simple bike speed question

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2004-07-21 10:05 AM

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Kennesaw, GA
Subject: simple bike speed question
I’m just curious at what speed does everyone else “spin out” on your bike? (I call spinning out when I just can't pedal any faster, I don't know if there's a better term for it)

As a side goal of mine I’m trying to get over 47 mph on my bike. That’s my PR for bike speed for my descents down hill. I “spin out” at about 35-37 mph, my long legs just can’t rotate that big gear any faster and I just tuck down and ride out the hill trying to let gravity do the rest of the acceleration. Is that about par for course or not?


2004-07-21 10:28 AM
in reply to: #39315

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Pro
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St Charles, IL
Subject: RE: simple bike speed question
Yes, it can happen.

Think of it like a car that won't shift past 2nd gear. If your body has more output but you're out of gears, you could try changing
the gearing on your bike, so that you have a taller top-end gear. Maybe loose one of the low gears and move everything up a step
or two.

Just a thought.
2004-07-21 11:02 AM
in reply to: #39315

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Champion
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Subject: RE: simple bike speed question

To get over 47mph, you're going to need a bigger hill., a bigger than normal gear, or some really fast legs

135 rpm in a 53x12 gear = 47.07mph according to analytic cycling

2004-07-21 11:07 AM
in reply to: #39335

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Resident Matriarch
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Subject: RE: simple bike speed question

135 rpm in a 53x12 gear = 47.07mph according to analytic cycling


where do you find this stuff??

2004-07-21 11:11 AM
in reply to: #39315

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Resident Curmudgeon
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Subject: RE: simple bike speed question
OK, if I'm using Sheldon Brown's calculator correctly, and you push a 52-tooth chainring on a 12-tooth cog at 120 rpm with 700 wheels, you will be going 40.7mph. I would say somewhere slightly above 120 rpm you would be "spinning out."

Edit: someone beat me to the calculator. I found mine at http://www.sheldonbrown.com/gears/

Edited by the bear 2004-07-21 11:12 AM
2004-07-21 11:16 AM
in reply to: #39315

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Champion
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Subject: RE: simple bike speed question
That's about the same thing for me. There is a very steep hill that I do descents on once in awhile that is about a 20% grade and is 1.6 Km (almost a mile) in length. Whenever I reach 75 Km/ph (46.5 mph) it is no use pedalling anymore so I get into a tuck and usually hit 80. I am still trying to break that barrier!!!

2004-07-21 4:10 PM
in reply to: #39337

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Subject: RE: simple bike speed question

I am a complete and unrepentant bike-geek

http://www.analyticcycling.com/

Warning!!!! DO NOT ENTER IF YOU HAVE ANY OBSESSIVE/COMPULSIVE TENDANCIES YOU WILL BE THERE ALL DAY!!

2004-07-21 4:17 PM
in reply to: #39342

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Subject: RE: simple bike speed question

Jeez! You guys are speedy!! I went (for the first time) down a rather large hill with the cycling group and hit 37 mph (coasting) and got so freaked out I rode the brakes for the rest of the ride down. I'm a beginner, but making real cycling progress. I also need new brake pads.

LW

2004-07-21 4:32 PM
in reply to: #39456

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Champion
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Subject: RE: simple bike speed question

Brakes....schmakes

Brakes only slow you down.;-)

My road bike is 7 years old and I changed the pads just this year.

2004-07-21 4:37 PM
in reply to: #39315

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Subject: RE: simple bike speed question
ride_like_u_stole_it,
wow! Thanks for the link. It just got put in my favorites folder, I think I can waste a good bit of time there.
2004-07-21 4:41 PM
in reply to: #39315

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Champion
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Subject: RE: simple bike speed question

I found out, much to my dismay, that my bike is 22 years old!!! (A guy in the cycling group had an almost identical model, the Trek 1400 with the same paint scheme as mine, (mine is a 1000...) and he got his in 1982 when it was state of the art, and he was doing triathlons...before the birth of his first daughter, who is now in college!!!)

Anyway, the way the brakes squeal and squeak, I'm nearly positive the brake pads have never been addressed. It's embarassing. I tried sanding down the brake surface, but that didn't really help.

(!!!!)

LW

2004-07-21 5:42 PM
in reply to: #39462

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Pro
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Subject: RE: simple bike speed question
Take it in to your LBS and have them look at the brakes!

Since you are Crystal Lake, just hook down 31 to the Prarie Trail Bike Shop ( west side of 31 just south of Algonquin/62 ).

They are very helpful and knowledgeable there. Try to resist looking at the bikes there though.

Also, not sure if you know, but there is a Tri specific store in Elgin : http://www.missionbaymultisport.com,which fortunately is
slightly further away so I'm less tempted to go and spend lots of money there. :D

-Chris
2004-07-21 5:44 PM
in reply to: #39315

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Subject: RE: simple bike speed question

I'm going to have to buy blinders. (!)

Thanks for the tip!
LW

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