Tall gearing

[justin1620]

has anybody tried a 24 tooth top gear....I like the idea of large gears for top speed but I want to keep my reverse gear ......want to gear up this winter when using my race map for 1000’ speed runs. For gears I have 22, 24 top and 37,39,41 bottom right now....I’m leaning towards a 22/37 or 24/39...1”track 2.86 pitch

 

[Fleecer]

Cats come with 24 top gear from factory, so it fits and has been done. Either of those ratios will work for 1000ft, but hard on belts in the trails.

 

[Turboflash]

Not sure what tune you're running but the question to ask yourself is what ballpark top speed do you anticipate in 1000'? Reason I say this is according the the chart, 22/37 gear is good for 143 MPH @ 8800 RPM. 24/39 gear is good for 148 MPH. This is with 9 tooth drivers and 2.86 pitch track, and 10% OD.
For example, if you think you can see 120 MPH in 1000' then with 22/37 gear you will not even be at 1:1 ratio at 1000'. (143 -10% = 128.7 MPH. This is a shift ratio of .93). (This assumes zero slippage which isn't reality).
If you run 24/39 gear and see 120 MPH at 1000', then you will only be shifted out to about .90 shift ratio.
There are many expert speed run guys on this forum that know more than me but the most efficient ratio is around 1:1. So, if I was going to speed run 1000', then I'd gear to try to cross the finish line somewhere around 1:1 or thereabouts, maybe some OD.
In my example of seeing 120 MPH at 1000' with 9 tooth 2.86 drivers, a 21/41 ratio yields 123 MPH at 8800 RPM.
If you're thinking you'll be at 140 MPH at 1000' then you can do the math to come up with what gear to run.

Speed run experts, am I all wet here?

 

[AAD]

I have run 22-37 SRX tunes and studded 1000ft 123.8 MPH on VBOX
Stock 21-41 was 120.5 MPH
1/4 Mile was 129.9 with 22-37 /125.1 with 21-41
Trail riding with 22-37 definitely hard on belts

 

[mainedrummer]

So if point-and-shoot, turn-to-turn, max acceleration in the trails is the only goal, what would be the best gearing for a big tune (300 HP+) and still be able keep the belts together (most of the time )?

 

[Turboflash]

Based on approx 5,000 miles and 3 sleds, 21/38 (and lots of long carbide studs ). I've run 22/37 too but it was too hard on belts so I went back 21/38.

 

[waldo1]

running 1.58 ratio 24 38 84 this year with 3.0 8 tooth smaller driver so ratio is like 1.68 compared to a 137 2.86 9 tooth... taller is better - clutching has to be alligned, nice round rolling rollers, billet helix. and a good clutch set up..

 

[Byam]

So if point-and-shoot, turn-to-turn, max acceleration in the trails is the only goal, what would be the best gearing for a big tune (300 HP+) and still be able keep the belts together (most of the time )?

22/41 without a doubt

 

[ClutchMaster]

has anybody tried a 24 tooth top gear....I like the idea of large gears for top speed but I want to keep my reverse gear ......want to gear up this winter when using my race map for 1000’ speed runs. For gears I have 22, 24 top and 37,39,41 bottom right now....I’m leaning towards a 22/37 or 24/39...1”track 2.86 pitch

24/41 with 9 tooth drivers is what I run. This gearing is actually easier on the chain.
Belts get changed at around 1200 miles and they aren’t bad at all.
Big speed gears need a low finish angle helix.
If your running the SRX reverse angle helix, I would change to a straight 35 with those gears you listed.

 

[waldo1]

has anybody tried a 24 tooth top gear....I like the idea of large gears for top speed but I want to keep my reverse gear ......want to gear up this winter when using my race map for 1000’ speed runs. For gears I have 22, 24 top and 37,39,41 bottom right now....I’m leaning towards a 22/37 or 24/39...1”track 2.86 pitch

24 41 - forgot to mention, to do that set up - u need a custom 88 link chain, because BW dosent make em. or call scotty T ... or shorten a 90 or 92 - u have to have a special chain linker thingee.. but thats a great gear - ran it for a season - the adjuster is all the way in with that set up - which i didnt like but it was ok..

 

[ClutchMaster]

24 41 - forgot to mention, to do that set up - u need a custom 88 link chain, because BW dosent make em. or call scotty T ... or shorten a 90 or 92 - u have to have a special chain linker thingee.. but thats a great gear - ran it for a season - the adjuster is all the way in with that set up - which i didnt like but it was ok..

https://www.hurricaneperformance.ca...t-performance-products/7-8-hyvo-chain-88link/

 

[Sledbrapping88]

What would you guys recommend for max 1/4 runs for racing with buddies. Im running hurricane 270 ss tune sm bundle with dalton's dtay1 set at 78.5 stock 35 helix with blk/org secondary aet 6-3. I ride mainly twistys with some meadows not much lake racing but want it snappy and pull your arms off up to 1/4 .

 

[waldo1]

https://www.hurricaneperformance.ca...t-performance-products/7-8-hyvo-chain-88link/

170? jeez - wont use hurricane - ive had bad luck with dave

 

[ClutchMaster]

https://wahlracing.com/product/hyvo-chain-7-8-wide/

$140 sounds better, still pricey tho.

 

[ClutchMaster]

What would you guys recommend for max 1/4 runs for racing with buddies. Im running hurricane 270 ss tune sm bundle with dalton's dtay1 set at 78.5 stock 35 helix with blk/org secondary aet 6-3. I ride mainly twistys with some meadows not much lake racing but want it snappy and pull your arms off up to 1/4 .

Riding twistys and racing 1320’ on the lake are worlds apart. A good compromise is the gearing I use.
24 tooth top and 41 on the bottom with 9 tooth drivers 2.86 pitch track.
Big tunes like big gears!