FlashBazbo

The current fad is to make interior wheel widths as wide as possible. We've gone from 15mm to 21mm and 23mm in a matter of a very few years. There are benefits. But . . . how wide is too wide? And, have tire manufacturers changed their designs to keep up?


Here's why I bring it up. With wider wheels, more of what used to be sidewall / transition area is now in constant contact with the road. I notice that I get more flats -- usually in this area of the tire -- with the widest wheels. And when I'm really heeled over in a turn, the sidewall is supporting the bike. With narrower wheels, this part of the tire doesn't have to be built very strong, because it never touches the road. With wider wheels, the "tread" portion of the tire really needs to wrap a lot more of the tire -- but are tire manufacturers doing that?

PepeM

There are 23mm internal wheels?

69chevy

I think you have confused yourself into thinking you are riding on sidewall...

mcours2006

The profile of the tire, regardless of size is always going to be, more or less, a circle, wide or narrow tires. So no, the same patch is going to contact the road, wide or narrow. Unless you can lean your bike well past 45*, you're not riding on the sidewall.

Your flats may be due to the lower pressure you're running with the wider tires.

FlashBazbo

I'm convinced! The chart seems to indicate pretty clearly that the wider rim fad really is just a fad. It doesn't make that much difference. (And Mavic was right, all along!)

rpenmanparker 

I think you have jumped from one false conclusion to another. That graphical depiction of tire profiles is instructive, but it can be misleading. Not all of the inflation pressure/tire width/rim width combinations represent sensible situations. IMO here is a useful takeaway from all of what we have been told about tire and rim width and inflation pressure: yes, the contact patch is larger when a tire is mounted on a wider rim than on a narrower. That allows lower pressures to be used for the same % tire drop under full load. No, it is not so large that places outside of the main tread area are in contact with the ground even when the bike is heeled over in a curve.

Remember that tires are specified for a wide range of inflation pressures corresponding to a wide range of loads on the bike and rider preferences about effective tire drop (comfort, rim and tube protection, etc.). That means that the tire is built to accommodate a wide range of contact patch areas. There is plenty of tread rubber area to spare for the contact patch situations you encounter when mounting a tire on a slightly wider rim. As you go to wider and wider rims, you would get to an unsafe mounting situation (insecurity of the tire on the rim due to risk of blowing off) long before you would run out of useful lateral tread area.

FlashBazbo

I knew I would get push-back, rpenmanparker. Today's wide rims are religion. Much like press-fit bottom brackets were a few years back.

I don't have a dog in this hunt. You are correct that wider is not always better. (Is any racer REALLY worried about pinch flats on the road?)

Marcus_Ti

If you don't have a dog in this fight...why start the thread?

motosonic

There are a lot of factors that go into this, but there's substantial evidence out there that a wider tire has it's benefits depending on the application.. Not only for bicycles, but for automobiles, motorcycles, etc... let's also not forget rider weight plays a factor in tire pressure and surface contact. Do the pro's outweigh the cons? It's entirely possible, but you as a rider really have only one way to determine what's right for you.. and that's trial and error.. Unless you decide that what you have is good enough... in which case, that's fine too. There's no right answer IMHO when it comes to tire width.... to me it's just personal preference. I noticed a substantial difference on my bikes when I switched from 23 to 25 and a lower tire pressure. But, my results may not be 'typical'. I doubt I'd ever go wider... but I never say never.

FlashBazbo

I did it just to annoy you. That's how important you are to my decision processes. In fact, I woke up this morning wondering to myself, "How could I REALLY get under Marcus_Ti's skin this morning?"

It worked.

Spoonrobot 

Ya there are a few, AFAIK they're mostly disc specific. I'm riding these with 32mm tires that measure closer to 34.5mm when mounted.

https://www.bikehubstore.com/product-p/tl23.htm

WhyFi

^^^ the ENVE 4.5 AR Disc are also 25mm internal. Huge.

69chevy

How wide is the wheel that is giving you "more flats"? Or since you "don't have a dog" in this... Did you make that part up?

zymphad

As addressed by others, I think you meant the outside of the wheel. My wheel is 21 interior and 24 outside.

I'm riding 25mm tires which ride more like 26-27, I agree the tires ride different on wider rims. But that's also why I am more critical of tires now. I don't care about how much protection a tire has at the top, that's a given. I can't remember if I ever got a flat from the top, it's always been from the sidewall. This is why I only ride Kenda Endurance series as they have full coverage from side to side TWICE. My current has 2 layers of kevlar and still lighter than a GP4000.

It's why I wonder why Continental GP4K has so much love as it has absolutely no sidewall protection, it's pathetic. And I am not the only one, I have seen reviews on YT that discuss this, with the wider tires, the GP4K running on wider rims get shredded from the side. 25 is bad, 28 is supposedly horrendous.

I think you are onto something and hopefully tire manufacturers start considering most of us do not ride on a track or a perfectly clean road during a tour, but our roads are littered with broken glass from bottles, car accidents etc.

BillyD

Calm down. What he means is that he's not going to squabble over it.

FlashBazbo

I've had problems with Conti GP4K and even Gatorskin with wider wheels. Nothing through the primary tread, but cuts and punctures through the sidewall transition areas.

BillyD

HEY!! You guys need to calm down. It's nothing to fight about. I won't have no lynch mob forming here.

FlashBazbo

Wow. You're going for "Troll of the Day," aren't you! Do you actually own a bike or are you just here for the trolling?

As if it matters to you . . . 21mm inside width. (And I know I shouldn't feed trolls, but I felt compelled to answer.)

DrIsotope

Is this assumption, of have you made efforts to prove it empirically? Because it seems to operate on the compounded false assumptions that tires do not deflect, and that sidewalls have any appreciable amount of grip. Because in practice, if you were to lean far enough over to be on the sidewall alone, with no tread left in surface contact, you would find out immediately. And here, immediately = catastrophically.

zymphad

Eh, I think he is right, this is also why wider tires are more stable in the tires. More surface is gripping the road, including the sidewall, it's logical. And I agree, this is where I am getting all my punctures. The tire companies are behind the times, they are not keeping up with the wheel industry.

Even ZIPP who are now making tires, have said, the biggest gains to be made with wheels is tires. Hopefully we will start to see better performing tires with better protection for every day use for wider rims.

zymphad

Press-fit suck and offer no benefits. The weight saved is minimal. 30mm has more friction, and the BB30 is too narrow, it's actually not as strong as the traditional 90mm wide threaded.

Anyway, while I think the punctures are a problem. You should try riding the wider rims. The 23mm tires do ride better on 23mm wheels. I definitely will be riding 25mm wheels next year. And if I was riding CX and needed 28mm or wider, definitely would want 27mm wheels.

I believe most of us who like the wider rims and tires agree, this you can feel. I think it's more tangible than the lightest, more aero or most flexing frames.

Doge

That tire selection is, or should be very much based on road. In some areas goat head thorns rule and sealant works best, and in others small pieces of glass and in others construction derbies that like to cut sidewalls. The more tread coverage the higher the Crr (usually) and if you need it it beats a flat, but if you don't it is extra weight and resistance. Where I live going south (open) vs north (populated) will generally lead to different types of punctures.

I bought some cool brakes for my son for Christmas because he wanted them and they were light. Thing is to use on a 25mm wide brake track the pads hit along the tops. Bottom line is they are not really good brakes. But as I pull out the old stock of 20mm wide rims I think to myself (and this forum) that they were/are just fine. And the brakes hit better. My world is mostly tubular (with clincher mixed in), but I am gluing some 26s (reported 27s) on some 21s and they look great.

69chevy

Believe it or not, I do have a bike. One equipped with 20.7mm internal width wheels. With my gp4000ii tires on them, my 25mm tires are 29mm wide. I have yet to flat on these wheels with these tires. Two seasons ago, I flatted three times. I am not trolling, I just question things that are clearly false.

Doge

As a tire leans in a corner vs leaning as someone leans the bike while going straight the contact part is different.
Looking at the cross section, it does not rotate sideways like a photo image would if you had the software rotate 30degrees. Depending... Tread can less than the lean angle and stay on the road when the wheel is leaning over more than that. So a 45degree lean can be done with tread barely over the sidewalls.

WhyFi

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