Friday, November 24, 2017
 
www.cyberspacesolutionsinc.com

 

Follow Us On: FacebookTwitterYouTube

www.cyberspacesolutionsinc.com Bookmark and Share
Search
 
Gearing Minimize
How Does it Work Series - Gearing

The question of gearing is pretty complex. It is seen as a way to put the power down to the ground to where it should be. So follow along as I try to clarify the matters of gearing your bike.

It's all a matter of ratios. The ratios in the gearbox are basically fixed, but there is the matter of final drive between the countershaft and the rear sprocket.  The ratio is just the relationship in the number of teeth between the countershaft and rear sprocket. More teeth also means that the sprocket has a larger circumference. So in layman's terms the ratio tells us that for every turn of the rear sprocket, the countershaft turns an amount equal to the ratio. Most mechanics use the term "taller" gearing to denote an increase in the ratio between the countershaft and the rear. This actually reduces the overall speed of the bike because the countershaft now has to turn more times to make the rear sprocket turn once.  But this drop in speed also increases the torque needed to turn the sprocket; this torque demand upon the engine slows down the build up of revolutions within the engine and provides a more tractable power delivery. The opposite happens when your drop the gears. The torque load is reduced so the power is built faster and then combined with the decrease in the number of times the countershaft has to spin for one turn of the rear sprocket, the overall speed increases.  Also the "distance between gears" decreases, which means that the time it takes for the engine to build revs is decreased and the less time it takes to build enough revs to shift.

OK some more about the application of torque.  The smaller the countershaft, the less torque force is applied to the chain and the torque load is increased to the engine.  The rear sprocket then translates the force applied to it by the chain. The larger sprocket increases the effect of a given force applied it by the chain.  Thus it will provide more torque to the rear wheel. (Are we going nuts yet?)

[Actually the greater radius of the larger sprocket generates more torque. Then there is the matter of energy expended in the getting the greater mass of the larger sprocket to spin.]

That's the theory of gearing in a nutshell. Now you are going to ask how to apply it to real life. Well, I would strongly suggest doing some research on the project.  (The price of sprocket sets will motivate you to ask a few questions.)

If you want to go fast then gear the bike up by decreasing the number of teeth. Do note that changing the amount of teeth on the countershaft will have the equivalent effect on of going up or down several teeth on the rear sprocket.

Gearing Chart

Countershaft Teeth (Down)  Rear Sprocket Teeth (Across)


42 43 44  45  46  47  48 49  50 51  52 53  54 55
17 2.47 2.53 2.59 2.65 2.71 2.76 2.82 2.88 2.94 3.00 3.06 3.12 3.18  3.24
16 2.63 2.69 2.75 2.81 2.88 2.94 3.00 3.06 3.13 3.19 3.25 3.31 3.38 3.44
15 2.80 2.87 2.93 3.00 3.07 3.13 3.20 3.27 3.33 3.40 3.47 3.53  3.60 3.67
14 3.00 3.07 3.14 3.21 3.29 3.36 3.43 3.50 3.57 3.64 3.71 3.79 3.86 3.93
13 3.23 3.31 3.38 3.46 3.54 3.62 3.69  3.77 3.85 3.92 4.00 4.08 4.15 4.23
12 3.50 3.58 3.67 3.75 3.83 3.92 4.00 4.08 4.17  4.25 4.33 4.42  4.50 4.58
11 3.82 3.90 4.00  4.09 4.18 4.27 4.36  4.45 4.55 4.64 4.73 4.82 4.91 5.00
  
 
 

 

 

WARNING! DO NOT USE ANY OF THE INFORMATION CONTAINED ON THIS SITE UNLESS YOU READ AND AGREE TO THE FOLLOWING INFORMATION.

 


Involvement in off-road motorcycling and related activities carries a significant risk of damage to property, personal injury or death. Participate at your own risk!
The publishers of
www.dirtridersofcolorado.com recommend the use of professional instruction before entering into any sports or physical activity. You should become knowledgeable about the risks involved and assume personal responsibility for your actions.
The information contained within
www.dirtridersofcolorado.com may or may not be accurate and is open to interpretation. Opinions concerning the technical difficulties, fitness requirements, safety, and ratings, are subjective and may differ from yours or others opinion, therefore be warned that you must exercise your own judgment as to the difficulty and your ability to safely protect yourself from the inherent risks and dangers. Do not use the information provided on this site unless you are a skilled and experienced sports person who understands and accepts the risks of participating in dangerous sports and activities.
Whilst
www.dirtridersofcolorado.com makes reasonable efforts to include accurate and up to date information on this website, errors or omissions sometimes occur, therefore the information contained on www.dirtridersofcolorado.com is provided "as is" and without warranties of any kind either expressed or implied. Viewing, reading, or any other use of the information contained within this web site is purely the voluntary will of the viewer or user. You, 'the viewer' or 'user' shall not hold the publisher, owner, authors or other contributors of www.dirtridersofcolorado.com responsible for any incidents related directly or indirectly to the materials published within this site or its network of web links. www.dirtridersofcolorado.com assumes no liability or responsibility for your actions.

Please see our complete terms of use by clicking the "Terms Of Use" link at the bottom of this page.
 

 

www.cyberspacesolutionsinc.com
 
 
www.cyberspacesolutionsinc.com www.cyberspacesolutionsinc.com www.cyberspacesolutionsinc.com