This is handy, but the good news is that if you're dealing with anything made in the last 30-40 years, it's all but guaranteed to have the ETRTO measurements marked on it somewhere.
Practically speaking there are two rim diameters you'll likely come across on all but old, "unusual" or high end bikes:
559mm: the ubiquitous "26 inch" mountain bike tire. Has largely fallen out of favor on high end mountain bikes, but there are zillions of bikes with 559mm wheels and frames sized for them out there. On high end mountain bikes, largely displaced by 29" or 27.5" setups.
622mm: "700c" road rims or "29 inch" mountain bike rims. Nearly universal on modern road bikes. If you have something else on a new road bike, you probably already know it.
Other sizes you might find in the wild:
630mm: The largely obsolete "27 inch" road rims. uncommon on new bikes, but you'll still find plenty of them on older bikes. Not even the slightest bit interchangeable with 622mm. Usually, you can't even switch to 622mm rims on frame built for 630mm because the brakes won't reach 4mm closer to the axle. Easily mistaken for 622mm if you aren't paying attention.
584mm is the "27.5 inch" mountain bike standard that splits the difference between 26" and 29". If you have this, you probably know already.
Once you've got the rim diameter right, the tire width is pretty straightforward: if it looks right, it is right. It'll be pretty obvious that a "29 inch" mountain bike tire doesn't go on a road rim, even if the diameter on both is 622mm. If you have needs under which that doesn't apply, you're probably already aware of them.
You can put hooked tires on straight sided rims safely (I have), but likely not the other way even if you could find dedicated straight sided tires.
Tubulars are a while 'nother animal, about which I know nothing :-)
ETRTO made it much, much simpler to get the rim size right when all of the various standards had different names to different people.
On non-disc road bikes, the tire size is limited by not only the width of the rims, but also by what the brake calipers can accommodate. For example, newer Shimano rim-brake calipers can accommodate tires up to 28mm in width, whereas older versions only up to 25mm in width. With disc bikes, the tire size is limited by what the wheel and frame can accommodate.
Gravel bike tires are all over the place, with companies making frames that can accommodate 700c, 29", and/or 27.5" wheels. And thus tire variations can be quite overwhelming.
Frame clearance can get you too. Cantilever brakes will allow you to fit a lot of tire, but you'll likely rub the frame long before you rub the brakes.
another "interesting" thing to consider is that some 700C gravel or cyclocross frames, designed for disc only, can take either 700C wheelsets or 650B. Because you no longer need to consider the vertical distance between the rim and the top of your fork, other than the general width between forks and rear stays for tire clearance.
650B is becoming increasingly popular for gravel.
There are a number of 650B tires that have intentionally higher than normal sidewall heights, so the total wheel+tire diameter is actually not that different from something like a 622x23 (aka 700C) skinny road bike tire on a traditional pavement only road bike.
If you have a disc only frame with wide tire clearance there exists the possibility of swapping between wheelsets that are either 650B or 700C depending on what type of riding you have planned in the near future.
My all road bike was built with 650b wheels since I didn't want skinny tires. The issue is that with this wheel size the bottom bracket is about 15…30 mm lower compared to 700c so you'll have to be careful with crank length due to the increased risk of pedal strike. Most of these bikes have a bottom bracket drop of 70 mm or more, while a frame designed for 650b specifically will have 54…60 mm. I don't know why the industry doesn't build frames with 65 mm BB drop since it would be in between, but I'm inclined to believe they prioritize 700c with 40…50 mm tires. But then one wouldn't be able to use anorher wheelset with skinny 25 mm tires for road, so you'll probably need a road bike. While designing for single wheel size only, the industry also ignores the needs of shorter people and most women.
No one really makes 26” mountain bikes anymore everything is 27.5 or 29 not just “high-end” bikes. Unless you’re talking about 26” bikes that kind of look like mountain bikes but aren’t really mountain bikes at all.
26" is still a thing in the market towards the lower end of the price range for something like a hardtail XC bike under $1200, that has some real capability.
But I do get what you're saying about things that are more like bicycle-shaped-objects sold at Walmart.
As an owner of a Walmart bike, this stings. I have a blast every time I ride that thing. I don’t ride enough to warrant a more expensive bike and this one has t limited me yet. Is all of high end biking this snobby?
I'll answer from the perspective of wrenching on bikes, which I did on a volunteer basis for a couple of years around 2006.
Walmart bikes are typically made with fairly low quality components. They're a total pain to put in correct adjustment, and they rarely stay correctly adjusted for long. It's also incredibly rare that they're put together right and adjusted properly from the store.
That said, I don't begrudge anybody for what they ride. If you're happy, I'm happy. If you find yourself riding more and visiting your LBS more in the future to get little annoyances taken care of, that's when it's time to spend more money on a slightly higher quality bike.
And if your LBS is a bunch of dicks about your Walmart bike, by all means go find a different shop. Good shops will educate you without talking down to you and let you make the right choice for your needs. If it puts a smile on your face when you throw a leg over it, it's a good bike for you!
I wouldn't say that everything has to be snobby - but there is a WORLD of difference between a $250 walmart "mountain bike" and something like a basic hardtail mountain bike you might be able to buy for $950-1200. I realize that maybe not everyone can afford that.
If a person has sufficient finances to allow for the purchase of a better bike, they will have a much more enjoyable overall experience of cycling on something like this, which although towards the lower end of the "real" bike spectrum, is still worlds better than a department store bike.
One of the reasons for the disdain towards walmart bikes among the cycling community is that many people have seen issues with them that are fundamental to safety - brakes that aren't set up right or don't work properly, wobbly wheels with loose spokes being sold as fit to be ridden, and so on. On the one hand you have questions about whether it's a good quality bike and will be enjoyable to ride, on the other hand there are often real and valid fundamental concerns about safety.
I owned a Walmart bike when I was 16-17. Rode it into the ground and had a blast. I did zero maintenance on it for two years (not ideal) and it serves the purpose. Bought a much nicer entry level Trek in my mid-20s and hardly rode it. It wasn’t until much later that I bought a bike that I rode more. It just happened that I could afford more and decided to spend more, but it absolutely wasn’t necessary. In fact, a guy I ride with in summer works at a LBS and still rides his trusty 1990s MTB (mid level). Oh, still regularly beats on most other riders too on it.
Nowadays Walmart is actually quite involved in the biking community and used to sell moderately high end bikes, though they may be out of the game now. Most people looked down on these bikes for some reason even though the entire group set was equivalent to a major brand high end bike. But it was sold by Walmart so how bad could it be? I suspect you don’t own one of these but the point is the same - as with many other hobbies, snobbery is very much thriving in cycling. Hell, I’m guilty of it to an extent too.
The Walmart thing is a bit interesting. A couple of the Walmart heirs are avid mountain bikers. They pretty much single handedly created Bentonville AR as a mountain biking destination.
I'll be the one guy: Don't feel badly about your ability to enjoy an inexpensive bike. I've ridden both high-end and low-end bikes. The high-end bike is definitely a better experience over long distances. On the other hand, I actually prefer my cheap beater (a Retrospec, a little above department store quality but not that much) when exercising on shared use paths, because it keeps me a bit slower around joggers and such.
While there is definitely a difference, it really doesn't matter if you get where you're going and enjoy the trip.
Yes, but like I said, if it isn't obviously wrong, it's probably close enough to work. I've put 35-559 and 54-559 on the same generic mountain bike rims. They both worked.
My road bike has 25-622 in the front and 28-622 in the back because a little more padding under my ass is pretty welcome at the end of a long day. I'll note that if you run radically different widths (and by extension heights), you'll likely find that you need to change the saddle angle to keep your weight on the parts of your body the can support it comfortably.
I can't imagine that the speed gain from a narrow non-driving wheel with less weight on it is worth the added danger on descents. Your front tire will wash out way before the rear starts to slide with that much different in traction.
This nails it. The nominal sizes are mostly (for some insane reason) based on the outside diameter of the wheel and tire. 27" road tires would have a 30mm tire size, whereas 27.5" mountain bike tires are probably running close to 60mm these days (haven't been keeping track of what's in vogue).
ETRTO is based on the bead seat diameter, which is what matters when you're buying a tire.
actual "27" is very old standard you might see such as if you discover an unused road bike from the early 1980s deep in somebody's garage. It's quite rare these days.
27.5 is used for mountain bikes so the rim profile and tire widths are a completely different thing than old "27"
As regards to tubulars and glue-on tyres: Only modification needed to tour on Spandex-worthy 622 mm racing rim was to screw a bigger hole for the valve, ie from Presta to Schrader.
In addition to your comments I would recommend that people upgrading or shopping for tires for a road/city bike familiarize themselves with bead types and tire weights.
Something like a "cheap" 700C 28mm tire with a wire bead can be quite a lot heavier than a folding bead (kevlar) more expensive road tire such as one that costs $55-70 per tire. Additionally there is a big difference in the quality of the compound used in the rubber for a cheap tire vs an expensive road tire. There are also specialty city oriented tougher tires like the gatorskip series that sacrifice some grip and cornering ability for purported resistance to punctures, also at the expense of being heavier.
If you ride regularly and have something like a flat bar road bike, and change the tires from 28mm cheap/wire bead to folding bead, you will IMMEDIATELY notice the difference in pedaling effort and cruising speed , subjectively measured by your own effort on a flat/level road, average effort, no wind.
You can feel this in the tire weight if you take the old wire bead tire off your bike and hold it one hand, and hold the unfolded new folding bead tire in your other hand.
If you're using tubes there are also a number of benefits to be found from using the proper size/diameter range of tube, correct valve stem length of tube for your rim, and quality material tube. A good quality tube will cost a few dollars more than a cheap generic one. Using the example above of a 28mm road tire the appropriate size range of tube should be marked on its box from 25-32mm.
One other thought on rim type: If you are buying a $1700+ road bike new these days it most likely will come with a tube-using setup, but the rims will have the "new" square profile for bead lock that is also compatible for upgrade in the future to a tubeless tire setup with special rim strip and sealant. Older 700C clincher wheel sets generally are not compatible with the square profile bead lock required for tubeless. Newer 700C wheelsets should be compatible with conventional tube-using clincher beads as well as tubeless.
Terminology: To avoid confusion, tubeless and tubular are two different things. You're very unlikely to see tubular (glued directly to rim) tires in 2022 unless you're a professional, extremely serious about triathlons.
Correct tread pattern and pressure for conditions will make a significant difference in rolling resistance, far more than just about every other tire property (weight, suppleness, etc). Different conditions require different tread patterns and different tire pressures. As for weight, you’ll save maybe 100g of weight per tire, which is admittedly amplified due to rolling. Drop a single water bottle and you’ll be back on top. You won’t of course find many “performance” bikes with wire beaded tires.
Most paved paths are best paired with slicks/semi-slicks, even when wet (snow/ice is a separate discussion). Yet many hybrid/city bikes are equipped with a bit of tread depth. The tradeoff is durability and puncture resistance - slicks/semi-slicks can’t compete. And for people buying these types bikes, it is far more important that they reliably get from point A to point B without any flats or maintenance costs than saving a minute off their daily commute, so it is a fair trade off.
As for tubeless setups, I would hesitate to recommend those to anyone that needs this site (not that you’re suggesting that). If you don’t know what tire you need I would be willing to bet you have no idea how to fix a tubeless puncture, top up sealant, or remove/reinstall the tire.
Re: the weight of a water bottle, rotating weight is very different than static weight.
My experience with 28-32mm sizes tires on pavement in an urban environment has been that tires with tread on them actually have much less overall grip and cornering ability. This seems to correlate with data I've seen from third parties measuring the actual square mm area of a typical "contact patch" between tire and pavement. It seems counter intuitive, because on a car you want and need tires that aren't bald. But on a city/road bike, the best possible performance on pavement in the size range of 23-32mm with seems to be gained by having a treadless tire with a grippy compound.
That’s exactly my point :) Puncture resistance may be improved with more aggressive tread but handling and rolling resistance will definitely suffer. It’s all about the amount of contact patch on the ground. Same reason why on ice you want to run very shallow tread while on snow or mud you want a very aggressive tire. You can correlate this with slick car race tire vs a rally tire. One is great on road while the other wouldn’t get you far.
For a fun experiment, head out on a wet day and try to corner on both 28mm slicks and 33mm+ tires with a decent amount of tread (bonus points if you use a mud CX tread). Personal experience dictates that aggressive tread will treat you to a good dose of road rash while slicks will continue to grip far longer. I’ve far more experience with this than I should (one should be plenty).
As for the water bottle vs. rotating weight, I noted that as well. Which is why I compared dropping 100-200g of rotating weight (tires) to dropping a 500-750mL water bottle. It is a very rough comparison, I haven’t ever done the math to figure out how close they are, but I suspect it is close enough. Even 200g of rotating weight isn’t THAT significant when you consider the likelihood your pair of wheels weigh 2500g+ (assuming low end box wheels since we are discussing wire beads).
As with some other highly technical disciplines I think what we're seeing is the possibility of going down a rabbit-hole of optimizing for 1-2% extra efficiency in various subsystems/components...
For people who road cycle very seriously this will lead towards things like bikes that have a $6000-8000 all up cost with deep aero section wheels, expensive tires, ultra lightweight components to put the whole thing near a UCI-illegal weight, and so on.
It's probably easy to spend $1500 on a road bike combined aero bar-stem package that comes out of a single piece CF mold and has very marginally better aerodynamic performance in wind at >35km/h, but the returns are minuscule.
There is definitely a phenomenon of diminishing returns with increasing money spent above a certain point, that would be difficult to subjectively notice unless tested by a person that rides a very large amount like >10,000 km/year.
Let's also not forget the impact of visiting or not visiting a toilet before riding. The weight change dwarfs most of the differences between single component choices, possibly all the way up to most of the components combined.
Don’t underestimate middle aged men in lycra with too much money to burn. They’ll spend hours obsessing about individual components and won’t bat an eye when it comes to spending $15k or more (Canadian, a bit closer to $10k USD/EUR) on a brand new bike every couple years, $3-5k on the newest dimpled wheels from the big Z manufacturer, tires, and so forth, all in the name of besting their mates in the Saturday morning world classic coffee ride.
While I don’t strictly identify as above (I’ve more sense than to spend $1000/watt, or so I like to claim anyway), I do my fair share of purchasing the extra few watts. I’ve spent an embarrassing amount of time obsessing about what the optimal tire choice is for my next Cat 3 CX race. At least I’m realistic enough to know the hoards of 16-20 year olds with more handling skills and less fear will destroy my every day of the week. Joke is on them because they’ve real life coming to crush them :p
In all seriousness, I know fully well the 5-10W gain is marginal for me at best and will only get me so far. Genes, age and hours in saddle cannot be purchased. Being a late comer to the sport and not being blessed with the requisite body type, I can’t have any one of those three, but I can however throw more money at the hobby, unlike the younger ones can. And why not enjoy myself while doing so and ride around in style.
As for diminishing returns, don’t talk to bike enthusiasts about those. They’ll only be outdone by audiophiles
> Don’t underestimate middle aged men in lycra with too much money to burn.
I think without middle aged men in lyrca spending $10k on bikes, most of the performance/road oriented bike shops in major metro areas would go bankrupt, because the profit margin on some of that stuff has to be insane. Particularly the accessories. Yes, I totally need a $95 carbon fiber bottle cage... Hook me up!
> I think without middle aged men in lyrca spending $10k on bikes, most of the performance/road oriented bike shops in major metro areas would go bankrupt, because the profit margin on some of that stuff has to be insane. Particularly the accessories. Yes, I totally need a $95 carbon fiber bottle cage... Hook me up!
The markup on higher-end parts and bikes is quite ridiculous. I've SRAM Red eTap on my road bike and cassette alone is over $500. Compare that to a Rival eTap cassette at $180 (two steps down) or Force eTap at $260 (one step down) and it is enough to make your head spin. Or if you want to stick to "old technology" and go with 11sp Force/Ultegra, you can get them for $130. I half-jokingly say that I'll sell the bike before any part wears out as it will be more cost effective to replace it.
My approach is to purchase lightly used high end bikes through private sales. Find a trusted source and let them take the initial hit. Covid put a bit of a dent in those plans due to lack of bikes everywhere, but at least there's still some deals to be had as you approach top range. You can forget any deals for bikes under $5000, you're likely to pay similar prices for used as for new.
Side note - loving the downvote! I can only guess a local Cat 5 legend got upset they didn't win their Tuesday night worlds even after spending $4k on Zipp 454s. That or didn't bother to read my whole post where I'm poking fun at myself for doing precisely this :p
As somebody that's now literally a middle aged man in lyrca sometimes - I find the whole phenomenon really amusing, but then again, I've also been riding since I was a lot younger, and poorer, and the best I could afford was an all-aluminum specialized allez with 9-speed 105 stuff on it.
Back in the day, I probably rode 4-5x more cumulative km per year than I do now. And at that time, I found middle aged men in lyrca with more money than common sense to be equally funny.
Have you taken a look at prices of a used Allez lately? Put a few IG/TikTok faces to it and it doubled the cost. Once upon a time it was a cost efficient way to race crits and not worry too much about cost of crashes. Now it is apparently a high end highly desired bike …
Edit: I’m also a ma… hang on, when does middle age start? I may still have a year to go technically! (But not in reality)
In 2005 I paid $1500 (USD) for an aluminum allez elite with the 9 speed 105 on it... Cheapest things on it were the FSA crankset and the fairly cheap 20 front/24 rear generic specialized house brand wheelset. Equivalent thing today would probably be a lot more. 10 speed tiagra is probably superior in every way to the groupset I had then, but a comparable bike now might be $2600? Or more.
Thanks for putting this together! There are probably another half dozen vastly less common sizes that you might encounter in reality (e.g. kids' bikes, adult BMX, folding bikes, jogging strollers and bike trailers). I can see this being a huge help if you have one of those and you're trying to find a tire in a pinch.
I have a Brompton and a BOB trailer. I have no idea what size tires they take. The BOB must be a common size for a kid's bike because I blew a tire and had to replace it from Walmart while touring. Being able to type in the size and know wtf I need would be a huge help if you're calling around and the shop can't see the tire in question.
Practically speaking there are two rim diameters you'll likely come across on all but old, "unusual" or high end bikes:
559mm: the ubiquitous "26 inch" mountain bike tire. Has largely fallen out of favor on high end mountain bikes, but there are zillions of bikes with 559mm wheels and frames sized for them out there. On high end mountain bikes, largely displaced by 29" or 27.5" setups.
622mm: "700c" road rims or "29 inch" mountain bike rims. Nearly universal on modern road bikes. If you have something else on a new road bike, you probably already know it.
Other sizes you might find in the wild:
630mm: The largely obsolete "27 inch" road rims. uncommon on new bikes, but you'll still find plenty of them on older bikes. Not even the slightest bit interchangeable with 622mm. Usually, you can't even switch to 622mm rims on frame built for 630mm because the brakes won't reach 4mm closer to the axle. Easily mistaken for 622mm if you aren't paying attention.
584mm is the "27.5 inch" mountain bike standard that splits the difference between 26" and 29". If you have this, you probably know already.
Once you've got the rim diameter right, the tire width is pretty straightforward: if it looks right, it is right. It'll be pretty obvious that a "29 inch" mountain bike tire doesn't go on a road rim, even if the diameter on both is 622mm. If you have needs under which that doesn't apply, you're probably already aware of them.
You can put hooked tires on straight sided rims safely (I have), but likely not the other way even if you could find dedicated straight sided tires.
Tubulars are a while 'nother animal, about which I know nothing :-)
ETRTO made it much, much simpler to get the rim size right when all of the various standards had different names to different people.