Commuting - Going Bigger Than 32cm?

I just swapped out some skinny 23cm slicks on the Cross Check that I picked up off CL with 32s Vittaro Randonneur Cross tires. They are much better, but I am thinking maybe bigger would have been even better. I picked them up at REI, so I could always return.

How much is lost in speed by going bigger? What size do you guys like riding (considering I am not a racer)?

How much is lost in speed by going bigger?

None, unless you're climbing big hills.

You'll have a heckuva time finding a frame to clear 32cm tires! :lol:

I see quite a few guys on the randos riding 32mm tires. Fewer riding 35mm, but there are some. Most seem to be riding 25 or 28mm.

I have 28mm Gatorskins on my commuter/brevet bike, and 28mm Rando-Cross on my fixie.

The Cross Check will clear 700x45 WITH fenders..

I'm among the fewer that ride on 35 mm. tires. Of course speed is not my concern. The wider tires give me a lot more confidence on slipery road, particularly where there are motor vehicles speeding nearby.

The Cross Check will clear 700x45 WITH fenders..

His comment about frame clearance was because you wrote 32cm instead of 32mm. 32cm is about a foot across. that would be a seriously wide tire!!

I ride 32mm on my C-dale touring bike. I really like this width tire. I think it gives a nice balance between speed and comfort.

But I am going to switch to 28mm soon because I want something just a hair more zippy.

I started with 38mm, then went to 32mm and I'm now using 28mm.

The rims that were holding a 23mm should also hold a 32mm, but will not be wide enough for anything bigger.

Unless your roads are really bad, the 32 should be wide enough. I can't think of any benefit to a wider tire on pavement.

Michael

I, uh, think you mean millimeter, not centimeter. 32cm tires would be over a foot wide.
I switched from the 38s my bike came with to 32s. I think I might go to 35s next, though it's easier to find 32s. I don't have a lot of feel for how much difference there is. I really don't think there's all that much. I think speed depends more on pressure than on size, but smaller tires usually can hold more pressure.

700x42c (85 max psi) combination tread, here, but I ride on a wide variety of surfaces.

For me, bigger tires are usually better. I smashed my frame's rear chain stays so it would clear 35mm Kenda KWest tires. Reminds me if my old Schwinn with 1 3/8" tires, nice a smooth for the urban road, works great on crushed lime trails.

I have had comfy rides on 35 mm.

I run 23 and 35 the 35 are much more comfortable but I do find them a bit more work. I think for me, my ideal is about 25-28.

I switched from 35s to 32s, and these particular tires were actually faster. I guess it depends on what you get. FWIW, the faster 32s are Continental City Rides. Faster tires weren't what I was interested in, just fitting them better under fenders. :)

I'm among the fewer that ride on 35 mm. tires. Of course speed is not my concern. The wider tires give me a lot more confidence on slipery road, particularly where there are motor vehicles speeding nearby.

I ride 35mm tires (Schwalbe Marathon Supreme) on the La Cruz, with 45mm fenders. It's awesomeness. :)

I use Panaracer Pacela 700-35 on my two primary commuter bikes. Some tire manufacturers don't accurately mark their tire widths. Panaracer was guilty of this up until a few years ago. What they formerly sold as a 35mm tire was closer to 32mm, and so on down the sizes. Now when you buy a recent vintage of Panaracer 700-35 you get a nice fat round tire, a true 35mm.

Skinnier tires are going to be faster, because they weigh considerably less. Tire weight isn't the same as the weight of other components, either; it's much more important, because your tires (along with the rest of your wheels) spin quite speedily. Breaking the inertia of a heavier tire/wheel will be harder, because that's how physics works.

If there's anywhere on your bike you want to keep the weight down, it's the bits that move, ie. wheels, tires, and to a lesser degree cranks.

If you're talking about roads I think 32 mm is plenty big and 40 mm would be on the large side. I don't know if there would be that much difference between 32 and 35. As said before, tire manufacturers don't always report sizes accurately so a 35 might actually measure around 32 mm anyway.

As said before, tire manufacturers don't always report sizes accurately so a 35 might actually measure around 32 mm anyway.

I've found most of the larger tire sizes to be pretty close on the stated size. I think the shady reporting is usually on the smaller tire sizes so manufacturers can claim a "lighter than the competitor" advantage, when in reality they're saying it's a 25 but it's a 24.
I have heard of some going the other way, though. Grand Bois Cypress tires run 1-2mm larger than stated; a buddy of mine couldn't clear a pair in his fenders due to misrepresented sizing.

I've found most of the larger tire sizes to be pretty close on the stated size. I think the shady reporting is usually on the smaller tire sizes so manufacturers can claim a "lighter than the competitor" advantage, when in reality they're saying it's a 25 but it's a 24.
I have heard of some going the other way, though. Grand Bois Cypress tires run 1-2mm larger than stated; a buddy of mine couldn't clear a pair in his fenders due to misrepresented sizing.

You see some interesting stuff. The 35 mm Nokian W106 I got last year said 35 mm on the cardboard label wrapped around it, but the tire itself said 37 on the sidewall. I believe what was going on there is that the width was 35 mm but it was a bit taller than a normal 35 mm tire so the sidewall said 37.

Sure enough, it wouldn't fit under the front fender of my old road bike, but a 35 mm Marathon Winter would (barely). The Nokian A10s were listed as 32 mm but they were more like 30 mm.

I like 28 as a summer tyre and 32 for winter. My tourer usually has 32 and I ride tracks and trails with a load.
Regarding accuracy of the specs, the worst offenders are around 25-28mm. I would never buy this size without seeing it first.

i think 28-32 tires are ideal in almost all situations (not racing) unless your roads are bad (cobblestone) or you frequently cross tram/train tracks.

You see some interesting stuff. The 35 mm Nokian W106 I got last year said 35 mm on the cardboard label wrapped around it, but the tire itself said 37 on the sidewall. I believe what was going on there is that the width was 35 mm but it was a bit taller than a normal 35 mm tire so the sidewall said 37.

Over a year ago I ordered a pair of 28mm Gatorskins.
When they arrived, I carefully checked the cardboard labels to ensure they both said 28mm.
After I mounted them, it was clear something was wrong.
Checking the sidewalls revealed one was a 23mm.

I recently replaced my stock 32mm Kendas for 35mm Schwalbe Marathon Plus'. The MPs are much heavier, but offer better flat protection and I feel they give me a slightly smoother ride. I don't notice any difference in rolling resistance or speed.

I wouldn't bother. I started with 38 hybrid tires on one bike and 2" tires on another. I went back to old school 27 x 1 1/4" for most of my season on two other bikes. I'm bringing the converted hybrid back into service which now runs 35 "city" slicks. I've been thinking about bringing that bike down to 32s and moving to a straight slick like my 27" Armadillos which served me so very well. I'm always looking to make my life easier, cuz I'm a lazy bastard.

32's are my largest non-studded size. I can ride the local gravel and crushed limestone paths with the 32's no problem, and they are good for the road as well. For pure road riding I use 23 or 25's, but I have multiple bikes. If I had just one bike, I would make it 32mm for all around versatillity.

I just swapped out some skinny 23cm slicks on the Cross Check that I picked up off CL with 32s Vittaro Randonneur Cross tires. They are much better, but I am thinking maybe bigger would have been even better. I picked them up at REI, so I could always return.?

There is a HUGH very noticeable difference between 23mm and 32mm. However, IMHO, you will see diminishing returns going larger.

But I am going to switch to 28mm soon because I want something just a hair more zippy.

"Narrow tyres are faster" is one of those things that everyone knows and is wrong. Jobst Brandt is a legendary expert on bicycle technology - an ex-Porsche engineer who worked at Avocet and published the bible of bicycle wheel building. This is what he said about tyre width:



http://yarchive.net/bike/slicks.html

The question often arises whether a small cross section tire has lower
rolling resistance than a larger one. The answer, as often, is yes
and no, because unseen factors come into play. Rolling resistance of
a tire arises almost entirely from flexural rubber losses in the tire
and tube. Rubber, especially with carbon black, as is commonly used in
tires, is a high loss material. On the other hand rubber without
carbon black although having lower losses, wears rapidly and has
miserable traction when wet.

Besides the tread, the tube of an inflated tire is so firmly pressed
against the casing that it, in effect, becomes an internal tread.
The tread and the tube together absorb the majority of the energy lost
in the rolling tire while the inter-cord binder (usually rubber) comes
in far behind. Tread scuffing on the road is even less significant.

Patterned treads measurably increase rolling resistance over slicks,
because the rubber bulges and deforms into tread voids when pressed
against the road. This effect, tread squirm, is mostly absent with
smooth tires because their tread cannot be deformed laterally by road
contact. Rubber, although elastic, is incompressible.

Small cross section tires experience more deformation than a large
cross section tire and therefore, should have greater rolling
resistance, but they generally do not, because large and small cross
section tires are not identical in other respects. Large tires nearly
always have thicker tread and often use heavier tubes, besides having
thicker casings. For these reasons, smaller tire usually have lower
rolling resistance, rather than from the smaller contact patch to which
it is often attributed.

These comparative values were measured on various tires over a range
of inflation pressures that were used to determine the response to
inflation. Cheap heavy tires gave the greatest improvement in rolling
resistance with increased pressure but were never as low as high
performance tires. High performance tires with thin sidewalls and
high TPI (threads per inch) were low in rolling resistance and
improved little with increasing inflation pressure.


I.e. wide tyres made out of good, not too thick, rubber are faster than thin ones, but were hard to find when Brandt posted this. Conti Sports Contacts and what have you have broken this mould.

Narrow tyres do have less air resistance - and this becomes more important than rolling resistance at TDF speeds, which is why narrow tyres rule there. But air resistance varies more than RR with speed - at commute speeds the RR advantage of a high quality wider tyre should more than compensate, plus you get better cornering, better braking, and more suspension.

There is a HUGH very noticeable difference between 23mm and 32mm. However, IMHO, you will see diminishing returns going larger.

That would depend on the rider's weight and road conditions.

I ride 35mm tires (Schwalbe Marathon Supreme) on the La Cruz, with 45mm fenders. It's awesomeness. :)

Excellent choice of bike and tyre. Supremes are a real super tyre - you can get somewhat faster rolling rubber, but only at a serious cost in toughness and durability.

i switch between 25C gatorskins and 40C vittoria randonneurs during the spring summer and fall months. i find 40C to be more comfortable and a better ride overall, but they're more difficult to climb and accelerate with. almost always take the 25C on days when mileage > 35.


Nokian Hakkapelitta 700X40C 240(?) studs in the winter with fenders.

edit: i ride a cross check as well.

I ride Schwalbe Marathons on my 26inch wheeled LHT. They are stated to be 37c but really they are 1.75 inches wide which means what, 42-44c? I like them a lot.

lab vs real life is a funny thing. thinner higher pressure tires are faster in real life.

The Cross Check will clear 700x45 WITH fenders..

Hi,
I am thinking about buying a Cross Check. You mentioned that the Cross Check will clear 45mm tires with fenders. This is exactly what I would like to run. I have had troubles with fender clearance with various other frames in the past. It would be great to know what brand of 45mm tire and what type of fenders are you using on your Cross Check? Thanks.

love the panaracer tservs in 700x 35 for the wet months and loaded touring. fabulous ride, very lively, and they feel fast except uphills.

As we say around the parts counter, "once you go fat, you never go back" :D

My two main commuters run 700:28 Marathons and 26 by 2 Schwalbe Hurricane Sport tyres (559:50) and although there is a definite difference in rolling resistance the 26 by 2 tyres (at 75 psi) still roll out very quickly and I can maintain very good speeds.

The 26 inch tyres eat up the bad roads with wanton abandon and I roll over and through things I would be dodging with the 700:28's which run at 90 psi.

At the end of the day, (or the commute) there is not a lot of difference in travel time... and the bike running the 26 by 2 inch tyres is also a fixed gear.

I also have several fixed gear touring bikes that run 26 by 1 1/8 tyres (vintage Dunlops) and 26 by 1.5 Marathon tyres and have been clocked on the 26 inch Marathons at 37 kmh (cruising) and have been able to maintain a speed of nearly 40 kmh on the vintage bike for an hour straight.

I was simply amazed that a smaller diameter, higher volume tyre could roll out so fast, especially when their max pressure was 60 psi.

Of course... when I want to go faster I saddle up the vintage racing bike that runs on high psi tyres that are 630:20.

The rims that were holding a 23mm should also hold a 32mm, but will not be wide enough for anything bigger.

This is what conventional wisdom dictates, but isn't really true IMO. I run the stock road wheelset from my trek 1500 (was 23mm tires, rim width is 13.5 inner) with 37mm tires on my surly LHT. There has been no issues whatsoever running 55 psi....it doesn't even look "funny" or anything. Actually, it looks much better than many stock mountain bike tire/rim combos you'll see in a bike shop.

Running larger tires (and at lower psi) is definitely slower - it's all a trade-off.

Do you want to maximize your speed or your comfort? You have to pick one. Or, just run a medium width and be happy with a blend of both.

I have two wheelsets for my crosscheck- one with 25mm gatorskins and the other (outside of cross season) with 40mm Vittoria Randonneurs. The 40mm tire adds a few minutes to my 40 minute commute, but is infinitely more comfortable and fun to ride than the 25mm. I even did a 300 mile tour this summer (grand canyon, zion np and bryce canyon) on the 40mm randonneurs with no problem. 65/70psi.

i will note that the 40mm randonneurs are large for their size. i've been having trouble finding fenders that will fit over them in my cc frame, but it's definitely doable.

As we say around the parts counter, "once you go fat, you never go back" :D

I like a big fat tire too - it takes a lot of the road shock out of a rigid bike and that's worth whatever extra weight or resistance there might have been - which I didn't notice. And if you're not riding a rigid bike, then the extra weight will be insignificant compared to the weight of the suspension, so why bother beating yourself up about it?

A lot depends on the terrain you ride on. It is very hilly where I live, so wheel weight is very important. So I use lightest tire that is still durable and comfortable. For me, that means 700 x 25s. I may buy some 28s next time I get tires as long is the weight is still in the same ballpark, but I wouldn't go for 32s unless I was touring.

I go with 35mm because I really like them for longer rides and touring - more comfort at the end of the day, greater stability. I would imagine that I give up about one mph compared to a thinner tire. This is insignificant in my commuting situation, with traffic lights and stop signs. In other words, my elapsed time on a commute is not affected by the tire size. What does count is freedom from flat tires.

I'm running 32mm Schwalbe Marathon Plus tires on my Quickbeam, which is the bike I use most for commuting. On the Atlantis I usually run either 35's or 38's. I like the fatter tires for the fact that they're more capable when you're riding crappy pavement or go off-pavement, which I do somewhat regularly. The first 1/2 mile or so of my commute is on dirt/gravel (I cut down a sod farm access road) and the 32's on the Quickbeam handle it just fine. If I go down to 28's, they tend to knife in and squirm more. I once threw a set of 700c X 47mm Continental Top Touring tires on the Atlantis and they fit just fine, even with fenders. They were great off-pavement and provided a nice cushy ride, but I did feel like the 47's were sluggish on the smooth pavement.

I just put some 700x35 Schwalbe Marathon Supremes on my Miyata, and I love them. When I initially switched over to 700's wheels on the bike, I used a wheelset from an old road bike which had 700x25 Marathon Plus tires. The 25s rolled nicely, but they were definitely a bit of a harsh ride, and I was always worried about pinch-flats when I hit some of the bigger bumps along my commute. The upgrade to the Marathon Supreme (generally considered a slightly faster tire than the MP) combined with the extra width made a huge difference for me. Speed is about the same, but the cushioning is greatly improved.

I am thinking about buying a Cross Check. You mentioned that the Cross Check will clear 45mm tires with fenders. This is exactly what I would like to run. I have had troubles with fender clearance with various other frames in the past.

I just got a Cross Check frame. It's in the shop right now for a color change. Before I sent it off, just for grins, I tried to slide the 29x2.0 (700x50) Marathon Supremes (not knobby) from my 29er on the rear. It wasn't even close to fitting, so personally I'm skeptical about the 700x45 claim. I pulled my 700x40 Continental Town Rides from storage and will be trying them when I get the bike back (hopefully within a week). Check back then if nobody answers your question sooner.

Also, see this link, which apparently answers your question and rebuffs my skepticism:

http://www.flickr.com/groups/417924@N22/discuss/72157603219872633/

I ride Marathon Supreme 35's on my Tricross. They roll faster than the stock Specialized Borough 32's that came on the bike. No flats and high volume works well for me in Colorado. I ride a lot of mixed surfaces and they work great. Sometimes I wish that I had gotten them in 32's only because the options for wheelsets open up exponentially. I wonder if I could mount a 35 on a DT Swiss 1.1 Rim, everything seems to point to a 32 being the max. Keep that in mind.

I noticed tubes run on two sizes 32MM - 25MM and 35MM>
So 32mm tubes are easier to come by?

lab vs real life is a funny thing. thinner higher pressure tires are faster in real life.

In the lab studies, one must control pressure and size as independent variables. The pressure part - which you added - is very important.

People usually look at it backwards, but what you should do is decide what pressure ranges you want to run, then decide what tire(s) will run those pressures (also taking rim compatibility into account). The desired pressure range is further dependent on issues like speed vs. comfort vs. stability and such.

So, to anyone who asks 'will Xmm tires be better than my current Ymm tires?', the necessary follow-up question is 'what pressure do you (want to) run?'

28 Rando in the front with a 32 Panaracer Ribmo in back...it's a fun combo

I ride Marathon Supreme 35's on my Tricross. They roll faster than the stock Specialized Borough 32's that came on the bike. No flats and high volume works well for me in Colorado. I ride a lot of mixed surfaces and they work great. Sometimes I wish that I had gotten them in 32's only because the options for wheelsets open up exponentially. I wonder if I could mount a 35 on a DT Swiss 1.1 Rim, everything seems to point to a 32 being the max. Keep that in mind.

And I went opposite direction when my Boroughs wore out. I got Conti 4 seasons in 700x28. These are wicked fast, in fact felt twitchy at first. As a light Athena I did not notice much difference in comfort, I run front tire about 10psi lower than back anyway, for my wrists.

SF

I went with a 32 Vittoria Cross Randonneur. I like em. I am thinking fatter may have been even better, but this is a good tire.