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seb-stott seb-stott's article
May 17, 2022 at 2:26
May 17, 2022
Nerding Out: Why a Lower Shock Position Doesn't Make a Bike More Stable
Just to add something to the difference you point out between a frame bag and seat bag. The seat bag is not only higher but further back (I notice this effect even more with a child seat directly over the rear wheel). Either way, this brings the COG backwards towards the rear axle. This means any small steering correction at the front wheel is minimised by the ratio of the distance from the rear axle to the COG over the total wheelbase, so you have to do more exaggerated steering correction to remain balanced with a COG further back. There's more here: https://en.wikipedia.org/wiki/Bicycle_and_motorcycle_dynamics#:~:text=The%20farther%20forward,wheel.%5B11%5D
seb-stott seb-stott's article
May 17, 2022 at 2:17
May 17, 2022
Nerding Out: Why a Lower Shock Position Doesn't Make a Bike More Stable
Thanks! That's a good suggestion, I'll do some thinking.
seb-stott seb-stott's article
May 17, 2022 at 2:14
May 17, 2022
Nerding Out: Why a Lower Shock Position Doesn't Make a Bike More Stable
Raising the COG moves it away from the roll centre (which is basically on the ground for a bicycle with narrow tyres, but slightly below the ground for a motorcycle with very large tyres), and this makes changing the lean angle slower. (there's a section on this in Tony Foale's Motorcycle Handling and Chassis Design, chapter 3, p25.) I don't know much about MotoGP but I suspect that if they were deliberately moving the COG upwards for handling reasons it was to reduce twitchiness and make it easier to control a slide.
seb-stott seb-stott's article
May 17, 2022 at 2:00
May 17, 2022
Nerding Out: Why a Lower Shock Position Doesn't Make a Bike More Stable
At very low speeds (e.g. a track stand) a better model is a double-inverted pendulum, where the rider balances by pivoting her mass relative to the bike (I think this is what you're saying?) and so arguably the COG location of the bike itself is more relevant. But at higher speeds (most of the time during non-trials mountain biking) the single inverted pendulum model is more appropriate. See here for more: https://en.wikipedia.org/wiki/Bicycle_and_motorcycle_dynamics#:~:text=A%20bike%20is%20also,racks.%5B39%5D
seb-stott seb-stott's article
May 17, 2022 at 1:52
May 17, 2022
Nerding Out: Why a Lower Shock Position Doesn't Make a Bike More Stable
For sure with many kilograms of bikepacking luggage, it is important, not just the height of the mass but also the front-to-rear distribution. A shock is a much smaller mass and it has a much smaller range of available locations - you can only really move it up or down (not front to back) and only by a few cm. The main point of the article, though, is that a lower COG isn't necessarily more "stable" as it would be with a four-wheeled vehicle. The inverted pendulum model of a bicycle implies that a higher COG is usually easier to keep balanced once up to speed.
seb-stott seb-stott's article
May 17, 2022 at 1:43
May 17, 2022
Nerding Out: Why a Lower Shock Position Doesn't Make a Bike More Stable
I live in Scotland. Sometimes I do. Okay, it was a bit tongue in cheek but a pair of thick socks could be in the region of a couple of mm.
seb-stott henryquinney's article
May 4, 2022 at 8:27
May 4, 2022
The Good, the Bad, & the Ugly: 10 Editors' Clipless Pedal Setups
Did you have the long or short axles on the Mallet E? The short ones are unrideable unless you have pixie feet. If you get on with the Shimano mechanism there's no reason to use anything else IMO.
seb-stott henryquinney's article
May 4, 2022 at 8:24
May 4, 2022
seb-stott henryquinney's article
May 4, 2022 at 8:23
May 4, 2022
The Good, the Bad, & the Ugly: 10 Editors' Clipless Pedal Setups
Just wondering, what caused your Mallet Es to fail? I've had bent axles and worn internals, but not three times a season and nothing that can't be fixed.
Added 2 photos to Checkout-2
Apr 26, 2022 at 10:23
Apr 26, 2022
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