Author Topic: Competition Dragonfly gearbox?  (Read 4632 times)

0 Members and 1 Guest are viewing this topic.

Offline Doug

  • Administrator
  • ****
  • Join Date: Mar 2004
  • Posts: 4323
  • Location: Glen Mills, PA, USA
Competition Dragonfly gearbox?
« on: 21 May 2008 at 01:20 »
Seen at a recent USA motorcycle meet, was a Dragonfly with a curiously stamped gearbox-



Stamped "COMP RATIO" as seen here in close-up-



For real, or somebody's idea of a joke? A clue might be that which was stamped at the far end-



Which looks like the date and the initials of the owner that carried out the modification.  Registration is TYP 779. Anyone know its story? It is in the LDMCC register, but apparently has been stateside for a while.

-Doug

Offline eddie

  • Master Member
  • ****
  • Join Date: Mar 2006
  • Posts: 1715
  • Location: Hampshire, UK
Re: Competition Dragonfly gearbox?
« Reply #1 on: 21 May 2008 at 06:31 »
Some of us in the Douglas club do some weird things, but a Dragonfly for trials? - even I'm not that daft!
      Seriously though, when the Dragonfly came out, it was a heavier machine than the previous Mark model, but had slightly higher gear ratios, so getting away from a standstill required a little more slipping of the clutch. If this was combined with living in a hilly area, the owner may have fitted the lower ratios for 1st and 2nd to give the clutch an easier time. The only disadvantage would be the resulting wide gap between 2nd and 3rd which dictates a lot of revs in 2nd if the engine is not to go 'off the boil' on changing up.
      The change of ratios should be straight forward, providing there is room in the box for the larger pinions (genuine Comp boxes were machined to give more clearance than a standard Mark box). Also,the depression in the top of the gearbox (to clear the bottom of the carburettor) could make assembly more complicated, as the complete gear cluster probably wont feed in from the front end, requiring the gears to be stacked against the rear bearing before inserting the main shaft.
       It would be interesting to find out the real reason for this modification - so Doug, can you give us any more details?, such as where this meet took place (the US covers a large area), then we can do some detective work and, hopefully, find the owner and the reasoning behind the mod. It would seem that it was done methodically, as the owner had marked the box up with the details and date - perhaps this was only one of many experiments!!

                              Eddie.

P.S.    Could G V E   refer to   *********  Vintage Engineering?

Offline Doug

  • Administrator
  • ****
  • Join Date: Mar 2004
  • Posts: 4323
  • Location: Glen Mills, PA, USA
Re: Competition Dragonfly gearbox?
« Reply #2 on: 21 May 2008 at 12:30 »
Eddie,

I should add that in all other respects this Dragonfly was in standard condition, no knobby tires and high-level exhaust systems! It looked as if it had been restored some time ago, right down to the Pride & Clarke badge on the front mudguard,  and kept in very good condition since. I will see about getting an overall picture uploaded later today.

The bike belongs to an acquaintance, who had it along to the mid-April AMCA meet at Oley, Pennsylvania (eastern PA, near Reading.) He bought it locally off a collector, but prior to that it apparently had been in the American southwest.

-Doug








[images added, 21may08, Doug]
« Last Edit: 22 May 2008 at 02:55 by Doug »