Scythe really high cross %

G

griff42088

Member
Hi all, new to the forum and just getting my two boys into karting. I have a 2020 Scythe that when scaled out the LT side and nose numbers are right where we want them but the cross is really high (78%). This is for a red plate driver at 250 weight requirement (FYI I have added 50lbs of lead to make weight). I have moved the lt front spindle almost all the way down (washers on top) and the RT front spindle almost all the way up (washers on bottom) and still have this high of a percentage. Is there any way to lower the cross while minimally changing the other percentages. Any insight is greatly appreciated?
 
What tire staggers ?
Where is the lead placed ?
What are all the other numbers ?
Front ,left and cross .
Your sure the axle isn't in the wrong holes .
Air pressure set and driver in kart with scales level ?
 
Thank you for the response!

Front stagger - 1 5/8"
Rear stagger - 1 3/4"
Lead placed - 4 blocks (20lbs LT side of seat) 4 blocks (20lbs RT side of seat) 2 blocks (10lbs rear of seat)
Front - 46.5%
Left - 54.5%
Cross - 77.8%

Axle is in the same holes LT & RT side. Arrows on casset lined up to top of hanger as per PRC.

Air pressure, RT side at 6psi and LT side 5psi

Yes, driver in kart and all scales level.
 
Too answer the cross question
Adjusting the spindles is really the only way to change cross with out affecting the other numbers .
Tire stagger also affects it .
 
That puts
29# lft ft
87.25 rtf rt
107.25 lft r
26.5 rr
A call to PRC might be best .
Thats not what i would want for numbers either .
 
If using wired kart scales, are all under the correct wheel?
With correct cord plugged in?
Tires at race pressures?

Numbers definitely weird.

Without driver, one wheel should be not touching.
 
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flat top, thanks for the advice. I will call PRC if I cannot get it straightened out.

ColeAchey, have our suspensions of something being bent and I did see they offer a no cross spindle so was thinking of trying that as well. Thank you for your reply.

95shaw, these are individual scales and have been leveled and weight accuracy confirmed multiple times. Tires are currently 5lbs LT side and 6lbs RT side. Yes without driver the left front is barely touching the scale (has only 12lbs on it). Thank you for the reply
 
griff42088 said:
flat top, thanks for the advice. I will call PRC if I cannot get it straightened out.

ColeAchey, have our suspensions of something being bent and I did see they offer a no cross spindle so was thinking of trying that as well. Thank you for your reply.

95shaw, these are individual scales and have been leveled and weight accuracy confirmed multiple times. Tires are currently 5lbs LT side and 6lbs RT side. Yes without driver the left front is barely touching the scale (has only 12lbs on it). Thank you for the reply
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Try 1 1/2 stagger in the front and 1” I’m the back. Unless you’re racing a bullring that’s a lot of stagger. It’s not uncommon to see 68- 72% cross in PRC karts.
 
Low cross spindle , is only going to get you 2 maybe 3% or slightly more . Definitely not 10%.
If you got it second hand , twiseted is possible .
I would call prc see if they can tell you with the spindles evened out what it should scale out like.
 
First thing, the Scythe has a lot of cross built into it. It's not uncommon at all! We were close to you when we started with ours.

Second, if you're red plate you're probably running your right sides at 34.5 or close to it since that's the max, assuming you're on a gear rule?. So that's really going to throw stagger for a loop. We generally go 1.25 rear.

I would set the Right front two thick washers on the top, and where it falls try it. It might surprise you. We're running a lot more cross in ours than we normally would for most chassis and the kart really likes it. Then if it seems to be a problem, start looking for a solution. Sometimes you could do more harm trying to get the numbers you "want."

(Edit)
I'd try melting some of the 5lbs into 10's and put two 10's on the left. Then stack two 5's on top of the 10. Then, put the rest to make weight back on the right side. That will get you more left side, and keep the total where you want it. You could potentially put three 10's on the left, but those seats are tiny. If your seat is mounted correctly, transfer should still happen.
 
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Many PRC riders that I know don't even look at cross. It's all about washer placement for them. I believe that's what James at PRC suggests as well. This could change for a JR driver.
 
With 1.75" rear stagger, you have 78% cross....something dont sound right to me there. If you put in an inch of rear stagger your cross will raise more.
Seat mounted wrong, hub placement, cassette, spindle, something isnt quite right.
 
Yeah I always just set the washers and make sure everything else is right and leave it. Two washers on bottom of right and two or three on top of left. Leave it like that and check everything else
 
SoCo Tire Treatments said:
With 1.75" rear stagger, you have 78% cross....something dont sound right to me there. If you put in an inch of rear stagger your cross will raise more.
Seat mounted wrong, hub placement, cassette, spindle, something isnt quite right.
Click to expand...

I'm betting the scales are off. At 78% cross loaded with the driver, that would put cross in the 90% range unloaded, and the LF wouldnt even touch the scale, where as OP says unloaded he has 12 LBS on the LF scale.
 
Not that long ago there was a similar post real high cross, of course scales and air pressure was pointed out, of course the guy asking said pressures were good, 2 days later he discovered 20 plus 1lb of air in the RF he put it in to grow the tire and forgot about it, as mentioned I'd recheck scales and air pressures.
Good luck !!
 
t
95 shaw said:
If using wired kart scales, are all under the correct wheel?
With correct cord plugged in?
Tires at race pressures?

Numbers definitely weird.

Without driver, one wheel should be not touching.
Click to expand...
thats what I was going to say, I had one gave me a fit one time and that's what it was, one scale was at the wrong place.
 
griff42088 said:
Hi all, new to the forum and just getting my two boys into karting. I have a 2020 Scythe that when scaled out the LT side and nose numbers are right where we want them but the cross is really high (78%). This is for a red plate driver at 250 weight requirement (FYI I have added 50lbs of lead to make weight). I have moved the lt front spindle almost all the way down (washers on top) and the RT front spindle almost all the way up (washers on bottom) and still have this high of a percentage. Is there any way to lower the cross while minimally changing the other percentages. Any insight is greatly appreciated?
Click to expand...
First Call James at PRC. We just left red plate to Junior 1 and we're on a .083 2020 Scythe. 78% is high than we were, but we got to 74% or so. I'm not going to mention anything else because you really should talk to James. They really been trying to reestablish connections with their people and James is their lead for Trackside support. If you hit up James Stanley-Racing on FB he'll message you back in a timely manner.
 
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