Penton Owners Group

General Discussion => Penton Talk => Topic started by: wfopete on July 01, 2009, 01:07:48 PM

Title: 520 Jackpiner Drive Train
Post by: wfopete on July 01, 2009, 01:07:48 PM
Does anyone offer a 520 size sprocket kit for the Jackpiner?

Pete Petrick
175 Jackpiner
Slow but Good
Title: 520 Jackpiner Drive Train
Post by: Lew Mayer on July 01, 2009, 06:16:22 PM
Al has the 520 countershaft sprockets but I had to get Rebel Gears to make a rear sprocket for me. I assume you mean for the straight hub bikes.

Lew Mayer
Title: 520 Jackpiner Drive Train
Post by: wfopete on July 02, 2009, 09:09:40 AM
You are correct Mr. Mayer, straight hubs. I have a 12/52 set up which needs to be "tightened up". 11/52 just seems like to small of a front sprocket so I figured I'd go with a 520 set up and 12/56, 58 or?

Pete Petrick
175 Jackpiner
Slow but Good
Title: 520 Jackpiner Drive Train
Post by: john durrill on July 02, 2009, 02:27:24 PM
Pete,
 We got a 520 counter shaft sprocket from Barry Higgins a few years ago.
It was a KTM LC4 sprocket with a 1 mm spacer in the package. The Spacer was, as i remember  ( its been a while chuckle chuckle! ) one of the tooth thrust washers from the transmission ( Part # 51.33.020.000 ?).
John D.


Title: 520 Jackpiner Drive Train
Post by: Lew Mayer on July 02, 2009, 08:50:01 PM
You're right, Pete. An 11 is too small a countershaft sprocket. For reference, I run a 12/55.
(Mr Mayer???)

Lew Mayer
Title: 520 Jackpiner Drive Train
Post by: wfopete on July 02, 2009, 09:54:08 PM
Thanks guys.  From the looks of things I'll be running the 'piner in the ISDTRR this year.  I wanted to ride my GS250 but I broke it at Combs so once again, I will rely on the true vintage bike to get the job done.

Pete Petrick
175 Jackpiner
Slow but Good
Title: 520 Jackpiner Drive Train
Post by: john durrill on July 03, 2009, 12:07:14 AM
Pete,
 Found this web page that should help you with picking a sprocket combo.
http://www.sprocketspecialists.com/SprocketOptimizer2.aspx

Here is one we did for a friend for a mouse.

(http://i439.photobucket.com/albums/qq113/sachs175/Bobs15x56.jpg)

(http://i439.photobucket.com/albums/qq113/sachs175/bobsstock14x56.jpg)

It gives you and idea , taking into consideration tranny , primary ,sprocket ratios coupled with wheel , tire size and engine power band.
Gives you a min speed in any gear that should work.
Pop in the #'s and hit optimize and you can see what 1 tooth should do for you.

John D.