dado5

I am looking for a new bike. I am a recreational cyclist, am currently riding a year 2000 Klein quantum race with 25mm tires. I am planning on getting a carbon, ultegra, disc road bike. Prob endurance variety and plan to run 28mm tires tubeless. I was thinking of a Roubaix or domane since they each have their own way of helping with smoothness. But I imagine 28mm tubeless tires would make more of a difference than either of those. IF that's the case then I could look at any brand bike. Any thoughts?

WhyFi

I have a Domane with 30mm tires and it's far, far better with bumps and cracks than my gravel bike with 40mm tires. People that have never ridden one like to **** all over IsoSpeed, but it works and it works well.

bbbean 

The short answer is yes. The longer answer is that all the major (and most of the minor) bike makers have excellent offerings in that price range, with each bike having its own unique combination of features. Go ride a half dozen or more bikes to narrow down the options, then buy from the shop that offers the best service and price.

BB

Spoonrobot 

IME frame compliance is more important than tires. They're both important, but frame and subsequent fork interaction vastly underrated. Stay away from oversized steerers, gravel bikes and bikes that don't have a nominal weight as part of their marketing/geometry if you're interested in a well riding frame for average weight riders.

Maelochs

I'd imagine any endurance-geometry frame is going to maximize suppleness, because that best serves the intended usage. Even racier frames will probably have some give in the seat stays, while being really stiff at the bottom brackets. Nowadays i think only aero frames make no concessions to comfort.

I second @bbbean----ride a bunch and see what resonates.

JohnJ80

This episode of the Marginal Gains podcast has a Q&A with Josh Poertner CEO of Silca who addresses this very topic. Turns out that the tires size and pressure makes about an order of magnitude more of a difference than the frame compliance. I found that pretty interesting because that's exactly the experience I found in fooling with a bike I had that was uncomfortable to ride. I switched out the handlebars, fork, seat post as I upgraded the bike and kept track of what was happening to ride quality. Then I swapped out the tires from 23c to 30c and was blown away - like a whole new bike that was a lot more fun to ride and ... which really surprised me ... as fast or faster than with the 23c tires. IIRC, I think he used the Spec Roubaix as an example - the frame compliance is about one tenth or less the effect that the tire had when properly inflated. In short, the tire effects completely swamp out the frame effects.

Poertner also gets into tire inflation and all the testing he did while at Zipp and then continued at Silca. He gives some rules of thumb about getting to the right tire pressure - it's better to be slightly low (say 5psi) than high by the same amount. Riders tend to confuse the high frequency vibration they often feel through the frame as "fast" when it turns out smooth or the absence of that vibration is actually fast. So pump them up hard and ride a loop, letting out 5psi each loop until it feels "smooth" rather than "fast." The reality, according to Poertner is that smooth actually is fast and fast, as we would claim by road feel is actually slow.

Worth listening to. Very interesting pod cast.

RChung

I like that podcast a lot and Josh is both smart and fun to talk with. The "springs in series" model makes good predictions, so we have a lot of faith in it and, as Josh says, tire compliance dominates by about an order of magnitude the kinds of compliance you see in frames. The only exception would be frames/forks/headsets which include a suspension since you can add a spring that has compliance in the range of tires. But you have to be careful to design it right for road use -- the kinds of suspension you find on MTBs doesn't work as well for road bikes. Josh should get someone from Specialized to come onto the podcast to talk about their road shock system.

noodle soup

The results of a tire size increase of over 25% was surprising to you?

Seattle Forrest

I had a really harsh riding bike back in the day, on 28s that I'd pump up until they were rock hard, because I didn't know any better. But put the right amount of site in them and they're pillows.

Darth Lefty 

WhyFi

This thread was specifically asking about two bikes that have significantly more than usual compliance built in. While I can't speak to the Spec, the Domane certainly has much more compliance than properly inflated 30mm tires.

FlashBazbo

I have ridden IsoSpeed. I own a bike with IsoSpeed. I have ridden IsoSpeed for over 750 miles on all kinds of surfaces. I HATE IsoSpeed and believe sincerely that it's a blot on cycling. If I wanted my bike to handle like a hobby horse, I would buy a . . . hobby horse.

But they make more than one kind of bike because there is more than one kind of bike rider. To each his own. You love it. I hate it with a burning passion. Both are valid opinions -- but obviously different. Everyone should try extensively before they buy.

FlashBazbo

I think it's important to test ride as much as you can, in order to determine the right balance for you. One person's "suppleness" is another person's "excessive flex." One person wants a stiff bike, for efficiency's sake, that takes advantage of the shock absorbing qualities of the tires to tame the bumps. Another doesn't mind losing pedaling efficiency so long as the ride is smooth -- and full suspension would be perfect for them. I would advise testing the options to see which balance is right for you.

DrIsotope

/end thread

Plenty of people out there on CAADs, and I'm sure they enjoy them. I test rode one and it was the worst feeling bicycle I've ever been on. Absolutely awful.

So the wholly subjective stand of "this brand's frame with flexy-****ers is better than this brand's frame with flexy-****ers" is like saying one flavor of potato chip is better than another.

I personally wouldn't buy a Spesh because I don't like them as a company, and there are plenty of other brands out there that will give you more bike for the money.

jlaw

If your Klein is aluminum (?) and you are riding 25mm tires then almost any other bike is going to be 'smoother'. (only half-joking!). I beat myself up on a 1999 Cannondale with 23mm tires until I bought a Roubaix in 2007. What a difference in comfort and enjoyment! The carbon frame was the reason. I have since moved on to other options - most recently mid-80's steel sport/tour frames with 32+mm tires - even better than my Roubaix.

There are many possibilities to get what you want - and as others have said, test ride a bunch of different bikes and bike styles because much has changed since 2000 - mostly for the better.

Good luck and check back once you have your new ride - with pictures.

WhyFi

To make the IsoSpeed bounce, I have to intentionally pedal in a choppy manner with 30mm tires. How is it that you're bouncing around so much? And I assume that this is with some large (40mm+) tires on your Checkpoint?

FlashBazbo

No, I've just always liked a stiff, efficient frameset. I don't like frame flex and I like to take long climbs while seated, bracing off the saddle. The IsoSpeed introduces intentional flex that especially shows itself when you're trying to put power down while seated. You don't mind the flex -- you may not even feel the flex. I do. We're just different cyclists. There's nothing wrong with that.

But for the record . . . the tires are 35mm. (Was this a trick question? With a Di2 front derailleur, the Checkpoint won't mount 40mm tires. They won't even turn.)

RChung

Suspension systems can certainly have more compliance -- the question is really about how that compliance is distributed, and the "hysteresis" in the system.

I think this video shows why tire compliance matters more than non-suspended frame compliance. Note especially what happens to the tire around 1:38 and the wheel losing tension at around 2:08.

WhyFi

I'm not a small guy and can hit decent numbers seated - I *should* be among the worst case scenario, but to induce bounce requires a sloppy effort that would leave me bouncing on a completely rigid frame.

And no, not a trick question - genuinely curious. My Domane came stock with 35s. The first ride on it left me a little concerned, wondering if there was indeed too much bounce. Those concerns were completely erased when the snow cleared and I put on 30s (I haven't put the 35s back on since, FTR).

WhyFi

Oh, I'm not arguing against tire compliance - I'm a believer. I won't buy another frame that can't clear at least 28s (but preferably 30mm).

JohnJ80

A *big* part of the compliance for any bike is in the "properly inflated" tire comment. According to the podcast, most people do not properly inflate their tires and do, in fact, over inflate them considerably. I'd bet pretty heavily that that is a bigger factor than the Domane elastomers in the frame - at least it did on my daughter's Domane.

J.

RChung

Right, you don't want your tires to be so hard that the elastomers are the most compliant part of the suspension. That's part of the "springs in series" issue.

JohnJ80

Yup. Exactly. If the tires are too hard, then the elastomer becomes the only spring. And that's the point - most people tires are pumped up are far too much. I think it's fair to say that in any of the road bikes with built in compliance elastomers that the tires represent a much bigger spring than does the elastomer. As the tire size goes up, I would have to believe (but don't know) that goes up in a nonlinear way too. For example, a 40c tire is much more spring than a 20c tire by more than a factor of 2.

Just as a figure of merit, on the 30C tires I was riding, I had been pumping them up to their max pressure of 85psi. The ride was still much better than on the 25c tires I had been riding. I fiddled with tire pressure, and discovered that the ride was super plush at around 60psi and the bike was faster. That's a significant change. So while I haven't fully experimented with Poertner's algorithm for tire pressure, I believe he's probably right.

J.

JohnJ80

That it was better, no. That was as dramatically improved as it was, yes. The bike went from very uncomfortable, to the point where I hardly rode it, to plush and almost my favorite ride. I did not expect the different to be that profound.

RChung

Josh has some pretty cool stories about testing tire pressure and rolling resistance for Paris-Roubaix. To make sure they hit the right resonance frequency they had to test over the Arenberg at full speed. As an aside, do you recall the win streak that the Rock Shox Ruby road fork had at Paris-Roubaix? Ever wonder why the peloton stopped using them? https://www.bikehugger.com/posts/roc...y-years-later/