Project Predator Advise

SAS289

Active Member
#46
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I wasn't able to find anything bigger than a 60t for the 420 chain that I have. However, I did find this nice little calculator:

https://www.gokartsupply.com/mobile/sprocket.htm

I have a 12t sprocket and it seems I should be able to get higher speeds per the calculator by leaving the 60t in and replacing the 10t with the 12t. Would you be able to confirm that is correct?
Do not use a 12 tooth. You would be gearing in the opposite direction and would run out of engine sooner than you are now. You need a higher numerical ratio between the two sprockets. Ole was correct that you should go with a 72 tooth if you want higher RPM at top speed. The 12 tooth you have is probably for a 35 chain anyway. You have a 420 chain.

Those speed calculators are a nice reference but take a couple important things for granted like the load and available power at the given RPM.

Another option would be to get an 8 tooth to go with your 60 tooth. You would need to be careful with pulley alignment because the 8 tooth may be a different width than the 10 tooth you have. I just found this out when I got my 9 tooth which was wider than the 10 tooth that came with the TAV. I had to make a washer to make up the difference for pulley alignment. The 8 tooth may also have a built in key that may be smaller (3/16) than the keyway on your driven pulley shaft which could be 5mm. It would work but is not ideal if the shaft has a 5mm key.

Some people do not like the smaller sprockets like the 8 tooth because there is more friction due to the smaller turn around for the chain..
 
#47
.


Do not use a 12 tooth. You would be gearing in the opposite direction and would run out of engine sooner than you are now. You need a higher numerical ratio between the two sprockets. Ole was correct that you should go with a 72 tooth if you want higher RPM at top speed. The 12 tooth you have is probably for a 35 chain anyway. You have a 420 chain.

Those speed calculators are a nice reference but take a couple important things for granted like the load and available power at the given RPM.

Another option would be to get an 8 tooth to go with your 60 tooth. You would need to be careful with pulley alignment because the 8 tooth may be a different width than the 10 tooth you have. I just found this out when I got my 9 tooth which was wider than the 10 tooth that came with the TAV. I had to make a washer to make up the difference for pulley alignment. The 8 tooth may also have a built in key that may be smaller (3/16) than the keyway on your driven pulley shaft which could be 5mm. It would work but is not ideal if the shaft has a 5mm key.

Some people do not like the smaller sprockets like the 8 tooth because there is more friction due to the smaller turn around for the chain..
Thank you for the info! I went and checked to see how many teeth the old sprocket had and it was 10 as well, so I guess I don't have a 12 after all. I will look into the 8 tooth, I think I seen one for the 420 chain. If I were to change out the sprockets would I be able to put a different chain on it or do I have to stay with the 420? I feel like there aren't many options in the direction I'm looking to go with the 420 and more on a 35 chain. I just don't know if that's something that is recommended to change.
 

SAS289

Active Member
#48
No doubt there are more options with the 35 chain. The smaller 35 chains are strong enough to handle big power if you get a good one. I do not know any of the details of making that change on your bike. There is probably an adaptor plate that bolts to the wheel, then you bolt the 35 chain sprocket to that. And some of those 35 sprockets are split and you do not have to pull the axle out to change them. Pretty nice.
 
#49
No doubt there are more options with the 35 chain. The smaller 35 chains are strong enough to handle big power if you get a good one. I do not know any of the details of making that change on your bike. There is probably an adaptor plate that bolts to the wheel, then you bolt the 35 chain sprocket to that. And some of those 35 sprockets are split and you do not have to pull the axle out to change them. Pretty nice.
Yea, there's an adapter that you put in place and then attach the sprocket to that, looks like you can do the split sprocket as well. I'm going to look into maybe changing the chain then to something a little easier to find options for. I appreciate your input on this and clarifying that I could in fact change the chain out.
 
#50
I was just able to order the Juggernaut today, I'm super pumped can't wait to get that in the mail, I'm going to assume I will have it by the end of the week to the beginning of next week. I also ordered the yellow spring for the driven and should have that any day now. I'll keep you guys posted to the results!
 

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