Fifty Plus (50+) - * Bike geometry is a whole other world

And, honestly, I never gave it a lot of thought.
I'd sit on the bike... ride it around and it felt good or not.
But now that I'm even remotely considering building up a Soma, I've taken an interest in what all the numbers are and what they mean.
Does a point five change in head tube or seat tube angle really make a difference?
Wow... kind of mind boggling but it does make you think about these bikes of ours in a whole different way.

And, honestly, I never gave it a lot of thought.
I'd sit on the bike... ride it around and it felt good or not.
But now that I'm even remotely considering building up a Soma, I've taken an interest in what all the numbers are and what they mean.
Does a point five change in head tube or seat tube angle really make a difference?
Wow... kind of mind boggling but it does make you think about these bikes of ours in a whole different way.


Have you taken the "eyeball" test?

If you don't score under 4, you need to reconsider thinking about "geometry!" :p

And, honestly, I never gave it a lot of thought.
I'd sit on the bike... ride it around and it felt good or not.
But now that I'm even remotely considering building up a Soma, I've taken an interest in what all the numbers are and what they mean.
Does a point five change in head tube or seat tube angle really make a difference?
Wow... kind of mind boggling but it does make you think about these bikes of ours in a whole different way.

Yes.

Yes.

+1

Little differences in geometry can make important differences in the ride and handling characteristics of a bike.

And I would think that steeper angles, a more upright seat and head tube, mean a "racier" performance?

Research, baby, Google is your friend. (but yes, generally, especially the head angle)

You have your work cut out for you, but it sounds like a fun project. I hope you pics of your progress.

A very slight difference in seat tube angle on its own means nothing, as you can correct for it by sliding your seat forward or back or getting a seat post with a setback. However, it may be accompanied by a slightly different rear triangle geometry and change in wheelbase, so that can affect the handling and feel of the bike. A change in head tube angle would likely have more obvious impact on the feel of the bike.

Wait until you start trying to understand fork rake and trail...you will have to pick a fork for the Soma, right?

Just imagine adding frame tube thickness to the mix. Chain stay frame tubes could be made out of Ti pipes that are this thick or made out of pipes that are that thick. Start figuring out what changes those choices in thicknesses of material make to the ride quality beyond the geometry will give you a heck of a headache.

Add head tube length into the mix.
Start adding center/forward or center/rear lengths.

Is there anyone else out there with my attitude toward this? My take is that I do not have time to get into all this. I like to ride, and that takes up most of my free time, if I really knew what free time meant. Then add in time the wife wants for all types of projects, other family duties with the kids, that are supposed to be grown, and community activities. Then the 800 pound gorrilla in the corner that goes by the names of work, career, etc. I let the bike manufacturers work out the numbers.

Is there anyone else out there with my attitude toward this? My take is that I do not have time to get into all this. I like to ride, and that takes up most of my free time, if I really knew what free time meant. Then add in time the wife wants for all types of projects, other family duties with the kids, that are supposed to be grown, and community activities. Then the 800 pound gorrilla in the corner that goes by the names of work, career, etc. I let the bike manufacturers work out the numbers.

I take your approach to this....sort of. I'm not really interested in "learning" all there is to know about frame geometry. Rather, when I have a bike the feels really good and performs as I want it to perform, I make sure I keep a record of important details. This way I can replace the bike with the same geometry. Currently my favorite ride is:
Seat tube length - 57.3 cm
Seat tube angle - 73.5 cm
Head tube length - 144 cm
Head tube angle - 73.5 cm
Bottom bracket height - 26.7 cm
Top tube length - 56.0 cm
Stand over height - 80.6 cm
Chain stay length - 40.5 cm
Wheel base - 98.1 cm
Drop out width - 130 cm.
Fork Rake - 42

I suppose there are other things that I "should know", but I'm more interested in riding.

All these things make differences, but the reality is that you can ride bikes with differences and enjoy them regardless. I have a crit bike, a touring bike, a road race type bike, and a sport-tour type bike. They all have their own feel, and handle different ways, but they can all be used for anything I would do. The big difference is the harsh ride of the crit type frame, but this is partly due to the stiffness of the oversize heavy gage steel frameset. The upside is the thing turns better than any bike or motorcycle I've ridden.
SKT, you will be happy with any Soma you get, if you're looking for a steel framed bike.

It only matters if you are purchasing a frame set or building a custom bike for which you want to control some of the performance parameters. Many if not most folks will just purchase what's available.

On the other hand, some wish to know just for the heck of it.
Some actually do build their own bikes.
Some want additional information to assist in fitting their next bike.

For additional comparisons, see:

Sterio enthusiast
Computer enthusiast
Automobile enthusiast
Tool enthusiast
Gun enthusiast
Any one who want new shoes
Almost any woman who is shopping for clot...........anything.
Skiers
Tennis racquet buyers



actually anyone who is an enthusiast about anything.

Or Tom.

:p

If you just ride and don't pay attention to how the bike feels or reacts, that's fine. However once you start noticing differences between bikes, it opens up a lot of new things. At first, the differences are subtle. But the more you notice, the variations become larger,

Seat tube angle, by itself, isn't much. The seat position can compensate for a 0.5 degree. But the seat tube angle also affects the rear triangle (seat stays and chain stays). The chain tube length affects how "snappy" the bike accelerates or how comfortable and smooth a ride is. It also affects the top tube length. TT length might mean a different size stem. But you get the idea.

The two often overlooked things that impact the ride of a bike are geometry and wheels. Often they are more important than frame material.

Or Tom.

:p
:lol:


I'm in the camp with those who don't get into the mathematics much. Although I do consider myself to be a pretty good mechanic, (in spite of DnvrFox's geometry test :bang:).

For some reason, there are only two bike-frame geometry numbers that I can remember without looking stuff up: chainstay length and wheelbase.

- A wheelbase over 41 inches will mean the bike is more suitable for relaxed riding and touring
- A chainstay length over 17 inches long suggests the same thing (more relaxed wheelbase, chainstays long enough that you can put panniers on the bike and avoid striking your heels).

The wheelbase number is the product of a lot of different decisions - chainstay length, frame angles, top tube, fork rake, etc. I've never ridden enough similar bikes back to back to understand whether I can feel each of those differences independently (I'm sure I couldn't)....but there is a *huge* difference in the rides between a 39-inch and a 41-inch wheelbase bike. At 41 inches it means the bike maker has made lots of smaller decisions that will add up to a bike that feels more relaxed than one at 40 or 39 inches.

I take a tape measure with me when I look at used bikes and always measure the wheelbase.

The chainstay length is a good number to remember when looking at bikes that are pitched as "all rounders," like 'cross bikes that can be used for light touring or commuting. Some of these bikes have chainstay lengths just under 17 inches (say 16.5), and some are just over. The shorter ones would likely ride a bit snappier but not have enough chainstay for mounting large panniers.

Unless you are planning to design or build your own frame, you really don't need to know this stuff. If you are looking to buy a new bike, simply ride different bikes and choose the one that fits and handles in a way that you like. Most manufacturers have already separated their lineups into categories based on their intended use and the geometries they chose to accomplish that.

But some of us are just more curious than others about how things work and why they work like they do. For example, Specialized has the Tarmac line of bikes with traditional racing geometry for quick handling and the Roubaix line with slacker geometry for a more relaxed and comfortable ride. Look at their geometry charts to see how they use different head tube angles and chainstay lengths on bikes the same size between those two lines.

When looking at new potential frames for future bike builds, I like to compare the geometry of the new bike to the geometry of my best fitting and handling bike to get an idea how it might handle. Frames that come closest to my gold standard (Ribby) with 575mm effective top tube, 73.5 degree head angle, 73 degree seat angle and 410mm chainstay length are the ones I would expect to match my idea of a sweet handling road bike.

Tom's rides form a valuable data base for this forum. Much of his information is priceless.
Blues Dawgs bikes have pushed the design parameters as well. (finding out what works and what doesn't takes time and money.....its always nice to be able to use someone elses ideas.)

I became a geometry obsessive last year when I began the construction of a TT bike. They are so different that little of my prior experience with conventional designs was of help. Especially since it couldn't be a TT for the typical rider. (there are no designs for the average 60+ first time TT'er who hasn't ridden him/herself into TT shape) Off to school (the hard way by digging it out on my own). In the process of learning about TT fit, it was necessary to absorbe lots of info on the fit of normal bikes. Very little of this info is in the form of firm hardcore facts. There is a world of opinion as to how many degrees of this and how many centemeters of that should be combined with 1 eye of newt to produce a bike that handles just so.

The end result was a TT bike that works pretty good for me.......at this time.........on my roads.......at this level of fitness........with enough adjustability to possible work next year and the year after that. Even at that, my learning curve helped only just enough to get the frame right. I still have 3 sets of bars, 5 stems, 2 sets of brake handles and 2 forks invested in the bike, mostly so that I could put real performance changes together with theory.

As a spin off though, I began construction of "Dormouse" at the same time. I wanted an MTB based bike that would handle most terrain but still give the handling feel of the TT so that I could get some training benifit from most of my flatter offroad rides. I managed to get that also, but you couldn't buy that bike in any LBS because it flys in the face of what is presently being sold.

That's when understanding bicycle geometry becomes valuable. That point where you know more about what you want the bike to do for you than someone else does. It's one thing to copy what already is. Its something else to head off in a new direction but with some idea of what your going to do and how.

My head hurts :lol:

edit: I'd imagine, then, that this would be a pretty "snappy" performer?

SIZE 55cm
CENTER of BB to TOP of TT 21.69/551
EFFECTIVE TT LENGTH 22.44/570
HT ANGLE 72°
ST ANGLE 73°

CHAINSTAY 16.73/425
WHEELBASE 40.33/1024
FORK RAKE 1.69/43
BB HEIGHT 11.02/280
HEADTUBE 5.31/135
STANDOVER 32.36/822

inches/mm

If you think bike geometry is hard, try bike algebra...or worse yet, bike trigonometry. Egads!

My head hurts :lol:

edit: I'd imagine, then, that this would be a pretty "snappy" performer?

SIZE 55cm
CENTER of BB to TOP of TT 21.69/551
EFFECTIVE TT LENGTH 22.44/570
HT ANGLE 72°
ST ANGLE 73°

CHAINSTAY 16.73/425
WHEELBASE 40.33/1024
FORK RAKE 1.69/43
BB HEIGHT 11.02/280
HEADTUBE 5.31/135
STANDOVER 32.36/822

inches/mm

Looks like a cyclocross bike to me. The head angle is pretty slack for a typical road bike. The chainstays and wheelbase are long for a road bike but short for a tourer.

Looks like a cyclocross bike to me. The head angle is pretty slack for a typical road bike. The chainstays and wheelbase are long for a road bike but short for a tourer.

Hm. OK... this gives me a little clue anyway.
These are the specs of the Jamis Aurora Elite, which Jamis considers a touring bike

Hm. OK... this gives me a little clue anyway.
These are the specs of the Jamis Aurora Elite, which Jamis considers a touring bike

As you are thinking about N+1- look at the type of riding you want to do. Your OCR is a comfort geometry bike. Ideal for the type of riding you currently do. Now if Jamis consider the Aurora as a Touring bike- Will it really fit in with the type of riding that you do?

Think you and I do the same type of riding. We just go out and ride. You are beginning to get your distance up- so is a touring bike the ideal for you? I have two bikes- both have performance geometry and they both suit my style of riding. They are set up a bit differently though and IF I am out for more than a 60 mile ride- then I take the TCR Bars just a bit higher and bar reach about 1 cm longer. Boreas is great for riding but is not quite as comfortable on the longer rides.


I would suggest that you try out the "Performance" geometry bikes aswell. In fact check out as many bikes on test rides as you can. I would hate it for you to get a bike that is not as good as the OCR and it rarely gets taken out.

And as to the geometry-It will not matter as long as it rides well for you. My experience is on Mountain bikes and I found that there are some bikes that suit me and others that don't. The only way I found out was to borrow them from my mates- or arrange test rides.

I guess the main reason I'm curious about geometry is that there aren't a lot of ready-built Somas to test. So, if I can get an idea of what I have and what parts of the geometry contribute to the feel, this helps me know more about what I might like to get. Besides, as far as the Jamis goes, I like the idea of a comfy cruising bike... kind of like the Kaitai but without the extra bulk and weight.

Looks like a cyclocross bike to me. The head angle is pretty slack for a typical road bike. The chainstays and wheelbase are long for a road bike but short for a tourer.

yeah, very 'cross', pretty much what I would say from those specs.
For a long time, especially for Italian road bikes, the 270 BB Drop was almost sacrosanct. Back in the late 70's many Brits and some Japanese shops were starting to commonly use 275, especially for roadies headed to the US market. With the preponderance of crits in the States, everythin gto get more cornering clearance was deemed good. I tried some of those machines - an MKM, Bob Jackson, Raleigh Pro and Ron Cooper. Didn't grab me. In fact I went back to bikes with 270, right quick, which back then meant mostly Eye-talian (stopped messin with french threadin back in '74, a wise decision...)
Its such a tiny 'number' difference - who woulda thunk it would make sucha huge diff.?

and with a 57 TT for a 55 ST for that Jamis, that oversquare means more weight on the rear and less on the front. personally, that makes for a sketchy descender for my tastes - and I'm all about going down...
but then everyone buys teensy bikes these days, so they can ride in a scrunched up, little ball.
for steel bikes, geometry has been very predictable for quite a few decades. So before goin with some odd-ball ideas, I'd try a tried and true road geometry for comparo.
And just coasting around a block or 2 isn;t gonna get the measure. Gotta go up a good hill and then come back down. Lotta bikes feel great at 15 - 20 mph on a flat, but take em down a good hill at 35+ and many will make you stain your chamois...

...just sayin

So before goin with some odd-ball ideas, I'd try a tried and true road geometry for comparo.
And just coasting around a block or 2 isn;t gonna get the measure. Gotta go up a good hill and then come back down. Lotta bikes feel great at 15 - 20 mph on a flat, but take em down a good hill at 35+ and many will make you stain your chamois...

...just sayin

Which, I guess, kind of leads me back to the Soma and that's fine.
But can someone give me the numbers for a traditional road geometry?

I absolutely agree about the test ride.
The longer, the better and I have to know how it goes up a hill. And down.
My current shop let me take the OCR out for a 10 mile romp which had it all.
The one thing that really sold me on it was how it dropped on a long winding descent.
Just reallt solid and in the pocket and as I've gotten better, so has it.

Which, I guess, kind of leads me back to the Soma and that's fine.
But can someone give me the numbers for a traditional road geometry?

Just a thought - try looking at the Surly line.

They have complete geometry charts for each of their bikes on their website. They tend to have good generic frames - compare the Surly Pacer, Crosscheck, Steamroller, and Long Haul Trucker.

Just a thought - try looking at the Surly line.

They have complete geometry charts for each of their bikes on their website. They tend to have good generic frames - compare the Surly Pacer, Crosscheck, Steamroller, and Long Haul Trucker.

Thanks... and my LBS carries both Surly and Soma.
Soma's kind of getting the nod at this point.

Which, I guess, kind of leads me back to the Soma and that's fine.
But can someone give me the numbers for a traditional road geometry?



When looking at new potential frames for future bike builds, I like to compare the geometry of the new bike to the geometry of my best fitting and handling bike to get an idea how it might handle. Frames that come closest to my gold standard (Ribby) with 575mm effective top tube, 73.5 degree head angle, 73 degree seat angle and 410mm chainstay length are the ones I would expect to match my idea of a sweet handling road bike.

The Soma Smoothie comes pretty close to matching this.
http://somafab.com/geometry03.html

Which Soma are you considering, the Double Cross? It looks pretty close to the geo numbers you listed for the Jamis.

The Soma Smoothie comes pretty close to matching this.
http://somafab.com/geometry03.html

Which Soma are you considering, the Double Cross? It looks pretty close to the geo numbers you listed for the Jamis.

Actually, no... I'm looking at the Smoothie or Smoothie ES-or even the Speedster, believe it or not but I haven't compared all the numbers. Terminology is so weird. You think of the Aurora as a CX but Jamis calls it a Touring bike. I wouldn't think they'd be anything alike. Oh well, as I said, it's a learning process for sure.

Hey wait! I know...
I like a responsive, stable bike... comfortable, yet quick, agile and solidly rooted in the turns.
A steel frame like my LeMond (whatever the specs are on that. Trek took down the site)
Or even like my Giant.
I know both of these bikes have wheelbases of 41" or less and chainstays of 17" or less.
The Giant numbers are available.

What numbers support those characteristics?

Do your own research. ;)

Do your own research. ;)

Oh yeah???? :mad:
Of course, you are right :D

So, I just printed off spec sheets for the Rivendell Legolas (sort of the retro steel benchmark, I guess), the Giant OCR c2 (duh. I would've printed the LeMond's, as well, but... well, thank you very much, Trek. Guess I'll have to measure it myself), the Soma Smoothie and Smoothie ES, the Bianchi Vigorelli, the Jamis Aurora Elite. What I believe I'll find is that the numerical differences are so minimal between what's considered, say, a CX and a Touring bike as to be meaningless to someone of limited experience. But, hey, I can sure get into numbers for numbers' sake. Numbers can be interesting.

Then, I have two bikes I like and they'd make a good starting point.
I need to find out -to qualify- what I like about them and what things I'd like to be different.

Heck, maybe all I need to do is change the crank on the LeMond.
One thing I've noticed is that the OCR is quick to respond with no feeling of effort.
The LeMond also responds quickly but there feels like there's the "push back" -this inertial- from it.
I think that's down to having a 39T and a 172.5mm crank on the Giant and a 42T and a 175mm on the Reno. See? There you go. The cranks are 2.5mm apart and I can feel that.

Surely 99.99% of the world's cyclists have never thought more than five minutes about bike geometry and proper sizing and all that crap, and yet they happily roll along.

That's why I have a road bike, a touring bike and a mountain/city bike. If you cross them up you bust your butt.

Generally, the most distinctive geometry differences between touring and cyclocross bikes is that touring bikes have longer chainstays (more heel room for panniers) and lower bottom brackets (CX bikes need them higher for clearing offroad obstacles). Compare the Surly LHT and the Surly Cross-Check. Then see which one is more like the Jamis.

Surely 99.99% of the world's cyclists have never thought more than five minutes about bike geometry and proper sizing and all that crap, and yet they happily roll along.

Take two bikes with different geometry down a fast and twisting descent. and differences in geometry can become very apparent. Or ride over a rough road surface. Or, sometimes, try to get a good fit for your unique body. Geometry can make a difference if you ride a lot ndmake your bike a second home.

Generally, the most distinctive geometry differences between touring and cyclocross bikes is that touring bikes have longer chainstays (more heel room for panniers) and lower bottom brackets (CX bikes need them higher for clearing offroad obstacles). Compare the Surly LHT and the Surly Cross-Check. Then see which one is more like the Jamis.

+1

Right. As said above, 17 inches or so is my "dividing line" between a "cross bike that can be used for light touring" vs. a "touring bike that can handle a big load."

Part of it is heel clearance. Part of it is that if a builder has put long chainstays on the bike, he/she is making lots of other decisions that generally tell you that they have a touring bike in mind.

Which, I guess, kind of leads me back to the Soma and that's fine.
But can someone give me the numbers for a traditional road geometry?


'numbers' can vary, dependin on the ideas of the builder.
for example, Lemonds (and others like the Jamis) are found with more over-square main triangle - meaning the TT is generally a tad longer than the 'virtual' seattube (giving consideration that sloping geometry is 'virtual').
and the combinations of all is what give individuality to frames.
but, as a middle ground, there's hardly anythinig more middlin than the early Treks. Fine bikes for a large percent of the rider pop.
check the chart here
http://www.vintage-trek.com/images/trek/Trek79.pdf
for the '79 treks geometry...
now, like many Brit bikes of that time they had plenty of fork rake... (and then the other side of the spectrum - steep and short rake - also was popular with many Brit machines of that day...)
'79 530,730,930 - very 'square' main triangle 73x73, typical chainstay, 77 BB drop (273 in other words...) lotsa rake - and so prolly a longish 'Front-center'. Your typical road machine.
Looking at the modern Madone, its more like traditional Italian Geometry - slightly under square, 74ish x73, shorter rake and shorter front-center, slighlty longer headtube.
The slighly steeper Italian geometry of traditional steel made for a quick handling bike, but combined with the rake many used (Colnago, CIOCC, Guerciotti, De Rosa, etc...) these bikes are v-rock-steady arrows on the descent (part of which I ascribe to a shorter 'front-center' and the traditional 270 BB height (same as 80 drop). More upright front & shorter Main Triangle means less torquing when leaned over - sortta like Motorcycle geometry. Meaning even though you have much of your weight on the outside, down pedal - the frame torques less and so holds a line Moe Betta...
Try it yourself... do a series of sweeping ESSes, tryit mostly weight on seat and then mid-turn come off the seat and drop the weight to that outside-down pedal, every bike will then wander slightly off the original 'line'.
A solid main triangle and longer stem with rider weight more forward makes for much more controlled and confident descending... you can have your cake and eat it also - same geometry also makes for better climbing feel also...
get tooo steep and short raked and it goes comepletly counter - like my Criterium designed Limongi, great on the flat at speed, but absolute nightmare descending...
...if I can find the specs for early Colnagos (70's and early 80's) I'll make those numbers available.
Maybe someone else has numbers for other traditional steel builders that are not 'custom'.

Soma specs, except for the road 'smoothie' which goes road traditional, the others seem to be some funky varios (IMO)...

Surely 99.99% of the world's cyclists have never thought more than five minutes about bike geometry and proper sizing and all that crap, and yet they happily roll along.

which is as it should be. ultimately we can all get along with whatever we have.
But thanks to finicky builders, teamed with finicky, 'what if' riders, bikes 'improve' and vary.
with the advent of MTB, bikes took a huge lateral jump in concept and design
changes in frame material changed many things
changes on component design echoed thru the entire bike design
all very fun and part of the charm of cycling.
I'm here to celebrate both 'simplified cycling' as well as the 'tweaker' in many of us.
one compliments the other and is endless - like a color wheel - it really is all good :thumb:

And the Smoothies are what I'm probably most focused on, especially the ES.
I still need to measure out my LeMond but the ES comes in pretty close to my Giant's specs and I love the way that bike feels and handles, especially downhill.

For the record -because a fair amount of emphasis has been placed on CX geometry- I am not looking at a CX... not a pure CX, anyway. It's not for me in any number of ways. I guess what I'm really after is two things: a rugged bike that can do paved and unpaved roads (but not offroad trails) that can fill the slot my Kaitai was intended to fill. A go-anywhere, do-anything kind of bike that's comfortable to ride for any distance but not a pig. If the Kaitai is anything on the road, it's a pig. Slow, heavy and just a chore to push around. So, a CX frame with road components (including a triple) and V-brakes might fit.

Or, a more leisurely, comfortable ride for longer slower rides or good for just a short romp around the homestead. In either case, I want a bike that's responsive, yet comfortable and, above all, stable.
I love my LeMond but it's always felt just a tad twitchy to me.

All of this info is great, folks. Please do keep it coming.
And, yes, I am most definitely doing my own research too ;)

Several have mentioned it- But speed on a fast descent.

I have two Performance geometry bikes. The Boreas Ignis and the Giant TCR-C. Boreas suited me right from the start- but this is a quality bike and I have even got the Bills to prove it. The TCR is a good bike- but the first time down a hill that I know and I was grabbing the brakes. It did not handle well at speed.

Made a few changes to it- Changed ride position on the downhills and improved it a bit- but I was still wary of it. Good bike though and it sails up hills. Then I started on tyres- tyre pressures and finally wheels. Although I am still cautious on the fast downhills- The TCR C is fast. All it took was getting the right wheels on it and it transformed the bike. And those wheels are the Handbuilt training Wheels I got 2 years ago that transformed the OCR into a good bike.

It is not always the rider or the frame that makes a bike work.

Several have mentioned it- But speed on a fast descent.

I have two Performance geometry bikes. The Boreas Ignis and the Giant TCR-C. Boreas suited me right from the start- but this is a quality bike and I have even got the Bills to prove it. The TCR is a good bike- but the first time down a hill that I know and I was grabbing the brakes. It did not handle well at speed.

Made a few changes to it-...Then I started on tyres- tyre pressures and finally wheels. ...The TCR C is fast. All it took was getting the right wheels on it and it transformed the bike. And those wheels are the Handbuilt training Wheels I got 2 years ago that transformed the OCR into a good bike.
It is not always the rider or the frame that makes a bike work.

Stapfam hit on the other key element, the rolling stock.
And its not always the most expensive wheels - although a well-build set of wheels really makes any bike shine.
Other thing I noted on my re-entry some years back, was the absolute crazy tightening of space at the chainstays. On many performance bikes you CAN"T get a 28mm tire between there, and a 25 almost rubs.
Does it make a performance diff.? aerodynamics might be a nano better, but certainly a wider anchor of the chainstays would make everything more 'solid'. So when I went to newer materials I looked for width at the chainstays - the Roubaix seems much better than most in that respect.
I do have one set of wheels that I keep with 28mm tahrs and use them even on the 'Nagos' iff'n I'm in a 'put-put' mood and planning to bump along some nice and lonely bi-way.
I've used 23mm tires (still have some layin around, never used, and even tried 19mm and 20mm...) , but really like and now never go smaller than 25mm.
Tire pressure is a game also. I've tried the really high pressures (120 and slightly above), but found them way too jarrin and puncture prone. 95 lbs front and 105 rear does me fine. Hard enough not to pinch flat or dent a rim, low enough to take the edge off rough roads and allow a nice grippy feel for downhills.