* LS, which appears to be Trials: only the constant mesh (4th.) gears differ from the HS.
* TT gears as fitted to competition models.
Post war, only the HS ratios seem to have been
manufactured, and as we know, the Flash used the Albion box, for which
a wide selection of gears were available. I do not consider either
the HS or TT gears were really the correct ratios for their respective
uses. It would, of course, be possible to redesign each set, which would
probably mean replacing virtually every gear in the box. However,
for road use, there is an interesting compromise based uniquely on pinions
which once existed: to use the standard 1st. and 2nd. pairs which presumably
exist in your present box, in reasonable condition, with the TT 4th. and
3rd. pairs of gear- that is, changing 4 pinions. This would give
ratios of 1:1, 1.16, 1.45 and 2.3, or 100, 86, 68 and 43%.
Bruce McNair 2/9/02
Pre-war Burman Transmission
spares list:
http://www.btinternet.com/~paul.wirdnam/sq4/1930/burman_frameset.htm
If this symptom can not be cured by adjusting the selector mechanism then the cast alloy block G49 needs opening out with a file to allow more travel. Check that this is infact the problem by carefully adjusting G57 stoplate adjuster so that more movement of G81 is required to engage both 3rd and 4th gear.
This will prove the need for the block to be opened out - a fairly simple job with a file and G49 in a bench vice 'a little at a time' till you have the right amount of travel - being careful to remove the metal off the place on G49 that stops the travel of the gear lever or maybe a little off both stops with G57 in the centre of its travel ( to make allowance for future adjustment). G49 has a concave shape where the metal has to be removed - there is no need for this shape, a flat surface is all that is required to limit the travel of the gear lever.
I have had to carry out this job on at least 3 separate bikes after which the gear change has been transformed - having giving the gear lever just that little extra travel.
I have also discovered the importance of adjusting the battery carrier
nuts E80 to compensate the load on the pivot bearing plate G50 when the
foot rest hanger bolt is nice and tight for a really nice gear change.
If there is any stiffness in the gear change when the engine is hot - try
slackening off the hanger bolt just to see if this is the adjustment needed.
If so, adjust
the 2 E80 nuts outwards and pinch up the foot rest hanger bolt again
and carry on riding.
Andrew Rackstraw 8/14/00
Even if you have as you say NOS parts or good condition parts in the
box, this is not a reason to say there is nothing wrong.
So what you have to do to check out the set up ,is to remove the detent
and visually check if the camplate is in position, when the box is
in second gear. If it appears to be, replace the detent spring, and
test ride. If the problem still occurs you have a problem with the
set up. The only way to check then, is to use my checking fixture and sort
out the problem. I won`t
begin to tell you what could be wrong. I`ve lost count.
Trevor 6/16/00
Many - even most of the Vincent
motors we have delt with in our work lack one small but
extremely valuable Works up-grade dating back to the very early years
. A simple looking alteration first suggested by one of the
fine road-testers active then , one Bob Brown . Very
keen and dissatisfied with the tendency to over-shift present
in too many units that he rode -Bob came up with the notion
of adding restraining tabs or ears to both sides of the
pawl carrier centralizer plate G 61 . This became G 61 /1 with the
addition of two projecting motion stops brazed one to each fore and
aft edge . So utterly simple it seems, yet properly positioned truly
worth more than its weight in Gold ! Perhaps because it is not so drawn
in our B/C Parts Books yet carries the corrected part
number. Few have picked up on it and the magic it performs . My first
exposure and explanation came to me way back in 1953 while shoping at the
Works Spares counter where the modified piece was handed me
and called the Bob Brown Special! Friendly chap behind the counter
there confided that Id surely want one of these as e/ dropped it into me
waiting hand. There is a subtle touch to getting it swung just so
in order to derive the best results out of those metal stops that
Ill try to convey to you my friends . Not easy ! The aim is to snub
off excess inertia / momentum imparted to the spinning cam plate
during a too spirited shift . This energy tends to rotate the plate
past its next notched position -- forcing excess rotation to drive
the plate - lifting the indexing plunger up out of that desired
notch and so allowing further rotation towards -or into the following
ratio selection . Over selection results . My experiance when fettling
these pieces is to allow the ratchet to closely approach -
not enter fully - the up comming notch .
Notice my word choice carefully . Closely approach only and NOT fully
enter the cam plate notch. Thus the tab contacts and acts to slow/snub
off the excess speed , to where the spring driven detent plunger
can take over control and deliver
sweetly to the bottom of the notch , that unwanted momentum
already absorbed in the slight flexing of the arresting stop . Only
the spring pressure remains to fully seat the plunger into its homing
notch . Barely any of the shift lever thrust and rotational
energy exists in the plate as it enters the edge of the notch slope
. Duplicated in both directions and I've seen very little
need to bend the stops much , and the shift becomes dead reliable
and pleasing beyond words . Much of the ease and sweetness is dependant
on full clutch release, and I shall delve into that clouded subject
in my next effort , however let me say that after all
these decades I am still and ready to prove that the original Vincent
clutch can deliver better feel and function than a multiplate
conversion for greater mileage and less parts wear than any
in my experiance .
Cheers! S.M. Biberman
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