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Bicycle Geometry Terms

99spokes.com

41–50 of 78 posts

Re: Bicycle Geometry Terms

#41

Although I'm an avid reader, this is my first ever comment. I built this site https://comparemtb.com/ to give people a way to visually compare the geometries of many different mountain bikes. I'd be interested in any feedback. Thanks.

Thanks for finally posting!

> I'd be interested in any feedback.

I'll start with pointing out that there seems to be no instructions or hints on the landing page.

Re: Bicycle Geometry Terms

#42
post #28

Odd how it does not give the weight of bicycles in the specs.

We rely on spec data published by manufacturers, and unfortunately many do not specify the weight. It's also possible we're just failing to match it. If you find a bike without a weight that the manufacturer does have on their site you can use the feedback form & we'll get it fixed up.

Re: Bicycle Geometry Terms

#43
post #28

Odd how it does not give the weight of bicycles in the specs.

Weight can vary quite a bit for the same frame based on easily changed components like (1) wheels, (2) groupset (gears, pedals/cranks, brake/shift levers, that kind of thing), (3) handlebar/stem/seatpost material.

I recently bought a medium-spec build of a lightweight frame bike, and could shave 2+ lbs with upgrades, if I wanted to. Not paying for those upgrades out-of-box saved me ~4800 euro up front, and the bike is 17.9 lbs instead of 16.2 lbs. Meanwhile, I could stand to lose 15 lbs myself. :-)

Re: Bicycle Geometry Terms

#44
post #13
post #7

Great explanations! It’s really silly that seat tube length is used as the single measure of frame size. Much more important is reach and standover height, since those can’t easily be changed. A longer or shorter stem will adjust reach at the expense of changing how responsive the steering is, whereas a short seat tube can be fixed with a longer seat post. Seat tube length is also measured differently by different ma…

My thoughts exactly. Being on the shorter side what matters is the stand over height - too high and it greatly limits on/off/standing manoeuvrability and agility. I was surprised to learn that the smallest adult bikes tend to have a stand over height of 68-70cm. For some bikes, it’s even higher. For the lower tail of the adult height distribution, this is too tall to use comfortably.

Look into bikes with 650b wheels for this.

Re: Bicycle Geometry Terms

#45
post #36

As a bicyclist, I'm amused this made it on to the HN front page. I'm not sure I agree with the description of stack. Cockpit height can be adjusted with riser stems and different handlebar shapes; it's not solely a function of axle-crown and headtube length. Without getting into it too much, some other descriptions are not great either. The general overview is ok but they make some overly strong claims. I'm not sure…

Wheelbase is important if you're using a bike for transportation. A longer wheelbase makes for more stability and helps with carrying groceries, children, or other cargo. It does make the bike feel less nimble so may not be optimal for purely recreational riders.

Re: Bicycle Geometry Terms

#46
post #36

As a bicyclist, I'm amused this made it on to the HN front page. I'm not sure I agree with the description of stack. Cockpit height can be adjusted with riser stems and different handlebar shapes; it's not solely a function of axle-crown and headtube length. Without getting into it too much, some other descriptions are not great either. The general overview is ok but they make some overly strong claims. I'm not sure…

Wheelbase is one of the most important measurements for mountain bikes. It determines stability at the cost of the ability to turn quickly.

Re: Bicycle Geometry Terms

#47
post #36

As a bicyclist, I'm amused this made it on to the HN front page. I'm not sure I agree with the description of stack. Cockpit height can be adjusted with riser stems and different handlebar shapes; it's not solely a function of axle-crown and headtube length. Without getting into it too much, some other descriptions are not great either. The general overview is ok but they make some overly strong claims. I'm not sure…

Everyone should think about this comment the next time they’re wow’ed by some link here.

When you’re knowledgeable about something and read an article/blog/whatever about that topic, it’s shocking how much is either somewhat off-base or just plain wrong.

The articles that aren’t about your areas of expertise are no different.

Re: Bicycle Geometry Terms

#48
post #36

As a bicyclist, I'm amused this made it on to the HN front page. I'm not sure I agree with the description of stack. Cockpit height can be adjusted with riser stems and different handlebar shapes; it's not solely a function of axle-crown and headtube length. Without getting into it too much, some other descriptions are not great either. The general overview is ok but they make some overly strong claims. I'm not sure…

Wheelbase is important if you're using a bike for transportation. A longer wheelbase makes for more stability and helps with carrying groceries, children, or other cargo. It does make the bike feel less nimble so may not be optimal for purely recreational riders.

Not only. Modern trail and all mountain bikes also have longer wheelbases so they're more stable at descending slopes at full speed.

Re: Bicycle Geometry Terms

#50
It’s been an interesting few years in relation to MTB geometry. Low bottom brackets with slack head angles and steep seat tube angles have really taken off. My last MTB purchase was in 2018 and it’s geometry seems pretty conservative to newer bikes.
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