I have a TAV2 on my Ty-Rail gokart. It came with a 6" driven. I assume it was chosen because it had a wider shifting ratio than the 7". I had a 7" with belts lying around from my old Yerf Dog. Tried it out, and 
hmy:, the TORQUE. It wasn't just the fact that it was an inch bigger, but the belt just hooked from a dead stop. The old 6" would slip around until 10mph when it decided to give a :001_9898:. This 7", because of the extra surface area, can handle the low end torque.
In the past, I've tried to gear the 6" way low (like 24mph top end), and I could never get the engine to rev past it's usual 3800rpm at top end. This 7" though, I had it geared to top out at 40mph and it revved! I got 4700rpm holding the governor open (little scary running stock).
I guess if you want low-end torque or if you're racing and revving in high gear, the 7" is a no-brainer. The 6" looks good on paper, but in real life it slips. It probably works for lower HP engines, but not my 6.5.
Disclaimer: This is just my experience. I'm not trying to be right, just sharing.
Ty
hmy:, the TORQUE. It wasn't just the fact that it was an inch bigger, but the belt just hooked from a dead stop. The old 6" would slip around until 10mph when it decided to give a :001_9898:. This 7", because of the extra surface area, can handle the low end torque.In the past, I've tried to gear the 6" way low (like 24mph top end), and I could never get the engine to rev past it's usual 3800rpm at top end. This 7" though, I had it geared to top out at 40mph and it revved! I got 4700rpm holding the governor open (little scary running stock
).I guess if you want low-end torque or if you're racing and revving in high gear, the 7" is a no-brainer. The 6" looks good on paper, but in real life it slips. It probably works for lower HP engines, but not my 6.5.
Disclaimer: This is just my experience. I'm not trying to be right, just sharing.
Ty
