Pulleys

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Jul 20, 2014 | 12:35 PM

#11

8541hog

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Joined: May 2008

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From: Ogden, UT

Quote:

Originally Posted by Red Dragons

The 30 tooth is the transmission, or front pulley. It's a small boost in low end torque, as you're only dropping down 2 teeth. If you really want a low end boost that will make your bike FEEL much faster, do the Andrews 30 and get a 70 tooth rear pulley. I honestly have hardly noticed the torque boost from the 30t. I mean, I'm sure it's there, but I didn't think "holy ****" after switching. And it wasn't exactly a simple replacement either.

But pulleys are a lot cheaper and mostly simpler than doing engine work. There is also a lot of evidence from people on this board that leaving the engine stock, with the exception of stage 1 upgrades, will lead to longer engine life. I'm sure some here will argue this point though. But there's no arguing that going beyond stage 1 is a lot more expensive than doing pulleys. And almost no street bike will miss the small amount of top end that you lose. Street bikes need bottom and mid range power, period.

Well stated.
I went with a 31 tooth front and my stock 70 rear since I have a 5 speed, and could not be happier. Where I really noticed a difference was riding 2up. It does make it a bit quicker off the line, and as you said, the top end loss is not an issue, I can be running on the freeway at 70 riding 2up and a quick twist I can be at 85-90 no sweat. Motor is stock with ThunderMax AT, Doherty AC and custom pipes.

Jul 20, 2014 | 12:38 PM

#12

cerelious

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Joined: Dec 2009

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From: Reno, NVs

Ok, so what engine components would one want to change for more power? I understand that by changing internals the engine may not last nearly as long, but I am curious

Jul 20, 2014 | 12:41 PM

#13

8541hog

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From: Ogden, UT

Quote:

Originally Posted by 06Sporty75

question...

so when you change a pulley you also have to change the belt right? or do you just adjust the back wheel forward or backward?

I might want to get a higher top speed & lower rpm's at highway speed, so what pulley should I buy?

a have a 2003 with 5 speed so I think it revs too high at interstate speeds.

All depends, changing the front pulley up to 2 teeth will not require a belt change, but, if you are opening the primary inspect your belt and replace while you are in there if you have any concerns. Better than opening it again in 6 months...

A 2 tooth change on a rear pulley is roughly equal to a 1 tooth change in the front pulley. Changing the rear by 4 teeth though will most likely require a different belt as you are not likely to have enough adjustment on the rear axle.

What do you consider too high of RPM at highway speed?

Jul 20, 2014 | 01:18 PM

#14

T Prescott

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Joined: Oct 2006

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From:

Quote:

Originally Posted by cerelious

Ok, so what engine components would one want to change for more power? I understand that by changing internals the engine may not last nearly as long, but I am curious

1st: Stage one kit, air cleaner, exhaust and dial it it in with an EFI device and go from there.
Stage two kit, cams, head work.... valves and springs with ported and polished heads.
Remember though..... There's no replacement for displacement.
It's usually riding style that breaks things.

Last edited by T Prescott; Jul 20, 2014 at 01:20 PM.

Jul 20, 2014 | 02:44 PM

#15

fatmanontwowheels

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Joined: Nov 2013

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From: Florida

The Evolution industries kit looks interesting. Anybody else runnin that? Is that basically the same as changing the trans pulley to a 30t? Definitely would be an easier mod imo.

Jul 20, 2014 | 09:59 PM

#16

dirtdobber

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Joined: Jul 2007

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From: sand mountain Alabama

I have never understood folks thinking by going to a 30/70 or any of the combinations will reduce top speed.
Question: how many bikes will hit the limiter in 5th or 6th gear? Not many and if it will it doesn't need a gear change, it has enough low end.
By lowering the gearing, smaller in the front or lager in the rear or both will help the engine use it's power easier. Less stress or energy used. I have changed the gearing on several of my bikes and I never lost 1 mph. The engine is capable of pulling higher rpm's in the upper 2 gears.
For a 5 speed they tend to run more rpm's at higher cruising speeds. Personally I prefer the 5 speed over the 6 speed if the engine is not up to pulling a 6th. The 96 inch motors pull okay in 6th but not like it should. If you have to run 80 mph before hitting 6th gear take a look at the front motor mount. You should be able to use 6th as low as 70mph without a hitch.

Jul 21, 2014 | 04:04 AM

#17

Jondalar

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Joined: May 2010

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For newer folks, imagine a 10 speed bicycle in 1st gear. It's very easy to pedal. By going to a smaller front pulley you have a gear that's a bit lower than that bicycle's 1st gear. You now can pedal even easier but have to pedal more times.