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BEC - Very Light Clutch
Jeano - 10/7/15 at 08:31 AM

After a week of owning my ZX12 Dax i find the clutch so difficult as it is so light and the clutch needs adjusting.

Can they generally be adjusted and are they generally this light?


INDY BIRD - 10/7/15 at 08:40 AM

yes they are normally very light and can be like a trigger, remember this was on a bike for hand operation, not ideal for road use or in traffic thoug,

i presume it is cable operation?

if so you could alter the point where the cable attaches to the peddle to alter the ratio etc but don't think there is much on the dax peddle box as there peddles are longer and a better ratio for brakes etc, but clutch can be light because of this


DRM Black7 - 10/7/15 at 08:43 AM

They are Light, took me a few days to get used to driving mine again.
But as long as the travel feels correct (ie no underlining problems) you could fit heavy duty clutch springs.
I've got a set ready to fit to my Blackbird engine
Think most people agree the Barnett ones are the better ones, couldn't fine any for my engine so went for EBC from TTS.

[Edited on 10/7/15 by DRM Black7]


smart51 - 10/7/15 at 08:46 AM

I found mine best when I moved the cable as close to the pedal pivot point as it would go. It was still very light. But it did give a little more pedal travel at the biting point, which gave more control for slow gear changes.

I put a 2mm thick washer behind the springs on my Barnett clutch too. It put a bit more preload on the springs, giving a bit more weight to the pedal.

[Edited on 10-7-2015 by smart51]


Jeano - 10/7/15 at 08:51 AM

im not in the mood to disassemble to fit clutch springs but may do it in the future, i have an adjustable pedal box so will look at bolting the pedals closer and seeing if i can adjust the biting point location on the pedal also.

Its literally just pulling away. Im fine just pulling away slowly and i struggle a bit if not a slope, guess this is normal by the sound of things, i want to get used to being able to pull away a bit faster at junctions for safety but i guess thats practice. Its nice learning to drive something tbh


DRM Black7 - 10/7/15 at 08:52 AM

That's a good idea with the washers the EBC springs are only 10% stronger


minitici - 10/7/15 at 09:00 AM

How about fitting a gas spring to your pedal to make the pedal have a bit more 'feel' whilst retaining the overall pedal travel?


adithorp - 10/7/15 at 09:20 AM

Generally you have 2 choices with a BEC clutch. You can have a light clutch with a longer travel allowing plenty of control at the bite point... Or a heavier clutch with little travel giving a very binary clutch (it's either on or off) thats easy to stall.

Lots of mechanical advantage by moving the cable or pushrod close to the pivot (or a smaller master cylinder if hyraulic) will give you the first. Less leverage will give you the second.


40inches - 10/7/15 at 10:26 AM

I found that you need around 125mm travel at the pedal, as Adi says get the cable clevis point as close to the pedal pivot as possible.
I did consider fitting a strong return spring on the pedal, but got used to the lightness before I got round to it.


Moorron - 10/7/15 at 12:37 PM

I found having a plate under your heal on that foot made it so much easier to operate. This way your are pivoting your foot not using your leg if you understand me correctly.

My ZX12 is very light even with upgraded springs but I wouldn't want to make it too heavy and load the release arm. Have you seen it? its like a 2mm pin and I have no idea how it doesn't snap under all that pressure.


40inches - 10/7/15 at 01:48 PM

The spring I was looking at was something like the VW Golf clutch pedal spring, all the tension is on the pedal itself


Jeano - 10/7/15 at 01:50 PM

i haven't really opened the bonnet as i only picked it up sunday. Im going to have a look Sunday and have a think.


K13JOB - 10/7/15 at 09:30 PM

quote:
Originally posted by Jeano
After a week of owning my ZX12 Dax i find the clutch so difficult as it is so light and the clutch needs adjusting.

Can they generally be adjusted and are they generally this light?


Yes, you just need to get used to it, nearly everybody who drives a BEC for the first time stalls it and needs to get used to giving enough revs and the feel for the clutch.


daniel mason - 10/7/15 at 11:11 PM

I agree with Adi 100%. Lighter peddle with more useable actuation suits me better. If you want to get off the line quick then more revs probably needed!


corrado vr6 - 11/7/15 at 07:39 AM

Hi there for my BEC Indy after up rating the R1 clutch springs I used the old springs, threaded bar, nuts and washers to make this



Now the pedal feels just like a normal car


DIY Si - 11/7/15 at 08:34 PM

One other thing that I had to get used to when pulling away was the amount of revs needed. Bashing it up to 5-6Krpm feels like far too much to start with, as that's redlining just about anything else. But when it's only half way round the gauge, and you get used to thinking about it like that, you'll soon get the hang of it.


adithorp - 11/7/15 at 08:57 PM

quote:
Originally posted by DIY Si
One other thing that I had to get used to when pulling away was the amount of revs needed. Bashing it up to 5-6Krpm feels like far too much to start with, as that's redlining just about anything else. But when it's only half way round the gauge, and you get used to thinking about it like that, you'll soon get the hang of it.


Do you really need 6k revs to pull away? Mine will pull away just above tickover on the flat and thats with race cams and a lightened crank.


MikeRJ - 11/7/15 at 09:20 PM

quote:
Originally posted by adithorp
quote:
Originally posted by DIY Si
One other thing that I had to get used to when pulling away was the amount of revs needed. Bashing it up to 5-6Krpm feels like far too much to start with, as that's redlining just about anything else. But when it's only half way round the gauge, and you get used to thinking about it like that, you'll soon get the hang of it.


Do you really need 6k revs to pull away? Mine will pull away just above tickover on the flat and thats with race cams and a lightened crank.


Depends on how quickly you want to pull away...


40inches - 11/7/15 at 09:32 PM

quote:
Originally posted by MikeRJ
quote:
Originally posted by adithorp
quote:
Originally posted by DIY Si
One other thing that I had to get used to when pulling away was the amount of revs needed. Bashing it up to 5-6Krpm feels like far too much to start with, as that's redlining just about anything else. But when it's only half way round the gauge, and you get used to thinking about it like that, you'll soon get the hang of it.


Do you really need 6k revs to pull away? Mine will pull away just above tickover on the flat and thats with race cams and a lightened crank.


Depends on how quickly you want to pull away...


My ZX9R would pull away at tick over, but I always had a moment at uphill junctions, usually ended up smoking the rear tyres, or stalling, lol