Wide Rims, Big Tires, Low Pressures

[Mr.Gib]

What about trying a more compliant frame? I’d think 25c tires on wise rims at -60psi should be as good as you could ask for if they’re supple tires.

Frame compliance is a fascinating issue. My initial thought is that once tire pressure gets down into the 60's psi, frame compliance becomes irrelevant. But, perhaps soft tires are only good at cancelling out certain frequencies and amplitudes of vibration, and it is possible to have a complimentary frame that deals with vibrations that the tires do not. Unfortunately I am aware of no data that would help inform me in this regard.

As it happens the bike I travel with has a lot of 27'2 seat post showing and a fairly compliant fork - a fairly comfortable ride. The rest of it is huge carbon tubes, light and stiff. I do wonder however about bikes like the Bianchi Infinito and Pinarello K10 and K10-S.

[spartacus]

What about trying a more compliant frame? I’d think 25c tires on wise rims at -60psi should be as good as you could ask for if they’re supple tires.

Frame compliance is a fascinating issue. My initial thought is that once tire pressure gets down into the 60's psi, frame compliance becomes irrelevant. But, perhaps soft tires are only good at cancelling out certain frequencies and amplitudes of vibration, and it is possible to have a complimentary frame that deals with vibrations that the tires do not. Unfortunately I am aware of no data that would help inform me in this regard.

As it happens the bike I travel with has a lot of 27'2 seat post showing and a fairly compliant fork - a fairly comfortable ride. The rest of it is huge carbon tubes, light and stiff. I do wonder however about bikes like the Bianchi Infinito and Pinarello K10 and K10-S.

Even at 60PSI the tire can only deflect so much, I think the frame compliance makes a big difference especially in how much shock gets transferred to the feet. I have a tetra-pro which some might consider too flexy by modern standards, but the shock absorbing feel of the frame is immediately noticeable compared to stiffer frames.

[Mr.Gib]

I run 28c tubeless tires on 25mm int width rims, which make it to 31.8mm effective tire width at 50psi. I'm 73kg. All high frequency vibrations are very muted with this setup but still have plenty of feel. High speed descend no problem. Very planted.

The wheelset I have is tubelss ready (Mavic Allroad) and I have some good 28 mm tubeless tires - Mavic UST. But I think I'd rather run the Compass or Corsa G's with latex tubes. Performance is as good or better and if I do happen to cut a tire it is less of a hassle. Simple and easy becomes a huge asset when doing big days in the mountains.

I am a touch heavier then you 77 kg and I find 65 psi is the sweetspot with the Corsa G's. Same with the tubeless set-up, maybe a touch softer.

[Mr.Gib]

What about trying a more compliant frame? I’d think 25c tires on wise rims at -60psi should be as good as you could ask for if they’re supple tires.

Frame compliance is a fascinating issue. My initial thought is that once tire pressure gets down into the 60's psi, frame compliance becomes irrelevant. But, perhaps soft tires are only good at cancelling out certain frequencies and amplitudes of vibration, and it is possible to have a complimentary frame that deals with vibrations that the tires do not. Unfortunately I am aware of no data that would help inform me in this regard.

As it happens the bike I travel with has a lot of 27'2 seat post showing and a fairly compliant fork - a fairly comfortable ride. The rest of it is huge carbon tubes, light and stiff. I do wonder however about bikes like the Bianchi Infinito and Pinarello K10 and K10-S.

Even at 60PSI the tire can only deflect so much, I think the frame compliance makes a big difference especially in how much shock gets transferred to the feet. I have a tetra-pro which some might consider too flexy by modern standards, but the shock absorbing feel of the frame is immediately noticeable compared to stiffer frames.

I think it goes beyond stiffness. The nature of the carbon fibre, resign, layup, the geometry, all could conceivably have an impact on the shock absorption properties of a frame. I notice my Colnago Extreme Power is really good at dealing with certain vibrations. Despite smaller tires (25mm) at relatively higher pressures, it feels very smooth on rough chipseal. It is easier on my hands and feet than my Parlee but the Parlee is easier on my ass.

[grooveninja]

Does Compass have any other tubeless other than the 700C x 35 Bon Jon Pass?

[NickJHP]

Does Compass have any other tubeless other than the 700C x 35 Bon Jon Pass?

Yeah, they also have tubeless in 700x38, 700x44, 700x55. I've used their 700x35 and 700x38 (both setup as tubeless) on my Open UPPER. If I want bigger than that then I swap to 650b wheels running their 650bx48 Switchback Hill (also tubeless).

[Marin]

Yes, IIRC all their tires over 35mm are now tubeless.

[grooveninja]

Sorry, I should have clarified, I'm looking for something tubeless for my road bike. I can barely squeak in Sector 32's into by frame, so I'm looking for a faster, more supple tubless tire in 28 or maybe a 32. These will be going on Enve 4.5 AR SES, so they need to be tubeless. Sectors are my go to training tire and have proven quite bomber, just looking for something more comfortable.

[mpulsiv]

Schwalbe Pro One recently released 30mm. These run ~2mm wider. www.merlincycles.com/en-us/schwalbe-pro ... 89170.html

[Mr.Gib]

Schwalbe Pro One recently released 30mm. These run ~2mm wider. www.merlincycles.com/en-us/schwalbe-pro ... 89170.html

I thought the Pro One was good tire though I had heard some who thought the wet traction was poor. I found no such issue. My issue was that it cut up very easily and I was constantly digging little flakes of glass or rock out of the tread.

My particular application requires smoothest ride and high reliability. For this reason I am abandoning the Compass Extralights and sticking with Vittoria Corsa's. Wish they came in 30 mm as I have a room for a bit more then 28mm.

The Corsa's have surprised me with their resistance to cuts. Where I live I see lots of little cuts in most decent tires over time. The Corsa's for whatever reason do not suffer from this problem. Perhaps it is the combination of the Corsa tread material and the particular nature of the debris where I do most of my riding.

[alcatraz]

I am seeking the smoothest, most vibration free ride for a pure road application. I have nerve damage in a toe and road buzz leads to severe pain toward the end of longer rides. A pebbly surface like rough chipseal is a killer for me, even with GP 4000 25mm at 80 psi on Hed Belgiums (17.5 mm internal).

I have some rim brake Mavic Allroad Elite (22mm internal) wheels and my plan was to run Mavic Yksion Pro UST 28 mm tubeless - the bike doesn't have clearance for anything bigger. As it is this will measure over 30mm.

The question is how low can I set the pressure at my weight of 170 pounds (77 kg). What are people getting away with - can I run 60 psi? Wondering about control when descending.

And also is the tubeless approach the best solution? What about a super supple tire like Compass with a latex tube?

How about getting a pair of shoes that are comfortable with thick insoles. Then perhaps do a little cut in the insole to give your toe some room. Ideally the shoes have a separate strap for the toe area that you can set a bit more loose and add tension to the other straps.

[fa63]

The question is how low can I set the pressure at my weight of 170 pounds (77 kg). What are people getting away with - can I run 60 psi? Wondering about control when descending.

For a 22c inner width rim, the Mavic app recommends ~60psi for 28mm tubeless tires for a 170lbs rider (assuming a 20lbs bike weight).

[Mr.Gib]

How about getting a pair of shoes that are comfortable with thick insoles. Then perhaps do a little cut in the insole to give your toe some room. Ideally the shoes have a separate strap for the toe area that you can set a bit more loose and add tension to the other straps.

Thanks alcatraz but I am all over the shoe thing. Using SWorks 7 with a Dr. Scholl's "air pillow" insole. A very inexpensive item that really takes some sting out of rough surfaces. The SWorks 7's are fantastic - very generous and comfortable in the forefoot while still holding the foot like a custom fitted ski boot.

The question is how low can I set the pressure at my weight of 170 pounds (77 kg). What are people getting away with - can I run 60 psi? Wondering about control when descending.

For a 22c inner width rim, the Mavic app recommends ~60psi for 28mm tubeless tires for a 170lbs rider (assuming a 20lbs bike weight).

Good info. Interestingly that is about the number I arrived at by trial and error. But I won't use tubeless tires. The Mavic Yksion UST are very good but not as good as Vittoria Corsa's with a latex inner tube. The Vittoria is fatter by a millimeter or two and gives a more supple ride. I had also heard the those Mavics can get cut up. If they are anything like Schwalbe Pro One in that regard then no thanks.

The roads in the mountains are beautifully free of glass and debris so the Mavics might see duty on a regular mountain adventure, just not for the Cent Cols Challenge.

[Lugan]

I have two data points to share about my wider road tubeless experience:

First, I am in my second winter of Seattle area riding in lots of rain on Schwalbe G One Speed 30c tires on Boyd Altamont Ceramic rims with 19.7 mm inside width. They are tubeless and are 31.7mm wide. I weight 180#/82kg and after much experimentation generally run these tires at 53 psi front and 67 psi rear. This pressure produces a ride that is plush with handling that is still direct and solid (no sideways squishy feeling in corners). The tires have been surpiringly durable, with just one super sharp steel staple penetrating the casing but being sealed quickly and reliably by the Orange Endurance sealant. The rubber is grippy on cold wet roads, but still resists cuts from glass and granite gravel better than average.

Second, I have a relatively new bike with Enve 3.4 disc with 21mm inside width and Schwalbe Pro One 28c tires. These too are set up tubless and measure 30.2 mm at 56 psi front and 70 psi rear pressure. After a few rides while the weather was still nice, my initial impressions of ride quality and handling are of perfection. Time will tell about reliability and ability to seal punctures. I definitely ride this and all tubeless bikes I own with a Dynaplug kit in my pocket, but have still never needed to use it.

[nachetetm]

Schwalbe Pro One recently released 30mm. These run ~2mm wider. www.merlincycles.com/en-us/schwalbe-pro ... 89170.html

I thought the Pro One was good tire though I had heard some who thought the wet traction was poor. I found no such issue. My issue was that it cut up very easily and I was constantly digging little flakes of glass or rock out of the tread.

My particular application requires smoothest ride and high reliability. For this reason I am abandoning the Compass Extralights and sticking with Vittoria Corsa's. Wish they came in 30 mm as I have a room for a bit more then 28mm.

The Corsa's have surprised me with their resistance to cuts. Where I live I see lots of little cuts in most decent tires over time. The Corsa's for whatever reason do not suffer from this problem. Perhaps it is the combination of the Corsa tread material and the particular nature of the debris where I do most of my riding.

Vittoria Corsa tubeless are starting to appear on some online stores. Corsa controls go up to 30c width; it could be what you are looking for.

I think my next combo will be Corsa TLR 28c front, Corsa Control TLR 30c rear. A bit more comfort, resistance and durability in the rear will probably be the perfect combination.