big_al

After thinking about it since the last time I bought new tires I decided to go to 700x28 tires from 700x35 what a difference I rode the same route I ride everyday for fitness which on my sprints I usually avg around 17mph well today I avg between 19-20mph and I think I could had gone faster. I am super sicked about the change. The brand I bought is SOMA everwear which is what they had in my bike store..

Talldog

No surprise from where I sit ... LOL.

nfmisso

Hi Big Al;

How different is the tread pattern between the two tires?

Do you have any pics of the old tires?

Thank you

big_al

here is a pict of my bike with the tires i just took off just a note the ones i have now have very few threads on them unlike the old ones..I see if i can post close up picts of both.

prathmann

My two road bikes have tires with widths of 23 mm and 35mm front/38mm rear respectively. Both have minimal tread pattern. The difference in average speed on flat ground is insignificant (a small fraction of a mph), but of course the wider tires are heavier (and the rest of the bike is heavier as well). That makes for slightly slower acceleration and hill climbing. Aerodynamics would probably become more significant as well if I were able to get my average speeds up above 20 mph - but at the moment it's not the bikes that are the limiting factor with that problem.

cranky velocist

Is it common to switch 35's for 28's?

I was told that that the wheels I have would probably be too wide to accomidate 28's but the person telling me this was trying to sell me a specific bike & dissuade me against another.

nfmisso

As prathmann notes - most if not all of the difference is due to the tread design of the two tires. If instead of going to 28s, you had gone with 35s with minimal tread, you would have noticed a similar change in speed.

mjwithtwins

I am planning to take the 38s off my bike this week and replace them with with either 32 or 28s. With less tread. Can anyone suggest a good tire that won't cost a fortune? I have been looking online but the choices are so great and price ranges so broad it is hard to know what to pick.

EsoxLucius

The Vittoria Zaffiro (not the II or Pro) in 700 x 28 are only $14 each at Western Bike Works or Bike Tires Direct. I've got close to 2000 miles on mine and no flats, decent traction and adequate efficiency.

prathmann

Can't know for sure without knowing the specific rim, but usually quite a range of tire widths can be used with a given rim. On my touring road bike I run tires ranging from 20mm up to 38mm without any compatibility issues with the rims.

khutch

Last week was bike to work week in the Chicago area. I took my folder on the train two days, got rained out two days, and on Friday I rode the whole way on my Fuji, 52 miles round trip. I was running 32 mm Hutchinson Acrobats with are rather lackluster when it comes to efficiency and no longer available in the US even if one wanted to try or replace them. The one significant leg of the trip that was on a road as opposed to bike paths is in rather awful shape in spots and I much rather would have had 38's than 32's and I was very glad that I had pulled my 25's off the bike in anticipation of this trip! I've gone back and forth but I am now thinking that I will indeed get a pair of 38 mm Vittoria Randonneur Hypers. They should be about as efficient as any tire that is rugged enough for day to day use and when you are on a bad road width is what you want to have.

Schwalbe has a chart of suggested rim/tire widths. Just note that the rim width in the chart is the internal width from bead hook to bead hook whereas rim makers generally give you the outside width across the braking surfaces -- if they give you width dimensions at all.

Ken

javal

Rolling resistance means tires and surface/traction. I´m not at all surprised, only glad you obviously noticed the difference. Dare pump ´em hard, and you`ll soon find thats the simpliest thing to make your bike go faster.

qmsdc15

False. Reread the post you are referring to, Prathmann has said no such thing. His post says narrower tires are faster because of the weight difference and aerodynamics. Did you know air resistance is the primary force one must overcome to maintain speed on a bicycle? Rolling resistance is second. Tire pressure plays a big role in reducing rolling resistance and narrower tires can typically be inflated to much higher pressure than wide ones.

cranky velocist

Bontrager 750 32-hole alloy rims according to the website for my 7.2 fx, which come with a 35mm tire.

I was told by a trek dealer that the Coda & Sirrus had narrow tires and I couldn't go much bigger - but then a Sirrus dealer told me I couldn't go any smaller than 32's on the Trek, anyway. I'm surprised they wouldn't just slap multi-width rims on all hybrids in the same price range if they are so common. I'm happy with the width I have though.

aprevo15

i did the same thing in switching from 35 to 28. but i am having problem with the tube popping.

the cyclops

common man

i agree with nfmisso. i had two hybrids with 28 mm no tread and 35 mm no tread, respectively. i didn't notice any difference in speed. that's very conclusive for me. i'm a simple man - i don't need to think further. a mountain bike with knobby tires couldn't pick up speed on pavement. i know the position of a road bike has significant aero advantages but that's different from this discussion.

i won't go less than 35 mm. i like the comfort. it corners better. feels more stable on bumpy roads. then again, i don't ride for speed. i ride for leisure and average 10-12 mph for 60 mile rides on the weekends on my trek 7.2 fx. i ride rail trails and canal paths which have other users. it's safer for everyone not to go too fast. plus i enjoy the scenery.

khutch

For most all riders grade resistance is the most significant impediment to speed that they face. Rolling resistance is in second place and the rolling resistance of your tires is the most significant impediment your tires present you with almost without regard to the speed you are going. It is true that the total aerodynamic drag force you must overcome does become the largest flat ground impediment to speed above 18-20 mph airspeed but the bulk of your aerodynamic drag comes from your person, not your tires. The aerodynamics of tires are important to those who race because any advantage, however small, can be turned into victory if the race is long enough. For the rest of us rolling resistance is more important, tire aerodynamics are too small a percentage of the total to mean much. Your bike and the accessories attached to it have as much or more drag than your tires, any attempt to reduce your total drag with thinner tires does not quickly reach the point of diminishing returns, it starts out there.

Low rolling resistance comes from thin, high quality materials which offer minimal puncture and cut resistance. For the most part the best of these are only available in the thin tires made for racers who may win or lose because of vanishingly small differences and therefore who benefit from the small aerodynamic advantage of thin tires. To some extent tire makers seem blind to the desire of wide tire riders to have efficient tires too but some of this "blindness" may actually be imposed by the physics of thin materials and "hoop stress". Hoop stress increases with tire size but it decreases with pressure and without knowing all the details that tire engineers know it is impossible to say if we are being ignored or if we are simply asking for something the available materials are unable to provide. When everything else is equal wide tires have less rolling resistance than narrow tires and some people have speculated that professional racers will eventually discover that even for them the optimum tire width, all things considered, is larger than 23 mm.

Ken

Fiery

European classics such as Paris-Roubaix and Ronde van Vlaanderen are regularly ridden on 25 and 28 mm tires, with some riders even going up to 32, so it's not like the professional racers never ride wider tires. I would assume they would quickly notice any competitive advantages of those widths over the standard 23 mm for general racing if they existed.
I believe one of the big reasons for using narrower tires in racing is their reduced weight too, which means quicker acceleration and easier climbing.

LesterOfPuppets

Actually Prathman pretty much does say such a thing. I'll repost so you can have a second shot of getting the gist of prathman's first line or two:

Here prathman is noting that because his two sets of tires are all of minimalistic tread pattern their speed differential is negligible (less than 1 mph) and implies that the OPs greater difference (2-3 mph) is primarily due to differences in tread pattern.

He goes on to note that he thinks aerodynamics don't have much effect until you get above 20 mph, which the OP is just barely attaining, it would seem. And he also notes that heavier tires are slower to spin up and harder work to get up hills.

OK, enough semantics and back to tires...

lungdoc

I know we all like to go faster, but if riding for fitness as the OP states speed is in fact irrelevant.

Burton

If I was competing then I might go for narrow tires but I`m not. So any `road bike` I buy in the future will be a cyclocross. At least then it`ll accept wider tires and brakes designed to stop a bike - not just slow it down.

After tracking my average and top speeds over hundreds of kilometers on road/asphault tires ranging from 25 to 60 profiles, I found my average speed within 0.1km/hr on all of them. Agreed -the skinnier tires will go faster in ideal conditions. In less than ideal conditions I`m on the brakes more on the skinnier tires and for that period of time my average speed is lower. And braking is far better on a wider tire.

And any of them can be pushed over 40km/hr so its really the engine that counts. There was no significant firrerence in top speed either. There was a significant difference in flats and rim damage - enough to make even the most expensive fat Schwalbes look like a bargin.

qmsdc15

I should have said air friction is the primary force one must overcome to maintain speed on level ground. I agree with you that narrow tires are superior to fat ones for overcoming wind resistance, grade resistance and rolling resistance.

Burton

If I was competing then I might go for narrow tires but I`m not. So any `road bike` I buy in the future will be a cyclocross. At least then it`ll accept wider tires and brakes designed to stop a bike - not just slow it down.

After tracking my average and top speeds over hundreds of kilometers on road/asphault tires ranging from 25 to 60 profiles, I found my average speed within 0.1km/hr on all of them. Agreed -the skinnier tires will go faster in ideal conditions. In less than ideal conditions I`m on the brakes more on the skinnier tires and for that period of time my average speed is lower. And braking is far better on a wider tire.

And any of them can be pushed over 40km/hr so its really the engine that counts. There was no significant firrerence in top speed either. There was a significant difference in flats and rim damage - enough to make even the most expensive fat Schwalbes look like a bargin.

big_al

I am speaking from my own results after riding the bike now for three days with the different size tires and my avg speed is definetly 2 miles faster on the same route I ride everyday. The competitive soul in me wants to go faster even when my phisycal ability is not quite to par yet. I am totally stoked with the results so far maybe is just a mental thing and I find my self kicking harder who knows.