I recently purchased a ST Locoblade and have noticed that the clutch is, at best, tricky. I know this is an inevitable consequence of a bec but I feel
mine may be worse than it should be. Very snatchy with loads of travel but only a couple of inches (if that) of it around the biting point which makes
it pretty hard to catch and hill starts are 'interesting'. Already I have become much better at it and have stopped stalling every 2 minutes but I
still seem to need an unhealthy amount of revs. I also find, if you have to do a few starts over a short space of time, it will start to slip quite
badly until you give it a few >10,000 rpm upshifts then it seems to rectify itself.
Any recommendations on the nature of my issue or resolutions to it? How can I get more feel into it and is the slipping due to my overenthusiastic use
of revs when pulling away?
I have an inkling that moving the cable to the additional hole on the bottom of the pedal (below the pivot point) will increase the amount of travel
on the cable when I depress the pedal and, therefore, will give me better control (or will it be the opposite?) I can't quite get my head around which
way it will go - I should have listened more in physics...the law of levers....magic.
Any help much appreciated.
For what they cost it may be worth getting some uprated springs from TTS, if you carry on slipping the clutch it will soon need replacing,
without trying it myself its hard to say, but after a couple of hours driving stalling should be thing of the past so you may well have a clutch
problem,
do you know any local BEC owners, get them to drive it or you drive theres for a comparrison,
10000 rpm starts should not be req'd, i can pull away on little more than tick over,....
probably no help but all i can add without trying it.................oh, if your using the clutch for upshifts try without, most BEC drivers only use
the clutch for pulling away and downshifts.........
A couple of things spring to mind, which may or may not have anything to do with the condition of your clutch:
1/ Is there any slop in your linkage?
2/ What lever ratio has your clutch pedal got?
I concur with what Jon says about the clutch itself. As the poor clutch is having to haul around a machine many times heavier than it was designed
for, you have to give it a fighting chance. Even if the clutch plates aren't buggered yet, they soon will be if you continue to let it slip.
First establish if your pedal/linkage are correctly designed and functioning. Then check if the plates are worn/warped, and replace them with uprated
ones if necessary. Fit uprated clutch springs.
Bike boxes use dogs for selection, not synchro rings, therefore, the clutch should only be used for pulling away or stopping. There's no point trying
to use the clutch while shifting up, as the gears are pre-engaged, and it's the dogs that actually "pull" the gears into mesh.
If you use the clutch while downshifting too, you stand further chance of damaging the selector forks/drum/ dog teeth.
The secret to slick changing a dog box is knowing when to unload and change. I've read on another forum, where loads of BEC owners are frequently
destroying their boxes, because presumably they drive them like their "other" cars.
I thrash the knackers off a ZZR1100 motor in an off-road buggy, over jumps etc, and haven't had any problems, though admittedly, I have an undercut
box (Only done a year or so ago), but I run a bog standard clutch, simply because it is seldom used.
Cheers guys.
I will investigate the springs and plates.
I am using about 3k rpm to pull away at the moment but this may just be me being club-footed (having had my abilities adled by driving a Ford Escort
for the last year!).
Hopefully, this will come down but the lack of feel is slightly disturbing - at lower revs I find the biting point fine but then it feels like (in
terms of pedal movement) it is only a few millimetres before the clutch is out and she stalls.
These clutchless upshifts - I know this is the way but I still have fear of some almighty gear-crunching (having only had about 3 hours in the beast).
I take it this is best done only in the 7-11k area or is it irrelevant?
I've found it doesnt really matter where in the rev range you do the clutchless upchange, but the best method is to put a little pressure on the lever
just before you want to change, then lift off and you should feel it naturally snitch over into the next gear with only a little more effort.
Chris