can short gearing actually hurt acceleration?

[300rman]

well, title says it all.
What are everyones thoughts?

running 18 inch tires on my 84 R, if i was to play with gearing, what would be a good change to get it closer to the stock gearing again?

[lndy650]

yes it does! in more than one case i had this happen... one time i had a banshee and a yfz450 the banshee was geared 12-43 and the yfz would smoke it off the line all the way up... i geared the banshee 15-43 and it smoked the yfz take off and top.

[300rman]

the only way i can change my gearing is by the front sprocket....i dont want to change my rear sprocket every trip to the dunes, as i will go from a 18 inch tire to a 21 inch paddle.

[DixiePlowboy]

Too short(low) gearing can absolutely hurt acceleration and performance in general.

There are many factors that determine just how low is too low, just as how high is too high. Being geared too low will tend to raise the rpm that your engine drops to after completing an upshift, as well as lowering the terminal speed you reach in each gear. If an engine has a useable power range of say(using a random stock 80's pushrod V-8 example).....1500 to 4500 rpm and if your new super low gear set means that your return rpm upon shifting from 1st to 2nd gear at full throttle is still 4000 rpm, you only have 500 useable rpm before you must shift again to keep in the "meat" of the power range.

That means a lot more shifting with less speed in each gear, and only a couple of seconds in each gear of acceleration before you're out of steam.

A great example would be a buddy's old '78 Trans Am w/a stock 455 big block, 4-speed manual tranny, and 4.50-something gears in the rear. It sure sounded mean when he could bark the tires HARD in all 4 gears without thinking about it, but I saw it get beat across the bridge by a lot of weak cars for the very reason I described. He switched to a 3.70-something ratio and improved nearly a full second off his 1/8 mile E.T. with about the same amount of wheelspin.

Yeah, I know this isn't Trans AM World or Super Ford, but the same principle applies to any engine with finite power to RMP limitations. You can gear almost anything too low to take maximum advantage of the horsepower/torque range your engine has available.

[The Goat]

one tooth in the front is about 2in in height on the rear tires...so you could go up either 1 or 2 teeth in the front and be more than okay.

[81Rmachine]

I figured out 1 tooth in front is about 4 in the back and like Goat said is 2 in in rear tires. I figured if I put 20s on my R I would have to go 13 to 40 or 14 to 44 to compensate but even with 20s it still felt like it didn't have enough time to really excellerate in each gear and would flat out scream in 5th. Thanks to Sykolincoln that rear axle I got from him had a 36 tooth sprocket specialists sprocket on it. I can't wait to try it.

[Dirtcrasher]

My thoughts.....

Every machine is different, you have to find the gearing that works for you and whether you want to reach a 1000ft mark quicker or a 10,000ft mark at a higher top speed.

I increased my 350X front sprocket and it still had great acceleration, but I think it could still pull some more on top. But, if I up the front or lower the back, I'm sure I'll lose a bit in the acceleration. The gears will be longer and in some situations, I'll have to clutch it a bit.

Then you have the flip side where the rear sprocket is increased or the front sprocket is decreased and it will have shorter gears and quicker acceleration. But, there are factors involved such as that if it's a built motor it can certainly pull a higher gearing and a lower gearing can hurt acceleration because it has so much more to give. And of course you can gear your stock motor too low that a lower gearing winds out so fast that you don't get the optimum surface speed versus horsepower...........

[cr480r]

With gearing too short a bike will often "miss" the powerband... the trans ratios wont pull the engine down to rpms where it makes power... my tecate does it when I put on 18's...

[300rman]

With gearing too short a bike will often "miss" the powerband... the trans ratios wont pull the engine down to rpms where it makes power... my tecate does it when I put on 18's...

hmm that could just be my issue. ill start playing with gearing and see what happens.