I’m buying a new BMX bike for my 7-1/2 year old. I know little about the specs on these bikes, but a few things struck me as odd.
First, the stock cranksets are all 170 or 175. Isn’t that long for a kid, or is that just what they ride? By the time the seat is low enough, his knees come up past his waist.
Second, most models come with rear brake only. Do kids not race BMX with a front brake?
Third, there seem to be “racing bikes” and “street bikes”, with the street bikes marketed for riding at skate parks and for tricks. They look the same to me. Any “real” difference there, at least in the standard brands and price ranges. The reason I would prefer the “street bike” is that it has a front brake.
My information is a little dated, so just be warned. Luckily my own 7yo rides a 24" mountain bike. (Trek, bombproof aluminum frame, ridiculously adjustable, and about 35lbs, with slicks from Biketiresdirect!)
Okay - kids bikes - the cranksets are (too) long to give a little extra leverage to the silly single gear. These kids don’t spin, and when they want to go fast, they simply stand their skinny asses up. The saddles are usually positioned very, very low to facilitate the bike manipulation necessary for launching 16lbs of suspension-less bike and 90lbs of kid (not our kids) off a 20 foot dirt ramp.
Street/freestyle bikes have that front brake so the kids can do wheelstands and other front-wheel tricks. They also have pegs on both axles, for dancing around on, or hauling friends who are willing to stand on the back for a while. The stock tires are a little narrower, and smooth and grippy on pavement. BMX bikes (for racing on dirt tracks) have massively knobby tires, and no front brake to save weight and give you a little less to worry about when you’re flying through the air trying to clear a half dozen whoop-de-dos without busting your nuts. Besides, who needs brakes!? That’s what dirt berms are for!
I remember riding my BMX bikes for miles and miles, literally all day long, all day - on a saddle that was nothing more than a plastic shell with some holes drilled in it. Those saddles make an Aspide or SLK look like a Simmons Beautyrest Deluxe with Pillowtop. How the hell did my butt ever handle that!?
Ok, my information is a bit old, but here are some basics with BMX.
Crank length? Have no clue. But you mentioned seat height. BMX bikes ARE NOT designed to be ridden in the seat for long periods. You are out of the saddle so often, it really acts more as a landing pad for your butt. If dad is thinking of taking the kid riding for long distances (5-6 miles), he should be on a mountain bike.
Why do you need a front brake for BMX? It’s just added weight and you would never use it when you were racing.
There is a HUGE difference between bikes built for parks and ramps and bikes built for tracks. Track bikes are lighter and much more fragile than park or ramp bikes - which are built like tanks. Ramp bikes come with front and rear brakes, may come with extra platforms (don’t know if they do this anymore, though), and you can spin the front end 360 degrees without the cables getting tangled.
Unless the kid is serious about racing, he would be better off with a street bike, which can be used off road. When I was a kid, we would do 80% of all of our riding on the street, making huge jumps out of scrap wood and landing on asphault - this would kill a race bike, especially the wheels. Of course, once I actually got a decent race bike, I built a big-ass quarter pipe and started riding freestyle on it…
At 7 1/2, I would just take the kid in and spend no more than $150 on whatever bike he wants and call it good. He will want a new one in a year or so anyway… Heck, he might even want a mountain bike by then.
here is another odd thing about youth “bmx” bikes: size. and weight ! mind you, a lower end street/park bike is gonna weigh an absolute ton. thus, a 7 y/o gets a trick bike and no way in hell can he even do so much as a bunny hop on it. also, the bikes are often pro models for famous trick riders who are massively fit, strong, and insanely tough grown men. what in the world is a 7 or 8 y/o doing on a bike designed for a guy who could be a strong safety for the miami hurricanes, one has to wonder?
of course, the answer lies in this - your kid needs more than one bike, if you plan on him riding bikes in any sort of traditional sense. for example, my boy has a mtn bike for getting around town, and a little tiny mini bmx bike for tricks in the skatepark which fits him. oh, and a newly built road bike.
if, however, he just wants something to sit on while gabbing with his buddies in the neighbor’s driveway - doesn’t matter.
He will use it a few times a year to go to the BMX park for parties with friends, but I doubt he’ll ever race BMX. Most of his riding will be noodling around the neighborhood and going to school. The one he likes the best is a street/park bike, so I guess I’ll get that. I’ll follow the same advice I’d give to anyone else when deciding what bike to buy. Buy the one that you will want to ride all the time because you love it.
Yeah remember those crazy single piece seat and seat post jobs called Uni Seats? I remember I used to race quite a bit, so weight was important. The seat / seat post weighed 4oz!!! It was definitely not comfy though. BMX ruled! - e
Racing bikes are longer and the freestyle bikes are shorter(wheel-base). This makes a big difference in handling. With the freestyle bikes, the bottom bracket tends to be higher also; for better clearance. When you purchase one, just makes sure that the bike shop/store makes sure to double-check the tightness of the pedals and crank-arms. There seems to be an epidemic of these going out without proper torqing and the kids are getting hurt.
I raced BMX for quite a while. Typically for racing we never ran a front brake to save weight and seat height is always low because you dont sit much because your out of the saddle and sprinting most of the race and on a freestyle bike you dont wont the seat too high so you wont be singing soprano while doing tricks. Crank length is usually 170 to 175. I ran 190s when I was racing although I was probably quite a bit taller than your 7.5 year old. Id probably get the freestyle bike vs. a racing style bike just for everyday riding. The two sets of brakes will be safer for your kid to ride on. Good luck trying to keep up with him!
I had a UNI seat! I was a serious weight weenie when racing BMX. I always rode 20 x 1.5" tires to save weight. Had these crazy Bullseye cranks that weighed nothing, but would only stay together for about half the day. Had a 24" cruiser too.
The brand of my frames? ELF = Extra Light Frame
Whoo weee did I have fun racing BMX. Until I got older and it got serious and then it wasn’t fun anymore, so I moved on. The experience still serves me very well anytime bike handling is an issue during a triathlon.
Oh Yeah, the SE-Racing Quad Angle was it!!! You were the envy of the school with a Quad. My rims were drilled out so I could used colored rim-strips. All I had to worry about was what color I wanted to be; Pink, Yellow, or Blue.
