Gears

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SHOPPING

Subpages: Cranks

http://www.ebay.com

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The first figure is the number of teeth on the smallest chainring (The gears at the front.)

The second is the number of teeth on the largest sprocket of the cassette (The gears at the back)

You then divide one by the other to get the gear ratio

A gear ratio of 1 means that everytime you turn the pedals one revolution the wheel will rotate once. A gear ratio of 2 means that for every half turn of the pedals the wheel will rotate once. Obviously the lower the gear ratio the easier it will be to climb a hill.

http://www.cyclebasket.com/sitepage.php?id=3

http://www.myra-simon.com/bike/cranks.html

https://www.stevehoggbikefitting.com/blog/2011/05/compact-cranks-vs-standard-cranks-gearing-implications/

http://www.bikecalc.com/gear_inches

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Converting to triple: http://www.stanford.edu/~dru/tripleize.html

VO Triple Crank: http://store.velo-orange.com/index.php/vo-triple-crankset.html

VO Grand Cru Fluted Triple: $195: http://store.velo-orange.com/index.php/components/cranksets/grand-cru-110-fluted-triple-crankset-24x34x48t.html

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http://www.bicycle-touring-guide.com/touring-bicycle-gearing/

The rear cogs or cassettes that are suitable for touring bicycles usually have a 12 tooth smallest cog for 8 speed systems or 11 tooth for 9 speed systems. For your lower touring gear, the largest cog should be either 28, 32, or 34 teeth.

When it comes to changing out your rear cassette, most long cage derailleurs should be able to handle up to a 34 tooth cog. Short cage derailleurs that are used on racing and sport bicycles will only handle up to a 26 to 28 tooth rear cog.

Some of the common front cranksets available for touring bicycles include:

• • Compact double: 50/34

  • Road triple: 50/39/30

  • Touring triple: 48/36/26

  • Expedition triple: 44/32/22

  • Mountain triple: 42/32/22

Below are suggested high and low gear inches for different types of touring:

(For ease of discussion here, I am going to assume that your bicycle touring will be over flat and hilly terrain, high mileage over multiple days, and a variety of calm and windy conditions.)

• • No load: High-125″, Low-30″

  • Light load with or without sag wagon: High-115″, Low-28″

  • Medium load with or without sag wagon: High-110″,Low-25″

  • Heavy load without sag wagon: High-108″,Low-22″

  • Heavy load with camping: High-100″,Low-18″

  • Extra heavy load, expedition: High-100″,Low-16″

  • Heavy load, mountain bike: High-98″,Low-16″

mountain double 42/28 and a 12-36 cassette. May throw on a 24t inner if we expect lots of mountains.

46-30 rings

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CASSETTES

Shimano 6 speed: 11-28; 11-30; 11-32;

Shimano 7 Speed: http://sheldonbrown.com/k7-7.shtml; 11-28; 12-28; 13-28; 13-30; 13-34; 14-32]

Shimano 8 Speed: http://sheldonbrown.com/k8.shtml

converting 7 to 8 or 9: http://sheldonbrown.com/k7.html#897

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OUR BIKES

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Synapse

NEW: 34/50 (11-28) [Gear inch range: 32-120]

ORIGINAL: 34/50 (12-25) [Gear inch range: 37-113]

Crank: FSA Gossamer BB30 Compact, 50/34 (crank length: 172.5mm)

Rear cogs- New: Shimano 105, 11-28, 10-speed [CS-5700: Sprocket Sizes 11-12-13-14-15-17-19-21-24-28]

Rear cogs- Original: Shimano 105, 12-25, 10-speed [CS-5700: Sprocket Sizes 12-13-14-15-16-17-19-21-23-25]

***** RANDO *****

Derailleur (rear): Deore DX (RD-MT650) [SGS (long cage) SS (short cage), 7speed STI compatible, Centeron Pulley] [BikePro info: It can be used as both a 6, 7, and 8 speed changer. Maximum rear cog is 32 teeth on the long cage. Total capacity is 38 teeth (super long cage), and 28 teeth (short cage)]

Derailleur (front): Deore DX (FD-MT62) [VeloBase info: trailing action mechanism, available in Alpine (AL) or Half-Step (HS) versions, band type for 28 - 28.6 and endless clamp (EC) type for 31.8 or 34.9]

Crank: Shimano Deore DX (FC-MT60): Super Glide chain rings, light alloy anodized finish, 26/36/46 or 28/38/48 with Biopace or round rings, 170/175 lengths, cups available in English (68/70/73 x 122.5/127.5) , 74/110 BCD

Cassette: Shimano Deore DX Hyperglide 7speed [13 - 15 - 17 - 19 - 23 - 26 - 30]

Crankset: Shimano Deore DX (FC-MT60): Super Glide chain rings, light alloy anodized finish, 26/36/46 or 28/38/48 with Biopace or round rings, 170/175 lengths, cups available in English (68/70/73 x 122.5/127.5) , 74/110 BCD

• Chain rings 28/44/50 (Specialized 28; Biopace 44 / 50)

• Crank length: 175 mm

Cassette: 13-30 [Shimano Deore DX Hyperglide 7speed; Sprocket Sizes 13-15-17-19-23-26-30]

Gear inch range: 25-104

POSSIBILITIES FOR MODIFYING THE DRIVE TRAIN

Questions:

(1) What is the smallest chainring I can put on the crankset? (According to the above, it is likely a 26)

(2) What is the largest cog I can put on the cassette? Answer: 32

(3) Can I put an 8 speed cog on it? Is it compatible with the derailleur (yes), and with the shifters?

Possibilities for lowest gear:

(1) Current cassette (low = 30) + new small chainring (26): [Lowest GIR: 24]

(2) New cassette (14/32) + current chainrings (28) [GIR: 24-96]

(3) New cassette (14/32) + new small chainring (26): [GIR: 22-97]

(4) Touring triple (26/36/48) with current cassette (13-30) [GIR = 24-100]

(5) Touring triple (26/36/48) with new cassette (14-32) [GIR = 22-93]

(4) VO Grand Cru Fluted Triple ($195) (24/34/48) with current cassette [GIR = 22-100] (Best)

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Complete make-over: Considerations- derailleur is getting old; A lower gear would be nice; update to 8 or 9 or 10 speed; New crank, cassette, front and rear derailleurs, and shifters

***** MINTY *****

Crankset: 42/52; Cassette: 13-26. [GI: 43-106]

Crankset: Shimano Biopace 42/52 (crank length: 170mm)

Cassette: 6 speed, 13 - 26

POSSIBILITIES FOR MODIFYING THE DRIVE TRAIN

Questions

(1) What is the minimum and maximum cog size? (Answer: The max is 28, given the current derailleur)

(2) What are the limits on the crank size?

(3) Can I convert to a 7 speed?

(4) What is a desirable gear inch range? (The Synapse is currently 32-120, and used to be 37-113. Rando is 25-104. I believe that 32-105 would be sufficient).

Possibilities

Current crankset (42/52) + new cassette (14-28): GIR = 42-100 (not low enough)

New crankset (34/46) + current cassette (13-26): GIR = 35-96 (not high enough)

New crankset (34/46) + new cassette (14-28): GIR = 33-89 (not high enough)

New crankset (34/48) + current cassette (13-26): GIR = 35-100 (pretty good) (see VO Compact Crank 34/48)

New crankset (34/48) + new cassette (14-28): GIR = 33-93 (not high enough)

New crankset (34/50) + current cassette (13-26): GIR = 35-104 (pretty good - probably the best)

New crankset (34/50) + new cassette (14-28): GIR = 33-96 (not high enough)

VO Compact Double Crankset (34/48): $100: http://store.velo-orange.com/index.php/components/cranksets/vo-compact-double-crankset-34x48t.html

Proposed crankset: 34/46 (assume crank length: 170mm)

[Same cassette: 13-26, GI with 28 tires: 35-95]

[New cassette: 12-28; GI with 28 tires: 33-103]

[New cassette & LC derailleur: 12-30; GI with 28 tires: 31-104]

TOURING BIKES

Novara Randonee: http://www.rei.com/product/816068/novara-randonee-bike-2013

(Shimano Deore LX, 44/32/22; SRAM PG-1050, 11-32, 10-speed; Derailleur: SRAM X7; GI: 19-108)

Salsa Vaya: http://salsacycles.com/bikes/vaya

(Travel: Shimano Ultegra 30/42/52T; Shimano 105 11-30T 10-Speed; Der: Shimano Ultegra GS Cage; GI: 27-127)

(2: SRAM Apex 34/46T; SRAM 11-36T 10-Speed; Derailleur: SRAM X.9; GI: 25-113)

(3: Shimano Sora 30/42/52T; Shimano 11-32T 9-Speed; Der: Shimano Deore; GI: 25-128)

Surly Long Haul Trucker: http://surlybikes.com/bikes/long_haul_trucker

(Crank: Andel RSC6, 26/36/48t; Cogs: Shimano 11-34; Der: Shimano LX, T661SGS; GI: 21-118)

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GEAR INCH RATIOS (LOW END) [Sheldon Brown's Calculator]

Cassette X Chainring = GI

• 36 X 24 = 18

• 36 X 26 = 20

• 34 X 24 = 19

• 34 X 26 = 21

• 32 X 24 = 20

• 32 X 26 = 22

• 30 X 24 = 22

• 30 X 26 = 23

• 30 X 28 = 25

INFORMATION

Chainrings

• http://sheldonbrown.com/harris/chainrings/74.html

• http://sheldonbrown.com/harris/chainrings/110.html

Derailleurs

• http://en.wikipedia.org/wiki/Derailleur_gears

• http://sheldonbrown.com/harris/derailers-rear.html

• http://www.stanford.edu/~dru/triplecheat.html

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CALCULATING MAXIMUM DERAILLEUR CAPACITY

• 1. Determine Maximum Chainring Difference by subracting the number of teeth in the smallest chainring from the number of teeth in the largest chainring [Rando's: 50T- 28T = 22T] [Possible new: 48-24 = 24T]

  2. Determine Maximum Cassette Cog Difference by subtracting the number of teeth on the smallest cassette cog from the number of teeth on the largest cassette cog [Rando's: 30-13 = 17T] [Possible new: 34- 11 = 23T]

  3. Determine Total Drivetrain Capacity by adding Maximum Chainring Difference to the Maximum Cassette Cog Difference [Rando's: 22 + 17 = 39T] [Possible new: 24 + 23 = 47T]

  4. Record the Maximum Cassette Cog (the number of teeth on the largest Cassette Cog) [Rando's: 30T] [Possible new: 34]

For Shimano derailleurs:

SS - Short Cage Road Double - Maximum Cassette Cog is 27 and Total Capacity is 29

GS - Medium Cage MTB/Road Triple - Maximum Cassette Cog is 34(MTB)/27(Road) and Total Capacity is 33(MTB)/37(Road)

SGS - Long Cage MTB - Maximum Cassette Cog is 34 and Total Capacity is 45

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Derailleurs

1993: Deore XT RD-M735 SGS (long cage), STI compatible 7speed SIS compatible

1993: Deore DX RD-MT650 SGS (long cage), 7speed STI compatible

1994-1995: Deore RD-M737 SGS (long cage), STI compatible 8 speed SIS compatible,

1996-1998: Deore XT RD-M739 SGS (long cage) , STI compatible 8 speed SIS compatible

1999-2005: Deore XT RD-M750 SGS (long cage) , STI compatible 9 speed SIS compatible

1994: Deore XTR RD-M900, 8 speed STI compatible

2005: Deore XTR RD-M960-SGS (long cage), 9 speed STI compatible

Deore LX RD-M571: 9 spd; Large 34, Small 11, Total 45, Front difference 22

Deore LX: RD-M581

http://www.peterwhitecycles.com/chainrings.asp

http://sheldonbrown.com/harris/chainrings/74.html

http://www.bikeforums.net/archive/index.php/t-351972.html

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Deore XT

• Deore XT M735 1990 6/7-speed

• Deore XT M737 1993 8-speed: Max 32T; Tot 33T

• Deore XT M739 1995 8-speed: Max 32T; Tot 38T

• Deore XT M750 1999 9-speed

• Deore XT M760 2003 9-speed

• Deore XT M770 2008 9/10-speed

• Deore XT M780 2011 10-speed

2 X 9 Drivetrains: http://www.bike198.com/mountain-bike-setup-2x9-drivetrains/

==

http://www.cyclingabout.com/wider-gear-range-road-shifters-gears-for-easier-hill-climbing/

https://www.cyclingabout.com/low-gear-ratios-from-modern-2x-drivetrains/

https://www.cyclingabout.com/category/equipment/bike-equipment/low-gears/

https://www.cyclingabout.com/gear-ratios-how-to-select-touring-bike-gearing/

https://www.bikeradar.com/advice/buyers-guides/gravel-bike-setup/

https://road.cc/content/feature/how-get-ultra-low-gearing-gravel-bike-adventures-246424

https://www.sram.com/en/life/stories/gravel-gearing-horses-for-courses

I’ve calculated the low gears for you in my Touring and Bikepacking Bike Buyer’s Guides, which are updated yearly for free and feature over 200 different bikes to compare. If you’d like to support this website, grab yourself a copy, and you’ll soon have a very sound understanding of the most important aspects of bikes.