July 1, 2014 at 5:26 am #29648
Ok I been wondering for a while if chain length really matters on the shifter karts?
Does it matter if you run short or long or medium and does it affect weight distribution by much. Obviously it depends on gearing but it’s just a thought I was wondering.
July 2, 2014 at 12:52 pm #29708
Bump to get more feedback. I am curious as well.
At the very least I am sure there would be some impact on balance. If gearing stayed constant, a longer chain would push the engine further forward, and a shorter chain would move it further back. So definitely a change in weight distribution. The armchair engineer in me says it would be smarter to use a shorter chain when possible; however, I have found a few things to be counter-intuitive in the past :P
2010 Spirit [Birel] SP32 // SRS CR125 - Stock Honda [#08]
Hill Country Kart Club - New Braunfels, Texas - http://daledaugherty.wordpress.com/
July 2, 2014 at 1:04 pm #29709
I too am curious on what the general knowledge is on how this applies to karting…
I know in the Formula 500/600 world, the answer is generally defined by how reliable you want the chain to be. A longer chain generally means a cooler chain (since each link makes fewer RPM, it has more time to cool each trip around)… but a longer chain also means a heavier chain, which translates into rotating mass and lost horsepower. For the F500/600 cars, which have a similar power::weight ratio, but roughly double of both – it’s generally preferable to go for the maximum chain length practical. This is done by either increasing the center to center distance, or by running the largest rear gear practical and then selecting the appropriate front gear for the track. A longer chain made by gear selection is also preferable to a longer chain made by c2c distance – since this also means the chain needs to bend less around the front gear (and thus less heat, less wear & tear, less parasitic drag).
July 2, 2014 at 5:06 pm #29716
I’m quite surprised no one has answered this one.
With the shifter kart you can only get 60link 428 chains but correct me if I’m wrong. Obviously with gearing bigger or smaller you have to shorten the chain or use maximum length.
If a kart seat 10mm further forward or back can make a difference I’m sure a engine 10mm further forward or back can also make a difference. Maybe I answered my own question but who knows. It’s got me thinking.
Anyway I will try a 59 link chain on Saturday, it’s 59 because my engine stop was at max length.
July 2, 2014 at 6:36 pm #29719
I had my kart on the scales this winter when I was installing a new seat, a friend and I played with moving the engine. Basically what we found is that the engine placement made very little difference. If we moved the engine roughly 4 inches it would only change the F:R bias 0.2% cross would not change at all. I was getting more weight transfer by putting my hands on the steering wheel vs my lap.
This was with my TopKart with a TM k9b. Engines don’t weight that much for a kart, yeah it is 32 lbs but when it is right next to the driver that weighs 150-200lbs. The driver is going to have a much greater influence on the kart.
Not to mention how the engine is mounted to the chassis vs a seat.
July 2, 2014 at 8:29 pm #29727
A lot of times chain length is determined by your chassis. Does your J arm clear the right side seat strut when going through shifting movements? Moving motor to far forward, the shift linkage might interfere with this member. Another thing to consider is actual motor clearance to you, the driver. If the motor is too far forward, the driver will be hitting his elbow on parts of the motor. I agree, a longer chain would run cooler, so run as large rear sprocket as you can to get the gear ratio you are looking for.
#55 Honda CR80
July 15, 2014 at 9:01 pm #30344
As mentioned above, you are mostly trying to find a good compromise with comfort (elbow), weight distribution, and clearance with the motor. Once I find that spot on the rails, I try not to move it much. I have 3 different length chains for my kart, 54-56-58 links. I use different size chains with different gear ratio’s, basically to help keep the motor from moving more than 3/8″ either way. I have a chart of the gear ratio’s I have available in my tool box. For example, if I go to a 16-26 ratio, I know a 58 link chain will keep the motor and the shift lever in the same spot. Makes gear ratio changes quick and easy in the pits.
August 18, 2014 at 7:16 pm #32253
To the gent who was talking about the formula 500/600 cars. The F500 will use a belt as their is no gear box but the F600 will use a chain as it does have a gear box.
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