Why is the rectangular opening on a JK 1/32 C5 chassis too short for a JK Hawk 7?
The opening is .925" long and an FK can is .990" long, requiring the gear end of the motor to sit atop the lip
Am I missing something here?
JK C5 1/32 chassis question
Started by
Pablo
, Jul 21 2026 12:14 AM
11 replies to this topic
#1
Pablo
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Posted 21 July 2026 - 12:14 AM
Paul Wolcott
#2
Mike Patterson
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Posted 21 July 2026 - 12:07 PM
Is there a reason you can't enlarge the opening?
It's weird being the same age as Old People.
#3
Brian Czeiner
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Posted 21 July 2026 - 12:50 PM
Is there a reason you can't enlarge the opening?
I would guess rule restrictions.
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#4
Pablo
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Posted 21 July 2026 - 01:30 PM
Sure I could hog out the opening. But why would they make the opening too small for the motor it was designed for (Hawk 7)?
Paul Wolcott
#5
brnursebmt
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Posted 21 July 2026 - 02:51 PM
Are all FK motors .990? I'm at work and can't measure one.
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#6
MSwiss
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Posted 21 July 2026 - 03:16 PM
FK"s are all approximately .990" long.
That chassis came out 2 owners ago.
If Pablo wants, I'll give him Jerry Kulich's #. Lol
We raced them in approx. 2013 at my last location.
I forget what motor we used.
It might have been a Hawk 6 or Proslot minimotor, which both have a real endbell and are much shorter.
- Pablo likes this
Mike Swiss
Inventor of the Low CG guide flag 4/20/18
Former IRRA® Components Committee Chairman
Five-time USRA National Champion (two G7, one G27, two G7 Senior)
Two-time G7 World Champion (1988, 1990), eight G7 main appearances
Eight-time G7 King track single lap world record holder
17B West Ogden Ave., Westmont, IL 60559, (708) 203-8003, mikeswiss86@hotmail.com (also my PayPal address)
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#7
Pablo
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Posted 21 July 2026 - 03:31 PM
Mystery solved, thanks Mike 
Next question - for a track like this, Hawk, or Hawk 6?
What ballpark gearing for .700-ish wheels?
Paul Wolcott
#8
MSwiss
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Posted 21 July 2026 - 03:33 PM
You should probably query the owner.
Mike Swiss
Inventor of the Low CG guide flag 4/20/18
Former IRRA® Components Committee Chairman
Five-time USRA National Champion (two G7, one G27, two G7 Senior)
Two-time G7 World Champion (1988, 1990), eight G7 main appearances
Eight-time G7 King track single lap world record holder
17B West Ogden Ave., Westmont, IL 60559, (708) 203-8003, mikeswiss86@hotmail.com (also my PayPal address)
Note: Send all USPS packages and mail to: 692 Citadel Drive, Westmont, Illinois 60559
#9
Pablo
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Posted 21 July 2026 - 03:54 PM
Track isn't set up yet. I'm just now setting up some cars for it.
Chattanooga, TN home track.
I did a Slotblog search Hawk vs Hawk 6, I'll try a Hawk 6 and gear it conservative.
Thanks for solving my quandary, now I can live happily at ground zero 
Paul Wolcott
#10
Bill Seitz
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Posted 21 July 2026 - 05:51 PM
I haven't run a track as short as this one looks, but my gearing guess for an H6 is 4:1 min. There was an early arm for the hawk that looks to be about a 30K motor, but today the main difference is the Hawk has ceramic mags, and the H6 poly neos.
#11
Dominator
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Posted 21 July 2026 - 06:39 PM
I would start with 64 pitch 10/36 then try maybe 9/35.
72 pitch 11/42 or possible 10/40.
72 pitch 11/42 or possible 10/40.
A motor is only as fast as the chassis it's in.
Dominic Luongo
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#12
Pablo
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Posted 21 July 2026 - 08:05 PM
Thanks guys 
Paul Wolcott
