For the first time in Olympic history, one of the BMX bikes will have more than one gear.
Dutch BMX racer Twan van Gendt revealed on social media that he plans to run a two-speed drivetrain with a modified Zee derailleur and what looks like a Zee shifter on his Meybo HSX carbon frame at the upcoming Olympic Games. He hopes that it will give him an edge on the opening straight, allowing him to take the holeshot. 80 percent of BMX races, van Gendt said, are decided before the first corner, meaning that every pedal stroke out of the start gate matters.
This is not a story of something that was banned becoming legal, as was the case with the mullet bike explosion in downhill racing. Rather, running multiple gears has been permitted by the UCI all along, but no one did it, at least not at the Olympics. There have been several attempts over the years to develop BMX bikes with multiple gears, but none of the attempts have gone far enough to disrupt the status quo, and some riders have criticized van Gendt's decision to step outside the norm. Culturally, BMX bikes are thought of as inherently single speed, even if the UCI rulebook doesn't say so.
Looking at the track, it makes sense that van Gendt would want a second gear. Lap times will be 20-25% longer this year than on typical Olympic courses, so all the pedaling sections and especially the opening straight will be longer than usual. van Gendt believes that the optimal gear for the start is different from the optimal gear for the rest of the race, and has tested his new setup extensively at the BMX track where he trains in the Netherlands. To help van Gendt give the Olympics his all, Red Bull worked with van Gendt to build a start ramp and opening straight that replicates the Tokyo track, designed carefully to match key measurements of the track he'll race next week.
All the Olympic riders are at the top of their game, and any marginal gain in speed is a good thing, especially at the start of the race. While critics say that a geared drivetrain is too likely to fail under the torque of an Olympic BMX race start, the widespread use of Shimano drivetrains in downhill racing should at least somewhat put those fears to rest, though it may not do much to soothe the fear of change. If van Gendt were to win next week — which he very well might, as the reigning BMX Supercross World Champion — it would certainly stir up the conversation and could change the way BMX race bikes look forever.
bmxmuseum.com/bikes/healing_industries/72158
Nowhere in this does it mention that a frame must be made of 2 triangles. Shockingly, there are very very very few rules governing bikes. Wheel size, requirements for a saddle, max bar width, max stem extension, and max bar height are some. They also limit how much axle can protrude past the end caps, and require a rear brake. But otherwise to me it looks like frames can be any weight, shape, size, geometry, or material.
And for sitting on when not racing.
Was a single piece, with a fiberglass rectangle fused to the top of a fiberglass post. Thing weighed like 3 ounces and was completely useless for anything except passing the ABA rules.
Trying to clip in on the gate while stood up can be unstable. Plus it's nice to have something to sit on while waiting for the race to start...
Funny, he is now running BMX operations at the Rock Hill, SC cycling complex. Great guy.
I'm disappointed.
Don't they take the Olympics seriously
2) The problem with shifting in BMX is that you typically never have a good opportunity to pause in order for the shift to be clean. The starting hills at an International level are very steep (26.3’) and the first jumps are typically very close to the start, not less than 15’ per UCI guidelines. As a result the top Olympians are accelerating in the first 50 feet at a clip that is faster than a super car and then transitioning into a 8’ - 12’ step up jumps. www.cbc.esp.br/arquivos/UCIBMXTrackGuide-Rev.12-12-2014_Neutral.pdf
3) Ultimately, prior Olympic tracks like Beijing and London just didn’t give you the chance to back off full throttle. Shifting in the first straight would cost you half a bike length or more which would allow your competition to slam the door on you going into the first turn. With a total track length of 900’ to 1,200’ per UCI guidelines this cycling discipline is all about the sprint - power wins races. Can’t find the link but there is a video of Team USA rider Nick Long training where he launches from a flat gate, pulls a few cranks, and bunny hops a picnic table training for the Olympics. These guys are on a whole different acceleration curve from a MTB.
4) Looking at the attached video, there were only 6-8 pedal rotations in the two sections shown going into the first turn. Given track length restrictions I’m just not sure this theory pencils out. That having been said, Twann is one hell of a good rider and he obviously thinks he is on to something. Should be interesting to watch.
So I wonder if his shift point is later in the track? or perhaps in the corner
IMHO Shimano HG+ system is still the best in terms of shifting under power.
I am perfectly willing to believe it's possible, but I would like to read something for myself on the internet, not just the word of an anonymous BMX fan. It's not difficult to type a wild number. Look:
Chris Hoy did 4300 watts in training all the time.
Try finding that on the internet - you can't because I just made it up. Like you did with the all top BMXers make 3000 watts easy comment.
If anyone reading this actually has any evidence that BMXers make 3000 watts I would love to read it. I know they are super powerful guys, and it makes sense that their wattage could be higher than an animal like Chris Hoy because the cadence is a lot higher. I believe power is revs X torque / 5252 so it absolutely makes sense that it could be done.... But saying it doesn't make it true.
I not sure of exact numbers, as this link was back in 08. I was a laboratory for a quick minute.
I would imagine wattage numbers are higher now. Honestly, I remember being in the 2k range but ♂️. The internet is a great place for fish stories !
2657W
Nic Long 2657w
2657W
Anyway, it is very impressive.
Material has improved over the years so it could very well work in the current age and more riders would shift to a geared bike.
Unless they're different wheel sizes, shock sizes, pedal-assist motors, tire inserts, fork offsets, steerer diameters. MTBers are pretty conservative but most aren't racing and looking for incremental performance advantages.
Personally, I like innovation. I've gone through phases where discbrakes are available but not that common, and still took the plunge when the chance arises. Cost around one month of my living cost at that time.
What I (and I guess most people) don't like is incremental changes dubbed as innovation when it is actually a planned obsolency to sell more stuff.
freehuanar.com/product_details/34288325.html
That'll certainly make the highlights packages easy to cut
boxcomponents.com/collections/handlebars/products/box-one-cromo-triple-taper-flat-handlebar
Considering that he placed the shifter upside down on the opposite side of the handlebar, it seems unlikely that he will shift into lower/easier gear. He will need to move his thumb from a natural under the bar position. Still curious though.
www.youtube.com/watch?v=VUjtaL-tfMc
The first BMX cruisers back in 1979 or so were 26” wheels. After a few years the advantages of smaller radius 24” wheels for acceleration were recognized and they became the norm after 1981. Either wheel size is currently legal in USA BMX rules but in National and International competition only the 24” wheel is used today.