Jake Hollenbach is a cyclist, accredited bike fitter, and father to an enthusiastic kiddo mtb'er, based in Richmond, Vt.  He is a long time employee of the Skirack, a Little Bellas partner shop in Burlington, Vt. In this blog Jake gives us some expert advice on how to make some simple bike adjustments that can have dramatic effects on young riders' mountain bike experience.

For young riders, new bike day is an exciting – but sometimes nervous – day.  Whether it’s a new or used bike, an upgrade or an awesome new paint job (exciting), it’s a bump up to a bigger bike (scary). Mountain biking is all about control and reaction. Getting a new bike that’s bigger and properly adjusted can make the difference between a confident and excited rider versus a nervous and reluctant one.

Seat height

There are several specific adjustments to kids' bikes that can affect confidence and excitement about riding the bike.  Start with saddle height.  Every kid has a different comfort level with regard to how high they are sitting.  Saddle height should be adjusted for the correct height when the rider is pedaling – but that might be scary at first on a bigger bike and a potential fall can scare some riders off of mountain biking for good. To achieve a proper saddle height, you can start your kiddo with the seat low enough so that the tiptoes can touch the ground while on the seat – this is absolutely fine, but the seat should gradually be raised to the correct height little by little.  The correct seat height for pedaling efficiency has the knee at a 30 to 35-degree bend at the point of greatest extension.  Apart from less efficient pedaling, putting the seat too low makes steering floppy and difficult, which won't work great on singletrack.

Handlebar height is another adjustment that can really affect confidence.  Too low and it's hard to lift the front wheel for rolling over obstacles. Wipeouts or crashes caused by handlebars that are too low happen quickly and can be scary. Too high, and the steering feels slow, plus the front wheel can wash out in turns.  Handlebar height is adjustable up and down by about 2-5 cm / ¾-2 in (depending on the bike) by raising or lowering the stem.  Most bikes come from the bike shop with their handlebars in the highest position (so lowering them is quite straightforward).  However, it’s more than possible for handlebars to be in their highest position and still be too low for the rider.  This isn't something to just live with. The small investment in a stem or handlebar with more rise (roughly $20-$50) is absolutely worth it.  When switching to a handlebar with more rise, just make sure the new handlebar is similar in width (many adult handlebars are 10-15cm too wide for youth riders).

Brake levers

Adjusting brake levers and grips is all about hand size.  Mountain bikes can have a variety of brakes: rim brakes, mechanical disc brakes, or hydraulic disc brakes.  The brake levers of almost all these brakes will have an adjustment that affects how far or near to the hand the lever is located. This adjustment is commonly called “reach.”  For a kid to be on a bigger bike and to feel like they don’t have control over slowing or stopping isn’t a good sensation.  The smaller hands of young riders will almost always need the reach to be shortened.  Also related to hand size is the thickness, or diameter, of the grips.  Handlebar grips come in a range of sizes, and generally 28-30mm grips are recommended for younger riders.  There are grips all the way up to 34mm in diameter, and really anything over 32mm will be hard for smaller hands to hold securely.  The new Specialized Jett and Riprock bikes have taken special care in using grips and brake levers that work especially well for smaller hands.

Tire pressure isn’t a body adjustment in the same sense as these others, but it’s just as important to smaller, lighter riders. When talking about tire pressure, it’s worth knowing that one gauge or pump compared to another can easily be off by 3-5 PSI, which might represent a 15-25 percent difference in the total tire pressure for a kids' tire.  Consistency is key, meaning you should use the same pump regularly.  If the tire has a recommended tire pressure range on its sidewall, I’d usually suggest starting at the bottom of that range, and then going down from there.  Yes, I’m saying that it’s quite common for the optimal tire pressure to be slightly below the labeling on the side of the tire.  This is true for adult mtb tires too, but especially for kids’ tires.  I recommend that a small rider will usually need somewhere between 10-20 PSI.  Narrower tires and smaller wheel sizes mean higher pressures, and wider tires and bigger wheel sizes mean lower pressure.

I hope this information is useful and helps bring awareness to the optional adjustments available for making a better riding experience for kids on new or existing bikes. This isn’t a comprehensive how-to guide, but rather a starting point to understand some of the key adjustments that affect control for smaller riders and that can help bring confidence and excitement to riding.  Often small changes or adjustments can make big differences in both stoke and safety on the mtb trail.  Bike shops, and other parents, can both be great resources for guidance.  Generally, all you should need to make most of the adjustments listed above is a good multitool, something like the Parktool MTC-30, which is small enough to carry with you on a family ride.

— Jake