johngwheeler

Here's a question for those of you who have ridden a variety of different road bikes:

Given two bikes of the same weight, would a bike with a "race geometry" (low headtube, longer top-tube, short chain-stays) feel and handle very differently to a similar quality bike with an endurance geometry?

Let's assume that they have the same frame material, and are running the same wheels & tires, but the "usual" features in frame-compliance found in each type of bike apply.

In other words, is the geometry and stiffness of the bikes a more significant factor in how the bike feels, or is weight the principal factor?

rgconner

In a word: yes.

Geometry is far more important than weight. Simply changing the fork on the same exact bike and making the trail longer or shorter will radically change the bike.

Bah Humbug

Almost everything is more important than weight.

Don't tell the weight weenies.

wphamilton

So with the brutally built-up stiff frame of the GMC Denali and its racing geometry, its feel is closer to a top end racing bike than a lighter vintage racing bike would be?

DrIsotope

Can't speak to the Denali, but the CAAD12 I rode was (to me) absolutely horrendous, and it was wicked light. In a 60cm frame, it was harsh and jarring, while being wiggly and noodly at the same time. The front end was as stiff as a bulldozer, and the rear end felt like it was made out of al dente spaghetti. My Cervelo weighs around a pound more, but is infinitely more comfortable.

Bah Humbug

Are we evaluating the frame of the Denali alone, or are we trying to pretend that heavy weight is its only flaw?

Seattle Forrest

Geometry = how your weight is distributed. Profound difference in handling.

Bike weight = 1 pound difference between two bikes almost vanishes when you add the weight of the rider.

Endurance bikes tend to have longer wheelbases to slow down the handling enough to make them feel more stable.

wphamilton

Well the topical question asks about weight and geometry ... and the other flaws don't affect the "ride feel" much ... so I'd say we're evaluating the frame and weight relative to ride feel.

chainwhip

The red ones are faster.

Rollfast

The name Schwinn or Rollfast helps a lot too.

Seriously, it's the gearing.

Bah Humbug

You still picked the Denali for a reason, and it differs from a classic steel race bike in a lot more ways than just weight. This makes me suspect you're trying to conflate those other flaws with weight to pretend that weight is a bigger factor than it is.

chainwhip

So, like, 24 speeds are faster than 21 speeds?

wphamilton

That's what the question is, isn't it? How big of a factor is weight, so what's wrong with picking a bike that's a lot heavier and apes the road bike geometry and looking at the "ride feel"?

What that choice might do is expose what people really think makes a difference in ride feel, if they're on the bandwagon of weight not being a factor, or at least one of the least factors. For what it's worth, I rode one for 5 or 6000 miles per year at one time, so I do have an opinion. Based on that experience, I'd have to say that ride quality was impacted by the tires, weight, and wheels, in that order. Other than that, there is no real difference in how I see the ride quality.

Bah Humbug

Or you could do a much more suitable comparison of an R2 and R5, instead of picking a "bike" sold at Target. Better still, we could attach ballast to a frame to really isolate weight as a variable instead of intentionally introducing confounding variables in an attempt to muddy the waters.

wphamilton

OK, have you attached ballast to the frame of one of your bikes, for thousands of miles? I presume that you haven't neglected weighting the wheels and tires which are also important characteristics of the bike's weight. How do you characterize the difference in ride feel from that experience?

Cyclist0108

Water bottles.

Lazyass

This '86 Trek 560 Pro is the fastest, twitchiest, sharpest handling bike I've ever had and it's over 20lbs.

Bah Humbug

Have you? Or have you ridden different bikes and decided to ascribe all their many differences to weight?

wphamilton

I think I already mentioned that I rode different bikes and examined the differences (not ascribed them all to weight ) You should infer that I also compared the tires, wheels and other elements because I listed them, and suggested the order of priority.

My take from this is that you are trying to criticize an opinion, and a bike, without having actual experience or knowledge of either how the opinion was formed or the bike itself.

Bah Humbug

I am indeed trying to criticize the opinion that weight (within normal bounds) is anywhere near the top of the list of important factors in ride quality for a bicycle, yes. Was I being unclear about that?

wphamilton

Well, you attacked the bike for no particular reason, then you suggested that my opinion was just being dumb ("did you ascribe all of the differences to weight") for no particular reason, so yes it was pretty clear to me that you had no particular reason for the criticisms.

You can correct that deficiency by bringing up some objective, factual objections.

Bah Humbug

Well, you intentionally picked one of the worst examples of a bike to make your comparison with. How close is the geometry on the Denali to your other bikes? Not just stack and reach, but chainstays, angles, and everything else? Why are you opposed to comparing bikes which are very similar other than weight? So yes, it was pretty clear to me that you were trying to confuse the issue with all the other differences between the Denali and nicer road bikes.

You can correct that deficiency by talking about lighter and heavier versions of the same bike, or a single bike with ballast.

Actually you can't, because I'll still trust the bike builders who've spoken on the topic over you. You could, however, at least convince me you're arguing in good faith.

seedsbelize 

And my 79 Trek 930 is my fastest bike. Faster and more comfortable than a somewhat lighter and stiffer Paramount (21 lbs.).

wphamilton

Why did I pick it? Because having about 20K miles on it I happen to know something of its characteristics, and because the most apparent difference - weight - is what's under discussion.

The head tube angle is 72°, the same or close to that you expect on similar road bikes. The chainstay length is 415, a standard size. Ditto the STA, standard. Stack and reach are a shade shorter than you might expect from a randomly selected "road bike". This bike is VERY similar in geometry to other road bikes - why do you ask a question that demands a false assumption? Do you have any factual basis for that? Have you ever even ridden one more than around the block?

Maelochs

Tell me … has there ever been a BF thread in which people actually replied helpfully to the Original Poster?

First, define “ride feel.” Second, admit since it is entirely subjective, it has not specific definition. Third, argue specifics.

Geometry affects handling … a short-wheelbase bike with a steep head angle will be twitchy no matter how much it weighs. “Handling” is all about geometry. Short chain stays, short wheel base, steep head-tube angle mean that the bike will change directions quickly. Slack head tube, long chain stays, long wheelbase, and it will be more stable, slower to respond. We know this. No point debating it.

One could ask what “Very” means, but anyone here with any experience can answer this honestly—if that person so chooses.

YES. The race-geometry bike will feel racy. Some bikes are like that … sneeze and you are in the other lane. The slightest lean or turn of the bars sends the bike immediately and dramatically into motion.

By this point, BF people were too busy bickering to notice that the OP had asked a second, and completely different question: Almost an unrelated question.

The first question posits two bikes of the same size, frame material, and weight, with radically different geometries.

Also, the first question asks specifically about Handling, whereas the second asks about “how the bike feels.”

At this point, the question is so subjective it is impossible to answer either correctly or incorrectly, until the terms are defined.

I will echo @wphamilton, that tires make the biggest difference in comfort, and wheels in acceleration as a rule. I did a test with three sets of wheels and tires on my Fuji, each set being lighter and more racy than the next. The bike went from pretty sluggish to almost not sluggish to pretty normal for an endurance-frame bike with each change. Considering the weight difference in total was maybe 600 grams I doubt “weight” was as much of a factor as where the weight was, i.e. rotating weight which drastically affected acceleration and deceleration of the bike.

Frame material and frame design is huge—but any material Can be made into any kind of frame. I am sure someone could make a weak, flexy aluminum bike (doubt it would last long.) A steel bike can be bone-jarringly rigid or unpleasantly whippy and wobbly. CF can be super-stiff or extremely forgiving. So frame material per se is not the deciding factor.

Frame design plays a huge role. Again, whatever the material, where it is put and how much is put there determines what it does.

How this affects “feel” depends on the definition of “feel.” Certainly, bikes with different frame designs could “feel” different.

Weight? Depends on a lot of things. I have two bikes with a “showroom” weight around the UCI limit, and a few tanks. ALL of them “feel” different.

My two Workswells are radically different in everything but weight. The racy bike feels quick and agile and eager … the endurance frame feels slow. Chain stays are pretty close, and the endurance bike actually has lighter wheels … but it feels slower. If has to do with half a degree of head-tube angle, slightly different weight distributions … and frame design in general. Neither flexes that I can feel it … with my amazing wattage output which approaches triple digits.

So … until we get absurd with weight differences … I’d say weight is the least affecting dimension. Obviously if one bike weighs 15 pounds and the other forty-five … but within a range of several pounds, I don’t see weight to be the biggest factor.

I’d say geometry first and foremost, frame stiffness Only if one is looking at an exceedingly stiff bike versus an exceedingly noodly bike …. Tire width, suppleness, and pressure next, wheel weight next ….

Whatever. It seems that Five Stooges are not enough, and BF has now created a sixth topic which has no objective answer, so we can all claim to be entirely and exclusively right about it.