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Discussion Starter #1
Just got my son a MX650 and he already busted the rear sprocket. Razor is sending a new one under warranty. What mods or aftermarket part can be used to increase the strength and reliability of this item? He only weighs 50 lbs. I know this is sort of a common problem so just looking for some real world solutions. I don't really want to have to purchase a $50 wheel every couple of weeks, especially since my son is upset can't ride it till its fixed.
 

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But who prays for Satan?
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Hmm, is it possible the rear wheel was / is out of alignment (not perfectly straight) ??? I could imagine that might have some unpredictable results when paired with an electric motor, and a kid trying to "Have Some Fun"

I'll do some searching and see what I can find out for you! <--It might take a day or two, I have not looked into this issue before.

maybe another member has a "Quick Fix" for this problem.

Good Luck.

Just got my son a MX650 and he already busted the rear sprocket. Razor is sending a new one under warranty. What mods or aftermarket part can be used to increase the strength and reliability of this item? He only weighs 50 lbs. I know this is sort of a common problem so just looking for some real world solutions. I don't really want to have to purchase a $50 wheel every couple of weeks, especially since my son is upset can't ride it till its fixed.
 

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Well you could buy a h25 chain that may help or you could buy a stronger sprocket they are not hard ro replace. Do not get a smaller sprocket if you are going to replace the sprocket because you would need a chain breaker the bike in my avatar photo has a 65 tooth sprocket and I needed to take 10 links off of the chain to fit it, you could get a sprocket custom made or find one online. Good luck!
 

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Also where did you buy it from because it could of just came with a bad sprocket and by riding it, it may of bent the sprocket even more making it impossible to ride.
 

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Discussion Starter #5
Sorry I think I might have explained the part wrong. I am speaking of the freewheel hub, freewheel clutch. The chain and sprocket are fine. You twist the throttle and the bike doesn't move, the chain spins free without engaging the wheel. So that is the part I am looking for.
 

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I think that the wheel assembly needs to be turned around but I am not completly sure if this would work.What I think happened is somethink in the wheel assembly broke making it do this but as I said I am not sure that is the problem.
 

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Try spinning the freewheel setup off the hub and turning it around first. It's on the left, I'm assuming? Anyway, keep it on the left side, just turn the freewheel assembly around, see if that helps. If not, time to get another one .... Like nick said, freewheels are like ratchets - they spin in one direction, and lock up to turn the wheel in the other.
 

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the springs on the freewheel are weak! any real resistance will strip them. My little e300 has 5 12v batteries and 2 motors...when it's cold out(50 or lower) the thing will just spin. if I push the bike back and forth a few times it will catch and I can go again. My guess is the torque from the 3 extra batteries.
I was going to convert a MX with a small gass engine and try to use the stock hub. it is not recommended because the free wheel is so weak.

a solution for you would be to remove the freewheel and sprocket. order a 90t currie sprocket. it will thread onto the wheel, and easily replace the freewheel. he won't beable to coast as well as before, but you won't strip the ratchet.
yeah you'll need a few extra links, but the bike will have a slower top speed, but much faster pickup. This is perfect for grass and dirt where you need more torque and less motor heat.
my bike will do 24mph on asphalt and 18-19mph in the dirt.
 

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the springs on the freewheel are weak! any real resistance will strip them. My little e300 has 5 12v batteries and 2 motors...when it's cold out(50 or lower) the thing will just spin. if I push the bike back and forth a few times it will catch and I can go again. My guess is the torque from the 3 extra batteries.
I was going to convert a MX with a small gass engine and try to use the stock hub. it is not recommended because the free wheel is so weak.

a solution for you would be to remove the freewheel and sprocket. order a 90t currie sprocket. it will thread onto the wheel, and easily replace the freewheel. he won't beable to coast as well as before, but you won't strip the ratchet.
yeah you'll need a few extra links, but the bike will have a slower top speed, but much faster pickup. This is perfect for grass and dirt where you need more torque and less motor heat.
my bike will do 24mph on asphalt and 18-19mph in the dirt.
Thanks bassiclyloudog !!!!!
 

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silly me....I want to specify that my speed results are stock gearing!!! I hit 24mph....with a 90t you'll be around 20mph or less, but I feel that your speed won't change much on dirt because of the extra torque. 10teeth will make a big difference.
I'd like to see an 80t and a 90t side by side in the dirt for a comparison.
 

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But who prays for Satan?
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silly me....I want to specify that my speed results are stock gearing!!! I hit 24mph....with a 90t you'll be around 20mph or less, but I feel that your speed won't change much on dirt because of the extra torque. 10teeth will make a big difference.
I'd like to see an 80t and a 90t side by side in the dirt for a comparison.
Thanks for the FREE info!

NASA.
 
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