Ross520

Update...

My friend objected to clip-less pedals, and I obliged. So I will be racing with flats.

Just waiting on him to set the date. I'm ready anytime, anywhere! 😎

ljsense

There are a few youtube videos of this kind of drag race, but the one I watched didn't make clear the distance -- it looked like maybe a quarter mile drag strip. It was a three way race, with a roadie, an off duty sandwich delivery guy on a crappy mountain bike, and a BMXer. The BMX rider got a clear lead, but faded. The guy on the crap mountain bike was never in the race. The roadie started terribly, looked pretty weak, but won easily in the end.

But that was I think a quarter mile course.

I think the 45 mph BMX launch is wildly exaggerated; I'm not super familiar with the sport, but from what I've read if they can hit somewhere north of 30 on a downhill sprint to the first jump, they're doing great. I don't doubt that the elite are launching it with maybe 1,800 watts for the first few seconds, but there's just no good way to have one gear that accelerates well but doesn't spin out at some point.

And the question here is not can an elite BMX rider beat a normal recreational roadie, it's whether two dudes who both ride a little get an advantage in a drag race with their respective bikes.

The 200 pounds gives me doubts, but I'll put my money on you for the win. Use your gears!

Rajflyboy

Supercross BMX track here has a 35 foot gap the riders have to clear on first jump. Fastest riders clocked as high as 45 mph

Caliper

If they are pedaling to 45mph, then some of the info above has to be incorrect... That would be something like a 275rpm cadence, which seems pretty high. Do you know what gearing they are using to reach 45mph? Honestly, that speed requires a decent cadence even on a 53/11 geared road bike.

pickettt

They’re leaving a start gate and going steep downhill.

Milton Keynes

Give me a steep enough downhill and I can reach 45 MPH on a start.

Caliper

Sure, but even in a straight freefall with no drag, it would take a drop of almost 68 feet to get to 45mph. That sure doesn't look like a seven story building that they are starting off, plus they have all sorts of drag to overcome...

Wilfred Laurier

So it can be done, but only be spherical cyclists in a vacuum.

Rajflyboy

I Do think 35 is the average but occasionally they get a little faster. 45 would be the max

almost as quick as a sports car out of the gate

ljsense

Cool video -- thanks for posting that. I've watched BMX, but it definitely refreshes my perspective on the sport.

It looks like they hit that jump about 2 seconds, or maybe less, after leaving the gate. The camera angle makes it impossible for me to tell if they spin out down that hill, or if they're still pedaling. I'd guess they're still hammering on it. It also doesn't show their speed. Curious to see more.

BlazingPedals

Reminds me of one of my friends' neighbors in my young days. He told my friend he could beat a motorcycle in a sprint, which he designated and was probably 100-50 feet. Sure enough, he was halfway to the finish line by the time my friend had the clutch engaged. The motorcycle never had a chance and multiple attempts didn't change the results.

This race may be the same deal if it's short enough. For the bmx bike to win, it needs to get to top end first and then immediately cross the finish line. I suspect 1/8 mile will be too long for the bmx bike to retain its initial lead, but who knows???

aclinjury

1/8th mile is a fair distance
My money is on the bmx by a hair

Rajflyboy

Same here

msu2001la

I love this thread.

I'm pretty sure the only way a BMX rider is 45mph is with a pro level rider clipped in, track standing on the barriers, and sprinting down a start ramp with a huge gravity assist. There's no way they are hitting those speeds on a flat road from a standing start with a foot on the ground. They run gearing in the neighborhood of 46/17 that will spin out around 20-25mph (and street/ramp bikes run even lower gearing).


If we're comparing pro-level riders, take a look at last weekend's UCI CX sprint start for an idea of what a standing start sprint looks like on a road bike.
The start of this race is at 11:50 in the video, and it takes them around 10 seconds to get to the edge of pavement, which is 350 feet from the start line. The riders are clipping in and shifting through the gears while sprinting up to speed.

I have a hard time watching this video and believing that a BMX racer would be ahead by much, if at all, at the edge of the pavement which would be a little more than halfway through a 1/8 mile race. The CX racers are north of 20mph at this point and would continue accelerating on a straight/flat road, where a BMX racer would already be spinning out after 10 seconds of sprinting (or sooner).


My prediction is that the BMX bike will be ahead for around 300 feet, where it will be at/near top-speed. At this point the road bike will quickly catch up and pass for the win in the final 360 feet. I don't think it will even be close.
Also, I hope the thread starter and his buddy swap bikes and try it both ways, so that fitness isn't a factor.

I look forward to seeing the results.

msu2001la

Has this race happened yet?

Leinster

I’m surprised by this. If I were him I’d insist on you having to clip in, it’s a potential 3-5 second headstart for him.

I have to say, I think a bmx is going to spin out gear-wise well before 1/8 mile, so all you should really need to do is find out what gear inches his bike is set up for, and then shift yours into something 2 cogs smaller (that is, if his is equivalent to your 34x17, you just go in the 15 or 14) and you’ll pull away from him in the final 50.

rebel1916

No.

burnthesheep

Sure enough. Referring to calculator says 'no, no it's not'.

Oh well.

Anyway..........updates?!

Sprecher919

I wanna see this epic competition ASAP!

Metieval

I think you should make it interesting.

Like instead of who is faster blah blah.

Make it a bet on Distance he can get before you pass him, measured in Yards or meters.

otherwise as in make it hurt for him... lol

canklecat

The BMX guy won't be able to resist slaloming through traffic, curb jumping and riding on the sidewalk. You'll win.