You are not logged in.

Compare Ratios of Gearing  RSS Feed

#26 2011-10-24 8:42am

MiguelESP
Pro Member
From: So. Cal.
Registered: 2008-09-30
Posts: 122
Bikes: 4

Re: Compare Ratios of Gearing

Marked. TY Hobbes

Offline

 

#27 2011-10-27 11:48am

tnyvillegas
Pro Member
From: Rialto, CA
Registered: 2008-10-20
Posts: 2982
Bikes: 15

Re: Compare Ratios of Gearing

Offline

 

#28 2011-10-27 4:49pm

Hobbes12
AdminDon’t Be a Wussy!
From: Lebanon Oregon
Registered: 2007-07-02
Posts: 37126
Bikes: 37
For Sale: 1
Website

Re: Compare Ratios of Gearing


hobbes1278@gmail.com
Auburn Blue Max DB Dyno ELF Fit FA GT Haro Hawk Hutch JMC Mongoose National Pro Redline Roger DeCoster Schwinn SE WTP

Offline

 

#29 2011-11-17 10:22pm

harlen
The Waco Kid
From: Waco, TX
Registered: 2009-03-10
Posts: 1469
Bikes: 8
Website

Re: Compare Ratios of Gearing

Distance traveled in one full crank revolution 178.80 per crank. How is that determined if I dont enter crank length?


46 year old New School BMX Rider
Old dog learning new tricks

Offline

 

#30 2011-11-29 4:25pm

TWENTYFOUR7EVEN
Pro Membermarvingarden
From: SOCALIF
Registered: 2010-06-27
Posts: 3123
Website

Re: Compare Ratios of Gearing

i have a 20 inch 46 up front. what should i rub in the rear? 16 or 17?


Check out youtube ch:
twentyfour7evenbmx

Want to buy:

Schwinn maximizer red orphan 20x2.125

NO TRADES

Offline

 

#31 2012-02-19 12:15pm

biggiefl
Intermediate
From: Ellenton, FL
Registered: 2007-03-26
Posts: 376
Bikes: 1

Re: Compare Ratios of Gearing

16 if street, 17 off road.


WTB: Left Maxy Cross arm 170mm any color or condition. Sunshine rear sealed hub(s) in blue/silver, red/silver and/or Gold/silver.

Offline

 

#32 2012-02-19 1:51pm

o1marc
Intermediate
From: Dawsonville, GA
Registered: 2011-12-28
Posts: 417
Website

Re: Compare Ratios of Gearing

Crank length has no bearing on distance traveled only how many revolutions the tire made by each revolution of the chainring. Whether the crank length is 3" or 12" one revolution is one revolution

harlen wrote:

Distance traveled in one full crank revolution 178.80 per crank. How is that determined if I dont enter crank length?

Last edited by o1marc (2012-02-19 1:51pm)

Offline

 

#33 2012-02-19 5:14pm

harlen
The Waco Kid
From: Waco, TX
Registered: 2009-03-10
Posts: 1469
Bikes: 8
Website

Re: Compare Ratios of Gearing

o1marc wrote:

Crank length has no bearing on distance traveled only how many revolutions the tire made by each revolution of the chainring. Whether the crank length is 3" or 12" one revolution is one revolution

harlen wrote:

Distance traveled in one full crank revolution 178.80 per crank. How is that determined if I dont enter crank length?

Yes your right by their calculations. Heres what Im saying is that the chainwhel doesnt turn itself the crank does, so the real ratio is crank to tire. If you change any of the following sizes it affect the ratio  chainwheel, sprocket, tire and crank. What you said if Im running 3" cranks and change to 12" theres no change in ratio. The 3" cranks turns smaller revolutions than the 12" cranks. Then that means I can ride any size cranks and it doesnt affect the way its rides.


46 year old New School BMX Rider
Old dog learning new tricks

Offline

 

#34 2012-02-19 5:22pm

o1marc
Intermediate
From: Dawsonville, GA
Registered: 2011-12-28
Posts: 417
Website

Re: Compare Ratios of Gearing

The cranks are the arms the pedals are connected to. The length of those will determine how much effort it takes to turn them but has no bearing on how far you will travel. Let say you have a 44T chainwheel and a 20t wheel sproket. If you change the wheel sprocket to a 21t your wheel will have traveled fewer revolutions for each revolution of the chainwheel. Try this, if you have a 44t chainring and a 44t wheel sprocket each revolution of the echain wring will turn the wheel one revolution. Now if you change the wheel sprocket to a 22t each revolution of the chainring will turn the wheel 2 revolutions. The latest combo will be easier to turn than the previous one. If you lengthen your crank arms it gets easier to turn but goes the same distance.
If you use the gear inch/actual rollout calculater you will see they don't ask for crank length because it is irrelevant. How it ridesmay be differant because what ever gear ratio you run if you have a short crank length at top speed your legs will be pumping like crazy where with a longer arm your legs will be pumping less. You can also adjust the effort by changing gear ratios.

Last edited by o1marc (2012-02-19 5:31pm)

Offline

 

#35 2012-02-19 6:58pm

harlen
The Waco Kid
From: Waco, TX
Registered: 2009-03-10
Posts: 1469
Bikes: 8
Website

Re: Compare Ratios of Gearing

If I run a 25/9 which has twice the revolutions than a 49/18 their not the same?


What Im saying is If I run 3" cranks and turn them 20 times then do the same with 12" cranks. The longer cranks will have more rational travel. The bike is powered by me turning the crank not by a motor turning the spindle. Now if a motor was turning the spindle those calculations would be correct.


46 year old New School BMX Rider
Old dog learning new tricks

Offline

 

#36 2012-02-19 7:17pm

o1marc
Intermediate
From: Dawsonville, GA
Registered: 2011-12-28
Posts: 417
Website

Re: Compare Ratios of Gearing

It doesn't matter what turns them a 3" rod or a 12' rod one turn is one turn. The smaller ratios will be easier to turn than the larger one. You will run out of power in your legs at a certain point and the speed that that happens at will be slower than it would with the higher numbered ratio.

Last edited by o1marc (2012-02-19 7:22pm)

Offline

 

#37 2012-02-19 7:45pm

harlen
The Waco Kid
From: Waco, TX
Registered: 2009-03-10
Posts: 1469
Bikes: 8
Website

Re: Compare Ratios of Gearing

So 3" rational travel in the same as 12" rational travel? Im just using the 3" and 12" hypothetically that was your example. 3" fast start run out of speed faster 12" slow start faster top end.  So your saying crank length doesnt matter?

Sprocket to sprocket 25/9 is 2.77 and the 49/18 is 2.72 just 500ths

We can compare 150mm cranks vs 185mm cranks.  Its still each turn of the crank that determines how far you travel. So if you turn those 20 times with same ratio which one travel further? Of course the 185mm has more rotional travel.


46 year old New School BMX Rider
Old dog learning new tricks

Offline

 

#38 2012-02-19 8:12pm

o1marc
Intermediate
From: Dawsonville, GA
Registered: 2011-12-28
Posts: 417
Website

Re: Compare Ratios of Gearing

You are correct,  Its still each turn of the crank that determines how far you travel. how big of arm you use to turn it has no bearing on distance traveled only on how much force it takes to turn it.

Last edited by o1marc (2012-02-19 8:13pm)

Offline

 

#39 2012-03-04 8:47am

mayhem16421
Museum Newbie
Registered: 2012-02-25
Posts: 10
Bikes: 2

Re: Compare Ratios of Gearing

44-16 for me is just right.

Offline

 

#40 2012-03-08 9:21pm

tnyvillegas
Pro Member
From: Rialto, CA
Registered: 2008-10-20
Posts: 2982
Bikes: 15

Re: Compare Ratios of Gearing

would 40-15 be crazy for a cruiser?

Offline

 

#41 2012-03-08 9:22pm

tnyvillegas
Pro Member
From: Rialto, CA
Registered: 2008-10-20
Posts: 2982
Bikes: 15

Re: Compare Ratios of Gearing

would 40-15 be crazy for a cruiser?

Offline

 

#42 2012-03-08 10:58pm

o1marc
Intermediate
From: Dawsonville, GA
Registered: 2011-12-28
Posts: 417
Website

Re: Compare Ratios of Gearing

You probably won't notice a lot of differance from it over the 44/16 as you have gone down on both sprockets. If your ratio were 100/50 for every turn of the crank the wheel would make 2 revolutions, if you changed to a 50/25 it would still be the same. Going from a 44/16 to a 40/15 each revolution you will go slightly less distance in one revolution. Going to the smaller ratio you have gone down 9% on the large ring and 9.5% on the smaller ring, hardly a change at all.

Last edited by o1marc (2012-03-08 11:05pm)

Offline

 

#43 2012-03-08 11:39pm

tnyvillegas
Pro Member
From: Rialto, CA
Registered: 2008-10-20
Posts: 2982
Bikes: 15

Re: Compare Ratios of Gearing

actually i have 40-17 right now

Offline

 

#44 2012-03-13 1:14am

TWENTYFOUR7EVEN
Pro Membermarvingarden
From: SOCALIF
Registered: 2010-06-27
Posts: 3123
Website

Re: Compare Ratios of Gearing

what about a 26 inch cruiseR?


Check out youtube ch:
twentyfour7evenbmx

Want to buy:

Schwinn maximizer red orphan 20x2.125

NO TRADES

Offline

 

#45 2012-05-12 8:16am

IPD
Pro Member
From: Dangerous independent thinking
Registered: 2011-08-13
Posts: 10941
Bikes: 3
For Sale: 2
Website

Re: Compare Ratios of Gearing

I'd like to inject that back in the day I rocked 44/13 everywhere.  My new build has a 30/9 which is virtually the same ratio--and I'm running that on 175mm cranks.

This is all-around, not a racing bike.  I don't think I'd really like a lower gear ratio & the slower top-speeds that it brings.


It's like the man says, there's no problems...only solutions.

Offline

 

#46 2012-06-12 3:57pm

astroidbeltwalker
Pro Member
From: mount kisco
Registered: 2011-10-07
Posts: 5482

Re: Compare Ratios of Gearing

what about chain lenght. do longer or shorter chains effect travel.


Current Position - Hit Man -
Wtb Mongoose 9142994654

Online

 

#47 2012-06-12 4:13pm

o1marc
Intermediate
From: Dawsonville, GA
Registered: 2011-12-28
Posts: 417
Website

Re: Compare Ratios of Gearing

astroidbeltwalker wrote:

what about chain lenght. do longer or shorter chains effect travel.

No

Offline

 

#48 2012-06-13 11:55am

JacksonHole22
"Closet Hutch Fan"
From: Jackson, WY
Registered: 2010-07-11
Posts: 610
Bikes: 12

Re: Compare Ratios of Gearing

needed that info from those charts. thanks!

Last edited by JacksonHole22 (2012-06-13 12:38pm)

Offline

 

#49 2012-06-13 12:13pm

Legendofjd3
Pro MemberWeight Weenie
From: New York
Registered: 2010-01-07
Posts: 2432
Bikes: 7

Re: Compare Ratios of Gearing

This got me thinking. It would be cool to see some of these different ratio's on video.

Maybe if I get REALLY bored...


Titanium

Online

 

#50 2012-06-13 10:36pm

astroidbeltwalker
Pro Member
From: mount kisco
Registered: 2011-10-07
Posts: 5482

Re: Compare Ratios of Gearing

yeah it would. can anyone comment if the difference between 17/43 , 15/43or44 is that much different.
i like riding 17/43 but could use a touch more middle top end. & and dont want to loose any
intial speed, maybe 180mm cranks if i decide to go smaller on the rearend


Current Position - Hit Man -
Wtb Mongoose 9142994654

Online

 

Board footer

View Cart →