Idle musings on what makes a bike ride 'smooth'

[thwart]

Originally Posted by NHAero

Just ordered a 27.2 to 25.4 shim, that will be a low cost experiment to put the Supersix set-up on the Bingham.

Unfortunately, you still have the rim depth and tire difference as well as the bars, so won’t be able to compare oranges to oranges.

Speaking of cost-effective… of course you could mount 28’s on the Bingham to likely make the two feel more similar. I’m assuming the Cannondale, given its vintage, has some tire clearance issues that mandate the 25’s? Even with ‘very good pavement’ you’ll feel a difference. Apparently increasing tire size trumps all other measures to make a bike ride smoother.

[NHAero]

Originally Posted by thwart

Unfortunately, you still have the rim depth and tire difference as well as the bars, so won’t be able to compare oranges to oranges.

Speaking of cost-effective… of course you could mount 28’s on the Bingham to likely make the two feel more similar. I’m assuming the Cannondale, given its vintage, has some tire clearance issues that mandate the 25’s? Even with ‘very good pavement’ you’ll feel a difference. Apparently increasing tire size trumps all other measures to make a bike ride smoother.

The Bingham usually wears 650Bx38 GK slicks so, as you note, tire size and pressure trumps it all. The Supersix as a 2016 Hi-Mod got increased tire clearance and would fit 28s. At 140 pounds on good pavement the 25s, which measure out at 26mm on these rims at 70 psi, are fine.

[Mark McM]

I've been using the same make/model of saddle on my bikes for many years. But I've found that there can be differences between even the same make/model of saddle. Sometimes the padding is denser/less squishy on one unit compared to others or may be distributed a little bit differently, or the shell may flex more or differently on one unit compared to others.

I've got a 2015 Cervelo S5 aero road bike that I use for crit. racing. The frame is laterally/torsionally stiff, and has deep section tubes and stays. It uses a deep section aero seatpost. By "traditional" thought, this should be a harsh riding bike, but I actually find it quite comfortable. That may be because the saddle is actually noticeably cushier than the same make/model saddles on my other bikes.

Speaking of saddles - I've also found that saddle tilt angle can make a significant difference in saddle comfort, and even in the overall feel of the bike. Just a variation in a 1 degree can make a difference.

[fourflys]

Originally Posted by Mark McM

Speaking of saddles - I've also found that saddle tilt angle can make a significant difference in saddle comfort, and even in the overall feel of the bike. Just a variation in a 1 degree can make a difference.

I'd 100% agree with this.. esp when you start talking about a not-flat saddle, at least for me..

[NHAero]

I will check saddle tilt forthwith!

[mhespenheide]

Do yourself a favor and pick up one of the Cannondale SAVE seatposts in 25.4mm and you'll be further impressed. When I had one on my Synapse, it was like gaining a tire size in dampening hits or subjective "noise" from the pavement.

I agree that the likely culprit here is the seatpost.

[Bob Ross]

Originally Posted by NHAero

the Supersix has a 20mm shorter chainstay and commensurately shorter wheelbase.

Huh...well, there goes that idea, I was all set to suggest the Cannondale had a longer wheelbase!

How about front-center, is that longer or shorter than the Bingham? Do you get toe overlap on either bike? Identical contact points don't necessarily mean that those points are equidistant from the wheels, just from each other; having your entire body farther fore or aft relative to the axles can definitely impact perceived harshness.

Also compare bottom bracket drop.

[prototoast]

There are so many things that go into making a bike "smooth," and it usually involves just the right amount of flex in the right places at the right time.

To take an extreme example, coasting down a bumpy gravel road, a full suspension mountain bike will feel much smoother than a road bike. But sprinting on smooth pavement, a road bike will feel much smoother than a mountain bike.

There are so many things that go into smoothness. Thinking about your Bingham and Cannondale, I think the fork on your Bingham is stiffer than the fork on your Cannondale, but I'd also guess the stiffness around the bottom bracket is higher on the Cannondale than the Bingham. Together, you're getting a bit more compliance at the front end over bumps, but the rear end feels more responsive to pedaling--both of which feel like different types of smoothness in your brain.

[NHAero]

Originally Posted by prototoast

Snip

There are so many things that go into smoothness. Thinking about your Bingham and Cannondale, I think the fork on your Bingham is stiffer than the fork on your Cannondale, but I'd also guess the stiffness around the bottom bracket is higher on the Cannondale than the Bingham. Together, you're getting a bit more compliance at the front end over bumps, but the rear end feels more responsive to pedaling--both of which feel like different types of smoothness in your brain.

I agree the front end is likely more compliant on the Supersix, the rim brake fork certainly appears to be much slighter than the disc fork on the Bingham, and the carbon bars may also matter. I may be confusing what feels like more compliance through the saddle with what happens at the front. Like I said, this may all be a figment of my imagination.

Neither bike needs any improvement - which is why the musings are idle. Together they have almost 60% of my 2024 miles, so that tells me something.

[dsjackson]

Yeah - for sure echoing sentiments here - but it is the seatpost and bar you’re feeling. Thin carbon vs fat aluminum. Nice tires and carbon bar and seatpost are the best way to make a harsh bike Cush.


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[cash05458]

still riding god forbid 23's...my ass seems to like the firmness...must be a generational thing I guess...

[nmrt]

Hah...I think it all depends how we not only define "smooth" but what we experience as "smooth". But i think you defined "smooth" as "plush".

Then again, different people will feel "plush" differently based on their butt-o-meter. I, for one, think that this iteration of the Cannondale S6 is "smooth" but man-o-man, it is not "plush" at all. On the contrary, it is one the harshest rides I have ever experienced EVEN on the velvety smooth Veloflex Annenberg tubular 25 mm tires.

One of the joys of cycling -- completely subjective on what defines "ride quality" -- what one feels transmitted through the handlebars to the hands and from the frame to the saddle to the butt/body.

[Likes2ridefar]

Originally Posted by fourflys

I'd 100% agree with this.. esp when you start talking about a not-flat saddle, at least for me..

Same, I couldn’t get comfortable on a bike over the summer and it turns out it was my saddle angle off by (tilted up more than normal) a very small amount. A level would be the only way to know. Exact same saddle model I’ve used for many years .

[Mark Davison]

You might want to refer to the following article on the sheldonbrown.com website: https://www.sheldonbrown.com/frame-materials.html

In particular the discussion of Stiffness and Ride Quality is worth reading.

The important distinction is that stiffness (or its opposite, complicance) is different than vibration dampening. Carbon fiber reinforced polymer laminates (CFRPL, jokingly pronounced “kah-ferpal”) in particular dampen vibration more than metal tubes, which can “ring,” which is what you experience when the vibration has a lot of energy in a band around a resonant frequency of the metal frame.

On any bike the most important components for dampening vibration from road surface roughness are the tires & the saddle.

You can further reduce vibration by introducing supension seatposts & stems. It is important to note that these involve by springs (for compliance) and dampers (for dissipating vibration energy into heat, and preventing undesired resonance.) Long carbon fiber seatposts can also serve as suspension.

[benb]

Originally Posted by Mark McM

I've been using the same make/model of saddle on my bikes for many years. But I've found that there can be differences between even the same make/model of saddle. Sometimes the padding is denser/less squishy on one unit compared to others or may be distributed a little bit differently, or the shell may flex more or differently on one unit compared to others.

I've got a 2015 Cervelo S5 aero road bike that I use for crit. racing. The frame is laterally/torsionally stiff, and has deep section tubes and stays. It uses a deep section aero seatpost. By "traditional" thought, this should be a harsh riding bike, but I actually find it quite comfortable. That may be because the saddle is actually noticeably cushier than the same make/model saddles on my other bikes.

Speaking of saddles - I've also found that saddle tilt angle can make a significant difference in saddle comfort, and even in the overall feel of the bike. Just a variation in a 1 degree can make a difference.

I am curious what saddle you're riding.

I definitely would believe what you're saying. But what I've seen is the saddle manufacturers are kind of impatient to change the design even when nothing is wrong with the original version.

They can't leave well enough alone and more often they deliberately change the design of the saddle without calling it a new model or do change the name slightly but get rid of the old version. So if you liked one after a while if you need another one you're kind of screwed and have to start over.

A bunch of my favorite saddles have gotten changed so much over the years that I couldn't necessarily even tell if they had variation as by the time I bought another one they had changed it anyway.

Fizik has called a lot of things "Arione" which don't necessarily feel anything like the original and if you liked the original plenty of the current ones might be unrideably different for you.

I rode the Flite a lot too and there was a period they changed that dramatically to the point it didn't work.

At least for both of these they have the "classic", "reissiue", whatever versions back now.