Author Topic: Clutch possibilites  (Read 3966 times)

0 Members and 1 Guest are viewing this topic.

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Clutch possibilites
« on: April 11, 2010, 04:57:24 PM »
This sank out of sight instantly in the other section so I'll try it here. 

78 CB550 clutch.

This may be a shot in the dark but has anyone eliminated the rivoted double steel plate in favour of an extra disc & regular plate? This was Hondas attempt at a quieter improved clutch, but this is for a race engine so quiet doesn't help but a larger stack might.

Once the bike is running I'll try it, there may not be enough play but just measuring looks like when totally disengaged the extra disc option yields 2.1mm free play, the stock 78 gives 3.33mm, and an earlier model 550 3.79mm.

I stacked all three into one pic trying to show available space disengaged, hopefully it's clear.

Left pic-extra disc, center- stock 78, right - earlier model 550 with Barnett discs.  


« Last Edit: April 12, 2010, 04:00:43 PM by bwaller »

Offline Big Jay

  • Expert
  • ****
  • Posts: 1,252
    • CBRzone
Re: Clutch possibilites
« Reply #1 on: April 12, 2010, 11:05:01 PM »
We have an extra plate clutch that will handle 9 second power.
http://cbrzone.com/clutches.html

Offline turboguzzi

  • Old Timer
  • ******
  • Posts: 4,084
Re: Clutch possibilites
« Reply #2 on: April 14, 2010, 09:27:59 PM »
Brent, left one doesnt look so bad after all, might work.

My initial setup was all stock + higher preload on springs via a 1.5mm ( I think) washers.

When that started to slip under power, Barnett plates cured that (I retained the higher preload springs)

Luckily, clutch is highly accessible so you can change things later too.

A third option that now comes to mind is much higher spring load and using my friend's hydro clutch solution....

Lever is way lighter than stock even with high pressure springs.

Neat.


Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: Clutch possibilites
« Reply #3 on: April 15, 2010, 01:58:04 AM »
Brent, left one doesnt look so bad after all, might work.

My initial setup was all stock + higher preload on springs via a 1.5mm ( I think) washers.

When that started to slip under power, Barnett plates cured that (I retained the higher preload springs)

Luckily, clutch is highly accessible so you can change things later too.

A third option that now comes to mind is much higher spring load and using my friend's hydro clutch solution....

Lever is way lighter than stock even with high pressure springs.

Neat.



Sorry for the hijack but Turbo Guzzi, would the barnett clutch be ok for a street bike or is it strictly for racing. The reason i ask is because the engine i am using for my 1000cc build has a barnett clutch, the gearbox is back cut if that helps.?

Mick
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline turboguzzi

  • Old Timer
  • ******
  • Posts: 4,084
Re: Clutch possibilites
« Reply #4 on: April 15, 2010, 02:06:38 AM »
Mick,

Power take up is definitely not as smooth with those barnett plates, not consistent either, some times more grabby some times less. Would not use them for loads of stop and go work. They are getting  a little better with use though,

all what am saying regards my experience with my 500 racer of course.

TG

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: Clutch possibilites
« Reply #5 on: April 15, 2010, 02:14:21 AM »
Mick,

Power take up is definitely not as smooth with those barnett plates, not consistent either, some times more grabby some times less. Would not use them for loads of stop and go work. They are getting  a little better with use though,

all what am saying regards my experience with my 500 racer of course.

TG

Thanks mate...

Mick
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: Clutch possibilites
« Reply #6 on: April 15, 2010, 03:53:21 AM »
Mick if I can add my 2 cents, I know a lot of guys swear by Barnett but my experience was similar to what TG explained. I spent more time adjusting the thing.

Try it & see but I like the stock Honda clutch & Barnett springs.

TG I have a master & slave cylinder off a VF500F but to mount it on the 550 clutch cover might make it too wide.

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: Clutch possibilites
« Reply #7 on: April 15, 2010, 03:56:58 AM »
Mick if I can add my 2 cents, I know a lot of guys swear by Barnett but my experience was similar to what TG explained. I spent more time adjusting the thing.

Try it & see but I like the stock Honda clutch & Barnett springs.

TG I have a master & slave cylinder off a VF500F but to mount it on the 550 clutch cover might make it too wide.

Thanks Bwaller, its in the engine now so when its all up and running i will soon know if i have to change things..

Mick
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline 754

  • Really Old Timer ...
  • *******
  • Posts: 29,058
Re: Clutch possibilites
« Reply #8 on: April 15, 2010, 08:15:03 AM »
Clutches should be switchable in 1/2 hr or less.

 I ran Barnett on most streetbikes I had. Yes they are grabby, but you can slip them endlessly. They are a bit harsh but they are a racing clutch. You have to decide what you are using your bike for, and choose accordingly.

 If you want to increase performance, you have to scrifice a few things on the way..

 I would like to try an APE though..
Maker of the WELDLESS 750 Frame Kit
dodogas99@gmail.com
Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline kos

  • Hot Shot
  • ***
  • Posts: 718
    • m3racing.com
Re: Clutch possibilites
« Reply #9 on: April 15, 2010, 04:09:37 PM »
We have an extra plate clutch that will handle 9 second power.
http://cbrzone.com/clutches.html


You have one for Cb500/550 Honda?

that is what he was asking for..correct?

KOS
220...221, whatever it takes.

Offline lordmoonpie

  • Master
  • *****
  • Posts: 2,053
  • Feal the Fear and do it anyway...
    • Moonpie
Re: Clutch possibilites
« Reply #10 on: April 15, 2010, 04:32:28 PM »
I swapped a Barnett clutch for my Honda stock item in the Moriwaki VTR superbike - apparently it wasn't the right thing to do. The trick is to substitute the stock riveted double plate for a stock friction disc and a dished steel disc - i.e. i fyou lay it flat the outsideof the steel disc touched the bench, the inside is raised above by abou 1-2 mm. It gives slick changes, good feel and durabilty...
1994 Ducati 888 SP5
1951 Ducati 50cc Cucciolo
1981 Yamaha XV750 SE

Offline Retro Rocket

  • Eggs are hard due too a
  • Really Old Timer ...
  • *******
  • Posts: 19,279
  • ROCK & ROLL
Re: Clutch possibilites
« Reply #11 on: April 15, 2010, 04:36:02 PM »
I swapped a Barnett clutch for my Honda stock item in the Moriwaki VTR superbike - apparently it wasn't the right thing to do. The trick is to substitute the stock riveted double plate for a stock friction disc and a dished steel disc - i.e. i fyou lay it flat the outsideof the steel disc touched the bench, the inside is raised above by abou 1-2 mm. It gives slick changes, good feel and durabilty...

Thanks LMP.....i will bookmark this page . ;)

Mick
750 K2 1000cc
750 F1 970cc
750 Bitsa 900cc
If You can't fix it with a hammer, You've got an electrical problem.

Offline MRieck

  • Really Old Timer ...
  • *******
  • Posts: 10,561
  • Big ideas....
Re: Clutch possibilites
« Reply #12 on: April 15, 2010, 07:15:11 PM »
We have an extra plate clutch that will handle 9 second power.
http://cbrzone.com/clutches.html


You have one for Cb500/550 Honda?

that is what he was asking for..correct?

KOS
I don't think so
Owner of the "Million Dollar CB"

Offline bwaller

  • Really Old Timer ...
  • *******
  • Posts: 7,484
Re: Clutch possibilites
« Reply #13 on: April 15, 2010, 07:18:38 PM »
LMP, It sounds like what I thought about trying except the dished steel part. Is this a warped disc or something special?  ;D

I'm still not sure in the 550 there will be enough play when the friction discs swell with oil, but I will give it a try.

Offline turboguzzi

  • Old Timer
  • ******
  • Posts: 4,084
Re: Clutch possibilites
« Reply #14 on: April 15, 2010, 10:46:56 PM »
We have an extra plate clutch that will handle 9 second power.
http://cbrzone.com/clutches.html


You have one for Cb500/550 Honda?

that is what he was asking for..correct?

KOS
I don't think so

A 9 second 550 deserves entering the Guinness book of records, me thinks.... :)


Offline lordmoonpie

  • Master
  • *****
  • Posts: 2,053
  • Feal the Fear and do it anyway...
    • Moonpie
Re: Clutch possibilites
« Reply #15 on: April 16, 2010, 01:30:13 AM »
LMP, It sounds like what I thought about trying except the dished steel part. Is this a warped disc or something special?  ;D

I'm still not sure in the 550 there will be enough play when the friction discs swell with oil, but I will give it a try.
I know what you mean Brent - it sure sounds like a warped disc but no it was a special part. Oddly enough it wasn't a moriwaki part, it was developed by the UK importer for his BSB rcae team. He had them made up locally by a specialist machine shop. The dish character of the plate acts like a tough big spring so when the plates swell it gives a little. I suppose he must have experimented to get the right thickness etc ut it did seem to work. Not knowing about this plate I swapped the original clutch for a heavy duty barnett kevlar clutch and the changes became very grabby and notchy. Luckily I kept the old plates (I'm a horder :-)) and managed to remedy the situation when I discovered the reason for it...
1994 Ducati 888 SP5
1951 Ducati 50cc Cucciolo
1981 Yamaha XV750 SE