Don’t know much about geometry…

[TwoWheelsDC]

My understanding of bike geometry is very basic and I can only make observations based on the measurements compared to the bikes I own…but those measurements look like they’d make for fairly relaxed rides. It looks like they’re relatively long (long-ish chainstays + lower HT angle), so they’d handle a little “slower” and not be as twitchy as a regular road bike, and I’d guess they seating position is fairly upright (low HT angles compared to TT length). If my observations are mistaken, I’m happy to be corrected by someone who knows better.

[KelOnWheels]

Well those are good observations! I’m wondering about things like: bike A and bike C seem pretty similar angle-wise, but bike C has a longer head tube, so how does that change things? Bike B has more rake, so will it handle differently than the others? One has different gearing, so what does that do? these are things I wonder about.

[DaveK]

A is a cross bike, which will have a great range for a commuter bike. B and C are compact double cranks, which would also be fine for commuting since they have that lower-tooth small ring than the cross bike but would also give you a little more top-end speed. The practical difference is that A’s gear ratios will be spaced more closely together. B and C will have a little more top end speed at the expense of a little larger gap between the big ring and the small ring.

[thecyclingeconomist]

Bike B is the most cushy and will track better at faster speeds… it has a deeper rake on the fork (more absorption of bumps) and a longer wheelbase, which means it’ll track better, but will be a bit less responsive due to both attributes. I think that Bike B would also allow you to run larger tires than the other options due to the longer chainstays.

Remember that gearing and drive-train components are readily changeable depending upon what you want the bike to do. I’ve flipped from triples to doubles, from mega-range mountain cassettes to tightly meshed road… all on the same frame depending upon the season and what I was doing at the time.

I’m becoming more of a fan of the one-bike-to-rule-them-all idea, and unless I’m racing (which I’ll never be), I think it is feasible (although, Elite’s would pass judgement, and I would be breaking ALL the rules listed on their site: velominati)

[KelOnWheels]

I was puzzling over the BB drop and found this article helpful: http://www.cxmagazine.com/bottom-bracket-height-dropping-in-cyclocross-bike-geometries

[dcv]

@KelOnWheels 43507 wrote:

I was puzzling over the BB drop and found this article helpful: http://www.cxmagazine.com/bottom-bracket-height-dropping-in-cyclocross-bike-geometries

lower bb = bad for fixed gear / pedal strike. you can’t coast / level your pedals through corners on a FG

[KelOnWheels]

@dcv 43509 wrote:

lower bb = bad for fixed gear / pedal strike. you can’t coast / level your pedals through corners on a FG

So if I have a higher BB I can coast on a fixie?

[KelOnWheels]

@KelOnWheels 43522 wrote:

So if I have a higher BB I can coast on a fixie?

But seriously, so if someone wanted a frame that would be good for converting to FG, then bike B would not be a good choice out of the three.

You guys are smart and know all the things! I like that.

[dcv]

@KelOnWheels 43556 wrote:

But seriously, so if someone wanted a frame that would be good for converting to FG, then bike B would not be a good choice out of the three.

Shorter cranks (165mm) would help offset a low bb. I’m more visual than numbers, post picts of the frames / bikes.

[Author]

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