Forum

[Steve T]

😎

[Steve T]

[Reg]

Just to add my tuppence-worth. I recently fitted our hosts gearbox cover stiffener kit which made a remarkable difference to the riding experience. Oddly, after fifty years of throttle-blipping on the downward change, I have now given this practice up and find the change much sweeter.

[jefrs]

I always blip the throttle changing down even though I have absolutely no need to do so - it makes a lovely noise 3:)



A synchromesh has little sprung dogs sideways between the drive cogs (it's so very simple) that spins up the shaft so the cogs engage without a nasty grinding. But bringing the motor up to road speed on the down shift by opening the throttle is not so you don't mash the gears but so the clutch can engage without undue friction, and tossing you over the bars.

[Dennis C]

Perhaps it's time for you to actually look inside a motorcycle gearbox?.

[papasmurf]

Jefrs there is no synchromesh in an Enfield gearbox.

[Dennis C]

Yes indeed papa, in fact the cogs don't engage at all when you change gear they are constant mesh and dogs on the gear sides engage. A synchromesh gearbox has a spring loaded cone shaped clutch which engages before the gear to bring them to the same speed, but our friend will be back with more utter rubbish to prove we are wrong as usual.

[simon]

Im up to three years now of faultless changes. My 90's 350 bullet motor clips in and out of gear hot or cold without a problem and i pretty much never miss a change. If your gearbox cover flexes then you need to stop it with a stiffener. Even if it works ok when cold it is likely to get hot and bind up even if you avoid sitting at the lights with the bike in gear. The other coup de gras for the ultimately well tempered clutch is to put in the cork lined plates that can be had for around £5 a pop (3=£15). This allows more ajustment as they are thinner than the ferrodo ones fitted. They also take up more gently and so stop the sudden lurch at the then end of a clutch release. I hear people saying that these clutches are just a bad design ir that they never work It is quite true that the quality of manufacture varied considerably over the years but the design is sound and if properly set up both the clutch and the Albion gearbox are fine.

[another Allan]

Proper adjustment is a given. However, what is 'proper?' The problem seems to be rooted in a lack of lift (separation) of the clutch plates. I believe that the 500 is likely to be worse in this respect, because it has more plates than the 350 and needs to accomodate an extra 'gap.'

If the clutch pushrod expanded due to heat, as has been suggested, it would take-up the clearance in the system. IME, the opposite happens, so I see no future for us in silicon balls.....
I have found that the free play in the cable increases in traffic, presumably because the plates expand when hot (again, the 500 is likely to be affected more than the 350.) Therefore, I set the free play to an absolute minimum (when everything is cold.) As I ride the bike and the clutch plates heat up, the clearance increases so that there is no undue pressure on the actuating mechanism which can cause wear.
Then, add to that the Hitchcock's gearbox cover stiffener (designed by a member on this forum) which enables another 2-3 mm of lift.
Then, throw away the dog-leg clutch lever. The maximum lift of the clutch and separation of the plates is restricted by the kink in the clutch lever coming into contact with the mount/perch; back-off the cable at the lever and see what I mean. Therefore, find a suitable non-dog-leg clutch lever and you gain at least 4-5 mm more lift. I bought a used lever off Ebay for a couple of quid including postage. No idea what it was from; I took a chance and it just needed a bit of filing for it to fit perfectly. It is a plain alloy finish, rather than black, but it works a treat! Those of us with a bike breaker nearby could take the guesswork out of sourcing a suitable lever, by matching the Enfield one with whatever the breaker has in stock.

[simon]

My feeling with the loss of clearance with heat is that the driven plates tend to buckle when hot which then reduces clearance the amount of metal expansion is I believe negligable. The secret is to stop it getting hot in the first place and as stated clearance is the key. Ive pulled a clutch that was ovefheated to bits and the driven plates were all over the place. A gentle beating with a hide hammer on a flat wooden surface and they were fine again but only until the next ride. I generally dont set mine up with more than nil loose clearance and as I have a fifties styled bitsa it has Doughty styled levers. Never understood the logic behind the kinked ones. With Doughty styled levers you can opt for different perch heights the ones on mine are 7/8" but 1" are available as are even taller ones. Clearly youll be limited at the clutch end but you need to take all you can get.