Our Guide to Kids BikeFit for Youth/Junior cyclists
Our Guide to Kids BikeFit for Youth/Junior cyclists...
It all starts with choosing their new bike size. Its understandable – but do try to avoid buying a bike that is too big , so they ‘grow into it’. We see this often, yet it puts the child at a real disadvantage. The heavier bike, often longer than they can safely handle – risks accident, injury and one demoralised rider!
Whilst we offer a Free basic bike fit (we use the Paul Swift ‘BikeFit‘ System for full bike fits) for all bikes collected in-store, if you have bought online here is some basic fitting guidance for you to set up your rider in the best position possible, making ongoing adjustments as they grow.
As with all bike fits, it’s about achieving the best possible fit for the rider on that bike. Perfection is not always possible, compromise is common. Especially with kids, as they tend to move around on their saddle and pedals more than adults.
Basic Bike Fit Principles:
With the pedal at the bottom of the crank stroke, ideally a knee angle between 27 degrees (road bike) to 37 degrees (MTB) – see Photo 1. Riders sat on the saddle should be on tip-toes on the ground (not always possible, dependent on BB height) but stable. Too high = hip rotation (hips rock side-to-side when pedalling). Too low = potential knee issues and lack of power.
Top Tip: place the pedal a the bottom of its stroke, inline with the seat tube and their heel on the pedal. Set the saddle height so there leg is straight (with the heel on the pedal).
Look to achieve a 90 degree angle between the torso and the upper arms, through the shoulders. See Photo 1 for example of 90 degrees. Over 90 degrees = too long, under 90 = too short, so adjust saddle fore and aft and/or stem length to correct this.
Look to achieve a 15 degrees to 25 degrees angle between the upper and forearm, through the elbow. Avoid elbow ‘lockout’, Photo 1 is a good example. Adjusting saddle fore and aft and/or stem length will correct this.
Riders In Cleat Shoes/Pedals:
Bike fit becomes more important for older riders (typically 8+ years old) wearing cleat shoes/pedals. The foot/pedal interface is fixed, so needs to be correct to prevent injury and ensure maximum efficiency.
This subject does get more advanced/complex, especially dealing with Leg Length Differences and Forefoot Tilt, but the basics can still be correctly achieved by yourself.
You don’t need a Laser for this task, but careful use of a plumb line will also work fine;
Cleat Position – Fore/Aft:
As seen in Photo 2, position the cleats to place the pedal spindle between the 1st and 5th MTP (Metatarsophalangeal – ball joint of the big and smallest toe!), ideally slightly closer to the 5th MTP. When correct, the KOPS (Knee Over Pedal Spindle) will be correct. Move the cleat forward/back on the shoe to correct this. Saddle position also affects this, by moving the knee forwards or backwards.
Cleat Position – Medial/Lateral:
This is adjusting the cleat on the shoe inwards or outwards to align the foot to the knee during the pedal stroke – see Photos 3 & 4. By observing the pedalling motion, you need to move the cleat towards the knee’s position, to achieve the best alignment possible. Getting the foot in-line with the knee is another common problem if the bike is too big for the rider, as a larger Q-factor will splay the legs.
Cleat Position – Rotation:
This is a check of the angle of the cleat on the shoe. Ideally you want as straight a foot (in relation to the bike) as possible. To test, push the heel in towards the bike, then pull outwards away from the bike. You need to feel that the ‘float’ in cleat is even in both directions. If not, rotate the cleat on the shoe slightly, until even ‘float’ is achieved.
With all points considered above, ultimately the bike should be comfortable for the rider, so listen to any issues they may be experiencing and adjust to suit.
If they are having problems, here are some common issues and possible solutions;
- Front Knee Pain = adjust Saddle UP & BACK
- Back of Knee Pain = adjust Saddle DOWN & FORWARD
- Outside of Knee Pain = adjust cleat in (move foot OUT)
- Inside of Knee Pain = adjust cleat out (move foot IN)
- Achilles Pain = adjust cleat back (move foot FORWARD)
- Saddle Pain (Front & Center) = Handlebars UP and/or Tip of Saddle DOWN
- Feet Pain = potential wedges/shims required – seek a professional BikeFit!