some PG short roller tuning data

[dv/dt]

Last week i bought this set of rollers, but i didnt get around to testing them until today.

https://www.treatland.tv/polini-16-x-13 ... 42.413.htm

I thought i'd mess around with my weights and see how it felt.

I started with 37.5g in the vari and it immediately felt overly revvy, like it was revving past the powerband. Went on a long road to test and it held about 10.3k rpm and maxxed at 55mph. Didnt feel good.

Loaded vari up with 39g this time. Now rpms held around 10k at wot and top speed was 58mph, felt slightly better but still not good.

Tried 40.5g and now rpms held around 9800 rpm at wot and it felt better, but top speed was still 58mph. Im thinking the wind was not in my favor on that run.

Lastly i tried 42g which held the engine around 9600 rpm and it felt great. Maxed out at 66mph.

Thats the biggest polini rollers i have, so i'm a little bummed i bought the wrong range of weights!

Anywho, im thinking the pg short powerband is somewhere between 9000 and 9700rpm. Anyone else have similar results?

[bakaracer]

now was that with 1 run with 42g in that it did 66mph or more than 1 run because thats a big jump in mph for only 200rpm difference . gps is not 100% accurate and it will jump mph at times when its trying to find the signal. u need to to do at least 3-4 runs and take the average and make sure you can see the speeds its displaying. because if your doing 55 then 58 and its taking a few to get to the next mph then all of a sudden you see 66mph, thats not correct. look how much of a difference it was just for you to gain 2mph from weight change and rpm diffence and what you felt. to gain another 8mph of topend that means you have to gain another 1-2hp and torque which by changing just 1.5g wont do.

[dv/dt]

now was that with 1 run with 42g in that it did 66mph or more than 1 run because thats a big jump in mph for only 200rpm difference . gps is not 100% accurate and it will jump mph at times when its trying to find the signal. u need to to do at least 3-4 runs and take the average and make sure you can see the speeds its displaying. because if your doing 55 then 58 and its taking a few to get to the next mph then all of a sudden you see 66mph, thats not correct. look how much of a difference it was just for you to gain 2mph from weight change and rpm diffence and what you felt. to gain another 8mph of topend that means you have to gain another 1-2hp and torque which by changing just 1.5g wont do.

Yea, that is true. I should get or make a mount so i can see the speed as i go. As it is i just use my phone gps and check it after i come to a stop at the end of the run. Suppose i could have someone follow me in a car too!

[bakaracer]

now was that with 1 run with 42g in that it did 66mph or more than 1 run because thats a big jump in mph for only 200rpm difference . gps is not 100% accurate and it will jump mph at times when its trying to find the signal. u need to to do at least 3-4 runs and take the average and make sure you can see the speeds its displaying. because if your doing 55 then 58 and its taking a few to get to the next mph then all of a sudden you see 66mph, thats not correct. look how much of a difference it was just for you to gain 2mph from weight change and rpm diffence and what you felt. to gain another 8mph of topend that means you have to gain another 1-2hp and torque which by changing just 1.5g wont do.

Yea, that is true. I should get or make a mount so i can see the speed as i go. As it is i just use my phone gps and check it after i come to a stop at the end of the run. Suppose i could have someone follow me in a car too!

thats the worst accurate way of checking your speed. the car can get up to 5mph difference in less than 2sec with just a slight push of the pedal and anyways the the speedo on most cars are off by about 3mph faster. tire wear will come into play also as that will show a slight faster reading and if the have aftermarket wheels then its a guess after that depending on the size rim tire aspect ratio and so on. you want a pretty accurate reading, find a cop that willing to check your speed with a laser gun or one of those radar guns are pretty accurate. the signs that post speed limits are pretty close too.again if your just getting to lets say 58mph and your in that range of speed +/-2-3mph then you see a speed like say 66mph, then no way thats correct. if you want to be honest on finding what speed your bike really goes, you wouldnt use that data when you see a speed like that pop up on the gps.unless you did a serious upgrade to the motor size to gain more hp.