Go Back   DIY Go Kart Forum > Building Plans And Advice > Mini Bikes, Trikes, and Choppers

Notices

Closed Thread
 
Thread Tools Display Modes
  #1  
Old 07-01-2010, 07:01 PM
Blazkowiez's Avatar
Blazkowiez Blazkowiez is offline
Kart Aficionado
 
Join Date: Feb 2010
Location: Houston, Texas
Posts: 2,538
Thanks: 22
Thanked 333 Times in 249 Posts
Default Strange Vintage 2 Speed Mini-Bike

Okay, I wanted to get your opinion/info on this little bike. I understand this is not mini-bike forums and they would be the ones to identify it. We're obviously going to sell it but I'm not trying to sell it here just looking for thoughts on this set-up. We don't run across it very often because torque converters basically made them obsolete but that's life.

I threw in some pictures of it so people can bask in the glory of dual speed drive. I'm sure it'll find its way somewhere, a great deal of the bikes we've been selling have been finding their way to Austin more recently. Must be some sort of retro surge.
Attached Thumbnails
vintage1.jpg   vintage2.jpg  

vintage3.jpg   vintage4.jpg  

vintage5.jpg  
__________________
gokartrepair.com. Family owned and operated in Houston for 40 years. Parts-Service-Advice
  #2  
Old 07-01-2010, 07:27 PM
oscaryu1 oscaryu1 is offline
Senior Member
 
Join Date: Mar 2008
Posts: 2,767
Thanks: 6
Thanked 148 Times in 60 Posts
Default

They used to sell these two-speed setups IIRC...
  #3  
Old 07-01-2010, 07:29 PM
Blazkowiez's Avatar
Blazkowiez Blazkowiez is offline
Kart Aficionado
 
Join Date: Feb 2010
Location: Houston, Texas
Posts: 2,538
Thanks: 22
Thanked 333 Times in 249 Posts
Default

Yes, they did. Comet made these, many heath kit bikes came with them but after 1960 they died out very quickly.
__________________
gokartrepair.com. Family owned and operated in Houston for 40 years. Parts-Service-Advice
  #4  
Old 07-01-2010, 11:17 PM
T-man's Avatar
T-man T-man is offline
Senior Member
 
Join Date: Aug 2009
Location: Missoula,MT
Posts: 1,232
Thanks: 30
Thanked 63 Times in 58 Posts
Default

that is interesting I would like to know how they did that.
hey blaz when you start to clean it up take some more pics of it because I want to see how they had that set-up work.
__________________
http://www.tmanskarts.com & 1 Primary youtube channel T-mans Go Karts
  #5  
Old 07-02-2010, 03:36 AM
sideways's Avatar
sideways sideways is offline
Unfinished projects king.
 
Join Date: Feb 2009
Location: Perth, Western Australia
Posts: 1,501
Thanks: 50
Thanked 164 Times in 115 Posts
Default

Soooooo you gona tell us how it works?

Thanks

Hayden
  #6  
Old 07-02-2010, 09:15 AM
Pellethuntr2 Pellethuntr2 is offline
Machinist
 
Join Date: May 2009
Location: NY
Posts: 224
Thanks: 2
Thanked 7 Times in 3 Posts
Default

Quote:
Originally Posted by sideways View Post
soooooo you gona tell us how it works?

Thanks

hayden
dito
  #7  
Old 07-02-2010, 12:06 PM
KieranM's Avatar
KieranM KieranM is offline
Doin It!!
 
Join Date: Aug 2009
Location: Kilkenny, Ireland
Posts: 1,409
Thanks: 90
Thanked 124 Times in 85 Posts
Default

reminds me of the duplex chain.
  #8  
Old 07-02-2010, 01:59 PM
Blazkowiez's Avatar
Blazkowiez Blazkowiez is offline
Kart Aficionado
 
Join Date: Feb 2010
Location: Houston, Texas
Posts: 2,538
Thanks: 22
Thanked 333 Times in 249 Posts
Default

It works by the first clutch which engages from the engine at the first ratio around 2,000 rpm(just like a normal clutch). This gives a solid take-off. The second clutch is a stall clutch which has a separate ratio which would act almost as if it were shifting simply by engaging. Once the second clutch which resides on the jack-shaft engages (depending on how far they set the stall 2600-3200) both clutches are locked up and the jack-shaft is forced to run on the lower ratio giving it a sort of overdrive. Its an older system but one that many people prefer over a torque converter but still kinda died out a very long time ago for the most part.
__________________
gokartrepair.com. Family owned and operated in Houston for 40 years. Parts-Service-Advice
  #9  
Old 07-04-2010, 05:24 PM
porsche930dude porsche930dude is offline
Senior Member
 
Join Date: Jan 2009
Location: Upstate, NY
Posts: 906
Thanks: 4
Thanked 115 Times in 88 Posts
Default

yup those work pretty good. Thats a montgomory wards / gilson bike . You should check out Oldminibikes.com . lots of info on those
__________________
"When in doubt make it stout"
  #10  
Old 07-04-2010, 11:39 PM
Blazkowiez's Avatar
Blazkowiez Blazkowiez is offline
Kart Aficionado
 
Join Date: Feb 2010
Location: Houston, Texas
Posts: 2,538
Thanks: 22
Thanked 333 Times in 249 Posts
Default

Cool man, thanks for that information. We see all kinds of bikes like that go through the shop, I just thought some people here would think it was neat to see the set-up since it is not fairly common from my experiences. I may actually sign up, it takes me a while to be willing to do things like this online with my limited spare time. I do appreciate the make info. I was thinking it was perhaps a HeathKit.
__________________
gokartrepair.com. Family owned and operated in Houston for 40 years. Parts-Service-Advice
  #11  
Old 07-05-2010, 01:40 PM
Kenny_McCormic Kenny_McCormic is offline
Kartless....
 
Join Date: May 2008
Location: Michigan Troll
Posts: 4,537
Thanks: 10
Thanked 201 Times in 182 Posts
Default

Last I checked, these setups and the parts are still available.
  #12  
Old 07-05-2010, 02:04 PM
Blazkowiez's Avatar
Blazkowiez Blazkowiez is offline
Kart Aficionado
 
Join Date: Feb 2010
Location: Houston, Texas
Posts: 2,538
Thanks: 22
Thanked 333 Times in 249 Posts
Default

Kenny, you're right. You can still construct this set-up fairly easily and buy replacement parts. That does not however make it stock.
__________________
gokartrepair.com. Family owned and operated in Houston for 40 years. Parts-Service-Advice
  #13  
Old 07-05-2010, 09:03 PM
motor_head's Avatar
motor_head motor_head is offline
expert garbage picker
 
Join Date: Apr 2009
Location: sutherland IA
Posts: 479
Thanks: 0
Thanked 40 Times in 29 Posts
Default

Quote:
Originally Posted by Blazkowiez View Post
It works by the first clutch which engages from the engine at the first ratio around 2,000 rpm(just like a normal clutch). This gives a solid take-off. The second clutch is a stall clutch which has a separate ratio which would act almost as if it were shifting simply by engaging. Once the second clutch which resides on the jack-shaft engages (depending on how far they set the stall 2600-3200) both clutches are locked up and the jack-shaft is forced to run on the lower ratio giving it a sort of overdrive. Its an older system but one that many people prefer over a torque converter but still kinda died out a very long time ago for the most part.
the second clutch is just like a normal clutch but engages at somewhere around 1600 rpm. the jack shaft actually spins the shoes. so when the engine gets up to 3600 rpm the jack shaft is spinning 1800rpm (because the ratio in 1st gear is 2-1) and the second clutch engages. then rpms go down (if the second clutch was dependent on engine speed this wouldn't happen and it wouldn't give as wide a range of speed) the second clutch stays engaged even when the engine slows because the jack shaft is now spinning 1-1 with the engine and the jack shaft rpm is still spinning around 2000 rpm.
  #14  
Old 07-05-2010, 09:55 PM
Blazkowiez's Avatar
Blazkowiez Blazkowiez is offline
Kart Aficionado
 
Join Date: Feb 2010
Location: Houston, Texas
Posts: 2,538
Thanks: 22
Thanked 333 Times in 249 Posts
Default

The first clutch is on the motor itself and like all normal clutches would begin to engage at 2,000 rpm correct? How can the jack-shaft engage period if it has no means rotation? I am fairly new to this set-up clearly but please explain further so I can make sense of what you are telling me. I always enjoy learning new things here its fun.
__________________
gokartrepair.com. Family owned and operated in Houston for 40 years. Parts-Service-Advice
  #15  
Old 09-07-2010, 10:58 PM
700 efi guy 700 efi guy is offline
Member
 
Join Date: Aug 2010
Posts: 35
Thanks: 1
Thanked 0 Times in 0 Posts
Default

Quote:
Originally Posted by Blazkowiez View Post
It works by the first clutch which engages from the engine at the first ratio around 2,000 rpm(just like a normal clutch). This gives a solid take-off. The second clutch is a stall clutch which has a separate ratio which would act almost as if it were shifting simply by engaging. Once the second clutch which resides on the jack-shaft engages (depending on how far they set the stall 2600-3200) both clutches are locked up and the jack-shaft is forced to run on the lower ratio giving it a sort of overdrive. Its an older system but one that many people prefer over a torque converter but still kinda died out a very long time ago for the most part.

in overdrive would both chains still be turning?
  #16  
Old 09-07-2010, 11:01 PM
Blazkowiez's Avatar
Blazkowiez Blazkowiez is offline
Kart Aficionado
 
Join Date: Feb 2010
Location: Houston, Texas
Posts: 2,538
Thanks: 22
Thanked 333 Times in 249 Posts
Default

The first clutch doesn't stop being locked up when the second clutch engages my friend.
__________________
gokartrepair.com. Family owned and operated in Houston for 40 years. Parts-Service-Advice
  #17  
Old 09-07-2010, 11:26 PM
700 efi guy 700 efi guy is offline
Member
 
Join Date: Aug 2010
Posts: 35
Thanks: 1
Thanked 0 Times in 0 Posts
Default

so could you build this with 2 clutches, 1 on the motor and 1 on a live jack shaft, with the smaller axle sprocket going to the jack shaft clutch and a bigger axle sprocket to a sprocket on the jack shaft? there'd be a total of 3 chains, or would it all bind up?
  #18  
Old 09-08-2010, 12:48 AM
Blazkowiez's Avatar
Blazkowiez Blazkowiez is offline
Kart Aficionado
 
Join Date: Feb 2010
Location: Houston, Texas
Posts: 2,538
Thanks: 22
Thanked 333 Times in 249 Posts
Default

Nothing binds up, as long as the clutches are not worn to the point where the bushings or springs are spent everything works great on these set-ups.
__________________
gokartrepair.com. Family owned and operated in Houston for 40 years. Parts-Service-Advice
  #19  
Old 09-08-2010, 03:07 PM
r97's Avatar
r97 r97 is offline
Measure twice cut once
 
Join Date: Jul 2010
Location: Massachusetts, USA
Posts: 3,793
Thanks: 39
Thanked 250 Times in 229 Posts
Default

Quote:
Originally Posted by motor_head View Post
the second clutch is set to engage at somewhere around 1800 rpm. it's that way because the shoes it the clutch are driven by the jackshaft with in 1st gear operates at 1/2 engine speed
i personally found the above descriptions of how it works to be slightly confusing (no offense to blaz or motor head).

my personal understanding is that there is an average clutch on the engine out put with 2 sprockets on it instead of just one, the first chain goes from the engine clutch to the large sprocket on the jack-shaft, this large sprocket has a built-in free-wheel device. the second gear is setup in a way so that the second chain coming from the engine clutch goes to a sprocket welded to the shoe assembly on the jack-shaft (not the drum like in a normal cent clutch) the shoe assemble on the jack shaft is also on bearings and has more spring tension so that it only engages when the jack-shaft is spinning near its max rpm, the jack-shaft clutch shoes expand and lock onto a drum fixed to the jack shaft, now the second gear is engaged, second gear spins faster than 1st so the free-wheel releases ands spins freely on the jack shaft. at the other end of the jack shaft is another sprocket which simply runs to the wheel. so engine cent clutch engages spinning both 1st and 2nd gear chains, first gear chain (roughly a 2 to 1 ratio) moves the free-wheel sprocket on the jack shaft faster than the shaft thus engaging the free-wheel and 1st gear along with it. next the engine revs to higher rpm which engages the second gear clutch which grabs onto a drum that is fixed to the jack-shaft(the heavier springs in this clutch make it engage only at high rpm), the second gear has a roughly 1 to 1 ratio so the jack shaft is now going to spin faster than the 1st gear free-wheel sprocket, when this happens it dis-engages the free-wheel. if you really wanted to you could install a free-wheel on the jack-shaft clutch drum and put on another, and another until you ran out of money, this would be quite bulky but would be fun! (every drum except for the last gear would have to be a free wheel though, also you would need to setup a second jack-shaft installed for chain alignment)

so sry about the all the writing but it is a full description, it would be alot easier to explain to you in-person with it in my hand, this pic should help.



also some good pics on this site, http://www.rcdon.com/html/grv-1_turb...t_12_01_0.html

p.s. blaz that looks like it will be a fun mini once its done!
  #20  
Old 09-08-2010, 04:17 PM
Blazkowiez's Avatar
Blazkowiez Blazkowiez is offline
Kart Aficionado
 
Join Date: Feb 2010
Location: Houston, Texas
Posts: 2,538
Thanks: 22
Thanked 333 Times in 249 Posts
Default

It'll be a good project for whomever purchases it, as I said it'll most likely go to someone in Austin... they seem to love the mini-bikes there.
__________________
gokartrepair.com. Family owned and operated in Houston for 40 years. Parts-Service-Advice
Closed Thread

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 09:33 PM.