Bike weight distribution ?
Last Post 05/19/2014 02:53 PM by Spudly Crumpett III. 8 Replies.
Author Messages
Ride On

Posts:433

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05/18/2014 01:45 PM
Seems like a bikes weight distribution would not be even left to right correct ? Drive train on one side, nothing on the other. Seems like that percentage of unevenness would be getting larger since frame weight , bars, everything that is split 50/50 left right has come down in weight by a large percentage over the past 10 years but drive train while it has gotten lighter might not have come down as much. A chain is a chain, sprockets are sprockets. Has this made any difference in how a bike rides ?
Oldfart

Posts:472

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05/18/2014 02:09 PM
No
Ride On

Posts:433

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05/18/2014 02:33 PM
It makes a difference in touring doesn't it? Load one side down with 20 extra lbs and you notice it. At what point does it start to matter ?
Orange Crush

Posts:1179

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05/18/2014 02:51 PM
When I pack my lunch* or my laptop in my left panier I can definitely feel it, but the effect of drive-train on a road bike? Nah. One it is not that heavy, two it is still relatively close to bike centreline unlike paniers which are further out.

* its a very big lunch :-)
79pmooney

Posts:1113

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05/18/2014 03:38 PM
What matters is leverage or "moment". That is the weight multiplied by the distance from the point of interest, in this case the centerline of the bike. Say we have a 5 pound drive train and it is 2 inches off the centerline. That is 10 inch-pounds. Now look at a 20 pound bag with its weight centered 6 inches off the centerline. That is 120 inch-pounds or 12 times the effect on the bike of the drive train.

Another way to look at this is: how far do you have to lean yourself and the bike to compensate? (Say you stay in line with the bike and lean everything like you and the bike are a unit.) Bike plus riders = 175 pounds. 175X = 10 inch-pounds. X = 0.08 inches = a little over 1/16". If your center of gravity is say 36" off the pavement, that is 0.1 degrees of lean. Not much of an issue. But that 20 pound pannier. That's 1 1/2 degrees. Ride-able but quite noticeable.

Now, put that 20 pounds in one low-rider pannier and add that to your steering and it becomes VERY noticeable!

Ben
Ride On

Posts:433

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05/18/2014 03:57 PM
Thanks Ben that makes perfect sense.
Spud

Posts:202

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05/19/2014 10:47 AM
When my wife won't sit still on the tandem. I can definitely feel it :-)
Dale

Posts:485

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05/19/2014 11:41 AM
Posted By Spudly Crumpett III on 05/19/2014 10:47 AM
When my wife won't sit still on the tandem. I can definitely feel it :-)


LOL! reminds me of a time when my then 11 year old daughter and I were on the tandem doing Biking Across Kansas.
I felt the bike get a little goosie and glanced to my left and saw the evidence of my daughter sitting up and making shadow puppets on the pavement … duck, dog, squirrel, bird. She kept that up for a mile or so until she became bored with that and went on to find some new entertainment back there.
Spud

Posts:202

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05/19/2014 02:53 PM
First ride with my step-son, the bike was all of a sudden tilting to the right. He was back there trying to slap the mail boxes as we passed by them.


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