Well, should have, and needs to have correct KPI turns out to be two different things when it comes to
cyclekarts. Ever since those Stevensons started with those straight Azusa spindles, with apparently no ill effect, the practice has continued. To the point that probably 95 pct run with no KPI whatsoever. Not to say that it's correct, just that it seems not to be as vital with the skinny tires.
CycleKart Tech Forum
Started CycleKart #3 with suspension
Posted by LowellR
CmdBentaxle
Dave D
Federal Way, WA, USA
![]() 1950 CycleKart Italian "1950 Ferrari 166 F2"
|
Oct 2, 2017 11:00 PM
Top Contributor
![]() Joined 2 years ago
1,099 Posts
|
Sponsored Links. Hide banner ads & support this website by becoming a > Gold Supporting Member <
1908Rick
Rick Eggers
Cape Coral, FL, USA
![]() 1900 Ford Model 01 "Quadricycle"
1908 CycleKart Vintage "Lizzy" 1908 Harley-Davidson Pre-War 1935 CycleKart Speedway Racer & more |
Oct 3, 2017 11:55 AM
Joined 10 months ago
167 Posts
|
Just trying to explain what KPI is, that's all. You can probably get away with a lot of things on a kart that's light weight not capable of very high speeds. That being said, if you're going to build it, why not incorporate all the things in the front end geometry that we know work. Like KPI, scrub radius and ackerman. These things are as important as castor camber and toe. When you're working with 6-10 horsepower, you don't want to be scrubbing off speed in the corners if you can help it You need all the advantages you can get.
moto-klasika
Zoran R. Pualic
Bern, Bern, Switzerland
![]() |
Oct 3, 2017 12:19 PM
Joined 5 years ago
1,199 Posts
|
In reply to # 26717 by CmdBentaxle
Well, should have, and needs to have correct KPI turns out to be two different things when it comes to cyclekarts. Ever since those Stevensons started with those straight Azusa spindles, with apparently no ill effect, the practice has continued. To the point that probably 95 pct run with no KPI whatsoever. Not to say that it's correct, just that it seems not to be as vital with the skinny tires.
====================================================================
Hello, Dave!
It seems that some art was lost in the history of CycleKarts, from Stevenson era up to now?
Most of their CycleKarts (Pete's, or son Mike's, or brother Bill's or of their friends) have proper king-pin inclination and often visible camber, with other steering principles of old Ackerman!
Attached is one Pete's hand-sketch and one similar, but computerised (maybe of some member?), and a pair of photos.
Maybe of some use or not, but as Rick said: "That being said, if you're going to build it, why not incorporate all the things in the front end geometry that we know work"...
Ciao,
Zoran
Zoran R. Pualić
(mostly living in Bern, Swiss & happy in my Belgrade, Serbia)
Sponsored Links. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Attachments:
Tempe, AZ, USA
![]() |
Oct 3, 2017 12:28 PM
Joined 3 years ago
244 Posts
|
I think the discussion of KPI, ackerman, Caster, etc belong in its own topic thread so folks can research, comment on it there.
moto-klasika
Zoran R. Pualic
Bern, Bern, Switzerland
![]() |
Oct 3, 2017 01:27 PM
Joined 5 years ago
1,199 Posts
|
Hello, Rowell!
Your complaint could be good in a case of general discussion about "... of KPI, Ackerman, Caster, etc ...", but comments started about YOUR design of YOUR steering on YOUR CylceKart in YOUR topic? ... and, you were active in that?
Your design and construction are magnificent, but some members found some issues about some details (steering or rear suspension), that could be useful for other members to be clarified!
All the best in following work, with or without other member's comments!
Zoran
Zoran R. Pualić
(mostly living in Bern, Swiss & happy in my Belgrade, Serbia)
Your complaint could be good in a case of general discussion about "... of KPI, Ackerman, Caster, etc ...", but comments started about YOUR design of YOUR steering on YOUR CylceKart in YOUR topic? ... and, you were active in that?
Your design and construction are magnificent, but some members found some issues about some details (steering or rear suspension), that could be useful for other members to be clarified!
All the best in following work, with or without other member's comments!
Zoran
Zoran R. Pualić
(mostly living in Bern, Swiss & happy in my Belgrade, Serbia)
CmdBentaxle
Dave D
Federal Way, WA, USA
![]() 1950 CycleKart Italian "1950 Ferrari 166 F2"
|
Oct 3, 2017 01:30 PM
Top Contributor
![]() Joined 2 years ago
1,099 Posts
|
I must agree with you guys that if a fellow has the means to build his own spindles, it would
be senseless for him to neglect getting it right. The extra complication of doing so, along with the ease
of getting prefab spindles without proper KPI must be what drives most builders that direction.
I stand corrected Zoran! I wrongly credited the Stevensons with the practice, but there is the evidence!
I wonder where it did start?
Anyway, nice build Lowell. I'm interested in how those little coilovers work
out.
be senseless for him to neglect getting it right. The extra complication of doing so, along with the ease
of getting prefab spindles without proper KPI must be what drives most builders that direction.
I stand corrected Zoran! I wrongly credited the Stevensons with the practice, but there is the evidence!
I wonder where it did start?
Anyway, nice build Lowell. I'm interested in how those little coilovers work
out.
Tempe, AZ, USA
![]() |
Oct 3, 2017 03:45 PM
Joined 3 years ago
244 Posts
|
In reply to # 26723 by moto-klasika
Hello, Rowell!
Your complaint could be good in a case of general discussion about "... of KPI, Ackerman, Caster, etc ...", but comments started about YOUR design of YOUR steering on YOUR CylceKart in YOUR topic? ... and, you were active in that?
Zoran
Your complaint could be good in a case of general discussion about "... of KPI, Ackerman, Caster, etc ...", but comments started about YOUR design of YOUR steering on YOUR CylceKart in YOUR topic? ... and, you were active in that?
Zoran
Ha, I wasn't complaining. Just suggesting that these are design topics that apply to all cars. And someone searching for the topic isn't likely to see it my Subject line.
Lowell
Sponsored Links. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Spokane Valley, Washington (WA), USA
![]() |
Oct 3, 2017 04:45 PM
Top Contributor
![]() Joined 1 year ago
264 Posts
|
Use the Search and check this thread from Rhys Nolan it's a good read. there are others also.
An essay on suspension design
Al Lies
The "Not-So Chinsee" guy
An essay on suspension design
Al Lies
The "Not-So Chinsee" guy
classical-gas
Scot Laughlin
Bellingham, WA, USA
![]() |
Oct 10, 2017 08:41 AM
Joined 2 years ago
25 Posts
|
+
You are going to need radius rods, along with that panhard rod, even without functional front brakes. Bump steer and other weirdness happens if the front axle can move any direction other than vertical.
You are going to need radius rods, along with that panhard rod, even without functional front brakes. Bump steer and other weirdness happens if the front axle can move any direction other than vertical.
Sponsored Links. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Tempe, AZ, USA
![]() |
Oct 10, 2017 01:50 PM
Joined 3 years ago
244 Posts
|
Tempe, AZ, USA
![]() |
Oct 11, 2017 02:08 PM
Joined 3 years ago
244 Posts
|
Make my first drive of the chassis! I have an engine miss that I need to address. It doesn't accelerate very well with misses and pops. I was so focused on the engine that I forgot to check the ride. So I made another round and I feel it definitely rides softer than my previous Cyclekarts. I didn't see much if any flexing of the front shocksprings. I'll try to get some video of the front and rear shocksprings in action.
RROLDSX
Randy R
Delta, BC, Canada
![]() |
Oct 11, 2017 04:15 PM
Joined 1 year ago
152 Posts
|
Lowell:
It would be real interesting to note the difference in “eyeball bounce” and loss of control,if any, between your non-suspension kart and this one. I’m keen to copy some of your design if it works.
Randy
It would be real interesting to note the difference in “eyeball bounce” and loss of control,if any, between your non-suspension kart and this one. I’m keen to copy some of your design if it works.
Randy
carChips
Victor Harnish
Kelowna, BC, Canada
![]() |
Oct 11, 2017 08:28 PM
Top Contributor
![]() ![]() ![]() Joined 6 years ago
2,063 Posts
|
Tempe, AZ, USA
![]() |
Oct 12, 2017 03:41 PM
Joined 3 years ago
244 Posts
|
I had modified my carburetor with a new emulsion tube and jet and I must not have done that correctly. I switched back to another stock carburetor I had and now the engine runs nicely. I drove the car over a few speed bumps in the neighborhood and I definitely think it rides softer that my other CycleKarts. I'm going to see if any of the grandkids have a selfy stick I can use to video the shock/springs while driving. If Iget some good video, I'll post it here.
Spokane Valley, Washington (WA), USA
![]() |
Oct 12, 2017 08:17 PM
Top Contributor
![]() Joined 1 year ago
264 Posts
|
Lowell
That would be cool to see or maybe I should say educational either way I would love to see it and hear your thoughts.
Al
Al Lies
The "Not-So Chinsee" guy
That would be cool to see or maybe I should say educational either way I would love to see it and hear your thoughts.
Al
Al Lies
The "Not-So Chinsee" guy
Sponsored Links. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Forums
CycleKart Tech · Custom Karts · CycleKart Events · Buy, Sell & Trade · Vendor Market · The Pub - Off Topic

Having trouble posting or changing forum settings?
Read the Forum Help (FAQ) or contact the webmaster