Shock question

Randy Grein randygrein at comcast.net
Sun Dec 16 13:28:58 MST 2007


I know him as well and your assessment is spot-on. Nice guy, but don't  
bother arguing - he'd rather have an opinion than facts, just like  
most racers.

I spent quite a bit of time talking to Max at traxxion a few years ago  
to understand these issues, and while there are people on this list  
who are better at suspension tuning (Hi Z!) I generally understand the  
issues and can explain the flawed logic that people like Mr. Sunshine  
uses. The blow-off valve mistake is common because few people  
understand how a shock works in detail. Yes, Mr. Sunshine got caught  
up in the high-speed/low speed response conundrum. If I understand the  
particular valve issue the blow-off is adjustable, if not he wants to  
upgrade his shock to the next model Penske which does have adjustable  
3 way tuning. IIRC our record holder is in the same pickle; he knows  
how to go fast but doesn't sort his own suspension. "I can't feel the  
difference between settings" doesn't mean much other than you have  
more immediate adjustability than you can feel, better than being  
caught between settings (4.5 clicks would be PERFECT!).

FWIW my Penske, still in use on my 1st gen bike was initially way  
better than I could feel, mostly because it was so much better than  
anything I'd ever used. As I got more speed out of the bike it started  
having problems - not from age, but because those of us at the front  
were pushing the new tires harder than ever. I finally sent it in for  
a Traxxion -recommended revalve; they had discovered tire wear  
problems because of a harsh spot where the high-speed/low-speed  
valving meets. As I have a 2-way adjustable shock I have to assume Max  
was talking about the blow-off valve; either that or they made a  
change in the shim stack. In any case when it came back my tire wear  
problems disappeared, although it felt no different to me. I could go  
faster in a race, but I couldn't feel the difference.

Randy Grein, WMRRA #41

On Dec 13, 2007, at 8:01 AM, David and Sumudini Guyer wrote:

> Ha! I know him, and I work at the same company. :-)
>
> I think he's entering his 2nd year post-novice in 2008.  As you can  
> probably
> tell, he's got fairly strong opinions and doesn't show many tendencies
> towards changing them.
>
> Generates some very interesting discussions on the at work social  
> discussion
> groups :-)
>
>
>
>
> -----Original Message-----
> From: Steve Aronson [mailto:stevewins at gmail.com]
> Sent: Wednesday, December 12, 2007 6:13 PM
> To: 'Suzuki SV650 Mailing List'
> Subject: RE: Shock question
>
> I let him know :)
> Do you guys know him, he's in Washington state and races one of his  
> SVs?
>
> Steve
>
>> -----Original Message-----
>> From: zoran [mailto:zv30 at sbcglobal.net]
>> Sent: Wednesday, December 12, 2007 8:44 PM
>> To: Suzuki SV650 Mailing List
>> Subject: Re: Shock question
>>
>> without blow of valve his compression would increase at high speed of
>> shaft.it would do exactly what he is complaining off,control damping
> instead
>> shim stack :)
>>
>>
>> Zoran Vujasinovic
>> Twin Works Factory
>> 775-690-5171
>> http://www.twfracing.com/index.html
>> ----- Original Message -----
>> From: "Steve Aronson" <stevewins at gmail.com>
>> To: "'Suzuki SV650 Mailing List'" <sv650 at micapeak.com>
>> Sent: Wednesday, December 12, 2007 5:05 PM
>> Subject: RE: Shock question
>>
>>
>>> I posted it.  His answer seems to make sense.  I dunno, maybe his  
>>> blowoff
>>> valve is screwed up and opens too soon?
>>> http://www.sport-touring.net/forums/index.php/topic,18002.25.html
>>>
>>> Steve
>>>
>>>> -----Original Message-----
>>>> From: zoran [mailto:zv30 at sbcglobal.net]
>>>> Sent: Wednesday, December 12, 2007 5:13 PM
>>>> To: Suzuki SV650 Mailing List
>>>> Subject: Re: Shock question
>>>>
>>>> you can post anything you want,leave me out of it :)
>>>>
>>>>
>>>> Zoran Vujasinovic
>>>> Twin Works Factory
>>>> 775-690-5171
>>>> http://www.twfracing.com/index.html
>>>> ----- Original Message -----
>>>> From: "Steve Aronson" <stevewins at gmail.com>
>>>> To: "'Suzuki SV650 Mailing List'" <sv650 at micapeak.com>
>>>> Sent: Wednesday, December 12, 2007 2:07 PM
>>>> Subject: RE: Shock question
>>>>
>>>>
>>>>> Should I just post it or do you want me to name my source and give
> you
>>>>> credit :)
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: zoran [mailto:zv30 at sbcglobal.net]
>>>>>> Sent: Wednesday, December 12, 2007 4:47 PM
>>>>>> To: Suzuki SV650 Mailing List
>>>>>> Subject: Re: Shock question
>>>>>>
>>>>>> shim stack has nothing to do with it.this is inside reservoir.
>>>>>> shim stack controls oil flow from one side of piston to
> other.however
>>>>> shaft
>>>>>> entering shock under compression is pushing oil out of shock  
>>>>>> body at
>>> same
>>>>>> time.this oil goes in to reservoir.your adjuster controls flow of
> oil
>>>>>> from
>>>>>> shock to reservoir.if velocity of shaaft is to great blow off  
>>>>>> opens
>>>>>> and
>>>>>> bypasses adjuster.
>>>>>> did I mention ohshit sucks :)
>>>>>>
>>>>>>
>>>>>> Zoran Vujasinovic
>>>>>> Twin Works Factory
>>>>>> 775-690-5171
>>>>>> http://www.twfracing.com/index.html
>>>>>> ----- Original Message -----
>>>>>> From: "Steve Aronson" <stevewins at gmail.com>
>>>>>> To: "'Suzuki SV650 Mailing List'" <sv650 at micapeak.com>
>>>>>> Sent: Wednesday, December 12, 2007 1:16 PM
>>>>>> Subject: RE: Shock question
>>>>>>
>>>>>>
>>>>>>> That's what I told them, some of the top racers in the country  
>>>>>>> use
>>>>> Penskes
>>>>>>> (I do too, but I'm a street rider)  I'm stingray in that thread
> btw,
>>>>>>> so,
>>>>>>> what would be a good technical response to set the record  
>>>>>>> straight
>>>>>>> on
>>>>> the
>>>>>>> subject.    Seems to me if he just needs a different shim stack,
> no?
>>>>>>>
>>>>>>> Steve
>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Ernest Montague [mailto:afm199 at earthlink.net]
>>>>>>>> Sent: Wednesday, December 12, 2007 4:05 PM
>>>>>>>> To: Suzuki SV650 Mailing List
>>>>>>>> Subject: Re: Shock question
>>>>>>>>
>>>>>>>> Yes.  There are a no SV guys riding Penskes in the AFM who  
>>>>>>>> get in
>>> the
>>>>>>>> top ten, except for nine of them.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On Dec 12, 2007, at 12:52 PM, Steve Aronson wrote:
>>>>>>>>
>>>>>>>>> Take a look at this thread, is Mr. Sunshine correct in saying
>>>>>>>>> that
>>>>>>>>> Penske
>>>>>>>>> shocks are impossible to tune because of the blow off valve?
>>>>>>>>>
>>>>>>>>> http://www.sport-
>>>> touring.net/forums/index.php/topic,18002.0/all.html
>>>>>>>>>
>>>>>>>>> Steve
>>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> --
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>>>>>>> 12/12/2007 11:29 AM
>>>>>>>
>>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
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>>>>>
>>>
>>>
>>>
>>> --
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>>> Version: 7.5.503 / Virus Database: 269.17.1/1182 - Release Date:
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>>>
>



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