Winter is over on the calendar but not in the air in Montana. We had a good two weeks in the high forties and even reached sixty a couple of days. Last night left us two inches of snow.

I don't think it is possible to repair a flat tire in below freezing weather because the glue would harden instantly. I've only had one flat in cold weather. The patch kit did work at 33ºF. It wasn't fun. My fingers had difficulty being precise. Attempting that repair at 15º-20ºF would be difficult.

This winter I switched to the Bell hard foam inner tubes. No added air is required. They weigh about two pounds each. Now that the weather is getting warmer I'm considering keeping them in.

On a forum thread I once read a discussion about overall average speed comparing heavy duty tires to light weight tires. The point was lighter tires get you there much faster but having just one flat tire that stops you for many minutes (depending on bicycle configuration and mechanical ability) might totally negate the average speed for specific trips over time.

For the past couple of years I've used thicker inner tubes with puncture sealant inside, thus my one flat last winter. I liked that setup but it wasn't flat proof, just very flat resistant.

On my comfort bicycle it takes a lot of time to get the rear wheel off and change a tire. That is why I'm considering keeping the flat proof inner tubes for year-round usage.

The ride is much firmer with the harder inner tubes. I don't know it but perhaps the harder tubes keep the tire stiffer thus giving less rolling resistance. I wonder if that makes up for some of the weight. No matter, the bicycle is definitely a little slower with the extra weight.

If a trip takes a minute or two more each day due to the slower speed of the heavier and firmer solid tubes, is the speed penalty worth it to be guaranteed never to get a flat tire? I'm starting to think the answer for me is yes. I'm not racing anybody and I really hate doing roadside repairs.

What do you think? Would you ride slower for a guarantee of no flat tires ever?

I don't bother with patches for the most part. I just ride puncture-resistant tires and carry an extra tube with me.

+1 Carry a spare tube and patch the bad one at home at my leisure

Hard tire doesn't necessarily mean lower rolling resistance/faster...



Aaron

I expect eventually my tires will wear enough that I start flatting. I don't worry about it much, since my "flat kit" is a bus pass.

I'm not superduper careful when I ride. I do keep my tires reasonably aired up. My guess is about 95% of my flat resistance is riding relatively fat tires. When these begin flatting, I'll probably switch to a somewhat higher pressure tire, but stay somewhere in the 26 by 1.5" or higher range.

My attitude would probably be a lot different if I didn't have the option of bailing to the bus.

I'll be honest: I haven't even bothered patching the bad tubes at home. It just hasn't been worth the effort when I can get a new one for $7.

Actually, I don't think I've had an actual puncture since I started running tire liners or puncture-resistant tires all the time....

My physics is very rusty, but I think that the tires--especially the rims of the tires--is the worst possible place to add weight to a bike. Somebody told me that 1 pound on the rims is like 10 pounds on the frames. If that's true, using the two hard inner tubes would be like adding 40 pounds to the frame or in your backpack or panniers. Too much for me!

I hope that somebody with better understanding of the physics can explain and correct all this!

It's a torque (which is effectively another word for leverage) thing.

Torque is nothing more than force applied at a particular distance to rotate something. 10 pound-feet of torque is 10 pounds of force exerted 1 foot from the center of rotation (the hub of the wheel), or 1 pound of force exerted 10 feet away, or 100 pounds of force exerted 1/10th of a foot away. More distance means greater torque for the same force. If you remember playing on a playground teeter-totter, the farther away from the pivot (hub) you were, and the closer to the pivot someone else was, the easier it was for you to move them. Torque is leverage.

Objects with mass, meaning wheels in this case, have rotational inertia. That's how prone they are to stay not-rotating if they aren't rotating, and how prone they are to continue rotating if they already are rotating. Much like a given force creates more torque the farther away from the hub it is, the farther away from the hub the mass of a wheel is the more rotational inertia the wheel has. The more the mass of a wheel/tube/tire assembly is distributed towards the rim, the harder it will be to get started but the longer it will keep spinning on it's own (all other things being equal). Whether the tendency to keep spinning on it's own is noticeable during riding is something I can't readily answer, and would easily be confounded by things like tire pressure and stiffness, rolling resistance, etc.

You can observe all this pretty easily if you have a free-spinning bike wheel handy. Just use your finger on a spoke out near the rim to spin the wheel, stop the wheel, then try again up close to the hub. It will be easier to start the wheel spinning near the rim than near the hub.

That's if I remember my physics correctly. I definitely don't remember enough physics to get very specific on the effects of the weight of the frame, non-wheel components, and rider.

Those solid inner tubes make the ride rough and they put more wear on your bike. All the air in a normal tire acts as a shock absorber. I think normal tires with a liner to prevent flats is a better solution.

I used a different kind of solid tire for a few years back in the 1980s. They were great as far as not getting flats, but in the fullness of time both of them eventually failed (the inner cords broke and the tires just fell off the wheels). I tried slime filled tires and they were great for not getting flats, but eventually I had a blowout and wow that was messy. I tried first generation Mr Tuffy liners and they prevented flats but they caused blowouts when water got into tire. I tried extra thick puncture resistant inner tubes and they prevented flats but they all eventually failed with leaks at the base of the valve stems (not repairable by patching). I think I'm open minded about anti-flatting ideas but for now I'm still using standard tires and tubes.

I see that carrying a spare tube is popular, but; nobody answered the question "Would you ride slower for a guarantee of no flat tires ever?"

For a recreational rider or someone not on a schedule, taking the time to repair a flat isn't too critical. For someone riding to work, being punctual is important. A flat tire could make one late for work. If one leaves earlier every day to ensure enough time is available to repair a flat and still get to work on time, isn't that extra time somewhat wasted if no problems happen?

Having a guarantee of no flats ever would allow someone to reclaim that extra time allocated for the just-in-case of a flat time. That could add up to many hours per year. Even if the overall trip took longer, the rider could stay home longer because there wouldn't ever be a flat to repair. So going slower overall might not result in more time on the road or away from home.

It is this logic that makes me think keeping the heavy inner tubes on my commuter bicycle all year long is a good idea.

Regular maintenance keeps the remainder of the bicycle operating properly. It is only the flat tire that is the real uncertainty in daily travel.

You can think about it this way... Say using the hard foam tubes makes you slower by a minute every ride. Then if you flat on average every 50 rides, your penalty would've been 50 minutes. If it takes you 50 minutes to change a flat you would "break even". On the other hand, one minute later is only a very small amount of time each ride so you may consider that negligible.

If you absolutely HATE to change flats, then it would be worth it regardless of the small time penalty. You gotta go with your priorities...

+1 to Aaron: Pneumatic tires (filled with gas at greater than air pressure) should usually be faster than a hard solid tire because they will deform when going over irregularities (rocks and cracks and stuff) and return a little energy forwards when it springs back into shape. A hard tire deflects you and your bike mostly upwards without getting that elastic boost forward.

I have read about solid tires on another forum and in articles. If you can get a good brand to fit your rim they work OK. If the solid tire didn't fit the rim well it caused problems with movement on the rim. Most people commented that the rubber compounds used didn't have the same level of traction as conventional tires. They also could get flat spots from skidding.

A good solution with solid tires would be to have a special compound to fill the rim and then add a conventional rubber cap to it for road contact. I don't know if anything like that is manufactured. It would seem to solve some problems.

My thicker inner tubes with sealant in them aren't old enough to be degrading at the valve stems. So far they've worked well in summer. I did get flats with a conventional inner tube with sealant added to it. A few years ago on my motorcycle I got a catastrophic gash on the front tire. It had a tube filled with sealant. That sealant sprayed all over me and the bike as it was leaking out of the tire. I had to stop two times on the way home to re-inflate it. It got me home. I used the same technique to get the bike to the motorcycle repair shop. That saved a $100.00 towing bill.

I have used tire liners without any flats. Fortunately I read about the liners causing problems for others. When I got them I took a finger nail file and rounded the edges of the liners so they weren't sharp. My inner tubes don't show any signs of cutting along the liner edges.

The Bell No-Mor-Flats inner tubes work with whichever tire you have within the 1.75"-1.95" size range.

Nah. Puncture-resistant tires or Mister Tuffy tire liners are good enough for me.

Your are totally right about this. For people who leave earlier as a precaution to have enough extra time for flat repairs there is a much bigger difference. That time cushion wouldn't be needed anymore with a guarantee of no flats.

Nobody loves changing a flat, but it isn't that bad IMO. I can change one in about 5 minutes, my son can do it in about 2 minutes. What takes the longest is pumping it up with a mini-pump or even a frame pump. I would put my money into a good pump rather than so-called flatproof tires or tubes. And if you get a lot of flats, check for other causes. Make sure your spokes are seated ok, and your rims are good. If you use a mini-pump, make sure you have good pumping technique so you're not damaging the valve. And use the right tires for the job.

And Smallwheels, thanks very much for your thorough and understandable explanation of the physics involved. I wish somebody would follow up with the formula for determining the effects of heavier tubes/wheels/rims.

Well, there are several ways around having getting to work early be a waste of time. It all depends on what you would do with that time if you were at home and whether or not you can use that time at work productively. The nature of my job allows me to use that extra time to do things that will let me go home earlier, for example, if I use that extra time in the morning before I teach my first class to grade papers I'll have fewer things to grade in the afternoon and can go home that much earlier. My job is pretty flexible and I'm not punching a clock and your job is probably different but it is worth thinking about.

The other thing you can do is get the flat changing time down. One thing I do is carry a fold-up spare tire. This saves me the work of having to search for what caused the flat before putting the tire back on (otherwise you really will be late with two flats). You can practice at home fixing flats and get it down to a short time. As was mentioned, using a pump that gets the tire to pressure quickly helps (CO2 cartridges are supposed to be fast but I've never used those so I can't say). I use a seat post pump that gets it to pressure really fast. If you carry the fold-up spare, a spare tube, and co2 you should probably be able to get the time down to under three minutes.

The other thing to consider is that the flat prevention options you are talking about not only make the bike slower but also compromise the handling making it more difficult to swerve around unexpected debris or the car that suddenly turns directly in front of you. Having just missed a left turning car by a few inches this morning (closest call in a very long time) I was glad I have very responsive tires on the bike.

"I'll be honest: I haven't even bothered patching the bad tubes at home. It just hasn't been worth the effort when I can get a new one for $7."


You must have a better job than me and I never pay more than $5 for a tube. Not to mention the whole liberal green landfill thing. I do limit tubes to about 5 patches though.

I got a flat the other day - on the way home- no hurries. It was our first 70's day of the year and near the village on the MUP, so I walked it down to the village and sat in the sun on a bench, watching the eyecandy go by whilest actually patching it rather than throwing in the new tube.

If I get a flat in the morning it's, Oh well, I'll be late for work. I work through enough lunches and stay late for no OT that it really isn't an issue. Heck, I roll in a few minutes late often enough when I don't get a flat. But that's just my job flexibilty.

I've only had one flat since I started riding Mister Tuffys mid-summer of last year, and that was the result of a seam in the tube of my front tire giving out due (I assume) to age. It was fine the night before, but I came downstairs the next morning to find my tire flat.

+2. In the interest of keeping bike lanes clean, I've even picked up and patched tubes that were tossed by evil, uncaring cyclists. $7 a tube and people toss them after one puncture.

Being green has its benefits.

No-flat tires are slower; agreed. I am going to assume 10% reduction in speed. If I commute 60 minutes a day (30 minutes each way) they are going to add 6 minutes a day to my commute. If I commute 242 days a year; that comes out to 1452 minutes (24.2 hours) slower. I can change a tube on my city bike in about 20 minutes, the one I have has an IGH and bolt on wheels with roller brakes. Much faster on some of my other bikes. I would have to average 72+ flats a year to break even with the time "saved" by using the flat proof tires. Not to mention the added cost of them.

I was car free for several years back in the early 80's. I was never late for work due to a flat tire, but plenty of my co-workers were late when their cars broke down or had flats. On that bike I was running the cheapest tires and tubes available, IIRC I was replacing tires about once a year. I only had one catastrophic tire failure when I slashed a sidewall on a broken bottle in the roadway.

Today there are excellent kevlar belted tires that will minimize the chances of getting a flat, paying attention to where you are riding and keeping your tire treads clean helps also.

To me the comfort of a good quality tube and tire combo with the slight possibility of a flat out weighs the minimal advantages of the no-flat tires. For someone that is mechanically challenged or doesn't care about the ride comfort the no-flats might be a good choice, but not for me.

Aaron

my favorite tires are speedmax and they have no flat protection and I paid the price last weekend. Two flats in one ride, I carry one spare tube and instant patches (warning though these last from a day to a couple months usually just use them to get me home replace either with real patch or new tube). I ride the tires I like and figure flats are just a part of the equation.

I do the same. I really can't tell the difference in speed between light and heavy tires, I carry a lot of crap anyway.

Same here, I'd do a better job at home and let the glue dry properly.

Many rim vendors and bike makers advise against those solid tubes. They don't distribute forces of impact over a broad area of the rim as compressed air does but more localized which puts more stress on rims.

I do patch mine, 5-7 bucks is still money and at least a couple of times I gave my spare tube away to some unlucky, unprepared cyclist on the road (I usually carry more than one spare). Although, except my two recent mishaps with Conti T&C tires, I get less than 1 flat per year. However, since Fall I've been riding significantly more so the number may go up this year.

Ooohh! good tip! And I have a matching spare folder....
Another good point, I mix it up in traffic for part of my commute, tires with compromised grip or handling are contra-indicated.

My commute varies from 50 minutes to an hour and a half, solid tires or tubes would probably add at least 5 minutes, changing a tube has not yet taken more than 10, and I don't get to practice very often as I use various Schwalbe puncture resistant tires. I usually pay $2.50 for a tube, and start wincing at $5. Solid is not for me, might make sense for some people, but for the majority, can't see it.

Another thing is if I called and said I had 2 punctures, was out of tubes, and I was going to be a couple of hours late while I get the bike back home and hit the bus, the only response would be "OK, stay safe"

This thread motivated me to go out and buy a set of tire liners yesterday. I just installed them.

If the weight of anti-flatting stuff is a problem, a possible compromise is to put it on the rear wheel only. I get flats on the rear much more often than on the front. I don't know why.