# Top speed with gear ratio... And how long was the duration.



## Cycles4Fun (Oct 16, 2012)

I have recently been focusing on cadence as a training measure. And I commute on my fixed gear most of the time. I hit a top speed of about 30.1 for a period of about 20-30 seconds with a 50/18 combo.. And that puts my highest cadence at about a 133.. So I was just curious what you all achieve as a top speed.. Just as a comparison..


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## serious (May 2, 2006)

I am a poor spinner so I won't impress you with my numbers. I can hit about 26-27 mph with 48:16 but it is a matter sof seconds (15-20) before I lose it. That is not even 120 rpm.


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## JustTooBig (Aug 11, 2005)

on a track bike, somewhere in the neighborhood of 40mph on a 98" gear (something like 51x14). Cadence around 135-140. That would be for something like a flying 200m, so duration is around 11sec.


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## Cycles4Fun (Oct 16, 2012)

^^^^HOLY CRAP! Lol


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## singlespeedbuss (Aug 6, 2009)

I have hit 30mph with a 45x17 gearing on my SS for a very short duration, my feet were a whirling dirvish and about flew of the peddles, not sure about the rpm`s though.


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## JCavilia (Sep 12, 2005)

I can't document anything, because I don't have a computer on the fixie, but I'm pretty good at counting and estimating cadence. My gear is almost exactly the same as yours (39x14) and I'm pretty sure I've gotten up in the range of 145 rpm briefly (on a descent, obviously). That's about 31.6 mph. It may have been a little faster than that. If you're talking about speed on a flat, that's more about power, not cadence. I've probably gotten up a bit over 25 mph on occasion, 115-120 rpm. The real trackies like JTB are a different animal.

BTW, if you have 700/23 tires, your 30.1 mph actually puts you at about 138 rpm. So you may be spinnier than you thought.


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## PSC (Mar 10, 2004)

Using a 42/17, I can cruise at 21-22 mph comfortably(108-113 rpm) and can sprint up to 28-29 mph(mid 140's rpm) for a couple seconds.


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## JCavilia (Sep 12, 2005)

singlespeedbuss said:


> I have hit 30mph with a 45x17 gearing on my SS for a very short duration, my feet were a whirling dirvish and about flew of the peddles, *not sure about the rpm`s though*.


I can do the math for you. Assuming you run 700/23 tires, you were spinning about 145 rpm. 

You say your feet nearly flew off the pedals. Were you doing that with flat pedals, no toeclips or cleats -- i.e., no attachment between shoe and pedal? If so, that is wildly scary, and impressive.


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## singlespeedbuss (Aug 6, 2009)

Obviously it only felt like my feet were ready to fly off the peddles. I have clipless peddles and if I had my fixed gear on and not the free wheel it would have gotten ugly in a hurry. I am running 700/25 Hutchenson tubless tire on the rear. I guess I need the cadence counter on my bike.


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## wtfbbq (Apr 5, 2012)

I lead out a single speed cyclocross race a few weeks back in a 42x17 and topped out around 28 and did a quarter mile in about 35 seconds from a standing start. In weekly cyclocross practice we do starts and I regularly hit 25 to 26 in my 42x17. There is a local Strava segment that is. 3 miles and slightly downhill and I've done that at 32mph average on my 46x17.

All I know is it's some crazy spinning and really works me over.


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## waldo425 (Sep 22, 2008)

With a 44x18 I did 39 MPH. I calculated it out to be about 192 RPM. I held it for a couple seconds. Funny enough that is not my max RPM which is a confirmed 218 RPM.


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## singlespeedbuss (Aug 6, 2009)

We're not Worthy!!!! - YouTube


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## serious (May 2, 2006)

waldo425 said:


> With a 44x18 I did 39 MPH. I calculated it out to be about 192 RPM. I held it for a couple seconds. Funny enough that is not my max RPM which is a confirmed 218 RPM.


 Now this man is a spinner.


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## am_dial (Aug 20, 2012)

I'm a SS mt biker who's been riding a SS road bike almost exclusively for the last two months. I got a KOM on one local Strava spring segment -- the segment's .3 miles, and I did it in 30 seconds even at 30.8 mph in my 42x16 ratio.

No idea on cadence, but it was high -- not 218 RPM, though! (Actually, I just checked an online cadence calculator, which suggests I was maybe doing 148 RPM.)


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## JCavilia (Sep 12, 2005)

am_dial said:


> I'm a SS mt biker who's been riding a SS road bike almost exclusively for the last two months. I got a KOM on one local Strava spring segment -- the segment's .3 miles, and I did it in 30 seconds even at 30.8 mph in my 42x16 ratio.
> 
> No idea on cadence, but it was high -- not 218 RPM, though! (Actually, I just checked an online cadence calculator, which suggests I was maybe doing 148 RPM.)


Yeah, that cadence math is about right, assuming you have common sized tires (700/23). 

I guess Strava rounds to the nearest tenth, but your segment was not .3 mile if your speed measurement is accurate. It's .2566 mile (about 15% shorter). If it were actually three tenths of a mile long, you'd have been going 36 mph. Your 30.8 is plenty impressive, but 36 mph would have taken more than half again as much power -- somewhere up in pro sprinter range.

Was this route flat, and did you have a tailwind?


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## am_dial (Aug 20, 2012)

The segment has a slight dip halfway through where the road crosses a stream, then a very slight rise. Per Strava, it has a -0.6% average grade. Starts at 269' elevation, dips to 255' at .15 miles, then rises to 260' from .23 to .3 miles. I don't recall a tailwind (or headwind), but the downslope alone probably accounts for my speed. I'm definitely no pro sprinter -- as my SS mt bike background probably suggests, I'm much more of a masher than a spinner.

I have a Cateye on the bike, and it did register 30+ mph during the ride, but I only glanced at it a couple of times. My Strava stats come from GPX files I upload from my iphone (running Cyclemeter), which, compared to the Cateye, routinely underestimates my total distance and average speed by small amounts on the road (or by 25%-33% in the woods). I wouldn't be surprised at all if the math's a little off somewhere.

Tires are 700/28, inflated to about 95-100 psi.


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## LivingstonArt (Apr 7, 2012)

Descending, I hit 51mph on a fixed bike.
Gear ratio was 53x14 (The gear I always ride in)
I will generally hit 41-2 mph on an average ride with a semi steep descent.
-A


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## Cycles4Fun (Oct 16, 2012)

LivingstonArt said:


> Descending, I hit 51mph on a fixed bike.
> Gear ratio was 53x14 (The gear I always ride in)
> I will generally hit 41-2 mph on an average ride with a semi steep descent.
> -A


So what's your average MPH on a ride with that combo? Cause that's a HUGE gear! I bet you hate hills, no?


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## LivingstonArt (Apr 7, 2012)

I'll usually average 20-21 mph, I live in a relatively flat area in Southern California. I don't mind hills, I can tackle anything up to 20% grades, steeper than that is almost physically impossible.


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## JCavilia (Sep 12, 2005)

LivingstonArt said:


> Descending, I hit 51mph on a fixed bike.
> Gear ratio was 53x14 (The gear I always ride in)
> I will generally hit 41-2 mph on an average ride with a semi steep descent.
> -A


Even in that monster (100-inch) gear, you were turning something like 170 rpm. Whew.

Do you really climb 20% grades with that gear? Just looking at some quick calculations, if you can put out 500 watts and you're average size, you'd be going about 6.7 mph, which means about 22 rpm. I can hardly imagine it. You must be almost coming to a stop at the dead spots in the power stroke.


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## waldo425 (Sep 22, 2008)

serious said:


> Now this man is a spinner.


Thats one thing that track racing will get you. I got that new record right before heading down to Elite track Nationals, so I was nice and limber after racing track all season. Of course my next goal is to one up that.


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