Veloflex wider tires

Discuss light weight issues concerning road bikes & parts.

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by Calnago

Hmmm... another “test”.... I only really concerned myself with the tubular version (27mm Ravens) which seem to be simply a Blackwall version of the Vlanderens, similar to the distinction between the 25mm Arrenberg and Roubaix. Same tires, just different colored sidewalls. So, in order to get a more “dynamic” ride, especially during accelleration and when swinging the bike left to right on climbs etc, the tester pumped up the pressure to 8bar, or 116psi!

So, he’s basically defeating the whole purpose of the wider fires and lower pressures... that being to reduce the dreaded “hysteresis” effect which most people are pretty vague on what it really is. Let’s just say for simplicity sake it’s the bouncing back and forth from the tire hitting small irregularities in the pavement. So, with wider tires and lower pressures the tire supposedly “rolls” with the flow so to speak as opposed to bouncing with the irregularities. Trouble is, fat tires at low pressures feel slow and I will say they are slower (gasp!), when run at the pressures they’re intended to be run at in comparison with smaller tires run at the pressures they’re intended to be run at, of course both scenarios being subject to rider weight etc. I have some Vlanderens (27mm tubulars) and a good pressure for me to run them at under my 200lbs is around 80psi. They are rough road tires. If I want good responsive road feel I’m choosing the 25mm Arrenbergs at about 100psi in the rear and 90psi in the front. Great comfort. Great feel. Good response and handling. I feel what the tester is doing by trying to emulate that feel (pumping them up to 116psi) is akin to creating a big hard beach ball effect and just brings back the hysteresis effect that is so “bad”. They’re both great tires but if you want to pump a fat tire up to the point where it feels as fast and responsive as the narrower tire, then why not just get the narrower tire and pump it to optimal pressure for your weight. Just food for thought.
Last edited by Calnago on Mon Jun 25, 2018 8:06 pm, edited 3 times in total.
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by cmoi

Indeed there was a mistake in the report, the inflate pressure was 7 bars (around 100psi) - to be corrected - which fit my optimal behavior. That being said you are correct with saying that the Raven are the black side color of the Vlandereen. But this type of tubulars are worth being considered for many uses:
1. Bad roads
2. disc brake rides (needs better road contact)
3. More comfortable and stable rides
I fully agree with your point, Arenberg 25mm are great and if I use to ride these tubulars most of the year , I am very happy to ride Raven during winter seasons. Safety with nice feeling, even during bad road conditions

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by Calnago

Yes, but even at 100psi, I would argue that you’re still creating a “hard” bouncy beach ball effect at the road surface with those tires, in comparison with appropriately pressurized tires at say, a 25mm width. I put “hard” in quotes because it’s going to feel “soft” to the rider simply because of the volume of air between you and the road surface (at some point you can’t even feel the road) but it is hard for tires of this volume. It essentially is bringing back the hysteresis effect at the road level that the whole fat tire trend was intended to avoid.
Also, on slick roads I don’t at all feel that a larger volume tire at higher pressures is even all that more safe, particularly if riding a little aggressively. It is much easier to slide out on road tires in a lean on smooth pavement with the increased surface area distributing the force, especially if the tire is pumped to pressures making it harder to conform to the road during leans. Becomes kind of like the saucer effect that kids use to slide down snow banks with. I recall as kids in the summer time, my dad had a little small 7.5hp outboard motor in a little tiny boat he’d throw on top of the car to go to the lake with. We would make a circle out of plywood, varnish it smooth, and voila... the po’ families waterski boat. But the surface area had to be big enough to skim over the surface of the water easily under such limited pulling power. With water skis you would have just sunk. Similar premise with the bicycle tires and two wheels. The water skis could provide extreme precise control while the saucer just skimmed the surface, but damn we had a lot of fun on that thing.
In my mind we’ve reached and surpassed the optimal width for road tires on a bicycle. Yet one of the first questions someone will ask these days about a new bicycle is “how much clearance does it have?” I guess the best response to that is “Well, how much do you need for what you’re doing?” I don’t think a blanket “bigger is better” is always the correct answer.
Last edited by Calnago on Mon Jun 25, 2018 8:49 pm, edited 1 time in total.
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by cmoi

I would recommend you to make an experimental plan on both 25 and 27mm
Again Arenberg 25mm are the best in class tubulars in term of performance for most ridders.
But did you ride disc brakes bikes ?
Urgency braking may become tricky with 25mm tubulars, whatever the ground surface. Therefore, wide tubulars are mostly recommended
100psi for dry roads and 85 psi on wet road for 75kg rider is a good value for me, below responsivness is not as good.
Ride a 100psi Raven and you will have improved comfort compared with a 120psi Arenberg, while keeping a good dynamic.
No hard bouncy beach ball, try it...
Optimal width of the tubulars, hum..., I am riding a TIME Scylon bike and the width of the tires perfectly match with the width of the frame.
I would say that tires width increase are going along with the frame width increase.
But I hate wide fat tires, and Veloflex is making possible wide tires with nice feeling ride.
For your information, I just tested Continental 25mm GP4000 tires which measures...27mm... are fat, hard and dead.
No comparison with the 27/28mm VELOFLEX.
Just test and adjust the pressure to you weight :-)

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by darnellrm

Silca has an excellent blog series on tire widths and pressures for any who haven't seen it:

It dispells at lot of the magical qualities attributed to wider tires with real testing = i.e. You can have faster or softer, but not both!

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by Kurets

How can anyone suggest running 100psi (7.3 bar) in a 27mm tyre? Thats will make the tyre very harsh riding. I personally run around 7 front and back with 23mm and 25mm respectively (tubular). And any notion that disc brakes require wider tyres is just complete bull.
I completely agree with Calnago here, 23/22 front and 24/25 rear is the sweetspot, all elsr is for bad roads only (unless you are spoon fed marketing speech).

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by nachetetm

I honestly do not know how all of you are riding still at those very high pressures. It is proven again and again that, other than in the super smooth surfaces, over a certain point, more pressure usually equals to MORE rolling resistance, and that dropping pressure, in REAL conditions (not on drum tests) barely affect rolling resistance. In many cases with rough surfaces rolling resistance it is even decreased together with the pressure drop. It maybe the case that you really ride on very smooth surfaces so all this do not apply to you, or you are just feeling you are riding faster with higher pressure when in fact you are just feeling more vibration.

The whole info is here (among other places): ... -impedance

Another thing I learn since I am using high thread count tires (the wrongly named open tubulars) is that handling is pretty much unaffected by how low the pressure is, only comfort increases (obviously with the limitation of having enough pressure to avoid pinch flats). This is completely opposite from my observation with vulcanized tires, that in my hands seem to have a quite narrow pressure range in which they work fine; get out of those limits and the handling is severely affected.

Again, are you completely sure you are not confusing "lack" of vibration with less sharp handling? Because another benefit of having wider tires is that braking and cornering should be improved with the right rim. Perhaps with tubulars is different, but these are my impressions with clinchers, better cornering and braking with wide tires on wide rims, and that seems to be in line with what people writes and thinks nowadays (including Josh Poertner) and I cannot stop wondering why my feelings are so different from some of yours.

Tu sum up, I have been waiting for 28c Veloflex clincher tires for a long time, and I can't wait to test them. Even waiting for the 30c or 32c version if they decide to do it. There is market for it, as Compass is constantly showing.

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by cmoi

100 psi is 6.9 bars.
I am 75kg, prefering fast and quick behavior of the bike rather than soft and comfortable rides.
I use to inflate 23mm @8bars (115psi), 25mm@7,5 bars (108psi) and 27mm @6,5-7bars (90-100psi).
This is personal convenience, I would understand riders prefering lower pressure.
With respect to disc brake, I had one year ago a rim brake bike and now since one year a disc brake bike, same model.
The power of the brake is higher no doubt. How do you manage to keep good road grip and adherence without a widder tire ?
Disc brake bike will allow you to adapt your way to brake, with better control and modulation. Then you use to shorten your braking distance and with this new type of braking you will need better ground contact. Otherwise there is no benefit of disc brake. Sometime, in case of urgency you brake as much as possible and then the limit factor is no more the braking power but the ground contact.
Thats real experience since more than one year, neither thinking nor theory.
Then, happy to have widder 27mm tires even, inflated between 6 and 7 bars (87-100psi) depending on road conditions.
Fully agree.
Indeed GP4000 25mm should be considered as 27mm wide tire on 19C rims !
Yes I inflate 28mm Veloflex tires between 6-7 bars (85 and 100 psi) mostly for sharp handling behavior, enjoying fast and dynamic rides.
One point that is overshadowed in the discussion is the inner tube type and dimensions for the tires.
I use to ride butyl inner tube, mostly because I was used to rim brake and latex tubes are forbidden.
The size and quality of the inner tube has major influence of the behavior and therefore affect the inflate pressure.
Compare a 25mm corsa with a 19-25mm and 25-32 inner tube and a 130gr and 80gr inner tube and you will feel major differences.
Thats why inflate pressure is nothing than universal, it is cyclist and material dependant.
But I can understand that most of cyclist will prefer widder Veloflex tires with lower pressure. Nevertheless, from my type of riding I found out that between 5-6 bars (72-85psi) the wheel was "pumping" while quick acceleration and cornering was not as accurate as with 6-7 bars (85-100psi). And this is also very nice for the coarse intermediate asphalt of my usual roads, with optimal pressure range 90-110 psi on your graph which fit my value !
But again, I do not want to give any mandatory value, try different pressure and make your own choice, Veloflex recommend between 5 and 8 bars (72-115psi)for the Corsa and Master (I prefer 6-7bars (85-100psi))
Last edited by cmoi on Tue Jun 26, 2018 6:33 am, edited 2 times in total.

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by RyanH

Contact patch significantly diminishes at those pressures, which negates a lot of the benefit of going wide.



I can't find another resource that has calculated contact patch area but I think it's possible the contact patch differences between a 23mm wide tire at 100psi is not much smaller than 27mm at 100psi and will feel significantly more agile.

Edited to add:
Found it, contact patch doesn't change with tire width if using the same pressure according to Stuart Baird in Performance Cycling:

"The omission is intentional, because the area of the contact patch does not depend on the width of the tire. Inflated to 90 psi and fitted to a bike under the same rider, a super-narrow 700C x 19 clincher would have the same contact patch area as a medium-width 700C x 25 or a 700C x 32 loaded touring tire. Only the shape of their contact patches would be different."

So, you may want to reevaluate as the idea you're gaining better braking power by running a larger tire should be incorrect.

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by romanmoser

Talk to us about rolling resistance
On regular roads

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by NiFTY

Cmoi on a road bike braking is mostly front wheel. Have you manage to lock up a front wheel on a bike? If not then you still had braking power in reserve with whatever width tyre you had.
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by Alexandrumarian

It should be fairly interesting to borrow an identical front wheel, dress one in 23 the other in 28 and do some repeated braking tests.

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by Marin

It should actually be fairly boring as there will be no difference. On my allroad bike, I run tires from 23 to 48mm and I definitely don't stop more than twice as fast on the wide ones. Neither do I corner faster.

Also, if you think a bigger contact patch means more grip, you're wrong.

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by Kurets

Any such tests would anyway result in pure confirmation bias.

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