What Determines "Ride Quality"?

Bicycle frame as architecture

I started writing this post nearly 18 months ago, trying to make sense of what makes a bicycle comfortable to ride. At the time, the particulars of geometry fascinated me. Later that year, my drive to find a bike that would let me ride longer and further without pain led me to having a custom titanium touring frame designed and built, and then a complete bespoke bicycle built up around that. 

After a year with the custom titanium bicycle, I have found myself wondering how much of my satisfaction with this bike is the result of the geometry (and size/shape/proportion) and how much is down to frame material (and tubeset). Would a steel frame made to exactly the same plan have done the job just as well as titanium has? 

G.E. over on the Endless Velo Love blog has been pondering the same question: What effect does frame material have (or not) on ride quality? 

Mulling that over (and formulating a comment or two on G.E.'s post) has prompted me to dust off my own scribblings from a year ago, which forms the basis of today's post. My own question was: What effect does geometry have on ride quality?  

I think you'll see, on reading both G.E.'s musings and my own below, that our respective questions are connected and interwoven, perhaps even impossible to untangle from one another. The big question we are each , in our ongoing quest for Cycling Nirvana (ha!), seeking to answer is: 

Which is more crucial to ride quality and comfort -- 

the design of the frame or the material it's made of? 

There is probably no single unequivocal answer. 

Curiously, G.E. and I have both gone down the custom route in the past year, with her having a custom steel frame built by Independent Fabrications and I having a custom titanium frame built by Enigma Bicycle Works. Subjectively (if not objectively), has she found her answer? Have I found mine? Does each of us wonder, "maybe I should have done what she did, instead..."  

I know this isn't the end of this journey. While, at the moment, I lean towards "design/fit" being the answer, nonetheless that doesn't quite explain my experiences with my own two "fast" steel road bikes... here is their story. 

What do you think?

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Geometry both fascinates and confuses me. It's quite clear to me that how a frame is made is fundamental to how the bike rides. This is down to both lengths/proportions and angles, and also the frame material including the diameter and thickness of the tubing. Materials and tubing is totally "beyond my ken", but the whole geometry thing is starting to make more sense to me in the context of how road bikes "feel"... and how they're put together. Please bear with me as I ponder geometry by reference to two very different steel-framed road bikes in my stable. 

A bit of background --

At the time I bought my vintage Puch Princess mixte, I had been cycling for about 8 months. I had no interest really in "road bikes" -- that sounded like something for athletes, which heaven knows I am not. Moreover, leaning forward like that just looked uncomfortable to me. 

But the mixte is light and responsive. Even with North Road bars, I felt I could go places far beyond just my neighbourhood. Setting off on the 120-mile Dunwich Dynamo was a big gamble in July 2010 -- I'd never ridden further than 45 miles in one go before.  But I made it. And my love affair with night riding began. That led me to the renowned "Friday Night Ride to the Coast" group. I rode the first two on the mixte. The limitations I encountered were my own, not the bike's.

A few months later, I bought my first road bike -- a Surly Cross Check. Looking back, I think I wanted a "jack of all trades". But the CC is unfortunately master of none. It is certainly bomb-proof and in that sense good for commuting. But it's also heavy. And -- outfitted for commuting i.e. with Marathon Plus tyres -- slow. 

So my quest for faster and further led me to the Surly Pacer in the spring of 2012. Its build (components and specification) was bespoke and entirely "curated" by me. As it happened, I have just sold this bike but I had 18 wonderful months of what the Americans call "spirited riding" on it, which gave me a good understanding of how it rode and handled, what it was good at (and of course refined my understanding of my particular fit issues).

The point however is, the Pacer felt familiar to me from the start. The fit was the best I'd had so far but it was the bike's handling that I loved -- it was light and nimble yet steady on the descents. In fact, it reminded me... very much... of the mixte.

And so my vague wonderings about "re-storing" the mixte to Road Bike Mode crystallised into a plan -- and came to fruition last summer. At some point, I couldn't resist setting the Princess mixte and the Pacer road bike -- two visually quite different bikes -- side by side just to see what might be at the heart of their striking similarities in feel and handling. 

The Princess is undoubtedly a longer bike, both in reach (what I call 'the cockpit') and in overall wheelbase.

In comparing the two bikes, my intention was to "leave fit out of it, for the moment" but it's very difficult to filter it out! However, from what I understand, provided the fit is good (the crucial disclaimer), the most important measurements in terms of rider comfort are the seat tube and head tube angles. Sheldon Brown says,

"Generally, frames with longer chainstays, and less vertical seat-tube 

and head-tube angles are more comfortable. 

This doesn't make them any slower, but may reduce 

maneuverability (also known as twitchiness.)" 

With these two bikes, the head tube angles are identical: 72 degrees which is widely accepted as ideal for road cycling.

What is obviously very different however is the fork rake (and also trail). I understand that the rake on the Pacer is "5cm". I am baffled by this piece of data from Surly, as I thought rake was measured in degrees, not distances. If a reader can help me with this, I would be so grateful.

I have no idea of the rake on the mixte or the trail on either bike.

Moving to the seat tubes -- the angles are very similar (perhaps only a degree, at most, "slacker" on the Princess) at 74.5/75 degrees -- also identified as contributing to long-distance comfort.

As you can also see, the Pacer has tighter wheel clearances for the rear wheel. Surly says there is room for mudguards ("fenders") with 28mm wide tyres, but it'd be a tight fit. Anyway, mudguards are not important to me on the Pacer. As the photos show, the Princess's rear triangle is much more 'generous' with greater tyre clearance and plenty of room for mudguards. As for what that means to ride quality, it does have longer chainstays and a longer overall wheelbase, this should translate into a comparatively "more" stable ride, especially on descents. However, I can't say I've noticed any difference between the two bicycles in this regard.

Neither bike has toe overlap. (Oddly enough, the Cross Check does have overlap, even though it is "longer" than either the Pacer or the Princess. I would need to check, but this may be due to a steeper head tube angle.)

The angles of the chainstays are close to identical in both bikes, though. And the angle of the downtubes look pretty close, too.

Again, I have tried to keep "fit" out of this analysis, as obviously each bike fits me differently yet my impressions of their ride qualities are strikingly similar. Further, anyone else riding these bikes may find that they fit completely differently. Would another person's impressions nonetheless be the same as mine, that the bikes feel very similar out on the road?

So, my question remains unanswered. The strong similarity in the ride qualities of these very different-looking bikes may be down to a couple of key factors. Or it may be because they're both made of similar grades of steel... or both factors together... or some other factor altogether... or combinations and proportions of them all.

I may never know.