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This page is dedicated to helping parents and racers in their search for information on bikes and gears. Scroll down to see information on framesizing, recommended tire sizes, crank length, andgear charts.

FRAME SIZE:
RIDER HEIGHTFRAME SIZE TOP TUBE LENGTH STEM LENGTH BAR RISE BAR WIDTH CRANK LENGTH GEARING
4'0" & under Micro 15-15.5 Mini 2-2.5 20- 21.5 See Chart Below See Chart Below
4'0-4'6 Mini 15.5- 16.5 Mini/MiniXL 2-3.5 21- 23 See Chart Below See Chart Below
4'4-4'10 Junior 16- 17.5 Mini/MiniXL 3-4.5 22- 24.5 See Chart Below See Chart Below
4'8-5'4 Expert 17- 18.5 Pro 4.5-6 24- 26 See Chart Below See Chart Below
5'2-5'8 Expert XL 18-19 Pro 6-7.5 26- 27 See Chart Below See Chart Below
5'6 - 5'10 Pro 18.5- 19.5 Pro/ProXL 7-8 27- 28 See Chart Below See Chart Below
5'10-6'1 Pro XL 19-21 Pro/ProXL 7-8 17- 28 See Chart Below See Chart Below
6' & over Pro XXL 20.5" & over ProXL/ProXXL 7-8 28- ? See Chart Below See Chart Below


TIRE SIZE:
MAX.RIDER WEIGHT RIM WIDTH
Up to 65# SEW UPS
50-90# 20 x 1-1/8"
85 - 120# 20 x 1-3/8"
115-150 20 x 1.50"
140# & up 20 x 1.75"


CRANK LENGTH:
RIDERS INSEAM under 19" 20" 21" 22" 23"
CRANK LENGTH 135mm 140mm 145mm 150mm 155mm
RIDERS INSEAM 24" 26" 27" 28-29" 30-31"
CRANK LENGTH 160mm 165mm 170mm 175mm 180mm


GEAR CHARTS:

Recommended Rollout for Boys over 9 years old:

Novice 57.0 -> 55.0
Intermediate 55.0 -> 54.2 -> 53.6
Expert 53.6 -> 52.4

Learning to spin is an essential skill to learn to compete at an expert level. A rider needing to "mash" down on the pedals is not going to be able to get the quick acceleration needed to be competitve.

To figure your rotation here is the formula:
sprocket / freewheel X tire diameter = inches travelled per one full rotation of cranks

<
Gear Chart 20 X 1.75

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
SPROCKET 34 35 36 37 38 39 40 41
Freewheel 14 47.4 48.7 50.2 51.6 53 5`4.4 55.7 57.1
Freewheel 15 44.3 45.4 46 48.1 49.4 50.7 52 53.3
Freewheel 16 41.5 42.7 43.9 45.1 46.3 47.5 48.8 50
Freewheel 17 39 40.2 41.3 42.5 43.6 44.7 45.9 47
Freewheel 18 36.8 37.8 39 40.1 41.2 42.3 43.3 44.4
SPROCKET 42 43 44 45 46 47 48

 
Freewheel 14 58.5 59.9 61.9 62.7 64.1 65.5 66.9

 
Freewheel 15 54.6 55.9 57.2 58.5 59.8 61.1 62.4

 
Freewheel 16 51.2 52.4 53.7 54.9 56.1 57.3 58.5

 
Freewheel 17 48.2 49.4 50.5 51.7 52.8 53.9 55.1

 
Freewheel 18 45.5 46.6 47.7 48.8 49.9 51 52

 

 

 

 

 

 

 

 

 

 
Gear Chart 20 X 1.50"

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
SPROCKET 34 35 36 37 38 39 40 41
Freewheel 14 46.8 48.1 49.5 50.9 52.3 53.6 55 56.4
Freewheel 15 43.6 44.9 46.2 47.7 48.8 50.1 51.3 52.8
Freewheel 16 40.9 42.1 43.3 44.5 45.7 46.9 48.1 49.3
Freewheel 17 38.5 39.6 40.8 41.9 43.1 44.1 45.2 46.4
Freewheel 18 36.4 37.4 38.5 39.6 40.6 41.7 42.8 43.9
SPROCKET 42 43 44 45 46 47 48

 

Freewheel 14 57.5 59.1 60.5 61.8 63.2 64.6 66

 
Freewheel 15 53.9 55.2 56.5 57.7 59.1 60.2 61.6

 
Freewheel 16 50.5 51.7 52.9 54.1 55.3 56.5 57.7

 
Freewheel 17 47.5 48.7 49.8 51 52.2 53.1 54.3

 
Freewheel 18 44.9 46 47 48.1 49.2 50.3 51.3

 

 

 

 

 

 

 

 

 

 
Gear Chart 20 X 1 3/8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
SPROCKET 34 35 36 37 38 39 40 41
Freewheel 14 51 52.5 54 55.5 57 58.5 60 61.5
Freewheel 15 47.6 49 50.4 51.6 53.2 54.6 56 57.4
Freewheel 16 44.6 45.9 47.3 48.6 49.9 51.2 52.5 53.9
Freewheel 17 42 43.2 44.5 45.7 47 48.2 49.4 50.7
Freewheel 18 39.7 40.7 42 43.2 44.4 45.5 46.7 47.9
SPROCKET 42 43 44 45 46 47 48

 
Freewheel 14 63 64.5 66 67.5 69 70.5 72

 
Freewheel 15 58.8 60.2 61.6 63 64.4 65.8 67.2

 
Freewheel 16 55.2 56.6 57.8 59.1 60.4 61.7 63

 
Freewheel 17 51.9 53.2 54.4 55.6 56.9 58.1 59.3

 
Freewheel 18 49 50.2 51.4 52.5 53.7 54.9 56

 

 

 

 

 

 

 

 

 

 
Gear Chart 20 x 1 1/8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
SPROCKET 34 35 36 37 38 39 40 41
Freewheel 14 48.6 50 51.4 52.8 54.3 55.7 57.1 58.6
Freewheel 15 45.3 46.7 48 49.3 50.7 52 53.3 54.7
Freewheel 16 42.5 43.8 45 46.2 47.5 48.7 50 51.2
Freewheel 17 40 41.2 42.3 43.5 44.7 45.9 47 48.2
Freewheel 18 37.7 38.8 40 41.1 42.2 43.3 44.4 45.6
SPROCKET 42 43 44 45 46 47 48

 
Freewheel 14 60 61.4 62.8 64.3 65.7 67.1 68.6

 
Freewheel 15 56 57.3 58.7 60 61.3 62.7 64

 
Freewheel 16 52.5 53.7 55 56.2 57.5 58.7 60

 
Freewheel 17 49.4 50.6 51.8 52.9 54.1 55.3 56.5

 
Freewheel 18 46.7 47.8 48.9 50 51.1 52.2 53.3

 

 

 

 

 

 

 

 

 

 
Gear Chart 24 X 1.75

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
SPROCKET 34 35 36 37 38 39 40 41
Freewheel 14 58.3 60 61.7 63.3 65 66.9 68.6 70.3
Freewheel 15 54.4 56 57.6 59.3 60.7 62.4 64.1 65.5
Freewheel 16 51 52.5 54 55.5 57 62.4 64.1 65.5
Freewheel 17 48 49.4 50 52.2 53.6 55.1 56.5 57.9
Freewheel 18 45.3 46.5 48 49.4 50.7 52 53.3 54.7
SPROCKET 42 43 44 45 46 47 48

 
Freewheel 14 72 73.7 75.3 77 78.9 80.6 82.3

 
Freewheel 15 67.2 68.9 70.3 72 73.7 75.1 76.8

 
Freewheel 16 63.1 64.5 66 67.4 69.1 70.5 72

 
Freewheel 17 59.3 60.7 62.1 63.6 65 66.2 67.7

 
Freewheel 18 56 57.3 58.5 60 61.4 62.6 64.1

 

 

 

 

 

 

 

 

 

 
Gear Chart 24 X 1.50

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
SPROCKET 34 35 36 37 38 39 40 41
Freewheel 14 55.9 57.5 59.1 60.7 62.3 64.2 65.8 67.4
Freewheel 15 52.1 53.7 55.2 56.7 58.2 59.8 61.3 62.8
Freewheel 16 48.4 50.3 51.8 53.2 54.6 56 57.5 58.9
Freewheel 17 46 47.3 48.7 50 51.4 52.8 54.1 55.5
Freewheel 18 43.4 44.7 46 47.2 48.5 49.8 51.1 52.4
SPROCKET 42 43 44 45 46 47 48

 
Freewheel 14 69 70.6 72.2 73.8 75.7 77.3 78.9

 
Freewheel 15 64.4 65.9 67.4 69 70.6 72 73.6

 
Freewheel 16 60.3 61.8 63.2 64.6 66.2 67.6 69

 
Freewheel 17 56.8 58.8 59.5 60.8 62.3 63.5 64.8

 
Freewheel 18 53.7 54.9 56.2 57.5 58.9 60 61.4

 

 

 

 

 

 

 

 

 

 
Gear Chart 24 X 1 3/8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
SPROCKET 34 35 36 37 38 39 40 41
Freewheel 14 58.3 60 61.7 63.3 65 66.9 68.6 70.3
Freewheel 15 54.4 56 57.6 59.3 60.7 62.4 64.1 65.5
Freewheel 16 51.1 52.5 54 55.5 57 58.5 60 61.4
Freewheel 17 48 49.4 50.8 52.2 53.6 55.1 56.5 57.9
Freewheel 18 45.3 46.5 48 49.4 50.7 52 53.3 54.7
SPROCKET 42 43 44 45 46 47 48

 
Freewheel 14 72 73.7 75.3 77 78.9 80.6 82.3

 
Freewheel 15 67.2 68.9 71.3 72 73.7 75.1 76.8

 
Freewheel 16 63.1 64.5 66 67.4 69.1 70.5 72

 
Freewheel 17 59.3 60.7 62.1 63.3 65 66.2 67.7

 
Freewheel 18 56 57.3 58.5 60 61.4 62.6 64.1

 

 

 

 

 

 

 

 

 

 
Gear Chart 24 X 1 1/8

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
SPROCKET 34 35 36 37 38 39 40 41
Freewheel 14 54.9 56.5 58.1 59.7 61.3 63.1 64.7 66.3
Freewheel 15 51.3 52.8 54.3 55.8 57.3 58.8 60.3 61.8
Freewheel 16 48.1 49.5 50.9 52.3 53.7 55.1 56.6 57.9
Freewheel 17 45.2 46.6 47.9 49.3 50.6 51.9 53.2 54.6
Freewheel 18 42.7 43.9 45.2 46.6 47.7 49.1 50.3 51.5
SPROCKET 42 43 44 45 46 47 48

 
Freewheel 14 67.9 69.4 71 72.6 74.4 76 77.6

 
Freewheel 15 63.3 64.9 66.3 67.9 69.4 70.8 72.4

 
Freewheel 16 59.5 60.8 62.2 63.9 65.1 66.5 67.9

 
Freewheel 17 55.9 57.2 58.6 59.9 61.3 62.4 63.8

 
Freewheel 18 52.8 54 55.3 56.6 57.9 59 60.4