Considering ANOTHER Gearing Change

[metalthrashinman]

Not wanting to compromise any top speed, and considering that my GTC 30 is not shifting to overdrive well; does anyone feel that dropping from a 9t front sprocket to an 8t will cause my desired outcome of faster and better TC shifting thereby increasing my kart's top speed, or will this gearing change be radical enough to slow me down significantly enough to decide that the experiment would be disappointing?

Note: 18" tires, 54t rear, 9t front (right now), 9hp Subie engine on GTC Tav2 30-100.

 

[Blazkowiez]

I do have to say that its not too expensive... these are relatively new items from Azusa however. I've never seen one on a kart, but I have yet to see them send us a bad product from their machines, they are really top notch people.

 

[Doc Sprocket]

You'll be going from 6:1 to 6.75:1. Not too radical. Under the circumstances, I'd say there's pretty even odds it will work out. I know that with my heavy kart and large tires, I did manage do gain both acceleration and top end by gearing a little lower (went from 4:1 to 4.8:1). This is with 300lb kart, GX340 11Hp, and Comet 40.

 

[metalthrashinman]

You'll be going from 6:1 to 6.75:1. Not too radical. Under the circumstances, I'd say there's pretty even odds it will work out. I know that with my heavy kart and large tires, I did manage do gain both acceleration and top end by gearing a little lower (went from 4:1 to 4.8:1). This is with 300lb kart, GX340 11Hp, and Comet 40.

Nice! Good to hear. Okay, I ordered the 8t today. I'll let you know how it works out.

Thanks to you too, Blaz. He took my order today.

 

[Camdat67]

80 tooth rear.

Hi Metal.
I got my 80 tooth rear sprocket from azusa today and I hope to get it drilled out and fitted hopefully this weekend. Its bloody huge (approx 13" diameter) but Ive got good ground clearance with the 22"s on the back. I will let you know the top speed and how the belts go once its on. I reckon going from an 9 to an 8 on yours will be a fairly small ratio change, but it should make it better. My CVT gets a bit funny when its really hot and getting dirty inside, so lots of compressed air and then I hit it with brake cleaner. You can also take the sprocket end pully off and put the internal spring in the softest hole which lets it shift up quicker. I put mine into the hardest one to slow down the change, but with the 13hp it was not really noticeable.
Cheers Cam.

 

[Blazkowiez]

Dude, have you tested it with the 8t yet?

 

[metalthrashinman]

Hi Metal.
I got my 80 tooth rear sprocket from azusa today and I hope to get it drilled out and fitted hopefully this weekend. Its bloody huge (approx 13" diameter) but Ive got good ground clearance with the 22"s on the back. I will let you know the top speed and how the belts go once its on. I reckon going from an 9 to an 8 on yours will be a fairly small ratio change, but it should make it better. My CVT gets a bit funny when its really hot and getting dirty inside, so lots of compressed air and then I hit it with brake cleaner. You can also take the sprocket end pully off and put the internal spring in the softest hole which lets it shift up quicker. I put mine into the hardest one to slow down the change, but with the 13hp it was not really noticeable.
Cheers Cam.

Thanks for the update. Good luck!

 

[metalthrashinman]

Dude, have you tested it with the 8t yet?

Thanks Blaz, I recieved the package yesterday (Tuesday). I have not put it on yet because I am sick. Got a 'Z' pack from the doc today, so I should be up and around soon. I will let you know how it works. I like how it is keyed and does not need that extra rectangular insert. Seems like a quality piece. Have you used one yet?

The belt that you sent me seems to be very high quality. I am excited to try the combination together (gearing and belt). I'm betting that this is it - what the 30 series TC needs to work at it's best. Probably in the spring I am going to search for a 40 series, though; as I feel that I will be able to go back to the higher gearing, and use the motor to it's full potential. It is a waste to have a wimpy TC on this beast!

The other option I am investigating is to purchase a used, broken down Warrior kart, and transfer the new motor to it. These have the EX27 and 40 series built in from the factory. It is a larger kart, and is made to handle the power that I have. Have you ever seen one of these?

 

[Blazkowiez]

During your downtime it would be very useful to get a dry moly spray for lubrication of the drive clutch. It does not require much lubricant but it his helpful for a long lasting belt experience, I know I really haven't hit much on this before but it will be useful if you don't mind keeping a good quality dry lube in your garage.

Warrior kart? By that do you mean a more upgraded XTK? I'm sure its a slightly larger Manco but would be just fine.

We actually have not gotten to use one of these yet, we will eventually when we get a use, and I agree it does look like a quality product. The people at Azusa are great.

 

[metalthrashinman]

Tell us more about this lubricant... Never heard of it. Even though I am down, my son continues to drive the kart. I have a lot of property, but he is wearing out a track for sure. Including a nice banked turn!

Should have the kart re-geared and re-belted by the weekend.

Warrior kart pics:

 

[metalthrashinman]

more:

 

[Blazkowiez]

Yeah, its just a little big bigger XTK, i'd bet they did very little to the kart to beef it up, these karts were beasts to begin with, heck. I rode the exact same kart you own (not modified) today following repairs on their brakes and steering.

I forgot to mention this earlier, you have a smaller manual disk brake on your kart currently trying to contain a massive powerplant?

We've had to convert a few of these karts over to 5-6" band brakes to make them lock up fully, occasionally they work well but it just is rare once the disks start to wear. Manco should have followed suit of Kenbar which used dual 9" disk brakes on their larger karts. Aside from that Manco really makes a fantastically high quality kart in every aspect, they're an exceptional company.

 

[metalthrashinman]

I forgot to mention this earlier, you have a smaller manual disk brake on your kart currently trying to contain a massive powerplant?

Um, yeah. The brakes are sub-par. I did not consider this when making the upgrade. If you step on the pedal really hard...

BTW-- If you drove the same kart today, while unmodified, what do you estimate it's top speed at? I foolishly did not measure that.

 

[Blazkowiez]

It most likely topped out at around 29 governed. These are large karts with a 6.5hp motor on them.

http://www.mfgsupply.com/m/c/204097A..html?id=BYa2KHww

Thats one item that you can most likely find at Grainers cheaper, its not going to be Comet brand but any sort of dry Moly spray lube would do the job.