Hello all
I’m wanting to enter LO206 karting. As I understanding it I need to buy a clutch sprocket which remains the same and just change the rear sprockets for each track.
Reading, #219 pitch give better options than #35 pitch.
May I ask what front sprocket size you all run and the pitch you use.
Thank you.
#219 19 front for rain/20 for dry.
Range is 67-71ish rear
At my track 35 pitch is required to race 206, my front driver is 15 tooth while my rear sprocket is 53 teeth (higher top speed on straights) or 54 teeth (more acceleration coming out of the corners).
My track is AMR Motorplex. Everybody runs more or less the same setup over here as far as gearing goes. I’d say it really depends on your track. I’d recommend asking a few people first as you don’t want to have 15 different sprockets (yet 
). Good luck!
Not as simple as 1 drive sprocket and changing the rear only. You may need to do both depending on the track you are at.
We’ve ran both 35 and 219. Typically 15-17 on the 35 and 19-21 with 219.
Link shows you how each size correlates.
gearing changes a lot from track to track. i run 35 chain, and use 15, 16, or 17 drivers (the front sprocket on the clutch) and for rear gears usually 56 to 63. your rear gear can get kinda close to the track surface when u get up around 64 on the back, so i don’t usually go over 63.
Depends on what track you running. I run a 17 or 18 front driver and 53-60 rear sprocket depending on what configuration we are running that day.
It will vary greatly with track layout and grip. We ran 19/65 to 19/69 (3.42-3.63) on the regular at NTK when we were running LO206. When we went to Waco we would be 17/69 to 17/72 (4.06-4.24) or so. I carried a 17, 18, 19, and 20 driver and ran 65-74 rear sprockets to hit most any combination we needed. I didn’t like running large rear sprockets on LO206 because that mid-axle sprocket was just asking to get nailed on a curb or ledge if you dropped a tire. We ran on about 7 different tracks in the 206 ranging from 400 ft straight and under 30 second laps, to 925 ft straight and 75 second laps.
If you stay at 1 place you will be able to get away with 1 driver and 3-4 sprockets. Find out what the locals run. Ask the fast guys and then buy a rear sprocket about 4-5 teeth larger and go from there. As you get smoother you will be able to drop teeth for more top end without hurting yourself out of the corner.
Hi guys, thanks for your responses. It sounds like you guys are pretty pro at this karting caper!
I’ll be limited to maybe 3 tracks so I’ll do as suggested and ask about. I know one of our sealed engine providers has homologated a 19 tooth clutch.
I really welcome learning about this scene.
Thank you.
I’ve managed “ok” with a 219 with a 18 in front, and then 66-74 or so in the rear. I run a sprocket guard so haven’t had problems with hitting curbs. Is there another advantage to 19-70 vs. 20-74, such that it’s worth changing the front sprocket out? Obviously it’s less work changing rear sprockets only.
Sometimes.yoi just need half a tooth on the ratio and you swap the driver and rear for that.
Example of what Burpo was saying. By playing with front drivers you can really split the gaps between ratios down super small. We only found need for that on occasions.
70/20 = 3.5
67/19 = 3.526
71/20 =3.55
68/19 = 3.579
72/20 = 3.6
65/18 = 3.611
69/19 = 3.632
73/20 = 3.65
66/18 = 3.667
70/19 = 3.684
74/20 = 3.7
67/18 = 3.722
71/19 = 3.737
75/20 = 3.75
68/18 = 3.778
72/19 = 3.789
76/20 = 3.8
I didn’t like running over a 74 rear sprocket in 206, kinda funny since now we almost never run that small on KA. 
This would let us hit a super wide range with 3 front drivers and 8 rear sprockets.
65/19=3.421
66/19=3.474
67/19=3.526
68/19=3.579
65/18=3.611
69/19=3.632
66/18=3.667
70/19=3.684
67/18=3.722
71/19=3.737
68/18=3.778
72/19=3.789
65/17=3.824
69/18=3.833
66/17=3.882
70/18=3.889
67/17=3.941
71/18=3.944
68/17=4
72/18=4
69/17=4.0588
70/17=4.118
71/17=4.176
72/17=4.235
I actually made my own in excel and colored and spaced it to make it easier to read. I hated all the ones online, just too hard to read.
I made my own as well.i added a couple of columns to show speed at 2 RPMs to help me visualize the change. At the time we were running cadet and being on the limiter wasn’t ideal.
Yeah, the actual ratio number is kind of abstract. What I want to know is when the limiter will kick in, what my min rpm will be for a given min speed, etc.
I made this one in Excel, printed it out then laminated it. I couldn’t find one I liked that had the full range of big and little gears. Has some extra columns for approximate chain speed and change per tooth. Also has a link count to length(ish) chart at the bottom.
I love the Comet chart but this one is special!
Can you elaborate on your comment about min RPM and min speed, please?
I’ve been trying to work out why but haven’t been able to.
Thank you.
Let’s say a critical turn on some track is 40mph. If your current gearing puts you at 4,500rpm through that corner, it is helpful to see what rpm a different gearing would put you (and consequently what hp you’d get). Same logic applies to the slowest corner (min speed) and top speed. If you are rev limited to 55mph with your current gearing, a 10% higher numeric ratio will drop your top speed to 50mph.
The whole “higher ratio = more torque” thing is based on the idea of a dead flat torque curve. In classes where you can rev well past peak hp, a lower gear ratio may actually get more pull out of mid speed turns.
An extreme example is Kid Kart where the comer is ran with spec gearing that puts peak hp at 20mph. No turn on the track is that slow, so we dropped a ton of teeth off the rear sprocket and picked up a lot of acceleration.
