cycle2

If someone averages 15 mph, how much quicker would the pace be if the tires were change from 32 to 25? Would it add another mile maybe? How low is it recommended to go on a Hybrid if you weigh 220 pounds? I'm 5'10"--What's the bike world call a biker over 200 lbs, a clydesdale?

nfmisso

if the surface is anything like the roads around here, and current average of 15mph with 32mm wide tires, switching to 25mm wide tires would probably make the average speed around 12mph. Local roads here are not that smooth.

15mph is too low a speed for significant aerodynamic concerns with respect to tires. Once you get to 25mph average; that is another matter.

I recently purchase a bike that the previous owner had installed 23-622 (700cx23) tires on it - the OEM tires were 38-622 - did not work at well; followed all the little cracks and roughness in the pavement. Those tires and tubes have been given to a 150lbs friend for his 15lbs fixie.

10 Wheels

I went to 700 X 28's on my touring and road bike.
Seems to be a happy medium.

Keep in mind that the sidewall listing may not be the actual size of the tire when mounted on your rims.
I have had 28's measuer 26 and 30.

Scooby214

I would also suggest going with 700x28. They will absorb road imperfections better than the 25s, but will still have a sportier feel than 32s. My road bike currently still has its 700x23c tires, and they are too susceptible to transmitting road imperfections up through the bike. They are so hard, when properly inflated, that they can actually be slower than wider tires when riding over rough surfaces. As soon as I'm able, I will go up to 700x28 (or 700x25 if my road bike doesn't have enough clearance for the 28s).

Barrettscv 

I'm also a bigger person (between 230 & 205 lbs) and went from size 700x38 to 700x28. There was a 1 mph improvement from the reduced rolling resistance. The 700x28 tires were a top-quality tire that I kept filled to 95 & 105 psi air pressure, the 700x38 were cheaper OEM tires with 70 psi max rating. The better tire with higher air pressure was the reason for the better performance, not so much the smaller size.

Also, a slick tire has less rolling resistance than a tire with a tread pattern, everything else being equal. Slick tires are safe on wet pavement, too.

I later added a lighter & better wheelset and the bike felt a little faster again, the improvement in hub quality is just as important as the better rim.

Eventually I added a drop-bar road bike and that was another substantual improvement.

AdelaaR

At that speed ... narrower tyres will make you slower.
I know that many people will tell you otherwise ... but they are all wrong.

To give you an example of what tyres can do ... I rode to my wife's parents' house yesterday ... 10 miles at an average speed of 22,5 mph ... on 35mm tyres.
At that speed a set of narrow racetyres would probably have given me a slight advantage but still close to nothing.

The quality of the tyre and it's associated rolling resistance is what matters most here, not the width.

khutch

I normally ride on 32 mm Hutchinson Acrobats which are decent overall but they have none of the features that make for low rolling resistance in a tire. My LBS recently let me borrow an old pair of Michelin Pro2 Race tires, 25 mm. I took them on a 40+ mile test ride. Here is where the real world interferes with science. On the test day the wind was awful and the limestone portion of the bike trail was soft. I think the tires were more efficient, but it was impossible to be certain under the conditions. Even so I am looking for a good tire for a century attempt and I went ahead and had him order me a pair of Pro3 Race tires in 25 mm, the Pro3 is the current model of the same tire. I haven't mounted them yet but I am running the 28 mm Vittoria Zaffiro's that came with the bike as a training tire. Both the Zaffiro's and the Pro3's measure 28 mm wide on my 18 mm wide (internal) rim. That may seem odd but the Zaffiro's are probably designed for a rim that wide while the Pro3's are probably designed for a 14 mm or narrower rim.

I'm not looking for speed, just efficiency. I want to finish the century and anything that will help me do that is on my short list right now. The faster you ride the less speed advantage you get from an efficient tire because the aerodynamic power requirements are going up with the third power of speed while the rolling resistance power is only going up linearly. So, in a way, efficient tires are helping slowpokes like me more than professional racers, it is just that a racer cannot give up any advantage, however small, or he/she risks losing. I'd buy a 28 - 38 mm Pro3 Race in a heartbeat but the high quality tires are made only for racers (I guess they think the rest of us don't care about efficiency) and at race speeds aerodynamics matter a lot so 28 mm tires are quite rare, 25's are a little hard to find, and most are 23 mm and down. I'm only going with 25's because I can't find anything as good any wider but I am quite happy to find that they measure out at 28 on my rims!

Ken

LesterOfPuppets

I've never had 32s before, but there are only a couple of surfaces on which I'm happier with my 38s over my 25s - chip seal, cobbles, dirt, etc.

I'm actually running 26s now, but they're kinda rare.

28s were nice on chip seal also, luckily that's kinda rare around here too.

prathmann

I've got two drop-bar road bikes. One is set up for touring with a rack, lights, etc. and currently has 38 mm tires while the other is set up as a sport road bike with 23 mm tires (both sets of tires are semi-slick tread). I ride the two bikes with the same group of riders in our local evening training rides and find the difference in speed to be pretty minimal - a fraction of a mph when riding at 20+ mph. And the main difference is that the touring bike is substantially heavier so it's slower on the uphills. So I use the lighter bike on fast rides that are going to involve much climbing.

cycle2

Thanks for the information!

aprevo15

what do you guys think about putting 25 on the front while keeping the 35 in the rear? will that be help me go a bit faster? the road is just normal street. some parts are pretty bumpy but mostly just like a normal street road.

AdelaaR

It depends on your average speed.

aprevo15

my average is 14 - 15 mph commuting. i just want to be able to shave off some time on my commute. its 14.5 miles one way.

AdelaaR

You commute 29 miles a day? Hat off to you!
15 mph average commuting in traffic with stops is pretty fast, depending on the number of stops or forced slowdowns.
At that speed the width of the tyre is irrelevant but better tyres with less rolling resistance will make you a bit faster.
I think 35's are perfect for that speed and use.

Going fast on a bike has everything to do with power outputted by legs and with aero profile.
Power in the legs can be trained up to a certain point. Not all people are able to achieve the same results, depending on genetic differences like size of the lungs and quality of the heart, etc...
Better aero can be achieved by lowering the handlebar or getting an aerobar. Lowering the handlebar will make your ride less comfortable.
Getting an aerobar could be more comfortable if not positioned too low, but I do not recommend it for heavy traffic situations as you will not be near the brakes. It's very handy for doing long stretches of low traffic roads.

qmsdc15

If a rider averages 15mph in stop and go traffic isn't it likely that he is spending a significant portion of the time he is actually moving at speeds which the aerodynamic advantages of a narrow tire could be significant?

AdelaaR

heheh indeed.
Depends on his commute.

Scooby214

Aprevo15, how long does your 14.5 mile one-way commute take you? My 13.5 mile commute takes me 45-50 minutes in the morning, and 50-55 minutes in the afternoon (due to increased traffic). Based on your statement that your speed is 14-15 mph, I'd say you are doing pretty similar to what I do. If you have as many stops as I do, I don't think narrower tires will give you much of a speed jump. You'd still have to push harder in order to accelerate faster in between stops. I don't like to push myself on my commute, as I enjoy the time between work and home as a stress release.

Here is my own commuting experience using wider and narrower tires. My own commute is 27 miles round trip, and it is stop and go cycling. If I didn't have so many stops, I'd see a greater speed increase when I ride my road bike with narrow tires than when I ride my commuter hybrid with wider 26x1.75 tires. The reality in my case is that I don't get to enjoy faster speeds long enough before stopping or slowing with traffic to see any aerodynamic advantages of my narrow tires. I recognize that there are other variables involved since I am comparing two different bikes, so my experiences are just my experiences and can't be considered as scientific proof.

One difference I do see is in hill climbing ability, but that is because my tire/wheel combo on my road bike is much lighter than my tire/wheel combo on my hybrid. The road bike is lighter overall, making it easier for me to climb that one big hill on my way home. When on fairly level roads, the increased weight of my commuter bike doesn't really slow me down much.

Rolling resistance of your tires also makes a difference when commuting, so I made sure that both of my bikes have tires that are known for low rolling resistance. You can have narrow tires that actually have greater rolling resistance than some of your better wide tires.

When I get out on longer rides, like my lake ride on Saturday mornings, I get to ride faster for sustained periods of time. In this case, the narrow tires on my road bike can make a difference. My short 18 mile lake loop takes a little less time on average on my road bike than my hybrid.

AdelaaR

My hat off again to scooby and his commute! :respect:

aprevo15

thanks. i started commuting 3 weeks ago and i am loving it. i am getting a great workout and at the sametime saving some $$$ on gas.

there aren't too many traffic lights for me. there's about 3 really major stops. there's a stretch of about 6 miles where i don't even need to stop really.

Scooby214

Since you don't have too many stops, improving your aerodynamics and rolling resistance can improve your average speed. Since you have only been commuting three weeks, I'd keep doing it with your current setup before throwing too much money at your rig. I started commuting in January, and find that my commuting times have decreased considerably since then (without changing any parts on my commuter bike). What used to take me over an hour can now be done in less than 50 minutes. I simply built up my muscles, worked on pedal technique, improved my endurance, etc.

jbchybridrider 

I agree with all that totally you can just say it better than me.

aprevo15

it takes me about 1 hour 10 minutes in the morning and 1 hour in the evening. that's cause my body is still stiff in the morning lol. best time i got going home was 48 minutes. the lights were green and i was kinda pushing it a bit.

reading from what you wrote, i'm good with the tires i got on. like you i don't get a long stretch to really let her loose. even though i got a long stretch with little to no signal, there are these stupid rail road tracks that are really bad so i have to practically stop and slowly go over.

pixelharmony

My bike came with Specialized All Condition 700x32 tires I jumped on a good deal for Continental Gatorskins (with Kevlar bead) 700x25c.

On tarmac I go about 18-20mph. I haven't ridden either tire to make a definitive statement that one is better than the other. at 120PSI the 25c tires have a firmer ride, and I can honestly say there's noticeably less rolling resistance. I wanted to see if my average commute time (moving) is down at all, but it was extremely windy and playing 2 hours of soccer yesterday did a number on my legs and I ended up taking 10% longer than usual.

I'm also going to take these on crushed limestone today, I'll see how that works out. 700x28 probably would've been a better choice but I couldn't pass up the price for these tires.

Scooby214

The Gatorskin 700x25c is a great tire. It is what I will put on my road bike when my Specialized Mondo 700x23c tires wear out. I don't think the 700x28c will fit my road bike's frame, or I'd try them out.

aprevo15

on my ride home today i was thinking, how about putting skinnier tires on the rear? wouldn't skinnier tires on the rear able me to get up to speed faster? therefore more distance at a higher speed. i would keep the front at 35 for handling purposes.