro , and . . anyone got one lying around looking for a purpose in the grande scheme of things ?
Villiers ?
Non Supercharged .
NOW ,
WHERE Were We .
:? :shock: :| Would YOU trust This Man , on Youre Motorcycle . :lol: 8)
WHERE Were We .
:? :shock: :| Would YOU trust This Man , on Youre Motorcycle . :lol: 8)
johnm said:
Thanks for that insight, John. It's also good to read factual evidence for increases in top speed. I never thought very much about Peel Mountain Mile fairings, but it makes sense to enclose the handlebars. I read that Peter Williams also paid attention to streamlining the rear of the bike since he understood that it was no good having clean air flow over the front, only to have massive turbulence at the back. I remember having a top box that opened fully at speed on my Honda 350 when I was a student. That demonstrated how just how bad the aerodynamics are on a naked bike!
SteveA
VIP MEMBER
I have just purchased a fairing based on the JPN design but with an increased depth in the lower section to allow fitment to taller bikes than the works Nortons.
I have also got a more typical Seeley type fairing so may eventaully be able to do comparisons, but don't hold your breath, this will be years in the coming.
On the topic of Primary Drive outriggers, the Redfern guys used an outrigger in the late '70s. I wanted to do the same and managed to get some information sent to me, 35 years later god knows what happened to it :roll: , I am sure there were a couple of sketches but I recall the words 'trapan a hole' and thinking....out of my league, I havent even got a drill stand at home....but I recall that the idea followed works practice using a (production?) cast inner primary case as the base and inserting a bearing into that amd fixing the gearbox mainshaft to crankshaft centres. They also welded the primary to the crankcase to gain maximum rigidity. Like the Mk III they used a chain tensioner arrangement. This was also a limitation for me since my engine was vertical in a Rickman, so I would have needed to change the engine plates, exhaust, carb manifolds and head steady to tilt it all forward.
The outer primary cover was made from welded plate to make a much lighter affair, but as the works with lots of screw bossed to add to the sealing and rigidity.
This would all work so much better now with a belt drive, but it is of questionable need with a TTi box, and BTW TTi's own clutch is smaller and lighter than the average diaphragm belt drum and runs 62 teeth! It was questionable for me back then, my alternative was to remain with the 4 speed box that was by nature stronger and the 33 tooth triplex engine sprocket and Commando clutch that actually did not cause me a problem in 4 seasons apart from spitting the triplex primary once, but that was made from two to get the longer length and never lubed as well as it should have been! I didnt take the outer cover off of the box once I had built it....
Today I would say if you balance the cost/effort of making a really good outrigger set up and using a more original style of box, it would be about equal to just paying for the TTi box and using a very lightweight belt cover...and your reliability would still be better!
I have also got a more typical Seeley type fairing so may eventaully be able to do comparisons, but don't hold your breath, this will be years in the coming.
On the topic of Primary Drive outriggers, the Redfern guys used an outrigger in the late '70s. I wanted to do the same and managed to get some information sent to me, 35 years later god knows what happened to it :roll: , I am sure there were a couple of sketches but I recall the words 'trapan a hole' and thinking....out of my league, I havent even got a drill stand at home....but I recall that the idea followed works practice using a (production?) cast inner primary case as the base and inserting a bearing into that amd fixing the gearbox mainshaft to crankshaft centres. They also welded the primary to the crankcase to gain maximum rigidity. Like the Mk III they used a chain tensioner arrangement. This was also a limitation for me since my engine was vertical in a Rickman, so I would have needed to change the engine plates, exhaust, carb manifolds and head steady to tilt it all forward.
The outer primary cover was made from welded plate to make a much lighter affair, but as the works with lots of screw bossed to add to the sealing and rigidity.
This would all work so much better now with a belt drive, but it is of questionable need with a TTi box, and BTW TTi's own clutch is smaller and lighter than the average diaphragm belt drum and runs 62 teeth! It was questionable for me back then, my alternative was to remain with the 4 speed box that was by nature stronger and the 33 tooth triplex engine sprocket and Commando clutch that actually did not cause me a problem in 4 seasons apart from spitting the triplex primary once, but that was made from two to get the longer length and never lubed as well as it should have been! I didnt take the outer cover off of the box once I had built it....
Today I would say if you balance the cost/effort of making a really good outrigger set up and using a more original style of box, it would be about equal to just paying for the TTi box and using a very lightweight belt cover...and your reliability would still be better!
Brooking 850
VIP MEMBER
Hi John, ay chance of some pics of your fairing set up, if not on here , then to my email
Regards Mike
Regards Mike
J.P.S. racing Norton front mudguard, weren`t they removed when the mono` had cooling/overheating issues due to the close frame/engine airflow clearances? The Kawasaki triple front guard was reputedly smooth[no stays] as a deliberate airflow device for the centre cylinder. As for M.S.`s assertion that equates 2T sonic-wave exhaust tuning with super-charging, well 2Ts can be fundamentally viewed as pulse-jet units that utilise the reciprocating mill as a mechanical transfer system by the harmonic gas-flow, for turning shafts.
As Sir Stanley Hooker, famous R.R. & Bristol aero-engineer said -"4 strokes = 1 stroke for power, 3 to wear the engine out."
& of course 2Ts can be super[mechaniacally, turbo, or chemically]charged as well, they are just not lazy without it.
As Sir Stanley Hooker, famous R.R. & Bristol aero-engineer said -"4 strokes = 1 stroke for power, 3 to wear the engine out."
& of course 2Ts can be super[mechaniacally, turbo, or chemically]charged as well, they are just not lazy without it.
johnm
VIP MEMBER
Hi Mike,
Should be able to find some photos of the Peel faring in a few days. They are not on my computer so need to find them.
I got mine from Australia but it looks the same as the TGA one.
With modern tyres and riding techniques we found we needed to modify it. Firstly it ground very easily even when mounted as high as possible. This could also be from 18 rims and modern tyre profiles.
Secondly my bike was being ridden by a very good modern style rider and he found the top of the side panels and the outside of the faring over the handle bars were stoppping him getting forward and over onto his knee. So for the interim we had to trim it back.
For a perfect solution you would need to modify the mould to bring the faring in tighter earlier at the bottom and open up around the handle bar area to fit modern riding styles and tyre capability.
If I can find it I will post a photo of the NZ Lodge ES2 # 88 bike which has won the 500 Australasian Historic championship several times now. In my opinion this bike has the perfect faring match of stream lining and adaption for modern riding style for historic racing.
John
Should be able to find some photos of the Peel faring in a few days. They are not on my computer so need to find them.
I got mine from Australia but it looks the same as the TGA one.
With modern tyres and riding techniques we found we needed to modify it. Firstly it ground very easily even when mounted as high as possible. This could also be from 18 rims and modern tyre profiles.
Secondly my bike was being ridden by a very good modern style rider and he found the top of the side panels and the outside of the faring over the handle bars were stoppping him getting forward and over onto his knee. So for the interim we had to trim it back.
For a perfect solution you would need to modify the mould to bring the faring in tighter earlier at the bottom and open up around the handle bar area to fit modern riding styles and tyre capability.
If I can find it I will post a photo of the NZ Lodge ES2 # 88 bike which has won the 500 Australasian Historic championship several times now. In my opinion this bike has the perfect faring match of stream lining and adaption for modern riding style for historic racing.
John
For what it's worth, I put a JPN fairing on my BMW race bike. It went slower at Phillip Island with the JPN than it did with a Ducati 900SS top half fairing.
The JPN has quite a bit more frontal area and although I thought I was going in the right direction, it didn't work and I don't know why.
Maybe it keeps the heat in and the carbs get hot air and I lose power, or maybe there's a low pressure region just where the carb is,
I don't know but I took it off again. I think it looks really nice, but it makes it a pain in the arse to work on the bike and just wheeling it around the pits is hard because you hands are tucked inside the fairing when you're trying to walk along side it. Also you need very narrow clip ons which make it hard work hefting a heavy bike around tight corners.
Ducati fairing
JPN fairing
It's a shame it didn't work. I'd be interested in any theories.
The JPN has quite a bit more frontal area and although I thought I was going in the right direction, it didn't work and I don't know why.
Maybe it keeps the heat in and the carbs get hot air and I lose power, or maybe there's a low pressure region just where the carb is,
I don't know but I took it off again. I think it looks really nice, but it makes it a pain in the arse to work on the bike and just wheeling it around the pits is hard because you hands are tucked inside the fairing when you're trying to walk along side it. Also you need very narrow clip ons which make it hard work hefting a heavy bike around tight corners.
Ducati fairing
JPN fairing
It's a shame it didn't work. I'd be interested in any theories.
pommie john said:
Possibly because the JPN fairing was designed with the rider as an integral part of that particular package, and was specific to the shape of that bike. Not only that, but the airflow through the front of the fairing over the engine would be different. You would need to look at front and side views of how the rider fits behind the screen of the works JPN and also the seat unit was designed to smooth the air flow over the rider's back and hips. Two big cylinders sticking out in the breeze probably doesn't help either!
Did Norton duct air to the carbs, which are in a different position to the Beemer's?
pommie john said:For what it's worth, I put a JPN fairing on my BMW race bike. It went slower at Phillip Island with the JPN than it did with a Ducati 900SS top half fairing.
The JPN has quite a bit more frontal area and although I thought I was going in the right direction, it didn't work and I don't know why.
Maybe it keeps the heat in and the carbs get hot air and I lose power, or maybe there's a low pressure region just where the carb is,
I don't know but I took it off again. I think it looks really nice, but it makes it a pain in the arse to work on the bike and just wheeling it around the pits is hard because you hands are tucked inside the fairing when you're trying to walk along side it. Also you need very narrow clip ons which make it hard work hefting a heavy bike around tight corners.
JPN fairing
It's a shame it didn't work. I'd be interested in any theories.
I would try and fit 2 small plastic funnels on the front somewhere and run a rubber hose pipe from them to each carb bell mouth.
I have done this on petrol and diesel engines and get an extra “kick” at around 60mph but I did not change the jetting as the engine was not run flat out as on a race track.
This would confirm on top speed if the fairing is starving the carbs of air, but you may have to run richer main jets.
johnm
VIP MEMBER
You are certainly correct about the big farings being a P in A to move around in the pits.
On the photo of the JPN faring BMW is that the carb bellmouth sticking out from behind the faring?
Airflow over the carbs is something I would think hard about.
In fact the whole issue about carbs, airfilters, dyno results with carbs versus airflow at speed is all something I know basically nothing about and its all guess work and rather unsatisfactory. My bike has two big open bell mouths but knowing at least two bikes that suffered very serious damage due to large stones going in I really should do something about it. I won't of course and one day the inevitable will happen!!!
On the photo of the JPN faring BMW is that the carb bellmouth sticking out from behind the faring?
Airflow over the carbs is something I would think hard about.
In fact the whole issue about carbs, airfilters, dyno results with carbs versus airflow at speed is all something I know basically nothing about and its all guess work and rather unsatisfactory. My bike has two big open bell mouths but knowing at least two bikes that suffered very serious damage due to large stones going in I really should do something about it. I won't of course and one day the inevitable will happen!!!
johnm said:
Yeah that's the bellmouth you can see.
I went to the dyno, got 8 horsepower more, fitted the fairing ( which I had to bring on a plane from England 'cos no postal service will send anything that big) and it went 200rpm slower down the straight.
Sadly, Phillip Island is 2000 kms from my place so I don;t get there very often so I probably won't get to test it again in the near future.
- Status