Quarter Mile ETs, forum members

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But we knew that 20 years ago , or more . :p :( And , the BRITTEN has a carbon fibre / kevlar frame , But it hasnt got a frame . :lol: 8) NOW , What was the QUESTION .?

1960 Build Bonneville , clapped out , did a 14.5 . 1951 A10 , vaves recessed 1`/8 in in small fin iron head from heat from 10:1 pistons :lol: did a 16.9 . UNFORTUNATELY
never did a measured / timed Quater mile on the Commando , think the XS11 was the only thing I dragged against too . . . such a lonely life then . :shock: :wink: :oops:
 
Its the Goldilocks question. How stiff is too stiff, how flexy is too much and where and how they might blend to bend or not the best. One thing I liked about some bending is at some point it seems to allow using the forks to press the rear down on edge grip harder. Have you heard about Yamaha' Power Bar to tame chassis flex into heat? I'm addicted to corner flings, you know my tool of choice so sharpening it up to play down and dirty.

A really weird thing happens with Peel that reminds me of compound bows more that sling shots, there's a point of tension the forces to hold it drop, then can hold it a long time till time to release.

Quarter Mile ETs, forum members
 
FULLAUTO, I never claimed that my old XS750 tripple or my CB750F SOHC had better handling than a Norton. I was commenting on the Ice Speedway youtube clip that was posted a couple of frames earlier. That clip made me think of my Dad during his racing days, then my reckless late teens/early twenties years doing tripple digits on public streets with grade level cross traffic. I think you're confusing me with someone else posting about pre unit vs.unit construction. Cj

"fullauto wrote: Yep those two would have had AWESOME handling compared to the rubbery old Commando.
THEY have unit construction.
 
Every body knows a wobbly old rubber Commando can't run with a modern unit construction bike. He He.

This is a year end finish on a rubber Commando in Supertwins in 2001. I was the only one riding on DOT tires. Competition was SVs, Ducatis, Hawks, Buells and a couple hot rod Harleys. Amazing that an old rubber bike could keep up huh. Jim

PS, I got 3rd the next year on slicks.

Quarter Mile ETs, forum members
 
hobot said:
Further insights on super rigid vs too flexy. Wonder if there's a Goldilocks compromise?

Frames have not been constructed of carbon fibre previously because it doesn't flex enough, and the dynamics of motorcycles have made good use of the frame flex offered by metallic frame construction. As the metal frames have been stiffened, motorcycle race constructors have found that the natural harmonics of the frame material can influence many factors, often introducing wheel chatter and other destabilising vibrations. The harmonics of the frame is responsible for a lot of the problems race engineers encounter while setting up a bike to perform at its optimum.

As John Keogh, the most knowledgeable journalist on the subject of carbon fibre usage in racing motorcycles wrote, Mamola and Haslam found “the suspension set-up and feedback from the carbon frame so fundamentally different that their normal bike adjustments and suspension settings no longer worked and that the bike raised more questions than it answered.”

Lots more in here.
http://www.gizmag.com/ducati-desmosedic ... ion/11456/


Better tell that to Ducati...............and of course Armstrong who successfully used composite frames many years before Ducati tried them.
 
Fullauto said:
cjandme said:
My Pops , Used to race speedway back in '47-'48. But said that he wouldn't race on ice, can't say that I blame him, those studded tired look wicked. He said that most tracks that raced at were 1/4 mi. Harringay,Norwich,Yarmouth & Wembly, he said that Westham was 1/2mi. His ride was a J.A.P. 500 with a clutch and a countershaft. I only ever did street racing ('77 Yamaha XS750 triple & '78 CB750F-punched out to 828,balanced & blueprinted, mikuni smoothbore carbs with K&N air filters & a Kerker header) looking back it's a wonder that I didn't kill myself. Cj

Yep those two would have had AWESOME handling compared to the rubbery old Commando.

THEY have unit construction.

Anyway, it's 4:45 on saturday morning and I'm just going out to load my rubbery old Norton up and do the equivalent of a John O'Groats to Lands end run for the weekend. Sure hope I don't fall off because of the crappy handling.


To confirm your rather curious understanding of best practice "engineering", I wonder if you could let everyone know which machines are today produced using "superior" pre-unit construction?
 
I do actually consider the chassis could be developed for a degree of extra ridgidity . Presumably the Rickman , being of larger dia. chomemolly tubeing , with a ridgidly mounted powertrain is
noticeably faster and more stable in demanding conditions . ?

The tour down the back lane Video posted today resembles a Kiwi Road , other than in N.Z. it was considerably more undulateing , had a few bridges , Was chip seal with only a few repairs ,
and had a few places where the Cows Crossed . Who Flung dung . You could fell what apeared to be the rear axle move to the left into one lefthander in particular . General technique was to
thread it down the road , mainly through lean . As milk tankers , mad farmers , or the odd Tractor could appear unexpectedly if you wernt vigilant . 4 x 4 low Orchard sprayer doing a 4 wheel
drift , exquipped with four tractor tyres , the drivers cabin slung near ground level fwd of the front axle , useing the entire road , would have cleaned me up on the two trickyer corners one
sunday , on a 20 mile ride ' round the block ' on a cool autumn day. Him takeing the opposite / head on course , had I not taken head of a ' funny feelin ' into the blind corners .Was left with a foot at the verge useing evasive action . Ruffled the first time , I was put out the second . But the local school bus & cattle trucks used the entire road on the gravle roads , so one tended to be wearie .
attempting to use ' youre lane ' youd end up as a hood ornament . :(

The Commando preferred the city Isle of Man like roads , through the bays ( and over the peninsulars in between ) , The ancient Bonneville more at home out of town , as it was generally rortyer and
mischevious , and relished high speed on the gravle , wet clay had no grip though , where the gravle had wased off . All sealed out there now , and most of the bends in the highway straightened out and ruined . The local hero thought his 11 minutes to kaiwaka , 16 kilometers unbeatable , in his Mitsibushi Gallant GTO 1850 .
A timed run on the Bonneville was eight , not wasteing any time , but exerciseing the usual caution . Getting a bit more entusiastic mightve knocked a minute off that , or addopting his gung ho aproach two , more likely to have had irrevocable consequences , or end up out in a paddock somewhere after going through a barbed wire fence though .


The Bonneville on the smooth twisty road out past St Heliers , two up with the 4:10 /19 TT100s would swivle the swing arm on one or two bends . It was mounted on the seat post , like a universal joint
Just a twitch and run back in .Would take a warm day and determined effort , over and power on . The sensation not unsimilar to that mentioned earlier re the Commando .
At times you were very concious of the three point mounting of the power train , but ordinarily the comparison was comparable to a 20 ft telegraph pole running trough the axle lines , fore and aft
with you centre . Youd lean it into / trough bends and had the sensation off that effect through the contact patches . A slide was allways a two wheel drift , when leant over .
The slack induced with the ISOs loosened to 5 thou , would have me reshimming ASAP . The two wheels starting to seem to have seperate courses .Id found 3 to 4 good, 2 1/2 to 4 1/2 Max .
The frame and all was straight and Id checked all alignments , so had no binding at tight settings .A few that had less than exact frames wouldnt shim in close without binding .
 
cjandme said:
FULLAUTO, I never claimed that my old XS750 tripple or my CB750F SOHC had better handling than a Norton. I was commenting on the Ice Speedway youtube clip that was posted a couple of frames earlier. That clip made me think of my Dad during his racing days, then my reckless late teens/early twenties years doing tripple digits on public streets with grade level cross traffic. I think you're confusing me with someone else posting about pre unit vs.unit construction. Cj

"fullauto wrote: Yep those two would have had AWESOME handling compared to the rubbery old Commando.
THEY have unit construction.

Sorry mate, I wasn't having a go at you. It was aimed elsewhere. Apparently my Commando couldn't possibly handle better than anything with unit construction. I was merely pointing out that quite possibly Commandos handle better than quite a few unit construction bikes. No offence meant in your choice of bikes. I have just returned from a 700 mile weekend and enjoyed every damn minute of it. It didn't try to throw me off once.
 
Carbonfibre said:
Fullauto said:
cjandme said:
My Pops , Used to race speedway back in '47-'48. But said that he wouldn't race on ice, can't say that I blame him, those studded tired look wicked. He said that most tracks that raced at were 1/4 mi. Harringay,Norwich,Yarmouth & Wembly, he said that Westham was 1/2mi. His ride was a J.A.P. 500 with a clutch and a countershaft. I only ever did street racing ('77 Yamaha XS750 triple & '78 CB750F-punched out to 828,balanced & blueprinted, mikuni smoothbore carbs with K&N air filters & a Kerker header) looking back it's a wonder that I didn't kill myself. Cj

Yep those two would have had AWESOME handling compared to the rubbery old Commando.

THEY have unit construction.

Anyway, it's 4:45 on saturday morning and I'm just going out to load my rubbery old Norton up and do the equivalent of a John O'Groats to Lands end run for the weekend. Sure hope I don't fall off because of the crappy handling.


To confirm your rather curious understanding of best practice "engineering", I wonder if you could let everyone know which machines are today produced using "superior" pre-unit construction?

I am not the one with "curious understanding". I live in the real world where I have a motorcycle with a bunch of qualities that suit me fine. Every motorcycle on the planet is just a collection of compromises. My motorcycle's compromises I can live with for the rest of my riding life. Pick a modern motorcycle which is as close to perfect as it gets (in your opinion) and I'll bet I'll find it wanting in many areas (in my opinion).

You know, I've never read what motorcycles you currently own.

Whatcha got? Really that is, not hypothetically.
 
1up3down started this thread by asking about Commando quarter mile times, not how they would do against modern bikes.

If you watch xbacksideslider's excellent on-bike camera video, he shows that a 40 year old street Commando can travel quite nicely along a twisty stretch of road. A Commando doesn't have to be pitted against modern stuff to prove itself but I would bet it would hold its own against stock Japanese machinery from the early 70s. This is where comparisons are valid. I have ridden all of the Commando's competitors from back in the day and I would happily take a Commando over any of them.

As far as unit vs pre-unit is concerned, I suggest that the quality of the chassis and suspension are more important. G50s and Manxes are pre-unit but my experience tells me they can track as well as a modern bike at comparable speeds. The proof of the pudding is in the eating.
 
Thanx for the entertainment of the vintage racers on all surfaces, but pahaw they are all on dedicated specialized cycles for each type of event. I personally found a way to have a C'do do it all but for lack of power to make a mark in the bee line sections. Speedway and flat trackers on dirt/clay/gravel/pavement are still limiting themselves to counter steering and feel so insecure these famous experts all put a foot down because they know how unstable wiggle worms they are thrown sides way. Not needed on a really truly Neutral Handling rubber baby buggy with double+ the load tolerance by over lapping linked together frame and power unit.

What works for drag racing is tucked down low especially the front but that shoots the cornering capacity clearance to death. Oh yeah and lots of power on tap to hook up w/o flying up.
 
1up3down said:
Just curious what any of us went through the traps at, presumably in our youth?

In 1972 I had a 750 Combat, standard 19 tooth countershaft, with a Dr Blair 2 into 1 into 2 exhaust, and had the rocker arms lightened and the inlet and exhaust ports "flowed" cleaned up. My bike was in top shape, I was a sea level, and I weighed 125 pounds then.

My best 1/4 mile time at the local dragster, after five passes, was 13.4.

I am NO highly experienced drag racer, but I was well coached and had over 20 runs on previous Commandos to give me some experience prior to my 13.4.

26 years later I owned an air cooled two valve Ducati 900 "Monster", and first pass clocked a 13 flat, bone stock.

Four years ago on my Honda ST1300 700 pound luxury tourer, I did a 12.8 quarter mile.
Two years ago on a 20 year old Honda 600 I managed a 12.2.

To return to the original post, here is an easy and cheap mod that would take a couple of tenths off your time.
This has worked on both petrol and derv engines.
Fit a small plastic funnel to the front of the bike and run some small bore heating hose to the airbox or bell mouth for each carburettor.
This will give a slight kick from about 60m.p.h but, if you do the full bore/throttle you may or may not need to rejet your carb.


Disclaimer!!!
If you do the full bore/throttle you may or may not need to increase the mainjet of your carb(s)!!!!
 
hobot said:
Thanx for the entertainment of the vintage racers on all surfaces, but pahaw they are all on dedicated specialized cycles for each type of event. I personally found a way to have a C'do do it all but for lack of power to make a mark in the bee line sections. Speedway and flat trackers on dirt/clay/gravel/pavement are still limiting themselves to counter steering and feel so insecure these famous experts all put a foot down because they know how unstable wiggle worms they are thrown sides way. Not needed on a really truly Neutral Handling rubber baby buggy with double+ the load tolerance by over lapping linked together frame and power unit.

What works for drag racing is tucked down low especially the front but that shoots the cornering capacity clearance to death. Oh yeah and lots of power on tap to hook up w/o flying up.


As you seem to be a better rider than just about anyone else on the planet, it would be interesting to hear full details of all the successes you have had in competition over the years?
 
Hobot, would mind changing your avatar picture from a Norton crashing to something else?

Personally, I find it as offensive as your previous avatar of your Norton on fire.

Obviously, you chose it presumably because you think it is somehow cool.

You have that right.

And I have an equal right to see a Commando on fire or crashing as repulsive, and without any redeeming "point"
 
Maybe a pic of hobot in the process of doing the feet up figure of 8 donut he suggests he can easily do, would be more appropriate? Thats a pretty difficult move, and he needs respect if he is actually able to pull it off!
 
Carbonfibre said:
Maybe a pic of hobot in the process of doing the feet up figure of 8 donut he suggests he can easily do, would be more appropriate? Thats a pretty difficult move, and he needs respect if he is actually able to pull it off!

It's really easy for you to put sh*t on other people but you can't even tell us what bike you own and ride. I suspect you've never even ridden a Commando, let alone own one.

Hobot, keep doing what you do and I for one want to hear all about it. With pictures.
 
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