Q. Will I benefit from different tire size or type?

[badandy]

I have 700 x 35 tires on my hybrid bike, and I've recently learned that I can change the 35 (width?) to a different size, ie. 32, 28 etc.
Question is, do I want to? I ride exclusively on pavement in a city, so I'd like to maximize tire efficiency for this type of driving.

- First of all, will it work to put different width tires on my hybrid/city bike, or is there an issue with narrower widths coming off the rim, etc.?

- Secondly, is there an advantage to using a different tire size if I can, or should I assume the original 700 x 35 tire size was already designed ideally for city driving?

- Lastly, I read expert testimonials that said slick tires are best for pavement riding, cornering, wet driving, traction and have less rolling resistance, basically because more rubber contacts the road. I was looking to buy the Michelin Transworld City, but its not a pure bald slick, it has fairly deep recesses, presumably to siphon off water (which I read isn't necessary for bike tires, and that this system doesn't work better than slicks). So my question is, would I be better off driving in my city with a pure bald slick, such as the
Avocet Road 20, instead of the Michelin Transworld City? Or is it even better to use DIFFERENT TIRES for the front and back? Any commonly known disadvantages to going with pure bald untreaded slicks on pavement, such as premature tire wear, as compared against tires with a tread?

[joshua_w]

Possibly but it doesn't mean siped tyres should be avoided, because they may happen to be generally excellent tyres still with plenty of grip (more grip than more heavily treaded tyres on road). There aren't too many totally slick tyres on the market so it's unwise to limit yourself just to them.

Front tyre takes less weight and gets an easier life so it can be different - different width, different tread, certainly different pressure. Grip is more of an important factor for front tyre as well.

Treaded tyres tend to have a deeper layer of rubber so are more puncture resistant and last longer. If this is a major concern, you could use a tyre like this at the rear with a lighter, slicker tyre on the front.

[travelernj]

I have the Continental Travel Contact in 26" on a city commuter mountain-type bike and have been very happy with it. I see that they make a 700x37...

http://www.conti-online.com/generator/www/de/en/continental/bicycle/themes/tires/city/travelcontact/travelcontact_en.html

There is a large center patch that is a slick for all intents and purposes. And when I go off-road (sort of, light off-road only with these), I can drop the pressure and get a little traction from the side knobs; nice to have that option. At first I was worried that I would be riding on the knobs in turns on the road, but that hasn't happened. I'd have to be making some fast turns at a good angle to hit the knobs, and I don't ride this bike that hard.

It is heavy, but rides very nicely. In 700 miles I notice almost no wear front or back. It took 500 miles just to wear off the center molding ridge on the back wheel. And I haven't had a flat yet. By changing the pressure, you can change the feel of the tire. After looking at a variety of smooth tread tires with some off-road ability, these seemed to be the best tread design I could find, and I am very happy with them.

[badandy]

32-38 sounds reasonable, I'm not sure its a good idea to push it to extremes, beyond the original design of 700 x 35.

I don't care to win any races, but less effort would be nice, because
I'm extremely lazy. Hence the reason I am looking at baldies; less rolling resistance. The streets the bike will ride on are all paved, but there are plenty of cracks to deal with, and often have to jump on or off the sidewalk, so there are bumps to deal with. I don't know that I need to corner "aggressively", because I'm not an aggresive rider; but I want to corner -safely-, particularly in wet conditions, if I get caught in the rain. I do not ever want to crash. It would help if I simply knew, in general, what the advantages and disadvantages are between "skinnier" and "fatter" tires.

My original tires were Japanese-made Panaracers (Ridge Line 2). So they weren't OEM's and they didn't seem cheap, but I'm replacing them because I recently learned they have no business being on a bike that is designed to ride exclusively on pavement.

You see, THIS is why I am thinking of exchanging the Michelin
Transworld City tire that I bought. Because I only learned afterward that tread siping only caters to ignorant cyclists; which I do not want to be! If I can get a better tire for no more than the price of the Transworld City, then I want to get the choice right now.

The Pasela is not a bald slick, it has some light treads (while the
Transworld City also has a tread, its quite a different surface than the Pasela). So I'm wondering between the two, which is better and why? (As for the IRC Metro, although its nearly treadless with little siping, I only see it listed in mountain bike tire sizes (26 x ?), and it looks like it will be near impossible for me to get at my local dealers).

[Mira]

You mean tread doesn't help. A big aggressive tread can reduce traction and slow the bike -- surely not irrelevant!

[shundewai]

I recommend that you measure the width of your rims, and then go to
Sheldon Brown's website to see what range of tire widths will fit properly.

http://www.sheldonbrown.com/tire_sizing.html#width

IIRC the number in the tire size (like your 35mm) is really the tire height, not the width, although the width is just about the same as the height.

The effort it takes to propel a bike is dependent on the tire rolling resistance. To a first approximation, rolling resistance is dependent on the tire pressure and width. Generally speaking the narrower the tire the higher the pressure and the lower the rolling resistance. Depending on your rim dimensions you may be able to use tires as narrow as 25mm. For my road work I use 700x23 and 700x20's, on narrow rims.

To further lower the effort required to propel the bike you can get light weight tires and tubes. This will lower the rotating mass and make it easier to accelerate the bike. The lower limit for clincher type tires is about 200 grams, some run up to 400 grams.

Tires narrower than 25 mm are sometimes difficult to mount, and require pressures of 90 to 120 psi. You may need a new pump. The narrower the tire, the higher the pressure, and the rougher the ride. I do not find my
20 and 23mm tires objectionable from a ride point of view, but my roads are not bumpy.

As for tread, at the risk of being flamed, it has been my experience that it really doesn't matter that much for road work. Just make sure that the tread is reasonably smooth, and does not have knobs. Buy a "road tire" and you should be OK.

[ChadRay]

Narrower tires will have the advantage of higher pressures. This will have more effect than the slight difference of rolling resistance.

As to traction, as in cornering and stopping, the wider tire will offer more, for the same reason that slicks do. More rubber on the road.

Wider will also offer better resistance to pinch flats, and a slightly more comfortable ride on rough or poor pavement.

Be sure to consider all aspects of your ride. It's not all as black and white as the tire manufacturers would like you to believe.

May you have the wind at your back.
And a really low gear for the hills!

Chris'Z Corner
"The Website for the Common Bicyclist":
http://www.geocities.com/czcorner

[travelernj]

The 35mm was chosen for its aesthetic appeal to the target market for the bicycle. I'd imagine that most hybrid buyers will put more value on comfort and the feeling of safety a bigger tire gives than on speed and efficiency.

There are advantages and disadvantages to narrower tires.

Since they are smaller and often have less rubber than wider tires, they weigh less and are easier to accelerate. My city riding has a lot of stops and slowdowns, so it makes a difference for me.

A smaller contact patch means less friction, so they are faster, but my gut says that this is actually a relatively small difference.

Higher pressure, so less time and energy spent over bumps, etc..
moving the tire itself rather than the whole bike.

Higher pressure and thinner rubber can mean more flats. And more road bumps transmitted into your body rather than absorbed by the tire.

Road cracks and potholes become much more important. Something that I can ignore on wide tires can catch a skinny tire and send me down if I don't pay attention.

For me, different tires and bikes lead to different riding experiences in a city. A narrow tire requires more attention to the road, I seem to go faster and so have to pay more attention to traffic, and going faster can be both stressful and fun. A fatter tire lets me be more relaxed about the road condition, is less jarring, and lets me jump curbs and do other things that I wouldn't try on narrow tires.

That's the trade-off I see- speed, precision, and the need to maintain focus on the road versus comfort, slop, and the ability to not be too concerned with the road. Each of us finds our own balance point.

I would suggest finding a 28mm tire that is lighter than your present one and trying it out. Maybe your bike shop has a bike similar to yours with tires this size, and you can run it around the block to see how it feels?

Don't forget how important tire pressure is, also. The same tire can take on very different characteristics at different pressures. I have some Continental Travel Contacts on a mountain bike, which are 1.75 inches wide. I can use than at 45 lbs or at 80 lbs, and it is close to changing tires when I change the pressure. If you are running your present tires at the lower end of their pressure range, go to the top end to get a taste of some of the changes skinnier tires will make.
Even five or ten pounds can make a huge difference in how a tire rides.

20mm tires in a city seems extreme. I ride 23mm on one bike and I think that the next set will be 25mm. 23 just requires more attention and care than I feel like giving all the time. Then again, I've ridden
23mms in a city for years and keep buying them. 32mm on another bike was just a bit too heavy and wide for my needs and taste.

Tire life depends on the thickness and quality of the rubber. Tread per se has nothing to do with it. No tread pattern or a minimal siping is what I look for. About all you gain from heavy treads is a funny road buzz and energy going into moving the tire knobs around rather than moving you forward. But as someone already said, marketing drives a lot of the tire design issues, so I wouldn't let minimal treads stop you from buying a tire outright. City riding is not about the absolute highest level of efficiency. What is very critical to a racer is one small factor among many for non-competetive city riding.

[badandy]

Thanks to all who have offered very helpful responses, I now have a much better idea of what tire I need for my city driving -- and the advantages are towards wider tires, so my next tire will not be any skinnier than the 700 x 35 I already have. I am even thinking I might prefer a 700 x 40. I definitely value comfort and safety over speed (although I do a lot of stop and starts as well, because of traffic lights at every block). I guess no one can tell me if a 700 x 40 would be more suited to my needs as I've outlined, so I'm gong to try to get a mountain bike to ride.

NOW FOR THE TIRE! I will accept minimal siping if I can't locally find a "full slick" in the 700 x 35/40 size I need. The Michelin Transworld
City I mentioned (http://cycleus.webmichelin.com/tires/transworldcity.htm) seems to have some pretty -deep- siping though (the only flat part is a narrow strip of tread in the center). So I'm not sure if its the best choice for safety's sake on pavement. Any better recommendations for COMMONLY
AVAILABLE tires, around the same price as the Michelin, that may be
"more slick" and thus provide better road contact on the pavement? (I don't know if I can get the IRC or Avocet brands locally; but I know for sure I can get Continental, Hutchinson, Panaracer, Michelin

[super dude]

www.sheldonbrown.com has an article on tire / rim sizes.
There are limits to how narrow or wide on can safely go on a given rim. Also a pointer to the faq, since tire width and tread have been discussed often (google groups lets you read old articles posted here).

I like 700*28 or 700*32 tires with a puncture-resistant belt and some tread. I don't always see obstacles in time to avoid them, and dropping a 700*23 tire into a sewer grate ain't fun :-(

Probably fine in terms of comfort and resistance to road hazards. Also, marked widths are not consistent, so a PanaRacer 35 may be narrower than a Kenda 35. And tire pressure matters - cheaper tires may have lower maximum pressures.

My limited experience has been that I get more punctures as the tread vanishes (around 5000 km, I usually replace at
7000 km). So a glass shard which I ride over with impunity on a new tire (tread) leaves me flat once the tread has worn away.

There's probably a trade-off. When I was using COntinental
Super SPort (slight tread, no puncture-resistant belt) I was getting 5 or 6 flats / week. People smash bottles on the bike paths. People sprinkle nails on the bike paths. And there's always accident debris on the roads - the "bike lanes" are such a convenient place to sweep broken glass and metal parts.