The Chainlink

Last summer I purchased a Specialized Sirrus Hybrid bike. There are currently 700x32c tires on the bike. Someone had recommended that I would notice a significant difference if swapped the original tires out for 700x28c tires, and still be able to keep my current rims. I was told that if I went down to as far as 700x25c tires, I would be "pushing it," and would have to purchase new rims as well. I'm not sure what was meant by "pushing it." If it means having such small tires could damage frame, then I definitely do not want to go with the 25s. What would be the best option? Sadly, purchasing a road bike would not be feasible at this time. Maybe down in future when I have more funds and space to have both bikes. Also, I would rather not trade in my current bike toward a road. It was a wedding gift to myself and it's my companion.

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Are you happy with the bike, and the way the tires ride and handle, as it is? If so, I see no real reason to change them. I imagine the person you spoke to was suggesting the bike would feel faster with smaller tires. If that's a feel you think you want, then you can consider a tire change but they don't have to be smaller. You can have fast-rolling tires that are relatively high-volume like the ones you have and with better ride quality.

Speed is the sole reason for the change, yes. I realized I should have been more clear. The bike rides very well and I am very happy with it.

Here's a past thread that you might find helpful. You don't identify the "significant difference" someone told you you would notice, but I assume it's something related to speed or rolling resistance. You should expect the difference in speed to be negligible going from a 32 to a 28 mm tire. What is virtually guaranteed is that it will be a less comfortable ride (higher pressure + narrower tire = less shock dissipation). My commuter/city bike is a hybrid. It was sold with 28 mm tires. The first time I replaced the tires, I got the same type, but went up to 32 mm tires. Same when I replaced the tires the second time. If you want to ride faster, ride intervals.

It is a myth, for the most part, that narrower tires roll better.  There are many factors -mostly sidwall stiffness.

As for what widths of tires are safe on which widths of rims we always have Sheldon to the rescue.

Which tire fits safely on which rim?
[all dimensions in millimeters]
Tire width
Rim width
(interior)
18 20 23 25 28 32 35 37 40 44 47 50 54 57
13 X X X X                    
15     X X X X                
17       X X X X X            
19         X X X X X X        
21             X X X X X X    
23                 X X X X    
25                   X X X X X
Note: This chart may err a bit on the side of caution. Many cyclists exceed the recommended widths with no problem.
Going with smaller tires tan recommended will increase your chances of a pinch flat greatly.

That chart errors way to the side of caution.  I have put stupid narrow tires on stupid wide rims and it has been fine.

That said while it is true there will be a little less rolling resistance the speed of the bike is going to be affected very little and you will see a big reduction in ride quality and the possibility of far more pinch flats.

You live and ride in a city with pot holes; leave the skinny tires where they belong, on race bikes that get to see smooth pavement.

+1

25 or maybe 23mm is about the bare minimum on Chicago's mean streets IMHO.  Anything less is just being a racer-poser IMHO.

notoriousDUG said:

That chart errors way to the side of caution.  I have put stupid narrow tires on stupid wide rims and it has been fine.

That said while it is true there will be a little less rolling resistance the speed of the bike is going to be affected very little and you will see a big reduction in ride quality and the possibility of far more pinch flats.

You live and ride in a city with pot holes; leave the skinny tires where they belong, on race bikes that get to see smooth pavement.

Man, what do you have against people who race bikes?  Did a paceline come by and steal your lunch money when you were a kid or something?  

Most racers use 23mm or 25mm tires and the trend has been towards wider rims and tires because they offer better comfort and rolling resistance and possible aerodynamics.  I think the only people using 21mm or 19mm tires even occasionally are the track guys and/or tt/tri people.  23mm tires work fine in chicago in my experience and I think one or two of the regulars here have been using 23mm tubular tires without too many issues.


James BlackHeron said:

+1

25 or maybe 23mm is about the bare minimum on Chicago's mean streets IMHO.  Anything less is just being a racer-poser IMHO.

notoriousDUG said:

That chart errors way to the side of caution.  I have put stupid narrow tires on stupid wide rims and it has been fine.

That said while it is true there will be a little less rolling resistance the speed of the bike is going to be affected very little and you will see a big reduction in ride quality and the possibility of far more pinch flats.

You live and ride in a city with pot holes; leave the skinny tires where they belong, on race bikes that get to see smooth pavement.

Switching from a 32mm wide hybrid tire to a 25mm high performance tire would make the bike feel a lot snappier, you will be removing close to half a pound of the rotating mass... Yes you probably could use a 22 or 23 mm racing tire, but you would not be happy with the durability on the Chicago streets.

Most of us racer posers ride 23-25mm tires, unless it is our tubular race wheels and then 22 is most common

I have nothing against those who race.  Racing is cool, on a track or on the road with a chase crew...

Ride a race bike on the street and suffer the consequences of your poor decisions.  These are facts of nature and physics. 

It's not hate on race bikes, it is hate on Chicago streets.  I consider 25 and below to be skinny tires.  I pretty much won't ride a tire under a 28.  I used to get pinch flats on 25s if I didn't keep up on the tire pressure religiously.

I just don't think the trade off is worth it for what I think is a pretty minor increase in performance.


S said:

Man, what do you have against people who race bikes?  Did a paceline come by and steal your lunch money when you were a kid or something?  

Most racers use 23mm or 25mm tires and the trend has been towards wider rims and tires because they offer better comfort and rolling resistance and possible aerodynamics.  I think the only people using 21mm or 19mm tires even occasionally are the track guys and/or tt/tri people.  23mm tires work fine in chicago in my experience and I think one or two of the regulars here have been using 23mm tubular tires without too many issues.


James BlackHeron said:

+1

25 or maybe 23mm is about the bare minimum on Chicago's mean streets IMHO.  Anything less is just being a racer-poser IMHO.

notoriousDUG said:

That chart errors way to the side of caution.  I have put stupid narrow tires on stupid wide rims and it has been fine.

That said while it is true there will be a little less rolling resistance the speed of the bike is going to be affected very little and you will see a big reduction in ride quality and the possibility of far more pinch flats.

You live and ride in a city with pot holes; leave the skinny tires where they belong, on race bikes that get to see smooth pavement.

Matthew, the width of tire has less effect on speed compared to sidewall flexibility, rubber quality, air pressure, and tread. Oftentimes skinny tires "feel" faster simply because they transmit more high frequency road vibrations. It's easy to equate that feeling with speed, but it's usually just a perceived difference.

If you want to go faster and keep a wide tire, find something without kevlar reinforcement, like a Grand Bois Cerf, Conti GP4000, or non-tourguard Panaracer Pasela.

Also, "pushing it" probably means that you have relatively wide rims on your hybrid, so you should not ride a narrow tire because it'll more likely damage the sidewalls and make the tire radius more square - therefore increasing rolling resistance.

I found a large speed difference by pumping the tires to the maximum 80 pounds on my Trek 7100 (35 mm tires). My experience: Last weekend I rode my brother's high end road bike with tiny tires for 20+ miles and was around 3mph faster on flat ground for the same effort (as measured by heart monitor) I was used to.

When I topped of my tires this week I put in 80 psi instead of 70 (I got in the habit of running lower pressure to add resistance thinking I'd get into shape faster, the ride is less harsh, and to increase traction) and was really surprised that I got back most of the 3mph.

Some observations from a hybrid rider who who spent time on a road bike for the first time: The road bike accelerates faster and is more responsive, but straight and level speed with no wind and moderate effort is close (15 mph +/- in my case). I could sprint faster but if there's any head wind, the hybrid slows down much faster than the road bike. To me hybrid is more comfortable, however.

Back to the tires, I too was thinking about narrower tires until my recent experience. Now I'll probably keep what I have until I have to replace them.

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