Gearing: real world experience

[BriNbigD]

Okay, I have read everything I can and have been hypnotized by all the numbers concerning gear ratios. I understand the ratios and what they do, but…
What is the REAL difference between my stock 0.35556 and 0.40 for street; or 0.308 for off roading? The numbers don’t mean anything to me. I want to know what y’all have experienced. And I have seen the “Good ol boys” video with speeds at different gearing. Didn’t really answer my questions.
Thanks in advance—this is a GREAT forum!

[Zapkin]

https://www.gearingcommander.com/

[BriNbigD]

https://www.gearingcommander.com/

Been there (a lot). Just a bunch of numbers. I’m looking for practical experienced opinions.

[Thumper]

The only way to stop being hypnotized by all the numbers is to determine your own motorcycle's speed at rpm. Just two things to note: 1) indicated, and 2) actual.

Do you have a highway that has mile markers? Or maybe you can find an ap for that. The bottom line is that every motorcycle is different. Personally, I like to see REAL mile marker times.

You want to KNOW how fast you are goin, NOT how fast someone else is going on the "same" bike.

Drive 60 indicated on the highway and time your interval to the next mile marker. Real world...There you go...

[sburk]

I have a 17 front and 45 rear and it dropped my rpms down a good amount. I have the basic hawk so no tach but the amount of noise and vibration is a big difference from the the stock 15/50 that was on it

[bigdano711]

The crazy thing is how much bearing rider weight and position have on speed. In 5th gear my bike struggles to hit 60 with a 16/47 set up, but if I lean over the tank and make myself more aerodynamic, 65 no problem.

[severely]

Why not buy a 1 tooth larger and smaller front sprocket, install one of them, and try it out? Then try the other one. You'll see very quickly the difference made with either one and have a more direct reference to the numbers. Good luck.

[XLsior]

If you're doing mostly off road then you want the torque of a lower gear ratio.



For general road speed limits and taller gear ratios that accommodate the transmission spread.


However you need to factor in what the engine is actually capable of. The Good ole boy test basically expressed that a 42 rear is too small when paired with a 17t front because the engine power band cant transmit the energy effectively.



If you live on flat roads 17/45 seems feasible...but as soon as you hit a hill with enough gradient you will find yourself dropping gears to find the power band...


I'm running 16/44 which has me dropping back to 4th gear on steep hills. But i still have the option of stepping up to a 17t front if I want to cover distance travel...
17t being the largest front sprocket that will fit 428 chain.


I wouldn't bother with trying to pin 65pmh as a metric....the engines are happier at 55mph.

[Thumper]

BriN
You can get a pretty accurate mph by timing yourself the through a measured mile.

Get up to speed, 60 is a good choice, and maintain that indicated speed when you cross the mile marker. Time the mile. It should be exactly one minute. If it is more, say 66 seconds for instance, then you are going a mile per 1.1 minute, or 60 miles per 1.1 hour. 60/1.1 is 54.4 mph. And you have about a 10% speedometer error.

So if it indicates 70 you are actually going a out 10% less, 70-7 about 63. The error should be linear, 10% at any speed.

One last thing. You can check the odometer the same way. Note the odometer reading as you pass a mile marker, drive ten miles and stop at the tenth mile marker. How many miles did the odometer roll up? 11? Then you also have about a 10% odometer error. You can calculate whatever you get. I just used 10% because the math is easy.

[BriNbigD]

Thanks for the replies! You guys are awesome!
I’ve got GPS and phone speedo, I know they lag a little. The best answers tell me what it feels like, especially off road. How much the engine will actually handle. All the calculators are ‘theoretical’. “I'm running 16/44 which has me dropping back to 4th gear on steep hills.”—thank you XLsior. My stock is 16/45. I could buy all the sprockets and do days worth of swaps and rides (not counting chain mods), but I’d rather hear from y’all and spend way less $$. And what length chains are you finding fit with your set-ups?
I have two sets of tires and wheels. One for on road (with stock tires), the other with 10/90 tires for off road. I just want to put one sprocket on each rear wheel and be good.

[BriNbigD]

I have a 17 front and 45 rear and it dropped my rpms down a good amount. I have the basic hawk so no tach but the amount of noise and vibration is a big difference from the the stock 15/50 that was on it

That’s a huge change! 17/45 would be 15/39! I wouldn’t have thought the bike would pull that. Therefore, 16/40 is doable!

[Bill Hilly]

I don't know what bike you have,but assuming it's a Hawk, then I will tell you my experience, and opinion. I weigh 250, live in the Mid Ohio Valley of West Virginia, which is not mountainous, but has it's share of hills. I have no need for my bike to run much faster than 55mph + a little more to basically go with the flow of the other vehicles. I already had an extra 46 rear, so I tried it with a 17 front, and it was geared a little higher than what I need, but it was livable. It did require me to down shift on hills that I knew that with just a little more power I would top in high, because on a 4th gear down shift, it would often wind itself back out, and be running nearly as fast as I would normally want to run, but at a higher rpm, and sometimes with a lot of hill left. If I was a lighter rider, and under 200 pounds, I think I would like something a step higher than a 17/46, like a 17/44, because when it did run out of steam in 5th, then 4th gear would often build the speed back up to normal, without winding the motor out past it's optimal power curve. I am now running the same 46, but with a 16 front, and it pleases me fine. The bike is not sluggish ( for an internally stock CG), and gets to 55+ pretty quickly, and is not under undue stress running that at a steady speed. I often run it in the low 60s out on the main roads when the rest of the traffic is flowing at that, but it's usually just for a couple miles. I honestly think that if a person was under 200 lbs, and didn't live in mountainous terrain, then you could gear it according to how much low speed power you need, because once you go high enough in gearing, you are going to be having a 4th that's as high as 5th was with lower gears. As long as you have enough grunt in 1st to EASILY take off from any situation, and to handle any low speed "off road" situation, and enough 5th to unstressfully handle your foreseeable substained top speed then your good.

[BriNbigD]

‘23 Hawk DLX. Thanks Bill Hilly! I’m near your weight and got it to 65 before the airbox delete/pod filter install. I’ve got everything I need to install patches to the ECU. Waiting on the 292 cam that Devin has sent. I’ll install that (if it fits) and patch the ECU. You guys are giving me some great info! I’m in DFW, so flat. Very few hills. Not worried about high speeds, I’ve got a Ninja 400 for that!

[letsride]

I simply went up one tooth on the front spocket of my KPX 250 and it dropped the cruise RPM by 500 at 55 mph. it doesn't seem to care at all off road either. I'm with Bill Hilly, 55 mph is plenty fast enough for me. I'm not trying to spin the little motor to death cruising at 65+ mph all day. But I have a little extra on tap if need be. Some folks get tied up in top speed. We should all remember you basically have a lawn mower motor with a gear box. LOL.

[Megadan]

That’s a huge change! 17/45 would be 15/39! I wouldn’t have thought the bike would pull that. Therefore, 16/40 is doable!

There are people that have run a 17 front 39 rear on the Hawks in pure road use. I personally find the 17/45 the best road use sprocket that can still manage light trail use. It is the best compromise of top speed vs. rpm vs. engine power.

[Bill Hilly]

I did a top speed run on mine earlier today, and it hit 67 mph , with an accurate speed odometer. It was beyond it's optimal power range, but I never run it that speed anyway.

[sburk]

That’s a huge change! 17/45 would be 15/39! I wouldn’t have thought the bike would pull that. Therefore, 16/40 is doable!

I live in North East Missouri so it's flat with small hills for the most part. My bike will be mostly for commuting for work . I'm about 200 pounds and all the roads here are 60 mph or less besides the interstate. Mine seems to handle it fine. I only have 170 miles on it just got it in Oct. I can't wait for spring lol

[XLsior]

If you already have 16/45 stock then getting a 17 and 15 front to experiment wont break the bank and will likely not require any links taken out of the chain...


Rear sprockets are the more costly to change.



I'd say for most user applications 45 rear is fine.

[Bill Hilly]

I have a few videos on YouTube, most on my Hawk, which as I mentioned before has 16/46. I usually just run at a common sense, pace, but there is a brief speed run towards the end of this video. You may need to adjust the video quality on your end of YouTube. You can find more on my channel as well. https://youtu.be/F7BXOen6Q2s?si=hzwRvmkUeVgLwfmL

[BriNbigD]

‘Good ol boys’ channel said he experienced a lot of “slipping” with the 15 front. Has anyone here had that problem? Your input is helping me a lot!

[Bill Hilly]

‘Good ol boys’ channel said he experienced a lot of “slipping” with the 15 front. Has anyone here had that problem? Your input is helping me a lot!

Probably the worst think in running a 15 with a small rear is the fact that the chain is going to be putting a lot more wear and tear on the slider. He may have meant wheel spin when he said slip, because I don't see how, it would cause the chain to slip, unless the chain was far too slack.

[BriNbigD]

Probably the worst think in running a 15 with a small rear is the fact that the chain is going to be putting a lot more wear and tear on the slider. He may have meant wheel spin when he said slip, because I don't see how, it would cause the chain to slip, unless the chain was far too slack.

I didn’t think of that! You’re probably correct. I’m not worried about that. I enjoyed your ride-along video. But the audio was not great. A little garbled in places. But still fun!

[Bill Hilly]

I didn’t think of that! You’re probably correct. I’m not worried about that. I enjoyed your ride-along video. But the audio was not great. A little garbled in places. But still fun!

That helmet fits me good, but it makes it hard to talk, because it's so snug around the jaws. I have also had a cold ontop of everything.

[buzz]

Hello just got done changing my sprockets, 17 up front 37 on the back. Now go 70 mph at top speed,was not sure about my bike had enough power to use these sprockets,it dose. 2021 TBR7,with 8300 miles. Very happy!!!

[BriNbigD]

Hello just got done changing my sprockets, 17 up front 37 on the back. Now go 70 mph at top speed,was not sure about my bike had enough power to use these sprockets,it dose. 2021 TBR7,with 8300 miles. Very happy!!!
That’s great!
Using the 428? And how many links did you end up at?

[Bill Hilly]

Hello just got done changing my sprockets, 17 up front 37 on the back. Now go 70 mph at top speed,was not sure about my bike had enough power to use these sprockets,it dose. 2021 TBR7,with 8300 miles. Very happy!!!

Concidering the larger circumference of the Hawk tire, about a 40 rear, and 17 front would be about like the 37/17 on the TBR7. I am thinking that Jerry runs about a 40/17 on his Hawk. He lives in Louisiana, and is not packing the extra weight that some of us are. LOL

[adb1779]

Hi,
I live in southeastern PA near Philly. I commute to NJ for work about 17 miles one way. Getting off the line at traffic lights was a problem as I was having to shift too soon and cars would come up close as I was not gaining speed fast enough. Went to 17/40 and the problem was solved. 5th gear is basically an overdrive so down hill I can almost pin the speedometer (It is 10% high). No vibration at highway speeds but 5th is definitely for level and slightly downhill grades. My TBR7 is stock. The higher gearing has definitely helped some of the fuel starvation problems you get with the stock carb.

[adb1779]

Hi,
I live in southeastern PA near Philly. I commute to NJ for work about 17 miles one way. Getting off the line at traffic lights was a problem as I was having to shift too soon and cars would come up close as I was not gaining speed fast enough. Went to 17/40 and the problem was solved. 5th gear is basically an overdrive so down hill I can almost pin the speedometer (It is 10% high). No vibration at highway speeds but 5th is definitely for level and slightly downhill grades. My TBR7 is stock. The higher gearing has definitely helped some of the fuel starvation problems you get with the stock carb.

[buzz]

yes 428 chain ,i think i got 130 link chain.Better to have to much.

[Bill Hilly]

[QUOTE=BriNbigD;402539. I enjoyed your ride-along video. But the audio was not great. A little garbled in places. But still fun![/QUOTE]

I went ahead and put the full video up on YouTube. I went for gas , and then came home a different route. You also get a tour of Ripley WV. The first 10 minutes are the same as the
Coyote Run video. I plan on making one on the KPX soon, probably either on the Kanahawa River to Point Pleasant, or the TNT Area (Moth man's stomping grounds). I don't believe in any of that, but some do https://youtu.be/aMWa-RkrRYw?si=qr4jFRhKrTaRbSrB