Gearing Question

[hondo]

Actually, two questions:
Is anyone running a belt secondary drive?
What pulley change(s) would allow running through the traps at 7,000-7,500rpm in fourth gear?

[Tomcatt]

Originally Posted by hondo

What pulley change(s) would allow running through the traps at 7,000-7,500rpm in fourth gear?

I'm going to assume you have the 1200 primary gearing.
There isn't a small enough front pulley to do what you want.
A 28T or 29T (depending on your rear tire diameter and HP) should be about right crossing in 3rd.

[hondo]

Thanks for the quick reply! I have a 29T front pully now so that doesn't leave many options except for converting to chain. I'm going to compare the price for a chain conversion vs a 28T front pulley and new belt.

[wrkdWS6]

I have a chain drive but my sprockets give a ratio that’s very similar to the stock belt setup. I did swap out the primary 38T sprocket for a 34T. That makes a big difference. I’m crossing the traps ~7,200-7,300 in 4th. 150/80B16 tire size.

I’d start with that, then go 28T front belt sprocket if ya need more RPM.

[IXL2Relax]

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[Tomcatt]

I actually run the 1200 primary gearing, a shorter 170/60-17 rear tire and a 28T front pulley on my '17 1200C.
I'd do full throttle auto tune runs in 3rd gear with a 6,700 rpm rev limiter. My GPS would show 96 mph top speeds when I got home.
My calculator says if I'd let it rev to 7,500 that would have been 107 mph.
Just FWIW.

[cycowrencher]

Just a little gearing enlightenment....

If I had all of this to do all over again.... This is the order I would go.
1. 30 tooth Evo industries primary sprocket with 56 tooth basket and k model primary chain.
2. Early 5th gear and output (course gear)
3. 2000-03 cartridge with billet door.

There is no bigger bang for the buck in gearing than that 30 tooth 1.87 ratio.
34 tooth 1.65.
35 tooth 1.6.
38 tooth 1.47.
Rounded up. Calculated with 56 tooth basket. I tried the 57 and didn't like it. Factory new HD 57 tooth basket ruined in 1 season. Had to modify shoe for tensioner as well.

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[Racepres]

I guess this is All about ET (bracket) racing...
Heads up??? Completely different scenario.. I would be just a Bit more specific on intended Use.

[cycowrencher]

And exactly how many of us can afford heads up racing... Good for you if you can. I've made it no secret that I et race...

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[mac93]

Originally Posted by Racepres

I guess this is All about ET (bracket) racing...
Heads up??? Completely different scenario.. I would be just a Bit more specific on intended Use.

What would be different?