Compact Frame Designs and Bikepacking

[worntreads]

Compact rears are all the rage right? Short chianstays, sloping top tubes, angled seat tubes, and bigger headtubes. I get the idea, they are more fun, quicker, nimbler etc. But does this compromise comfort over long days in the saddle? I understand that longer wheelbases make for more comfortable rides, but do 44mm headtubes and thru axles help compensate for the tighter geos?

Thoughts?

[Flounder]

You've got all sorts of geometry attributes all goofed up. A smaller main triangle does not have any impact on the ride quality. How the top tube slopes is irrelevant. It could be tied in a knot like a pretzel and it wouldn't matter.

A 44 mm head tube is a diameter of the tube, not the length. That is designed to achieve a larger/stiffer/lighter steerer tube, ideally to accommodate a steerer with a taper.

All seat tubes are angled, how much is really only varied slightly.

Thru axles make for less flex at the hub/dropout.

[Area54]

Sure gives you less framebag storage

But more seatpost hanging out the frame can increase the comfort, depending on your post choice - without going thudbuster.

[worntreads]

You've got all sorts of geometry attributes all goofed up. A smaller main triangle does not have any impact on the ride quality. How the top tube slopes is irrelevant. It could be tied in a knot like a pretzel and it wouldn't matter.

A 44 mm head tube is a diameter of the tube, not the length. That is designed to achieve a larger/stiffer/lighter steerer tube, ideally to accommodate a steerer with a taper.

All seat tubes are angled, how much is really only varied slightly.

Thru axles make for less flex at the hub/dropout.

I never said 44mm was the length. I meant more angled seat tubes, probably not written the best way.

[Flounder]

At any rate, this discussion is an echo from a decade ago when road bikes went from largely traditional (horizontal top tubes) to compact, or sloped top tubes. People thought the slope of the top tube changed the ride. It does not. Mountain bikes have had these attributes (sloping top tube) for the better part of a couple decades. It has become more aggressive (the slope) with the introduction of bigger wheels which mandate a taller head tube.

Plus, trends change, and those low front ends of the late 80s and early 90s just wasn't ideal. Riders prefer to sit upright more than they did then. Good thing, too.

With regard to geometry in general, all bikes will have a slight variance. I have a Form Cycles Ti bike that I had built with steeper seat and head angles with short stays and a lower head tube strictly for racing. It is not an ideal bikepacker, although not terrible. On the flip side, my Salsa Fargo has a very tall head tube, short top tube, longer wheelbase and stays, and is quite comfy on the long haul.

Again, many things like PF30 bottom brackets, tapered steerers and oversized diameter head tubes, as well as thru axles are designed to stiffen certain systems, increase bearing size, etc.  These have no impact on comfort one way or the other.

[worntreads]

I suppose I was referring more to the rear end of the bike, short stays, etc. Which you answered there.

[Jonathan]

I suppose I was referring more to the rear end of the bike, short stays, etc. Which you answered there.

Short rears are a trend related directly to 29" wheels. To have a wide-ish tire fit comfortably takes a bit of work balancing tire clearance and chainring clearance. Ultimately you can't move the seat tube to much forward because the rider needs to be able to achieve a certain setback which is why you see some curved seat tubes. None of this was an issue with 26" wheels.