Bicycle Question but not Bicycle-Fi
Apr 8, 2010 at 11:41 PM Post #2 of 16

nealric

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Depends on what you consider an "assist" and what counts as a "bicycle"


Drafting behind a car: 151Mph
152 MPH Pedal Bicycle - Intro

Fully fared recumbent: 81 Mph
Breaking the Speed Record: 81 MPH on a Bike

The hour record on a track (average speed for an hour) is just under 31mph:
Hour record - Wikipedia, the free encyclopedia

Hour record on a track with aerodynamic enhancements is around 35 mph
http://en.wikipedia.org/wiki/Hour_record

Downhill- 101 mph:
Cycling records - Wikipedia, the free encyclopedia

For whatever reason, they don't really keep track of the momentary record for a regular upright racing or time trial bicycle.
I'm guessing it's around 40-45mph. Tour de france riders regularly hit mid to high 30s in a flat windless sprint. Most fit people can momentarily hit 30mph on a racing bike.
 
Apr 8, 2010 at 11:55 PM Post #3 of 16

JSTpt1022

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In the final sprint of last year's Tour de France, Mark Cavendish supposedly hit around 75 kph after a good lead in. That's over 46 mph and on a flat road. He's one of the fastest guys on the planet for those sprints. You can go way faster on a downhill.
 
Apr 9, 2010 at 12:18 AM Post #5 of 16

outlawdon

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Quote:

Originally Posted by JSTpt1022 /img/forum/go_quote.gif
In the final sprint of last year's Tour de France, Mark Cavendish supposedly hit around 75 kph after a good lead in. That's over 46 mph and on a flat road. He's one of the fastest guys on the planet for those sprints. You can go way faster on a downhill.


That's haulin'! I've hit 40mph on downhills on my time trial bike and that's getting a little dicey already.

Badass and inspiring...
YouTube - 2009 Tour De France Stage 21 final sprint on the Champs-Élysées
 
Apr 9, 2010 at 12:35 AM Post #6 of 16

nealric

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Quote:

That's haulin'! I've hit 40mph on downhills on my time trial bike and that's getting a little dicey already.


Yeah, anything over 35mph on a bike feels like warp speed.
 
Apr 9, 2010 at 3:52 PM Post #7 of 16

krmathis

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Quote:

Originally Posted by JSTpt1022 /img/forum/go_quote.gif
In the final sprint of last year's Tour de France, Mark Cavendish supposedly hit around 75 kph after a good lead in.


This is about it I think.
Downhill (gravity) and drafting behind a car most certainly count as assist.
 
Apr 9, 2010 at 3:58 PM Post #8 of 16

nealric

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Quote:

This is about it I think.
Downhill (gravity) and drafting behind a car most certainly count as assist.


What about the fully faired recumbent? They've hit 130kph.
 
Apr 9, 2010 at 7:23 PM Post #9 of 16

krmathis

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Quote:

Originally Posted by nealric /img/forum/go_quote.gif
What about the fully faired recumbent? They've hit 130kph.


Oh, sorry. Saw the 81 number in your post and the 75 number in the text I quoted, and they were fairly close.
Missed than one were mentioned in kph and the other in mph.
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Apr 10, 2010 at 2:45 AM Post #13 of 16

JSTpt1022

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I've been over 40 mph on some nice downhills and it was an amazing feeling. Not for those lacking confidence though as any panic can send you to your doom.
 
Apr 10, 2010 at 6:27 PM Post #14 of 16

Lazarus Short

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Going downhill fast is great as long as any of three things do not happen:

1. Anything getting into your intended path.

2. Front end shimmy.

3. Front hub locking up (I did hear of a case of this - instant faceplant).

Hubs lock up because the little tabs in the bearing-ball cages get worn thru and wedge between a ball and the race. Caged bearings are for easy assembly in production, but ALWAYS replace them with loose balls, giving the hub more support points, and no chance of lock-up.
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Oh, four things:

4. A curve at the bottom of the hill.
 

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