A Junior’s Guide To Road Bicycle Sizing/Fit

A Junior’s Guide to Road Bicycle Sizing/FitThe purpose of this guide is to provide information and resources toparents of junior cyclists. This guide focuses on the process offinding junior road bicycles and properly fitting your juniorcyclist(s) to their machine. This guide will also provide anexplanation sizing and adjustments to maximize your junior cyclist’ssafety, comfort, and power output. Optimal angles for your cyclist’sjoints whilst on the bike will also be discussed. Links and resourcesto frames/parts will be provided.By: Aidan Pounder

Table of ContentsIntroduction 1Bike Frames 2Wheels 3Crankarms 5Handlebars 6Shifters/Levers 7Gearing 8Pedals 9Other Parts 10Bike Fit 11Website Links 12References 13

1IntroductionThis guide serves to provide information and resources to findproperly fitting road cycling frames, wheels, crankarms, and variousother cycling parts for junior cyclists. Besides discussing cyclingparts, this guide shall cover the proper fitting of your juniorcyclist on their road bike and the optimal angles of his/her joints ontheir machine. The purpose of covering a junior cyclist’s “bike fit”is to increase the cyclist’s control, safety, comfort, and poweroutput on the bike. A proper “bike fit” will also nearly eliminate thepossibility of your junior cyclist damaging their muscles or jointswhile pedaling their road bicycle.This guide will comprehensively cover junior road cycling bikes andequipment in an unbiased manner without promotion of specific productsor brands and will only highlight brands based on their suitabilityand attention to junior riders in their manufacturing. This guide willalso provide links to websites that have junior bicycle frames andvarious road bicycle parts to help you along your journey in gettingyour junior cyclist on the road!The figure below may serve as a reference point if the reader isunfamiliar with bicycle parts referred to throughout this report.Figure IBicycle Parts

2Bike FramesBEWARE, many bicycle distributors will attemptto sell you a bike frame based on your juniorcyclist’s age. Age IS NOT an accuratedeterminant in properly fitting a bike frameto your junior cyclist.The best way to find a suitably fitting roadbike for your junior cyclist is to base yourpurchase off your child’s height and inseam.Grab a tape measure and measure your juniorcyclist’s height and inseam as accurately aspossible.Note, your junior cyclist does not necessarilyneed a “road bike frame”, as cyclocross bikesand even BMX bikes can be converted.The best way to find a well-fitting bike framefor your junior cyclist is to have him/her tophysically sit on the bicycle.Using bike fitting methods while watching yourjunior cyclist sitting/riding on a bike andmaking an educated decision is the best way todetermine frame sizing.Figure IIGraphic Bike Chart

3WheelsThe best way to find suitably fitting wheels for your junior cyclist,is to follow the same method as listed above for bike frame sizing.Choosing a bike size based on frames or wheels, will most of the timepoint you in the same direction.Accurately measuring your junior cyclist’s inseam is very important forthis stage of building your bike.Figure IIIKids Bike Sizes ChartWheel size is one of the most confusing aspects of cycling parts, as thesame sized wheels can be referred to in a multitude of different waysacross the different disciplines of cycling.First and foremost, 24”, 650C, and 700C wheels will be the wheels youwill most likely come across in the world of road cycling.

4Figure IVBike Wheel ConversionsFigure IV above, details the different ways the same sized wheels canbe described.Wheels typically are described by the wheels’ diameter in inches up untilthe 24-inch size. A 26-inch wheel doesn’t exist in cycling, as that sizedwheel is referred to as a 650a/b/c.The a/b/c refers to the width of the tire that fits around the rim ofthe wheel. You will only need to be concerned with “c” wheels in roadcycling.A 28-inch wheel is referred to as a 700c wheel, the industry’s standardsize.

5CrankarmsAs a rule of thumb, crank arm length should be determined by your juniorcyclist’s height. The crank arm length should be 10% of the rider’sheight plus 5mm.Crank arm length in millimeters (cyclist’s height 0.10) 5mmFigure VCrankarm LengthCrankarms are difficult to find in small enough sizes for juniorcyclists, and the answer can sometimes be found in the BMX world.It is important to note, that the BCD layout should also be consideredwhen purchasing cranks.The BCD layout is the chainring bolts layout, or more simply put, howmany bolts are needed to attach the crank arm to the bike.As an industry standard, road bicycles are fitted with 5 bolt cranks.Smaller crank arms are more typical in the off-road disciplines ofcycling.

6HandlebarsFitting your junior cyclist with the proper handlebar width will notonly reduce their aerodynamic drag on their road bike, but moreimportantly improve comfort and control over the bike.The benefit of properly fitting handlebars also includes reducingshoulder tension, neck pain, jaw pain, or even hand fatigue whileriding.The most common advice you will likely receive involving handlebarwidth, will be to match the rider’s shoulder width to the handlebarwidth. Though this a good starting point, ultimately whatever widthfeels best to your rider, whether slightly narrower or wider thantheir shoulder width, is the best route to take.Figure VIHandlebar Width

7Shifters/LeversThe main concern when discussing shifters and brake levers for juniorroad cyclists is their ability to use components effectively.Braking is a necessity, and these bike components need to be operatedby smaller hands with weaker grip strength.Kids and junior bikes tend to come with older and heavier equipment,so keep that in mind. Shifting and braking levers are usually quitestiff and require larger hands with greater grip-strength.The best solution to this problem is short-reach shifters with doubletap shifting.Some of the best short-reach shifter options for junior road cyclistsinclude: MicroShift R9 Dual Control levers, Sram Red ETap shifters,and Sram Apex DoubleTap shifters.Figure VIIFigure VIIIFigure IXSram ApexSram ApexSram Apex

8GearingBEWARE, if your child wants to race on the road – no bicycle youpurchase will come with junior gearing.Junior gearing is implemented to encourage good pedal cadence andreduce chance of injury.Junior gearing is tested at all junior road cycling events, whetherroad race or criterium.The “rollout method” or “junior rollout” is a test in which the bikemust be rolled backwards 26 feet in a straight line in the bike’ssmallest cog (or hardest gear to pedal). The crank must be at a 90degree angle to the ground and must complete a full pedal revolutionwithin the 26 ft boundary.A 52x14 (52 tooth chainring and 14 tooth smallest cog) is the mostcommon gearing used to pass junior rollout.Other gearing combinations for junior cyclists include 44x34, 52x36,and 41x33.Figure XJunior Rollout

9PedalsFigure XIFigure XIIFigure XIIIStandard PedalsToe Cage PedalsSpeedplay PedalsThere is an abundance of different types of pedals: standard pedals,toe clip or toe cage pedals, power grip pedals, and clipless pedals.Any bicycle bought from a bike store or manufacturer will come withstandard pedals.Toe clip/Toe cage and power grip pedals offer an intermediate stepbetween standard pedals and clipless pedals.If your junior cyclist is at the point where they are ready to makethe next step to clipless pedals, then be careful which cleats/pedalsto use.The biggest concern with clipless pedals and junior riders is theirability to unclip from the pedals when coming to a stop.The best type of clipless pedals for junior road cyclists areSpeedplay Ultra Light Action pedals, Look Keo 2 Max pedals, and TimeXPro 10 pedals.

10Other Parts Side Winder bottle cage, as it needs to be as easy as possiblefor your junior cyclist to grab and put back their water bottle Think about looking at shorter stems for your junior cyclist, astheir elbows should not be locked and fully outstretched. Yourcyclist’s arms should be slightly bent to improve control overthe bike and limit impact on the cyclist’s joints Adjustable saddles are something worth looking into, as they canimprove fit and comfort for the riderFigure XIVAdjustable Saddle

11Bike FitBike fits are the process of fitting your cyclist to their bike,so he/she is as comfortable as possible, fully in control of thebike, and most importantly not damaging their tendons or muscleswhile pedaling.The first, and simplest step to your junior cyclist’s bike fit, istheir saddle height. Ideally, when your junior cyclist is sat onthe saddle, their toes should be touching the ground and the cyclistshould not be flat footed.With all steps of bike fitting, the best way to go about thisprocess is by use of a stationary trainer. Saddle height is bestdetermined by pedaling rather than the toe method discussed above.Your junior cyclist’s knee center should be directly above thecenter of the pedal when the crankarm is parallel to the ground.Your junior cyclist’s knee needs to be bent between a 27- and 37degree angle when extended at the bottom of his/her pedal stroketo prevent damage and injury to muscles/tendons while pedaling.The optimum angle for your junior cyclist’s shoulders is as closeto an exact 90-degree angle as possible between the rider’s torsoand upper arms.Figure XVSaddle Height

12Figure XVIFigure XVIIFigure XVIIIKnee Over PedalKnee AngleShoulder AngleAs shown above in Figure XVIII, the optimum angle for your juniorcyclist’s elbow should be approximately 15-degrees.If you follow the advice provided above and reference the figuresprovided, then your junior cyclist should be comfortable and incontrol of their machine!The information provided create the steps for a basic bike fit, butdiscomfort on the bicycle may persist. This oftentimes can be solvedby adjusting the cleat position on the base of the cycling shoes (ifyour junior cyclist is using clip-less pedals)BEWARE, adjusting cleat position can seriously affect the rider’spedal stroke and should be done under the presence of a professionalbike fitter

13Website Links Road Bicycles Designed for Junior Cyclists Isla Bikes Frog Bikes Specialized BikesClipless Pedals for Junior Cyclists Speedplay Ultra Light Action Look Keo 2 Max Time XPro 10 Other Parts for Junior Cyclists Side Winder Croder Cycling Cranks Sram Apex DoubleTap

14ReferencesBikeRadar. (2020, December 18). Speedplay light action Chromoly Pedals review. RetrievedApril 08, 2021, from sRacing.CO.UK. (n.d.). Our guide to Kids BikeFit for YOUTH/JUNIOR CYCLISTS.Retrieved April 08, 2021, from kefityouth-junior-cyclistsMartins, N. (2021, February 16). Kids bike SIZES guide and Chart: Don't buy the wrong SizeBike! Retrieved April 08, 2021, from de-a-new-trick-to-finding-the-best-fit/McKenzie, E. (2021, March 04). Kids bike size chart: The definitive guide to kids bike sizes infographic. Retrieved April 08, 2021, from s-bike-sizes-dont-buy-the-wrong-bike/Montague Bikes. (2021, March 29). Bicycle wheel sizes explained. Retrieved April 08, 2021,from 019/06/bicycle-wheel-sizesexplained/USA Cycling. (n.d.). Bike Racing 101. Retrieved April 08, 2021, cycstory.php?id 4203#: :text ght%20and%20power.Vastbinder, O. (2020, July 22). How to determine the correct saddle height. Retrieved April 08,2021, from e-correct-saddle-heightVectorMine. (2020, March 18). Bike Parts. Retrieved April 08, 2021, rts-labeled-illustrationdiagram 7291051.htmVeloNews. (2015, October 29). Technical FAQ: Junior gear options. Retrieved April 08, 2021,from -gearoptions/#: :text 023C%20rear%20tire.Woodman, O. (2020, December 22). Best road bike PEDALS 2021: 5 top-rated clipless pedalsfor your bike. Retrieved April 08, 2021, from -road-bike-pedals/

A Junior’s Guide to Road Bicycle Sizing/Fit The purpose of this guide is to provide information and resources to parents of junior cyclists. This guide focuses on the process of finding junior road bicycles and properly fitting your junior cyclist(s) to their machine. This guide will also provide an explanation sizing and adjustments to .