Author Topic: Clutch basket modifications?  (Read 1654 times)

0 Members and 1 Guest are viewing this topic.

Offline JLeather

  • Hot Shot
  • ***
  • Posts: 719
Clutch basket modifications?
« on: October 21, 2009, 06:11:44 am »
I was wondering what I should do while I've got the clutch basket out of the turbo build.  I'm leaning towards APE's new 9-plate clutch setup.  Should I have the basket welded?  Or can't you replace the rivets with bolts?  Anything need to be done to keep the fingers on it from opening up?

The bike's not really gonna be raced, but it will be making some serious power and I might hit the strip on the weekends.  What are the do's and dont's of clutch baskets?  It's a '76 K bottom end, BTW.

Online MRieck

  • Really Old Timer ...
  • *******
  • Posts: 9,643
  • Big ideas....
Re: Clutch basket modifications?
« Reply #1 on: October 21, 2009, 06:47:38 am »
The stock basket is pretty bullet proof...it's made of steel. I would try the OEM plates with Barnett springs. I believe MRE used to make a lock up for.....that may be history now. Lock ups certainly work as inteneded BUT make foot shifting almost impossible (especially 1st to 2nd) with any weight on the arms..
Owner of the "Million Dollar CB"

Offline JLeather

  • Hot Shot
  • ***
  • Posts: 719
Re: Clutch basket modifications?
« Reply #2 on: October 21, 2009, 07:02:53 am »
CycleX is now selling their new lockup, but as you've said it makes street riding tricky and this is primarily a street engine I'm building.  I have barnet springs and OEM plates going into my 836 N/A build right now.

Offline NitroHunter

  • Radical Street / Strip Turbo
  • Hot Shot
  • ***
  • Posts: 646
  • A man's motorcycle is a reflection of the man
Re: Clutch basket modifications?
« Reply #3 on: October 21, 2009, 06:18:29 pm »
MR I agree, my experience also was that even with no added counterweight, my MRE lockup was almost unshiftable BY FOOT at high RPM.
Since I have an air shifter this was never a problem - just don't get crazy if the tank's empty.  ::)
  BUT just putting around town, the lockup was not an issue.
Robbie the NitroHunter                      Fuel Coupe Hired Gun                  NHRA T/F 640

DRAGBIKE USA XH/MB Recordholder: http://forums.sohc4.net/index.php?action=dlattach;topic=127179.0;attach=332735
DRAGBIKE USA XH/SS Recordholder: http://forums.sohc4.net/index.php?action=dlattach;topic=63940.0;attach=103300
Young mans glory days in the lanes: http://forums.sohc4.net/index.php?action=dlattach;topic=45685.0;attach=66341

Online MRieck

  • Really Old Timer ...
  • *******
  • Posts: 9,643
  • Big ideas....
Re: Clutch basket modifications?
« Reply #4 on: October 21, 2009, 06:44:21 pm »
MR I agree, my experience also was that even with no added counterweight, my MRE lockup was almost unshiftable BY FOOT at high RPM.
Since I have an air shifter this was never a problem - just don't get crazy if the tank's empty.  ::)
  BUT just putting around town, the lockup was not an issue.
Nitro is right about the high RPM part...that shift lever becomes the immovable object. ::) ;)
Owner of the "Million Dollar CB"

Offline NitroHunter

  • Radical Street / Strip Turbo
  • Hot Shot
  • ***
  • Posts: 646
  • A man's motorcycle is a reflection of the man
Re: Clutch basket modifications?
« Reply #5 on: October 22, 2009, 02:51:57 pm »
Before we get off the lock up clutch subject, here's something else to consider.
(Yeah, I know, some guys would kill to have such a problem).  ::)
When you spin the tire at high RPM under serious boost (15+ psi), there's almost NO WAY to quickly stop wheel spin - NO pulling in the clutch lever with a lock up.
Short shifting (air shifter) and throttle chop can work if you catch it soon enough... but once the turbo is spooled up, you DON'T just shut it off like slamming the butterflies on a set of carbs! The inertia behind that impeller at full song isn't to be taken lightly - it pumps air for awhile.
Short shifting under big boost can actually worsen the tire spin, causing it to spin faster.
With a treaded tire on the street, it was a balance between OMG exhilaration and sheer terror. And with a drag slick, doing that one time too many put me into the wall - and permanently out of bike racing.

Also, when I tried the 9 plate clutches, it seemed the thinner discs had a tendency to gouge the hub/basket. I've had to file all the contact areas smooth a few times, but as a side note boy does it make the lever pull and release smooth! It's something I'd highly recommend for ALL clutches.
« Last Edit: October 22, 2009, 04:55:34 pm by NitroHunter »
Robbie the NitroHunter                      Fuel Coupe Hired Gun                  NHRA T/F 640

DRAGBIKE USA XH/MB Recordholder: http://forums.sohc4.net/index.php?action=dlattach;topic=127179.0;attach=332735
DRAGBIKE USA XH/SS Recordholder: http://forums.sohc4.net/index.php?action=dlattach;topic=63940.0;attach=103300
Young mans glory days in the lanes: http://forums.sohc4.net/index.php?action=dlattach;topic=45685.0;attach=66341

 

;