Kid’s Mountain Bike – Woom 4 in Review

The Appalachian mountains are great at growing rocks.  You clear a spot for a garden, wait a year and you’ll have a bunch of em just poppin’ up out of the ground.  Annoying things too sometimes.  They caused my dear kid to once again face plant on the mountain bike trail.  I was frustrated.  For my first kid I bought a used Jamis x.20 mountain bike for him and he loved it.  Rode it all over the place.  No trail could stop him.  I was so pleased with it that I bought another one for my next kid.

He did not love it, he hated it.  This is the third trail we had tried and the third time we had to turn back after about a quarter of a mile because he just couldn’t handle it.  He was not strong enough to pull the brakes, shift the gears, and barely could get up over the seat.  He also would get exhausted after only pedaling for a little while.

As an engineer I like to solve problems.  I dove into research and seriously considered buying him a 20 inch Flow bike for 1200. It had easy to pull disc brakes, is easy to shift, and designed so that the seat could be really low. The website claims it weighs in at 21 lbs. The Woom 4 is 16.7 lbs (at least the one i have). It also has easy to pull brakes, shifting, and a low seat. The flow bike looks like it is designed for the serious mountain biker. It looks like it could go on anything a professional mountain biker could go on. I weighed that against the skill level of my child and realized it was just too much for him at this time. The Woom 4 was lighter, cheaper, and much more at the skill level my kid is at right now. If it turns out he loves mountain biking then I can get him ‘In the Flow’.

The major problem with the Jamis is that it weighs 26.4 lbs. The kid riding it is only 48 pounds.  I weigh 180 and tried to imagine riding a mountain bike that weighed around 90 pounds.  That’s when I realized why he was getting exhausted.

I kept reading about these so called, “Woom” bikes.  The name itself turns me off, I don’t want to say “Woom”.  I know these are designed by Germans and in German the W is pronounced with a “Vr” so it really should be a “Vroom!” bike which is neat, but in English Woom doesn’t come out right when you pronounce it.  However the Woom 4 is feather lite, weighing in at just under 17 pounds, about ten pounds less than the Jamis x.20.  It is also looks weird, but that is because it has been ergonomically designed for a 6-8 year old kid.

I finally bit the bullet and bought him a Woom 4 and what a difference that made.  No more, “I hate bike riding.  I don’t want to go bike riding.”  Instead my kid was finally excited about it.  Proof in point is that he not only kept up with his older sibling, but the older guy was getting frustrated because he couldn’t out ride him anymore.

Quite frankly I was shocked at what cutting the weight by ten pounds did. I did not think it would make much of a difference, but it did. I suppose a little math could have helped me figure that out, 26.4/48 is 55%. This means that the Jamis bike was 55% of his body weight. 16.7/48 is 34%. The Woom 4 is only 34% of his body weight vice the Jamis which is 55% of his body weight. For comparison I ride an old full suspension bike that weighs 35 lbs. 35/180 is 19.%. I guess my kid will still have a harder time pumping up hills than me which is ok, it builds character.

You can click on the picture below to read the reviews about the Woom 4 on amazon and see for yourself:



  1. I’m looking at the Woom 5 for my almost 8 year old daughter. She likes to ride trails with me here in SW Ohio (not easy on her current 20″), but spends most of her time on the roads in the neighborhood and on our great local bike path. I’d like to ask what types of trail your son has been on with his Woom? We have pretty rooty trails around here and I’m wondering if the bike would handle it?

    1. They just came out with the Woom Off 5. Go for that one. The Woom 5 does ok on gravel, but not on rooty trails. Even gravel causes a lot of trouble with the arms shaking.

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