Norton number 3 fly press

Hi All

I have a small fly press if anyone wants it, asking price collect only, needs cleaning but it's yours if you want it.

Where can I get a good liner made as I need one for my new motor, advice appreciated.

On the subject of equality of weight, I seem to remember the mention of this when I wrote a post regarding JS and Mike Bridges at Cadwell, same bike, same conditions, Mike was quicker in his race and a good 2nd to Mike Cashmore who had 8-10mph on john in his race, mike being a lot lighter therefor the bike had less weight to carry.

All the best
Les 2012.

Hi Les ... 'scuse me for going a wee bit theoretical but it's the  acceleration  as well max speed that makes faster riders, winners when on the smaller capacity bikes... 

...the formula,     (Accelerating)  Force(F)  =   mass(m) x acceleration(a)  -- can be wriiten:-

              a  = F/m and when we put m = w/g ,  the equation becomes:-  

              a  =  Fg/w ----- Where w is the total weight of rider and bike.***

                so if (w) is ´LARGE (a) will be small  and the smaller(lighter)  bloke wil be quicker during acceleration...

    The (i)acceleration force  -- or force of (ii) deceleration when you hit the deck -- can be expressed as fraction of g and in the latter, as say, 2g -- then it really hurts..


I once published the difference in acceleration of riders of 10 stone to 12.5 stone with bikes also of increasing weights and it proves the point of that matter you mention.
Scrooge was about my weight which meant we battled frequently....

*** the skinny. liitle blokes will argue that the w difference is small because the rider's weight compared with the bike´s weight is small but a small minus in acceleraion shows up big when racing.

You are porobably well aware of the theory above and I apologise for being a such a boring AH...!!?.
Cheers!
JayBee.

The equation actually looks better as   F/m   = a  .....

   which is Fg/w  --- or fractions of g -- as accelertion....

... and with assumed riders weighing 20lbs different in the three cases  plus a constant  bike weight of rider plus bike  and cnstant force at the rear wheel contact patch , "w"  could well be,  (1) 300lbs,  (2) 320lbs &  (3)340ilbs  

Assumed values for F1 at 160lbs force, in 1st gear;  F2 at 120lbs force, in 2nd gear;  & F3  at  88lbs force, in 3rd gear.

Usingh 14, G/Box  x 48, R/Sprkt teeth  -- with a first gear of 11.78:1; a 2nd cear of 9.06:2;  and 7.66:1 for top...

the accelertion in first for (1) will be 160g/300  =   0.533g =   17.1ft/sec.ft/sec ....
                                  (2)    "  "  160g/320  =   0.5g    =    16.1 "     "
                                  (3)    "  "  160g/340  =   0.471g =     14.1 "    "


Which means, FOR EVERY SECOND accelerating in 1st gear -- on the straight & flat --
     (1)  "Skinny Dwarf"  is going to be 1 ft/sec faster than (2) "Fairly Normal" and 3ft/sec faster than
(3) "Chubby Chap " ....

 Which means,  in say 4 seconds on the straight and flat:_
(1) is going to be 4 ft ahead of (2) and 4 yards ahead of (3) when accelerating in 1st gear........


I have left the calculations  for 2nd & 3rd gear to those who might want to ....?? The amounts will be less in the two higher gears but it can be seen that Skinny Dwarf has a positive advantage when accelerating out of a hairpin bend requiring first gear etc... etc....  where Chubby CHap could never make up that bit of deficit no matter how hard he scratched!!

Cheers!

JayBee.


!

John formulas algebra etc are wasted on most of us but even a muppet like like me can appreciate it's a power to weight ratio thing.

Nice to hear frpm you again Ned...

I was just trying to say that if I hadn't have had such a propensity for nosh and a few beers I might well have been a senior more often.

But I enjoyed all of it anyway -- even having to attend The Hoop & Grapes as Chairman as you yourself know
.... I was always envious of the BRC Magazine during your time in the Chair and regretted not doing something similar but its  easier to be judge after the event....  

The third differential of weight to power is called pulse which is the accelertion of an accelertaion where g force gets quite  painful!  

Go well and keep well, Ned,

Cheers!