Gear ratio game changer

tmo1620

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Cause we all know how good brakes work going down hill......
Better than no brakes, wasnt the big straight hills that you climb and come down, more so the single track trail through cut blocks with hard 90's to turn, tough to do at free wheeling speed
 

Teth-Air

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QD-2 is not a game changer, only a long awaited improvement or evolution to the Quickdrive design. I have been selling gear down kits for several years and know the performance gains are real. It won't be as good as a system that uses a tensioner due to lack of top gear contact and need to run a tight ass belt but the gearing will certainly be better. I foresee that Polaris will have to now need to change the clutching for 2021 to make the best use of the gearing and extra power these 850's are making.
 

Rhodesie

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always wondered why on an aftermarket belt drive set up the tension is applied to the back of the belt. you end up with this big looey in the belt.
from what i've seen a lot of poly chain belts are tensioned from the inside. nothing can strain a belt as much as a fuel car. only time they blow a belt is if they sneeze the blower.
supercharger-belt-drive-system-on-the-front-of-a-dedicated-v8-drag-AX71JJ.jpg
 

Teth-Air

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always wondered why on an aftermarket belt drive set up the tension is applied to the back of the belt. you end up with this big looey in the belt.
from what i've seen a lot of poly chain belts are tensioned from the inside. nothing can strain a belt as much as a fuel car. only time they blow a belt is if they sneeze the blower.
https://c8.alamy.com/comp/AX71JJ/su...n-the-front-of-a-dedicated-v8-drag-AX71JJ.jpg

You can wonder no more. When you have limited space for a large bottom gear your only choice is to make the top gear smaller to get the ratio you are looking for. When you do this you limit the number of teeth in contact with the belt and the belt can get stripped quite easily. By wrapping the belt around the top gear you get the best of both worlds, small gear and lots of contact. To do this you need to tension the belt from the outside, which is perfectly acceptable to Gates.
 

Rhodesie

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when i worked at the dealership i talked to an engineer about their belt drive. in 2012 snowcheck season. i asked about a longer belt with a tensioner instead of what they had. he said they tried different combos like that and found them to be inefficient. apparently gates charged them 100g's to make the original mold for the belt drive.
 

Pistonbroke

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You can wonder no more. When you have limited space for a large bottom gear your only choice is to make the top gear smaller to get the ratio you are looking for. When you do this you limit the number of teeth in contact with the belt and the belt can get stripped quite easily. By wrapping the belt around the top gear you get the best of both worlds, small gear and lots of contact. To do this you need to tension the belt from the outside, which is perfectly acceptable to Gates.


I was going to explain it, but can't do it better than this. More wrap = more teeth in contact = more shear strength on the belt teeth. In this case, the tensioner from the outside on the back of the belt is superior.

Cheers guys, stay safe.
 

Caper11

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always wondered why on an aftermarket belt drive set up the tension is applied to the back of the belt. you end up with this big looey in the belt.
from what i've seen a lot of poly chain belts are tensioned from the inside. nothing can strain a belt as much as a fuel car. only time they blow a belt is if they sneeze the blower.
https://c8.alamy.com/comp/AX71JJ/su...n-the-front-of-a-dedicated-v8-drag-AX71JJ.jpg

Im pretty confident that a narrower timing style belt tied to a cyclical load of a snowmobile track would need the most teeth contact, vs the contact of that style of roots supercharger, its load would be very linear.
 
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