The Fastest Crank Size For BMX Racing

[@DRMDiscs]

When i started racing i went with 170 mm cranks. I had gone in for a fit on my road bike and they said 170 was correct for my leg length. I bought my chase element and it came with 180 mm cranks. I have since changed to 170 mm and my hips don't hurt like they used to with the 180s.

[@William.Driscoll]

Smart. I'll contribute that, as someone who's in his mid-forties and perhaps fast on a bike, I'm more interested in having a great time for another three decades on bikes: Avoiding joint injury is worth any number of compromises. "My body is my home."

[@mikeyseibert1406]

How tall are you?

[@jermainedow1481]

For myself older with knee issues ive noticed shorter cranks are better on my joints. Less strain on the knee. 6'1 270lbs ifbb pro who doesn’t compete anymore and 170s feel great.

[@FullTiltBikeCo]

Yes and that's the biggest thing, finding something that works for you and is comfortable! That will always be faster than whatever is the latest hot trend in the sport! Always go with what fits you best and seems you found just that!

[@NWDestroy]

I think these Brosephers are young and in shape my dude. you cant even pedal 43x9 unless you run 190s ya know..

[@cmcmillan22]

I’m 6’ 275 and I love 170’s myself.

[@matjohnson285]

Fun to watch. Glad for the replay slow to watch your box starts.

[@FullTiltBikeCo]

Thanks for watching!

[@PabloGonzalez-hv3td]

From a freestyle perspective. I'm 5'7" and 175-180 has more leverage but draws a larger circle and is slower in the end. 170 is the sweet spot for leverage and speed.

[@adamdombrowski193]

Longer crank arms give you more leverage along with the gear of your choice that you feel most comfortable with. So in my opinion depending on how long your legs are will determine what size you should use. You don't want your hips to rock while pedaling. 175 is the perfect size for me!

[@GrantHansen]

Great video, thanks! I'm 5'10" and currently thinking of going from 180mm down to 175mm, which based on your discussion seems like the sweet spot. I'd love your perspective on how a rider's height and bike size factor into length?

[@FullTiltBikeCo]

Man we could talk for HOURS on this topic. But really it's more of a visual thing for us. We look at how the rider's hips move throughout the pedal stroke and make small adjustments from there. Best bet is to see a professional or come stop by the shop if we're at a nearby national and get some advice in person!

[@gertmzazi7701]

Used to race in the mid eighties, one crankarm 187.5mm the other 185mm just to be faster out the gate and to get thru the deep mud

[@richardfireone]

astounding, never heard of that, and I been riding since the last ice age (blizzard of 78)

[@NWDestroy]

what?!

[@DannyPeters-w8d]

The knee pain from riding with your seat that low is worth it at all.

[@sherardg2836]

Race, you were smoother on the 170mm. Less bounce on the rollers, perhaps less dead spots, more efficiency . Jonnie, smooth as heck on both.

[@markscott2232]

What are you using for timer?

[@FullTiltBikeCo]

These are the browers black box timing system. Usually works really great! The batteries were just running low during our session so that caused a few miss reads.

[@shafiqjan1474]

177.5 to 180mm was my sweet spot for racing with my legs. Longer cranks were always a benefit in BMX, on road & with MTBs out here on the NE coast

[@FullTiltBikeCo]

Yes, Race was always a fan of the 177.5s seems having that extra leverage and nailing the start is what BMX is all about!

[@billteager3618]

What is the roller setup?

[@42pyroboy]

The brand is shown almost every run dude, come on.

[@jmhagle]

I said JEEE-zus! at the exact same time when he hit 35mph! haha

[@FullTiltBikeCo]

Hahahaha, check out this at home workout Jonnie posted as it should help everyone gain a few extra mph on their sprints 😉 kzbin.info/www/bejne/aH3ao4iLptOhqrcsi=V_tBP5pB8ukb_jZD

[@chrispatterson8572]

So both right on 54 gear-inch on a 1.75 tire?

[@FullTiltBikeCo]

Yes, both bikes on 1.75 tires and close to 54 gear inch rollout. Black bike was a 54.2 w 180s and the purple bike was 53.9 with 170s. When you factor the crank lengths into the rollout they come out nearly identical.

[@zac.bolin01]

I’m on 165 right now I’m not sure if I wanna go up or not Might go up to 170 or 175

[@eldavis4608]

Good shit!

[@gotmoto]

Fun vid. Am I the only one who noticed it was 32 mph not 31?

[@FullTiltBikeCo]

No you're right, it was 32mph. We just put the 31mph in there to clarify what we thought was a 37

[@chriss2928]

can you " spin- turn circles" that easy with Flats on ..

[@FullTiltBikeCo]

Like on the rollers or off the box? Definitely easier to spin with clips on, but still very possible to turn tight circles with flats as well. Just have to be pretty dialed in with technique!

[@angelroads574]

I need someone to yell for me so I can go faster.

[@FullTiltBikeCo]

PEEEEEDAAAAAAAAALLLLLLL! (Hopefully that helped...)

[@angelroads574]

We will find out this weekend. Thanks for the help.@@FullTiltBikeCo

[@greer776611]

I still run 180mm 1 piece cranks- i never could afford 3 piece growing up- and i'm still fast enough- just fatter and 50. Bmx still rules

[@pisstoffcat5136]

Ok , now try some 185mm . I had a wheelie bike with 185mm and a 46-16 , I don't know about the rest of it but was smoother to me when doing wheelies and I'm not tall , so I think more testing is required.

[@FullTiltBikeCo]

Would be interesting to look into! But one thing we can't forget about is the potential of striking longer cranks on the ground when coming out of turns or pedal manuals. I've never seen anyone race on a set of 185 but we might have to be the first to try hahaha

[@brianleeBMXDad]

Race may be alien, and Jonnie a scientist..Race was spoking the meter. j/k, great news the inseam charts prove what you found in the data vs feelings/ thoughts about what is a better length. now my next question is what's faster 54 or 56 gear ratio at race speed vs start.

[@FullTiltBikeCo]

You bring up an interesting point with gear ratios as that's a topic we have a for an upcoming video! 56 is quite heavy as it seems with the age of clip pedals, most racers are staying around 53-54 (every now and then we see a low 55, but 56 is very large for today's standards) of course that's personal opinion tho so take it with a grain of salt 😁

[@brianleeBMXDad]

@@FullTiltBikeCo looking forward to your findings. Based on your data here Jonnie puts up apex-means 35mph with a 54.x on 180, and 33mph with 54.x on 170 at race speed and .05 slower off the line on 170. The time he maxes out apex was quicker too. Jonnie rocking a 55 or 56 on 180 compared to 54… will go faster as long as someone is yelling pedal!!! Lol

[@user-do1fq8oy9c]

The white dude is exerting his energy in a vertical and the bike is coming off the roller. The black dude is much smoother and his wheel is always in contact with the roller. I think the frames should be strapped down to the roller frame to combat wheel hop

[@FullTiltBikeCo]

Nah that's cheating hahaha, just gotta practice that technique

[@larryjones7864]

Factory dads know best! My next born will be named pedal!

[@FullTiltBikeCo]

Kid will be guaranteed a NAG 1 plate at birth 😂

[@sandy_knight]

One advantage of shorter cranks that a lot of people miss is that having your feet closer together gives you more pump because your legs have more travel to work with. Or put another way, try jumping in the air with your feet together and apart, you'll get higher with your feet together.

[@JasonAdams-h7j]

The race is normally over before the 30foot mark. max power maters more than what your talking about.

[@sandy_knight]

@@JasonAdams-h7j That's fair enough, a small advantage over the rest of the track might not out-weigh the reduced power out of the gate. Would you say as long as you can keep power through the drive train until the bottom of the start ramp the longer the better? Its probably worth doing some real world starts, on a start ramp with gravity assist, to nail down the best length.

[@FullTiltBikeCo]

Personally, we think it's a mix of both elements! You want a set up that makes you feel comfortable/confident around the track. But it also needs to be effective out of the gate. When it really comes down to it, we think it's best to prioritize your bike set-up around effective gate starts over track comfort. As it's great to be fast around the track, but there's only so much you can do from the back of the pack. Seems the best bet is to nail the start and hope for the best around the track hahaha

[@NWDestroy]

Its so weird how stupid our bikes were when I was growing up. Keeping the seatpost damn near bar height got me smacked in the chin a few times sucking up rollers

[@FullTiltBikeCo]

Yes it's crazy how much things change! Like even bike pads, as you just mentioned, they were actually needed back in the day. I can't imagine what people would say nowadays if you showed up with a carbon race frame and bike pads hahaha

[@marlonmendes1954]

🔥👍

[@byc1013]

175s all the way.