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Why go tubeless?

19K views 126 replies 43 participants last post by  desertred 
#1 ·
I'm doing some upgrades to my bike, and I'm looking my options for wheels. I'm to the point know where I'm looking at tube and tubeless rims. What would be the main reason for going tubeless?

I'm sure it's a simple answer, but this noob needs some help.
 
#25 ·
The thing that put me over the top to convert to tubeless was getting a flat in a race that tubeless would have prevented. That's 95% of the reason I switched. In switching, I recognized the benefits of running a lower pressure than possible with tubes. The efficiency and performance gain was minimal.

You will likely not get a noticeable performance gain from losing the .25 lbs you will typically get from switching to tubeless. If you are buying a new set of wheels, you're looking at $750+ all in for anything that will give a noticeable gain. Is it worth it?

How much faster do you believe a set of wheels and tubeless tires will enable you to be? 1 minute per 10 miles? 2 minutes per 10 miles? 5 minutes per 10 miles?

You'd be amazed at how little gain it actually gets you. If you're racing, then it matters. If you're not, then it doesn't.
 
#27 ·
Increased traction doesn't necessarily mean increased rolling resistance. Traction stops the tire from slipping, but rolling is a different thing.

When going over irregularities, a tire without a tube will conform to the changes more easily, so it's more noticeable than on hard and smooth surface.

006_007, my observation could be placebo, because if the effect was as big as I perceive, it should be easily replicated in an empirical test. However, I think if you rolled as far with a tubeless setup - which is lighter and thus has less freewheeling effect - you already witnessed a lower rolling resistance. (Whether this can be noticed when riding is a different thing entirely.)
 
#28 ·
Traction and rolling resistance are different, though not exclusive. A smooth tire at 60 psi will roll better and have less perceived "resistance" than a smooth tire at 30 psi. Add in an actual tread pattern, trail surface irregularities, and fluctuations in rider weight and strange things start to happen. A softer tire will have more rolling resistance, since there is more tire material in contact with the ground. This will occur with or without tubes. You will also gain traction, as there is a larger contact patch. However, a different tread pattern may offer more traction at a given psi without impacting rolling resistance.

Hence a difference between 2" tires and 2.3" tires

I looked into tire mechanics a while back, and you would not believe how much science and engineering is behind upper-end tread patterns...they are not just the marketing department saying "looks cool to me"...there's work put into the design.
 
#29 · (Edited)
Karidne, I spent about $50 going tubeless. You can subtract from that $10 because otherwise I would have had to buy a spare 29" tube. The difference in how it rides is small. If it were just a matter of weight savings, even on the wheels, is it worth $50? For recreational riding, no. For racing or if you just enjoy going fast, probably. I did one race last year for bangs, enjoyed it, and plan to do three this summer. Seeing you are more into racing than I am, depending on your financial sitution, it would probably be a good thing for you. As things go, $50 isn't a huge amount of money to spend in this sport.

That's assuming you can do it for $50 on your bike. I don't know anything about Specialized or your bike other than that they are very popular around here:)

One thing, though. If you go tubeless, you don't want to have to rely on the LBS to maintain your setup. You need to know how to mount tubeless yourself. So do the conversion yourself. It isn't difficult. Getting the bead to seat enough to hold air using a hand pump is a bit of a black art at first, but not difficult after you do it once. I keep a Schrader adapter in my toolbox so I can use a compressor if I ever need to or am just lazy.

As for new wheels, I am a relative noob, but let me share this. My old bike is a steel '98 Schwinn Mesa weighing in at around 30 lbs. I brought it at a thrift store. It still had its factory tires. I replaced them with tires from the LBS and saved 11 oz per wheel! It rode like a different bike. Pedaled easier, accelerated and stopped easier, handled better, was more responsive. A HUGE difference.

A guy at the race had the same bike I had, a Superfly AL elite, but his had I9 wheels. He let me ride it around the start/finish area, and it was NICE. I'll bet the difference on the trail is substantial. So I plan to spend the $$$ I didn't spend on a carbon frame and get some really nice wheels sometime :). You benefit from more than just weight savings, you know. A good wheelset will be stiffer and the hub will have more engagament points. Also look into thru-bolt if you don't already have thru-axle.
 
#31 ·
The Schwalbe paper I mentioned a couple of posts ago claims that additional rubber on the road does not add to rolling resistance. The reason to go with narrow tires on a road bike is weight savings, but mostly lower wind resistance. It sounds like heresy based on everything I have read and been told with respect to cars, but just thinking about it logically, I see no reason why road molecules and tire molecules merely touching each other is going to generate heat.

I know, its seems counter intuitive to think lowering tire pressure doesn't slow you down. I get the increased traction, larger contact patch, but everything I ever heard says higher pressures equal less resistance. I guess I'm just going to have to try it.
 
#33 ·
Rolling resistance.

It may be the wrong choice of words to choose to describe the speed in which you travel with high pressure vs low pressure. If you are on pavement or smooth, hard packed dirt, higher pressure will require less energy to cover the same distance when compared to lower pressure. If you are on a surface with a lot of bumps, lower pressure will require less energy to cover the same distance compared to higher pressure.

Think of it this way. The shortest distance between two points is a straight line. A straight line is the most efficient path between two points.

Now, picture a bike from a side view and imagine a chart of the Axels' paths while riding a smooth road at 60 psi. In that scenario, higher pressure or lower pressure results in a straight line. Now, imagine putting a bunch of roots and rocks along that path and chart your axles' paths with 60 psi and also 25 psi. the 60 psi path will look like a heart beat monitor and the low pressure will look like a sound wave. Every time you change your axles' paths abruptly, you are loosing energy/efficiency.

If you have 100% energy devoted to moving the bicycle forward, any movement in any direction other than forward reduces your energy devoted to moving forward and converts it to energy in a different direction. It's the same reason we use suspension. It's all about energy efficiency.

There is a point of diminishing returns. It's all about trade-offs. That's why no one answer is best in every situation.
 
#34 ·
I have a dolly that i use to move stuff with. Usually, with the tires aired up, i strap something on it and push it along. Not much effort. The other day, the tires were lower than normal and squished about 1/4-1/2 its total sidewall height with the same thing on it. It took a bit of effort to roll this around. I doubt it was due to the added tread on the pavement. Probably more the "flattening" of the contact point. But, lower pressure does add to rolling resistance.

I'm sure that low pressures (big reason to go tubeless) has its traction benefits. But, there must be a rolling resistance added by doing it. Is this resistance noticed on a rocky trail while ascending or descending? I don't know. Does the resistance outweigh the traction benefits? Everyone has to make that decision for themselves.
 
#35 ·
This is not accurate for bicycle tires. Do not assume that lower air pressure results in higher rolling resistance. That is ancient thinking. Roadies used to believe that a tire with 120 psi would have less rolling resistance than a tire at 100 psi. This has been proven to be wrong.

Lower pressure does not add to rolling resistance.
 
#45 ·
CSC, you are right. Rolling resistance is rolling resistance. The terrain doesn't magically change the rolling resistance physics. Running lower pressure is higher rolling resistance regardless of the terrain. The same bike with the same rider with the same tires is going to have lower rolling resistance at 40 psi vs 25 psi regardless of terrain. The difference is the energy expended to make it from point a to point b on various terrain with 40 psi vs 25 psi. Running lower tire pressures is an argument of efficiency, not rolling resistance. The reason this is relevant is because you can run lower pressures, when necessary, with a tubeless setup compared to a tubed set up. Running lower pressures is not more efficient on every trail.
 
#64 ·
The same bike with the same rider with the same tires is going to have lower rolling resistance at 40 psi vs 25 psi regardless of terrain. The difference is the energy expended to make it from point a to point b on various terrain with 40 psi vs 25 psi. Running lower tire pressures is an argument of efficiency, not rolling resistance.
this is what matters... rolling resistance is often used in the same sentence with average speed and traction.

lower pressure tires may have higher rolling resistance (dependent on the design and thread - in some cases the difference is INSIGNIFICANT) but in most cases - off road - lower resistance means higher average speed OR less energy required to cover the distance between point A and point B.

lower pressure tires better conform to the rough nature of off road trails where the rubber requires less energy to absorb the roughness as opposed to the rest of the bike - suspension, frame, seat post, handlebar etc...

always added benefit is traction - which increases with softer tires.

about the only negative side is messy setup (non ust) and often tire changes - which i addressed by owning 2-3 sets of wheels - to address different riding/racing conditions (mostly racing). if you do not change tires often - this negative side may be easily ignored.

tubeless setup, in my case, is superior to tubed - for above mentioned reasons.
 
#58 ·
Note that my post could be used to solve:

wide vs. narrow handlebar threads
mechanical vs. hydro brake threads
FS vs. HT threads
650b vs. 29er (any wheel size) threads

The list could go on and on!
 
#63 ·
I'm doing some upgrades to my bike, and I'm looking my options for wheels. I'm to the point know where I'm looking at tube and tubeless rims. What would be the main reason for going tubeless?

I'm sure it's a simple answer, but this noob needs some help.
Dayum, so much for a simple answer. 3 pages rambling on about rolling resistance VS pressures. At least there were no charts involved. Charts are bad. Unless its a pie chart. Pie is good.

OP please do not hesitate to post again in the future. We have pie.

 
#67 ·
conforms to trail surface

Tubes hold the tire round at the bottom.
Tubless allows it to conform to the surface giving you wonderful grip.
As for rolling resistance....dont run super low pressures.
I run a 29er 2.35 with tube 32psi in rocky north jersey.
I switched to tubless and run 28-30 psi. Ride wt 200lbs
Incredible grip performance.......
When i run below 28 it feels sluggish.
At 28-30psi i have never flatted, burped or had trouble mounting them for an entire season.
I have even run none ust tires on none ust rims.....if they snap into the bead then it is a good candidate for tubless.......stans tape & fluid.
Go tubless for traction.
I only read a few posts that hit on traction.....but this seems to be the reason that i think you should switch.
For me it was not weight or supper low pressures.
After a season on them switching back to tubes does not feel as confident on tricky terrain.
 
#69 · (Edited)
CSC, seems that there was a bit of miscommunication and semantic differences at play. I also think we agree on almost everything with regards to tire pressure.

Just one thing I call to question, and it's the assertion that higher pressure always means lower rolling resistance. In my opinion it is only true on a perfectly smooth surface: tire deflection is a major contributor in that case. However, if you ride a rock hard tire on asphalt that has seen its better days, the rough surface under the hard tire will result in a higher rolling resistance, while the same tire with a bit less pressure allows the tire to soak up the bumps.

Here's a good post summarizing what I'm talking about with original sources listed: Road Bike, Cycling Forums - View Single Post - Reduced air pressure for "reduced rolling resistance"??

In short, I acknowledge that dropping the pressure too low will increase rolling resistance. Quite often tires roll better with a bit higher pressures than lower, but there is also an upper limit, a point where increasing pressure ceases to reduce rolling resistance.

Edit: A couple links and quotes.

Bicycle Tires and Tubes
"In practice, riding surfaces aren't perfectly smooth, and overinflation actually increases rolling resistance, due to vibration."

Rolling Resistance and Tire Pressure
"Wider 28-mm tires are as fast at 85 psi as they are at higher pressures."
"At 130 psi (9 bar), the narrow Clement Criterium rolled slower than it did at a more comfortable 105 psi. The wider Clement Campione del Mundo rolled slightly faster at 85 psi than at 105 psi."
 
#71 ·
CSC, seems that there was a bit of miscommunication and semantic differences at play. I also think we agree on almost everything with regards to tire pressure.

Just one thing I call to question, and it's the assertion that higher pressure always means lower rolling resistance. In my opinion it is only true on a perfectly smooth surface: tire deflection is a major contributor in that case. However, if you ride a rock hard tire on asphalt that has seen its better days, the rough surface under the hard tire will result in a higher rolling resistance, while the same tire with a bit less pressure allows the tire to soak up the bumps.

Here's a good post summarizing what I'm talking about with original sources listed: Road Bike, Cycling Forums - View Single Post - Reduced air pressure for "reduced rolling resistance"??

In short, I acknowledge that dropping the pressure too low will increase rolling resistance. Quite often tires roll better with a bit higher pressures than lower, but there is also an upper limit, a point where increasing pressure ceases to reduce rolling resistance.
Yes. The "butter zone" takes into account the upper and lower bounds of optimal tire pressure for a given tire.
A rock hard tire will ride over every single bump, effectively forcing the bike to travel a further distance than if the tire rolls "through" bumps. Think about tens of bumps, each causing millimeter rise and fall in the bike every second...over 20 miles, this will add up to quite a bit of extra distance traveled...hence the advantage of knowing the optimal tire pressure for a given tire, which will reduce this seemingly trivial but incredibly wasteful up-and-down motion of the bike...which also tires out the rider, by the way.
 
#70 ·
Good study. A couple thoughts:

1. This study was conducted using road tires.
2. This is interesting: "Riding your tires at the “optimum” pressure optimizes both comfort and performance. At lower pressures, you roll slower. At higher pressures your bike is no faster, but much less comfortable. Our tests of the same tires at various pressures determined the
optimum pressure for each tire for our rider/bike combination." Duh. The question is, how to determine optimum tire pressure for MYB tires. They suggest a method, but not sure if it pertains to MTB tires.
3. I did not find anything in that study that contradicted anything I've written in this thread.

I'm beginning to agree with you guys, WTF are we arguing about?

Why tubeless? Reduce/eliminate flats and have wider range of tire pressure adjustment in order to find "optimum" tire pressure for trail, rider and style.
 
#72 ·
1. Yes. The info from Schwalbe (who you quoted earlier) is also about road tires: Inflation Pressure | Schwalbe North America
"The following applies for the road: The higher the inflation pressure the lower the rolling resistance of the tire."

I think most (if not all) principles can be applied for MTB tires as well: slick is faster, hard is faster - up to a point where you don't gain advantage and start reducing performance.

A quote from wmac earlier in this thread: "If you are on a surface with a lot of bumps, lower pressure will require less energy to cover the same distance compared to higher pressure."

This is precisely what I'm also trying to get across. It seems I call this reduced rolling resistance, you call it improved efficiency, for CSC it's something achieved by a "butter zone" pressure. We agree on the practical side, but differ in semantics. I'm happy with that.

As for a method to find the right MTB tire pressure for yourself, I suggest the following:

1) If you only ride for your own amusement, try out different pressures and use what feels best.
2) If you race, time your laps on an actual trail to see which pressure allows you to ride fastest.
 
#73 ·
just an additional thought

i truly believe that using a tire pressure with in the range of the recommended pressure listed on the tire is crucial. The side wall is designed to hold strong between those pressures and support the volume of the tire under the rim. Below it and the side wall will collapse and roll out from under the rim causing a wash out. Especially true on a tubeless when there is no tube to help the tire's side wall from folding. The upper limit is more for rim/bead interaction.

In the Beginning…

Tubeless officially debuted for mountain bikes in 1999. Mavic, Michelin, and Hutchinson worked together to create a new standard for mountain wheels and tires called Universal System Tubeless, or UST. Under this new standard, the tire's casing is thicker all the way around - essentially transferring the weight and material of an inner tube on to the tire itself.

You need the proper inflation to support the volume of air and keep it under the rim.

this is actually very cool for determining a theroretical tire pressure
Recommend Tire Pressure « Vittoria
 
#74 ·
Saul: Agree, agree, agree. I think the point I was trying to make was that having a higher rolling resistance (lower pressure than butter zone) is a good strategy because many trails have drastically differing terrains and you have to make trade offs based on what is going to net you the greatest efficiency. So, a course that is mostly flat, hard packed with little variation may be best. Change that course to very technical rocky sections that require high traction and grip and you may be better off with lower pressure. Hence, ride the highest pressure possible while maintaining optimal traction in the most difficult sections - just like you also mentioned :)
 
#78 ·
Just one more thing, in the spirit of Columbo. Couldn't resist...

I think we went a bit off-topic with the tubeless thing when one benefit of tubeless was said to be the ability to run lower pressures. From there it went to pressures without regards to tube vs. tubeless.

We overlooked the fact that the comparison wasn't between the same setup with a higher and lower pressure, but rather "with a tube, higher pressure" and "tubeless, lower pressure".

I would argue that removing the tube has a positive effect on rolling resistance, which may be negated by lower pressure, so one hypothetic outcome would be "less pressure, same rolling resistance". I.E. when you go tubeless, you can run lower pressures for the traction and smooth ride without increasing rolling resistance compared to your old setup with tubes.
 
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