anybody go to 28mm tires, and NOT like the switch?

Discuss light weight issues concerning road bikes & parts.
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Calnago
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by Calnago

The thing about inflating high volume tires to high pressures in order to relieve the sluggishness is that you’re basically reintroducing the very thing that higher volume/lower pressure tires were intended to lessen... that being the hysteresis, or “bouncy” effect. I ran some 27mm Veloflex Vlanderens (tubular) for awhile to experiment. Experimented with pressures between 70 and 90psi. I thought ~80psi was a pretty good pressure for these tires on pavement supporting my 200+lbs. They were comfy for sure. But they also felt, and were, slower and slower handling. Just try riding up a long climb with your fat tires at the lowest pressure they can handle versus riding the same climb with narrower tires at the appropriate higher pressure. See which is easier, and faster. Tubulars are generally much more supple than clinchers (although the Specialized Turbo Cottons are nice) and far more supple than tubeless. and you can run smaller tires at lower pressure without getting the bouncy effect with sharper handling. 24-26mm tubulars are my tires of choice. I reserve the 32mm clincher tires for my fully loaded touring bike, 19mm internal width rims, inflated to about 60psi. That has supported my own weight plus 95lbs (bike and gear) through the Swiss Alps, gravel roads and streams of New Zealand, and many other places. I tried 37’s on that bike. Too big, the 32’s just were much nicer for the majority of conditions. This was all before all the hype about fat tires etc., just my own experimenting with what works best with which equipment and conditions. But on my pure road bikes, I really enjoy the feel and handling of nice tubulars in the 24-26mm range. 24mm for my standard width rims and 25-26mm (Veloflex 25mm and Specialized 26mm) for rims such as the Bora tubulars.
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pdlpsher1
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by pdlpsher1

ms6073 wrote:
pdlpsher1 wrote:
Thu Jun 20, 2019 4:56 pm
I weigh 61kg.
Back door brag duly noted. :beerchug:
Hardly a brag. There no point in giving tire pressure data without also giving rider weight.

I would have also given my tandem riding weight too but my wife’s weight is a secret that I don’t even know Image


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by Weenie


AJS914
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by AJS914

One thing about switching to 28s is having the tire somewhat optimized with your rim width. I switched to 25mm GP4000s one time (a 26-27mm tire) on a 14c rim and they sucked. They felt floppy and imprecise so I switched back to the 23s.

Now that I have wider rims, I ride those same 25mm GP4000s and they feel great. We have rough roads where I live and I wish I could fit wider tires on my bike but I can't. If I could fit 28mm tires I'd want them on even wider rims to avoid the lightbulb shape. I'd run them at 60psi.

zefs
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by zefs

25c vs 28c tires reminds me of the spinal tap reference, "it's one louder" or "they are one comfier".

Lugan
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by Lugan

I weigh 81 kg and am a 51 year old ex-road and current CX racer in the Seattle area where roads are often rough and climbs are often steep. My newest bike since last winter is a Mosaic RT1 Disc that essentially can take very wide road tires. Knowing this, as an experiment I spec'd the build with Enve 3.4 Disc (the original 21mm internal width version) and Schwalbe Pro One 28c, run tubeless at 55psi front and 70 psi rear. They are a revelation for me, and I am a crusty old ex-road racer who once would only ride tubulars for fast rides and races. The numbers tell me that these wide tires (combined with a bike that is neither aero nor particularly light) are at least as fast as everything else I ride now that I have air pressure dialed in. They also feel better in every way, and in particular they're several steps more secure/stable and therefore faster going downhill. Riding these makes me think I should sell my Argon 18 Nitrogen Pro with rim brakes that only takes 26mm tires maximum for a bike like the new Parlee RZ7 disc, and just put Enve 4.5 ARs on it with the same 28c Schwalbes - probably 32mm actual width with those wheels. I'll bet the numbers will show such a bike to be as fast or faster than any other clincher or tubular setup I have in my arsenal, but will ride much more nicely.
Last edited by Lugan on Thu Jun 20, 2019 9:49 pm, edited 1 time in total.

spdntrxi
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by spdntrxi

Lugan wrote:
Thu Jun 20, 2019 7:35 pm
snip...t put Enve 4.5 ARs on it with the same 28c Schwalbes - probably 32mm actual width with those wheels. I'll bet the numbers will show such a bike to be as fast or faster than any other clincher or tubular setup I have in my arsenal, but will ride much more nicely.
Correct.. that's what mine measure out to be. I have 28mm GP5000TL on my Roval CLX50's and they are 29.4mm now, Not many rides on the 5000's but they are not a comfy as the schwalbe's so far. I need to try to PR this climb this weekend and compare times..

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ms6073
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by ms6073

Calnago wrote:
Thu Jun 20, 2019 5:19 pm
The thing about inflating high volume tires to high pressures in order to relieve the sluggishness is that you’re basically reintroducing the very thing that higher volume/lower pressure tires were intended to lessen... that being the hysteresis, or “bouncy” effect.
I thorry. :beerchug:
I will stop over-inflating.
Michael - The Anaerobic Threshold is neither...

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pdlpsher1
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by pdlpsher1

Tire width needs is as indivual as tire pressure. It really depends on a lot of things, but primarily the road surface quality. I live in a county with the crappiest roads. Not pothole crappy but chip seal crappy. They chip seal all of the roads outside city limits, roads that I ride on. There's no doubt a wider tire will allow you to run lower pressures without the risk of pinch flatting. And with a power meter I just don't see the wider tires at lower pressures are slower than narrow tires. Those riders who ride on nicer roads can get away with much narrower tires than me.

zefs
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by zefs

Do a sprint or try to push power uphill with lower pressures (on any tire width). But since tire pressure can be adjusted you can have no power loss when you want to and comfort when you need to. So if you are going to ride a mountain you can start at high psi to minimize power loss and then drop it for the descend.

What would be interesting is a test between a 25c tire that measures 28mm on a rim vs a 28c tire that measures 28mm.
Which one will be more comfortable?

guyc
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by guyc

Who on earth is dropping tyres pressures for descents?

zefs
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by zefs

I am talking about wider tires and the fact that they are slower when going uphill, meaning you can inflate them higher than you normally would if you are going to do a long climb and don't want to loose on rolling resistance and then drop the pressure back to normal for the descend and/or rest of the ride. So if I was using 60psi on wider tires/flat roads I'd go to 80psi for the climb and drop it back to 60psi at the top (just an option).

But it's also down to the tire itself, the GP5K which is a fast rolling tire will have less of an impact when run on lower pressures compared to a slow tire.
Last edited by zefs on Fri Jun 21, 2019 8:58 am, edited 1 time in total.

Alexandrumarian
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by Alexandrumarian

Calnago wrote:
Thu Jun 20, 2019 5:19 pm
The thing about inflating high volume tires to high pressures in order to relieve the sluggishness is that you’re basically reintroducing the very thing that higher volume/lower pressure tires were intended to lessen... that being the hysteresis, or “bouncy” effect. I ran some 27mm Veloflex Vlanderens (tubular) for awhile to experiment. Experimented with pressures between 70 and 90psi. I thought ~80psi was a pretty good pressure for these tires on pavement supporting my 200+lbs. They were comfy for sure.
At 210 i settled on 95/90 with Vlaanderens. I tried 85/80 and they did feel slow and squished. My favourite is 100/95 with Arenbergs. As long as the road is decent, they feel faster and comfy enough. What I like the most is the bike feels easier to lean in corners. I guess we are the only two freaks left that prefer narrower to wider.

Did you use the Sworks enough to form an opinion? I don't think I'll get the Vlaanderen again especially since now they are 28, but those 26 could be nice.

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Calnago
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by Calnago

@Alexandrumarian: At about the same weight, we seem to have settled on similar preferences for the Arrenbergs. 100psi rear and 90psi front for me. And that was arrived at through a lot of trial and error and real riding in real conditions. Really good feel for any of the roads I ride on. Tires roll smoothly over bumps and “conform” to imperfections in the road. With the larger Vlanderens, you seem to be trying to duplicate that feel with higher pressures, yet while you’re making the fatter tires harder, you’re also reintroducing the very thing fatter tires were intended to alleviate... the bouncing over road imperfections (hysteresis) versus just rolling over smoothly and conforming to those imperfections. 95R/90Fpsi is a lot for those tires, even at our weight. So it’s funny when you see guys putting as fat as tires in their road bikes as they can fit then pumping them up hard to make them “fast”. I gave away my Vlanderens as they sat on some nice wheels which weren’t getting any use. But if I was using the Vlanderens I’d be using them at lower pressures.
The 26mm S-Works Turbo is a very nice tubular. At first I thought it was really the same effective size as the 25mm Arrenberg, but it is indeed a millimeter larger. With its slick center strip it just seems more of a “road” tire than the Vlanderen. I like them but I don’t know what the durability will be like. Seems fine though. And I know I’d like the 24mm version on my standard rims. That new Veloflex tubular looks interesting as well.
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Mr.Gib
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by Mr.Gib

I keep reading "feels" slow and sluggish. Isn't "feel" what led to the belief that skinny hard tires were faster? If it aint proper data than it aint worth much.

And whether the road is pointing up or down will make no difference to rolling resistance (speed might however). The real issue remains the smoothness of the surface. If you feel the bumpiness of the road remember that you are creating that bumpiness with your energy. If you feel road buzz (just smaller bumps) you are creating that road buzz with your energy. The question of whether the smoother (faster) ride of low pressures offsets the increase in hysteresis from the sidewall folding leads to my next point: it may very well be that the suppleness of the tire has a lot to do with whether a tire performs well at lower pressures. A stiff sidewall just won't be as efficient and folding and unfolding as a supple sidewall. Vulcanized type tires which are most common will not perform as well as supple cotton tires.

As for handling, if the contact patch is bigger, then of course there will be more friction when turning the handlebars so climbing out of the saddle will feel different. But riding seated, and normal cornering is fine, if somewhat dampened.

The undeniable upside beyond lower rolling resistance on rougher surfaces, is better traction in all situations. Descending, cornering, and braking with bigger softer tires is a revelation for many. A major safety advantage and well worth the downsides (if any).
wheelsONfire wrote: When we ride disc brakes the whole deal of braking is just like a leaving a fart. It happens and then it's over. Nothing planned and nothing to get nervous for.

Alexandrumarian
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by Alexandrumarian

I tried the 27 tubs specifically after falling during a descent. But it was on sand and in hindsight nothing would have saved me except maybe a mtb. Anyway, i can't say they improved my descending but i also did not go soft enough. Hard time getting used to that flat tire feel.

by Weenie


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