Motorcycle Racing Forum

Racing Discussion => Racing Discussion => Topic started by: gkotlin on April 11, 2011, 11:09:30 PM

Title: SV HPT Gearing?
Post by: gkotlin on April 11, 2011, 11:09:30 PM
Anyone have any idea what sprockets I need to bring?  I haven't been to HPT in years and when i did, it was on a 600.
Title: Re: SV HPT Gearing?
Post by: grasslander on April 12, 2011, 07:16:29 AM
HPT SV gearing:  15/47 or 15/48
Title: Re: SV HPT Gearing?
Post by: raven21 on April 12, 2011, 07:41:58 PM
15/48 is short. I would say closer to 15/45 it has long straights. I am running 16/45 and might try out 16/43 there on my superbike
Title: Re: SV HPT Gearing?
Post by: grasslander on April 12, 2011, 07:50:08 PM
Quote from: raven21 on April 12, 2011, 07:41:58 PM
15/48 is short. I would say closer to 15/45 it has long straights. I am running 16/45 and might try out 16/43 there on my superbike

Good Luck
Title: Re: SV HPT Gearing?
Post by: Jack_Brock on April 13, 2011, 09:34:21 AM
I always ran 15/45, and 15/46 with a headwind on the straight.  I've run as fast as 1:47 with the 15/45 combo, but you have got to be good out of the last corner to make it work.
Title: Re: SV HPT Gearing?
Post by: grasslander on April 13, 2011, 09:47:39 PM
Isn't there always a head wind on the front straight?  ;-)
Title: Re: SV HPT Gearing?
Post by: Jack_Brock on April 14, 2011, 05:15:58 PM
Quote from: grasslander on April 13, 2011, 09:47:39 PM
Isn't there always a head wind on the front straight?  ;-)

Like I said, 15/46:)

Oh yeah, 16/45 or 43 is way too tall for HPT.  That might work at Road America, and I would think it would take a pretty strong motor to pull it.
Title: Re: SV HPT Gearing?
Post by: tstruyk on April 14, 2011, 10:35:44 PM
raven has a pretty strong motor... way too tall for stock or super sport   
Title: Re: SV HPT Gearing?
Post by: raven21 on April 15, 2011, 06:46:31 PM
Like i said 15/45 or so for a stock engine.
Title: Re: SV HPT Gearing?
Post by: gkotlin on April 20, 2011, 08:32:18 PM
Thanks.  Thats about what I was figuring.  As for the 16/4* combo.  I've run it on a stock motor at Mid-Ohio and Road America.  15/46 is what I ended up running I believe.
Title: Re: SV HPT Gearing?
Post by: grasslander on April 24, 2011, 07:47:11 PM
Thanks Jack - you were spot on.
Title: Re: SV HPT Gearing?
Post by: raven21 on April 24, 2011, 09:10:42 PM
16-45 was perfect on my first gen, put me at 9100rpms at the top of alpha
Title: Re: SV HPT Gearing?
Post by: grasslander on April 24, 2011, 09:20:45 PM
Quote from: raven21 on April 24, 2011, 09:10:42 PM
16-45 was perfect on my first gen, put me at 9100rpms at the top of alpha

but that IS one heck of a motor...
Title: Re: SV HPT Gearing?
Post by: Jack_Brock on April 24, 2011, 09:56:57 PM
Quote from: raven21 on April 24, 2011, 09:10:42 PM
16-45 was perfect on my first gen, put me at 9100rpms at the top of alpha

How big of displacement is it?  I was thinking I was getting more than 9100 out of both my SVs(1 was stock, the other was a 677), but I've had a few concussions since then:) 

FWIW, I always paid more attention to how the bike came off of corners when selecting gearing much more than where I ended up at the end of the straight.  Obviously no gearing is going to work great coming off every turn, but I'd pick the gear that worked the best at most turns and the most important turns(leading onto straights).  Everything is a compromise and with this in mind, I'd try drastically different setups to see what would happen, and I was suprised to find things work that I thought wouldn't, and conversely.

Jim-glad the gearing worked out for you.  You doing the Mothers day TD?

I hope everybody had fun and was safe.  Race reports would be awesome for all of us wanna-bes!
Title: Re: SV HPT Gearing?
Post by: grasslander on April 25, 2011, 10:02:48 AM
Quote from: Jack_Brock on April 24, 2011, 09:56:57 PM

Jim-glad the gearing worked out for you.  You doing the Mothers day TD?


G-Baby Racing will be doing a practice at Hallett for the May 21 5 hour CMRA endurance on the 7th (CCW).  I'll travel home that night and will try to come up Sunday (20 min from my hose to HPT)
Title: Re: SV HPT Gearing?
Post by: raven21 on April 25, 2011, 04:26:49 PM
its a 677 probst built engine, the gearing was just about perfect everywhere only place i was between gears was 7.
Title: Re: SV HPT Gearing?
Post by: Jack_Brock on April 25, 2011, 08:11:33 PM
Quote from: raven21 on April 25, 2011, 04:26:49 PM
its a 677 probst built engine, the gearing was just about perfect everywhere only place i was between gears was 7.

With a Probst built engine, it will probably pull hard off the corner with about any gearing.  If I ever got back to racing SVs, I'd be calling Ben to have one done right.
Title: Re: SV HPT Gearing?
Post by: tstruyk on April 25, 2011, 11:11:26 PM
+1 

Of course the rest of the expert grid would prefer you keep it stock jack...
Title: Re: SV HPT Gearing?
Post by: benprobst on April 30, 2011, 08:55:41 AM
Quote from: Jack_Brock on April 25, 2011, 08:11:33 PM
With a Probst built engine, it will probably pull hard off the corner with about any gearing.  If I ever got back to racing SVs, I'd be calling Ben to have one done right.

Thanks for the kind words Jack.


Our 1st gen bikes specifically use some different gearing. We rarely run a 15t countershaft as it has us realing through the gears a little too much. My 1st gen stuff doesnt use much revs either, as Joe mentioned they like to be shifted below 9500, as opposed to 10 and up to 11 on the second gen bikes.