spilot101

I'm fairly new to cycling and just started Zwifting a month ago and been really digging some racing lately. Initially, been running 11-36 with 50-34 (10 speed), but to make things smoother, I opted for a 12-30 cassette.
Before, I would run the race in 13-50 and floor it 600m out in 11-50... maxing out at about 850 watts.
Now, for obvious reasons, my 12-50 isn't as fast and the emphasis is on higher rpm. But even with that, I'm noticing that i can barely scratch 800. Practice makes better, but from what I've noticed my highest output tends to be in a higher gear/lower rpm.
So I'm curious, where do you usually find your max power? (on a flat).

In retrospect, I wish I would have gotten an 11-28, but I didn't think it would fit my medium GS cage... and only later found out that it would.

Seattle Forrest

Higher cadences.

It sounds like you hit your biggest numbers mashing. Try comparing 20-60 minute average power spinning vs mashing. Huge numbers for seconds is a sprint, but you've got to be in sprinting distance for it to matter.

I use a compact and 12-28. On 28 mm tires, since tire height affects gear inches.

spilot101

Thanks, will do that. I actually ordered a 12-28 cassette a few days ago to use on my real back wheel...so I don't have to do much indexing when I switch to 'real life'

smashndash

This sounds like a trainer question, and I know nothing about sprinting on a trainer. But for me, peak power is way, way easier at 120+ rpm. For reference, my race weight is around 135lbs (currently around 145) and my 1s power is over 1300W. It falls off pretty quickly though (obviously. Otherwise I'd be a decent racer). 15s power is around 900W.

spilot101

Nice one. I'm 6'5" 200lbs (92kg) and I generally cruise at 80-85. From the Zwift data I can tell that I hit my max power at 90-95 rpm. Perhaps I can start exploring the lower gears a bit more

cielovia

Sprinting on a trainer is very unlike sprinting outside. On the trainer the bike is fixed, whereas on the road you can use your arms to a much greater extent to ensure your legs are over the pedals and driving down as hard as possible. I have a 500 watt difference between my all time best ever trainer sprint and my typical good road sprint.

I top out around 120 rpms on the road, probably 115-120 on Zwift.

And going from 600m out isn't a sprint. It's a very long, drawn out effort. I'd wait for inside 200m to go to get max power. Even worldtour sprinters don't go before 250 if at all possible.

spilot101

Wow, 500 watt difference. That's quite extreme. Thanks for the pointer.... No wonder my heart is exploding at the line

mstateglfr 

You bought a 12-30 because you werent sure if your RD could handle an 11-28?

I think I have my best burst of power with 50-12 or 50-13...I do know it varies depending on how exhausted I am. I rarely care though since even in a short zwift crit race I am at my max power for probably 2% of the time and even a 1min sprint at max would be maybe 5% of the race. I focus on hard consistent effort for the other 95-98% of the time, and I am rarely in my toughest gearing during that.

AlmostTrick

RChung

Max power occurs neither at max force nor max rpm. Max power usually occurs somewhere near (max rpm)/2. Here are two plots taken from the same ride but perhaps an hour apart. In the black dots, I was accelerating from a stop and caught in too high a gear: I hit max pedal force for the ride while trying to get up to speed at around 40 rpm; for that portion of the ride, max power was only about 600 watts. For the red dots, you can see I was already going about 30 km/h (my buddy and I were buzzed by a car; I took off to chase), accelerated quickly and hit about 500 watts higher than previously at around 120 rpm. (The biggest problem was that when I caught the ******* at the next stoplight, I didn't know what to do with him). The bottom plot shows how cadence, pedal force, and power are related. The thin grey lines mark 250, 500, 750, and 1000 watts.

aplcr0331

no way I'm trying to get max power on my trainer, lol...poor thing already creaks and moans like a wooden bridge with a semi truck on it.

WhyFi

So your max cadence is in the 240 range? Wooooo!

And hey - have I tagged you in any obnoxious threads this week? If not, I'm sure I can find something - brb.

caloso

I've never hit max power in my biggest gear. In fact, I lost a race trying to sprint out of the final corner in my 53x11 and just got completely bogged down. Learned a lesson that day.

And I've never even come close on a trainer. I'd probably break something trying to max sprint while locked in.

Seattle Forrest

Wait a minute I'm confused. You're saying there are obnoxious threads? In the 41??

WhyFi

You might need to venture in to General in desperate times, but it's still winter for a lot of folks, so we should be good in the 41.

RChung

For some of us, "somewhere near" is somewhat loose, at least sometimes. (Last time I measured it, my max cadence was closer to 200 than 240).

base2 

FWIW: In the Zwift, I tend to hit the sprint zones at a pretty high torque around 80 rpm & wind up to the low 100's by the end of the sprint zone. It usually works out to a 650-700 average wattage for the duration. I have a real hard time sustaining more than 750 for a sprint zone, but the sustained 600‐650+ watts at the higher rpm's for the second half of the sprint seem to consistantly yield top 10-15 finishes.

Obviously, being at a higher speed prior to entering the sprint zone helps, but that also means a lot more fatigue to fight & recover from. 7.6-7.8 watts/kilo is hard AF as it is. A good wind up from around 4 -4.5 watts/kilo at 80rpm about 500 meters ahead seems to be the sweet spot as far as I can tell for the best sprint area entry & still have enough to finish with out losing my lunch all over the trainer mat.

I'm not special. I've also never had the Kickr stay in erg mode above 165 rpm. For a sprint, if you've gotta shift, it's all over. Starting a sprint at ~400 watts (4.5 watts/kilo) at 120 rpm is easy enough, it just doesn't offer the headroom to go more with out the Kickr kicking off. So, IME you gotta start low rpm/high torque & wind up. Finishing at around 110-120 is about a 30-40 rpm spread & about as ideal as the equipment allows.

WhyFi

Heh. I ask mostly because my max power is somewhere in the same cadence range, but I don't think that I've ever come close to 200, let alone 240. Come to think of it, I don't know that I've ever tried to see how fast I could spin.

spilot101

I agree. Shifting up totally kills the momentum and that's why I've been a fan of just staying in a higher gear on the last 1000m or so, in the past. I've just changed my difficulty level from 50% (how it's always been set) to 100% to see if it'll give me more traction in 12-50.

I've heard that many prefer to race in "25-30% difficulty" - nice on a climb, but kills the straight-line speed. I'll see how it is at 100%.

Interesting to see that the opinions are evenly split. I guess weight/body type has a lot to do with it. Being a fairly big guy, less rpm/more torque seems more natural to me, perhaps.

spilot101

[QUOTE=RChung;21937502]Max power occurs neither at max force nor max rpm. Max power usually occurs somewhere near (max rpm)/QUOTE]

Funny, I noticed a similar tendency with my Zwift data, but I thought that it's probably due to some general inaccuracies of the software. Makes more sense now....

popeye

I crashed the trainer in a sprint.

shelbyfv

Is there any Road Cycling content here?

Carbonfiberboy 

That's what I noticed. The place to learn how to sprint is on the road. Accelerating mass on the road and increasing power demands at the cube of the speed is a whole different thing. Moving the bike and moving around on the bike is different. I like to do moderate gearing drills on the road until I have all the bits and pieces working right, then add more gear. I think Stomps are valuable, too. That's a road-only thing. Then there are hill sprints and flats sprints which are completely different. Sprinting well takes a lot of practice on the road. I never sprint indoors. Too many bad habits to shake.

topflightpro

Yeah, there's a common misperception that you're most powerful sprint will be in your biggest gear. But you need to be able to turn the gear fast enough.

I've seen studies on cadence and max power, mostly related to track sprinters, but I cannot recall the exact results.

colnago62

I haven’t seen any studies, but doesn’t it seem like like sprinters seem to aim for 140 +/- rpm? You don’t see many old school 200rpm sprinters much anymore.