• Welcome to the new B.I.R.D. Forum. Please be sure to read the "New Member / New Registered ? Please Read" thread in the Coffee Shop. This contains some important information. To become a full member ( £5.90 a year ) simply click on your user name near the top on the right I hope you enjoy the new site ................ Jaws ( John )

A whole load of figures ??

DLN1965

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Hi everyone

I would just like to pose a question or two..... Reference the 0 to 60 and the standing 1/4 mile

Ive read various conflicting reports what a bird can do, carbed versus Injection etc etc etc
Mine is injected 2000 model UK bike

So lets get the consensus

It depends on how you ride, any modifications AND conditions I know But what can be achieved IF all conditions are equal

Thanks
Darren:beer:
PS I have bought a smaller rear sprocket (42 teeth an original has 44) so in theory I should get 1.04 times top end AND 1.04 times more mpg and therefore should pay for itself within 8 months anything more than 8 months and I save !
But will place a slight bit more strain on the engine AND the speedo will be out a bit
Any Views ???
 
E

EdCBRCastrol

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You never know.......

The speedo might actually read the true speed now instead of the lies they usually tell.Dont know about 1/4 times on a smaller rear sprocket but i believe on a standard about 10.4 is achievable.
 

Jaws

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carbed version with huge tail wind 184.6mph thru the timing lights..
two years later EFI 174 mph in far from perfect conditions..
Both with fat bastard me riding...
can't remeber standing 1/4 times, but they would have been crap anyway with my reaction times being about .8 of a second most of the time :blush:
 
R

Red Baron

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Diddy sprockets

I think Darren could be on to something here. Jaws, can you make me a 6 tooth rear sprocket, that way I can do 350mph and go round the world on a tank full of petrol. Cool.:yo:
 

Jaws

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LOL !! At it happens, I have recently read an article in performing berks about this.. as far as I am concerned their basic premis is wrong as far as real world use goes..
I shall be doing some maths and showing figures when I get 5mins.
It is not that their figures are wrong at all, just that I have thought about this before and did some experimenting...
 

DLN1965

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The Theory behind this....IS......

I had a Triumph Trophy before my bird and I wanted more MPG
So I tried with a smaller rear sprocket and BINGO
More MPG, MORE top end, cruising at lower revs :yo:
BUT As I NEVER raced OR went too quickly (cruising at a ton was easy enough) The engine never was under too much strain

SO...Me thinks to try the same with my Bird....A little phone call to MPS and a new Fireblade 92 to 95 OR a NEW hornet has the same sprocket with 2 less teeth

TA...DA....!
I don't gain much on the mpg as the speedo reads at the engine (so quick calibration in my head) In theory I get 1.0476 times more MPG and speed for the same revs

Again as I dont let rip and therefore the engine is not under too much load and AT THE MOMENT I have had no adverse effect

However I did read that no more than 4 teeth difference at the rear sprocket OR 2 difference at the front sprocket would cause problems

ANY VIEWS Jaws ???(The font of ALL knowledge)
I am sticking to this for now
Cheers
Darren :beer:
 

Jaws

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it really is a total mine field mate..
What must also be taken into account is that if you tend to leave the bike in top gear and do 'roll on' overtaking, chances are you will use more gas as the lump will have to work that much harder, but in general, and in the real world we live in ( not some hyper performance world of the jorno ) I am with you Darren.
Like I said in an earlier post, I am gonna have to sit down with the slide rule and do some serious math !
At the moment I aint got a lot of time to spare, but rest assured if I get a quiet moment I will do the biz :-:
Oh, and could not agree more re the speedo becoming more accurate if you gear the thing up. Average outage on most Birds I have ridden is 10% right across the board.. So a 11.12 % rise in gearing will put speedo about right ! R#?
 
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