Yeah its called torque. I'd much rather know that my bike gained torque since torque is a measurement and horsepower is obtained from an equation consisting of torque and rpm. If the -1 tooth makes the rear wheel have more torque on the road surface at a given rpm, then yes it's going to have more HP at that rpm as well. It wont change anything at the crankshaft, but it will at the rear. You're only talking about 1,2,or 3 hp gains from other things you're adding. I guess i'm the assclown huh?

 

Will not change at the rear with gearing change. My assclown comment was aimed at someone pointing out that you could lower the rear teeth enough to bog down the engine and therefore make less power.

And you're right -- horsepower is a function of torque and rpm . But think of it this way ... when you're gearing down the torque may go up but how is that relating to your rpms? That's why you will not see an increase in HP from gearing changes.

Hey, it's easy enough to prove me the assclown -- just bring an assortment of sprockets to your local dyno and run 'em up boys. In the end you'll find you payed a lot of money and didn't really change power output at all.

 

And you're right -- horsepower is a function of torque and rpm . But think of it this way ... when you're gearing down the torque may go up but how is that relating to your rpms? That's why you will not see an increase in HP from gearing changes.

According to Banks performance (a big dealer in aftermarket diesel accessories) HP = Torque x RPM/5252. How accurate this is, I dont know. But, the overall relationship should be the same regardless. So when RPMs remain constant, if torque goes up, HP goes up. If the hp/torque doesnt show up on a dyno, then call me an assclown for saying it. You can join be being an assclown because that disproves what you said, and a dyno is ONE method for measuring power and torque, but not the only method.

You can only tell so much from a dyno reading. Its like a guy in the weight room. If he can bench 450lbs and the next guy can bench 375, all that it means is the one guy is stronger at bench pressing. The other guy may be able to whip his tail if they were to wrestle..... What i'm saying is this. A bike that does better on a dyno run is only proven to be better on a dyno run. I personally dont care what any of my bikes can do on a dyno because you dont race people on a dyno.

So, back to the point before digressing, I would put the bike 100% stock to dyno it for a baseline because that IS what a baseline is.

 

I refuse to argue over this anymore. Have a Merry Christmas dude!

 

umm.... wow, am I every sorry for introducing the term "*** clown" to this forum. I'm not in this for bragging rights. I don't race and I'm not trying to keep up with the Jones’s (or bones_jones for that matter... man, we can't get away from that name). All I am trying to do is put a value to the modifications. I have my reasons for making changes to my bike. If I can post the dyno runs... maybe someone can learn from it and save some money before upgrading and expecting a 20hp gain. That's not going to happen with a few simple bolt on mods. You know some ASSCLOWN is reading that... with this slip-on you get 15 extra HP and then he's thinking with a K&N I'll get another 4 to 5... then a PCIII will take me up more. I'm just trying to help that guy.

 

Nah, an assclown would never learn from your mods - -that's why they're assclowns

 

I just want to see dyno proof of a slip-on or full exhaust system that solely gives any newer sport bike 10 HP increase. Anybody have proof of that?

 

You can have two different types of dynos done. One being with the motor on the bike, the other with the motor off the bike and on a dyno stand. The first dyno will give a reading considering the amount of force used to turn the wheel. The second would give a more true reading of exactly how much power/torque the motor actually possess b/c their isnt any unsprung weight to factor in. You can however tell the person dynoing your bike that you have changed sprockets and he can compensate for that. This is the formula for figuring your percentage of torque gained after a sprocket change. ((new rear/new front)x(old front/old rear)-1)x100 After I went -1/+2 on my bike I gained 11.6% torque over factory. I havent however figured out how to convert this to ft. lbs.

 

Good post, I thought there should be some kind of formula to adjust for the gearing. I can't wait to see your numbers and not the manufactures horsepower numbers.

-Jesse-

BTW Merry Christmas everyone

 

I'm not arguing. I'm stating a fact. When a front sprocket is changed like that, it makes the bike accelerate faster. That means the bike is overcoming the inertia with an force that is in the opposite direction. This force times the radius of the rear wheel is torque (ft*lbs). e.q. 140lbs of force at 1 foot radius is 140 ft-lbs. Everybody on this forum agrees that a lower gearing does this. They should, its basic physics. Since the horsepower equation is based on torque and RPM, when either of the two increase, horsepower also increases. Therefore, for any given RPM, with an increased torque, there is an increase in horsepower. I'm no "moderator" but i do know my physics. Thats one of the two degrees I have. Again, not arguing, just stating a fact. Dont take it personally.