Premature clutch wear. 1st vs. 2nd gen?

Randy Grein rgrein at q.com
Mon Aug 12 22:42:11 PDT 2013


I have been caught with this a time or two - last time there was TOO much free play in the cable and turning the bars caused it to jump up from the adjuster hole to the edge and you guessed it - free spinning clutch. On advice from Zlocks I let it cool, put it back together, got the free play right (that included a minor cable reroute) and it was fine - on a 90 hp super bike. The other times I've had this I didn't have the actuator arm set right, so check that end as well.

Randy Grein
rgrein at q.com

''Death has a tendency to encourage a depressing view of war.''

—former Defense Secretary Donald Rumsfeld, 2003

On Aug 12, 2013, at 11:03 AM, Aaron Turner <synfinatic at gmail.com> wrote:

> How?  It's a painful long story.  Honestly, I don't know if the basket or
> pressure plate were swapped since I didn't do the work.  If I had to guess,
> I'd say they're off the 2nd gen but that's something I'll have to ask the
> shop.
> 
> Last oil change (right before the last 2 track days & race weekend) is
> Castrol 4T full-syn motorcycle racing oil 10W-40.  Oil level has always
> been visible in the sight glass.  Before that, I don't know other then oil
> levels were fine.  That was only the second time it's been filled with oil
> since it's been in my bike.
> 
> 
> Aaron Turner
> http://synfin.net/         Twitter: @synfinatic
> https://github.com/synfinatic/tcpreplay - Pcap editing and replay tools for
> Unix & Windows
> Those who would give up essential Liberty, to purchase a little temporary
> Safety, deserve neither Liberty nor Safety.
>    -- Benjamin Franklin
> 
> 
> 
> On Mon, Aug 12, 2013 at 10:07 AM, Chris Burgess <chris at chrisburgess.com>wrote:
> 
>> Why would Z say that?  I've used the Barnett clutch pack including springs
>> in my 90hp 2nd gen for some time.  I loved the stiffer spring at the clutch
>> lever.
>> 
>> I just completely rebuilt the motor (cases and all) and put in another
>> Barnett clutch with springs. Just got it fired so no time on it.
>> 
>> My question is how did you get the 1st gen clutch into a 2nd gen bike?
>> Are you using the 1st gen clutch basket? If so, why?
>> 
>> And what I would look at is oil.  What oil are you using and is the clutch
>> getting enough.
>> 
>> -Chris
>> 
>>> Subject: Re: Premature clutch wear. 1st vs. 2nd gen?
>>> From: jorhett at fastlizardracing.com
>>> Date: Mon, 12 Aug 2013 09:18:30 -0700
>>> To: sv650 at micapeak.com
>>> 
>>> Zoran told me not to use the Barnett springs in the 2nd gen clutch
>> unmodified. I can't remember what else he said, but I'd check with him
>> directly if he doesn't speak up here. Sounds like they are
>> not-quite-the-same.
>>> 
>>> On Aug 12, 2013, at 9:15 AM, Aaron Turner <synfinatic at gmail.com> wrote:
>>>> So I've been trying to diagnose why my clutch slips under hard
>>>> acceleration.  It doesn't slip a lot, just what feels like one
>> revolution
>>>> or so. Happens probably 2-4 times a lap at THill depending on how hard
>> I'm
>>>> on it.
>>>> 
>>>> So long story short, I have a nearly brand new (2 race weekends and
>> about 5
>>>> track days) 1st gen Barnett clutch pack installed in a 2nd gen motor.
>>>> (long story)   Although to be honest, the clutch has been slipping for
>> at
>>>> least half that time (I've had bigger problems to worry about).  I
>> tried
>>>> adding more play in the clutch cable last race round, but that didn't
>> help.
>>>> 
>>>> The clutch seat & seat spring washers from the 2nd gen clutch are NOT
>>>> installed.  4 of the 6 clutch springs were Barnett, the other 2 stock.
>>>> 
>>>> I measured the plates.  The thicker #2 friction plate is on the high
>> side
>>>> of being within spec.  Of the remaining 6 frictions, 4 are in spec
>> (barely)
>>>> and 2 are just out of spec.  All +/- .02mm of spec.
>>>> 
>>>> Steels look good, no bluing/etc.  Pack was installed correctly per 1st
>> gen
>>>> specs.
>>>> 
>>>> So, seems like I probably need a new set of frictions (I couldn't find
>> any
>>>> spec for total clutch pack height, does anyone have any numbers?).
>> What I
>>>> don't understand is why the clutch wear was so aggressive.  The motor
>> isn't
>>>> making crazy horsepower (less then 80HP) and historically my clutches
>> have
>>>> no problem lasting more then a full race season.
>>>> 
>>>> I know the 1st & 2nd gen SV are *almost* the same... stator, gear
>> position
>>>> sensor and oil cooler being the obvious differences on the bottom end,
>> but
>>>> maybe there is something different with the clutch basket/etc that
>> would
>>>> cause this premature wear?
>>>> 
>>>> Right now, the only idea I have is that the clutch cable was too tight
>> and
>>>> that caused the premature wear.  And by the time I loosened it up it
>> was
>>>> too late.  But honestly, I never felt any difference after adjusting
>> the
>>>> clutch cable.
>>>> 
>>>> Suggestions or ideas?
>>>> 
>>>> Thanks!
>>>> 
>>>> 
>>>> Aaron Turner
>>>> http://synfin.net/         Twitter: @synfinatic
>>>> https://github.com/synfinatic/tcpreplay - Pcap editing and replay
>> tools for
>>>> Unix & Windows
>>>> Those who would give up essential Liberty, to purchase a little
>> temporary
>>>> Safety, deserve neither Liberty nor Safety.
>>>>   -- Benjamin Franklin
>>> 
>> 
>> 



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