Wide Rims, Big Tires, Low Pressures

Everything about building wheels, glueing tubs, etc.
Mr.Gib
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by Mr.Gib

spartacus wrote:
Sun Nov 04, 2018 4:18 am
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.
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.

by Weenie


spartacus
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Joined: Mon Apr 04, 2011 6:53 pm

by spartacus

Mr.Gib wrote:
Mon Nov 05, 2018 6:57 am
spartacus wrote:
Sun Nov 04, 2018 4:18 am
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
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by Mr.Gib

jlok wrote:
Sun Nov 04, 2018 4:59 am
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.
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.

Mr.Gib
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Location: eh?

by Mr.Gib

spartacus wrote:
Mon Nov 05, 2018 7:07 am
Mr.Gib wrote:
Mon Nov 05, 2018 6:57 am
spartacus wrote:
Sun Nov 04, 2018 4:18 am
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. :noidea:
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.

grooveninja
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Joined: Fri Dec 14, 2018 3:33 am

by grooveninja

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

NickJHP
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Location: Canberra, Australia

by NickJHP

grooveninja wrote:
Fri Dec 14, 2018 4:24 am
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
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Location: Vienna Austria

by Marin

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

grooveninja
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Joined: Fri Dec 14, 2018 3:33 am

by 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.

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mpulsiv
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by mpulsiv

Schwalbe Pro One recently released 30mm. These run ~2mm wider. www.merlincycles.com/en-us/schwalbe-pro ... 89170.html
Racing is a three-dimensional high-speed chess game, involving hundreds of pieces on the board.

:arrow: CBA = Chronic Bike Addiction
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Mr.Gib
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by Mr.Gib

mpulsiv wrote:
Sat Dec 15, 2018 6:54 pm
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.
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.

alcatraz
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by alcatraz

Mr.Gib wrote:
Fri Aug 31, 2018 3:54 pm
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.

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fa63
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by fa63

Mr.Gib wrote: 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
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by Mr.Gib

alcatraz wrote:
Tue Dec 18, 2018 12:03 am
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.
fa63 wrote:
Tue Dec 18, 2018 12:16 am
Mr.Gib wrote: 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.
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.

Mr.Gib
Posts: 3236
Joined: Fri Mar 18, 2005 4:12 pm
Location: eh?

by Mr.Gib

dbl post.
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.

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