Extended Swing Arm Shock and Spring Rate

DEFINITELY need to run a higher spring rate than you normally would with the Pierobon

1299rFE said:

I will be interested to hear what you think of the GSXR on track VS your V4S.

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The GSXR, that’s a fully spec’d SuperStock race bike series bike dialed in for my weight etc is easier to ride in some ways….but the thing is I almost never ride it.

For sure it would have been an easier bike to learn on, but as I had already started on the Ducati and that was what I learned on in the beginning, it’s too disruptive to my learning curve to switch between bike at my relatively novice level of track riding.

In short, while still learning switching between bikes session to session turns out to be a very bad idea. Rick can get away with it because he has two fairly similar bikes and is a MUCH more experienced track rider.

For me though, even though the GSXR is ultimately an easier bike to learn to ride fast at the track, it’s also a big step back in the learning process adjusting to the different riding dynamics and geometry of the bike. So it mostly sits in my garage now, I didn’t even haul it with me as a backup bike to the last track weekend.

Steven31371 said:

DEFINITELY need to run a higher spring rate than you normally would with the Pierobon

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Yes think so, the arm is 6% longer so thinking a similar increase is spring rate is needed.

Jay111 said:

Yes think so, the arm is 6% longer so thinking a similar increase is spring rate is needed.

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I’m running a 115 spring and Ohlins is recommending a130 spring….so yeah somewhere in the neighborhood of a 6 to 10% increase…I also have the Forsaken Motorsports Linear lower rear shock linkage…that plays a part in the setup.

Ohlins is being VERY involved and helpful, to the point that they called Forsaken Motorsports to ask the exact curve of the linear link to insure getting both the spring rate and valving right.

I tried several other suspension options, MUPO, and MAXTON and neither came through, MUPO still hasn’t responded to a single question months later, and after several weeks MAXTON got back to me to say essentially that short of shipping the bike to Great Britain they didn’t want to even try to figure out the right setup.

Good old Ohlins though, they are coming through. When guys on here say Ohlins is great because of reliable support that’s no passing side comment, with this suspension setup stuff that support is mission critical to the whole process, so no matter how good the technical specs look on other suspension manufacturers what I’ve found is that none of that means anything WITHOUT access to technical support that’s relatively timely and detail oriented. So far only Ohlins has done that with me.

If anyone is running or planning on running a similar kind of setup PM me and I’d be happy to put you in contact with the guy I’m working with.

Any updates? Did you end up settling on a 130 spring?

SpeedOfSound said:

Any updates? Did you end up settling on a 130 spring?

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Yep 130 for me and it was perfect. The mod is very, very good on track. Much less physical a bike to ride with it fitted.

I took 3 seconds off my best lap at Jerez with just the arm mod alone.

Bike is being returned to road now so BSB engine, this Peirobon arm, wheels, brakes and suspension will all be up for sale soon.

130 is what I went with too, I ordered an Ohlins TTX GP rear shock that the engineers custom valved for my weight, the Pierobon Swingarm, and the linear shock link, and they recommended the 130 spring.

Jay111 said:

Yep 130 for me and it was perfect. The mod is very, very good on track. Much less physical a bike to ride with it fitted.

I took 3 seconds off my best lap at Jerez with just the arm mod alone.

Bike is being returned to road now so BSB engine, this Peirobon arm, wheels, brakes and suspension will all be up for sale soon.

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Thank you. I sent you a message.

Steven did you sell the swingarm? I posted in your for sale thread also. If you still have it I'll buy it.