Roadie1

I am building up a low budget project road bike and I have a couple of wheel choices and I am not sure which to go with. First, I am a 215 lb male and the bike will be used for sport riding and no racing and I take excellent care of my bikes and do not neglect them.

I am going to use a 700 x 25 tire on the front and rear. I am looking at two wheels both of which are 32 hole, three cross. One wheel has a 20mm wide rim and the other has a 25mm wide rim. I know this is an opinion question and everybody has opinions but which is the better wheel for me to go with? Thanks.

JohnDThompson 

I'd go with the 25mm rim and a wider tire, like 32mm.

Barrettscv 

I would use the 20mm wide rim. see: https://sheldonbrown.com/tire-sizing.html and scroll down.

The 20mm wide rim would have a 17 to 18mm wide inside width.

FBinNY 

+1,

If i were me, I'd choose a wider tire first, then use a tire/rim width ration chart to work back to the right rim.

However, since the OP already plans on 25mm tires (IMO too narrow for his needs), then the rim decision is easy, he has to use the narrower one, since the wider one is simply too wide for those 25mm tires.

Al1943

For "sport riding" my recommendation is the 20 mm rim and 25 mm tire. The bike will performe better with the lighter weight. Many road frames will not accept a larger tire so check before buying. 32 3-cross is a very good choice.

bigfred 

I wouldn't worry about rim width. If durability were my concern I would lean toward the rim of greater depth and weight.

SethAZ 

I'm confuselated by this. One of the alleged virtues of the wider wheels these days is the ability to have a straighter sidewall shape, less lightbulb-like. On my new wheels (the 24mm wide Pacenti SL-23 rims) I'm riding with 25mm Continental GP4Ks and due to the rim width the tire inflates to a measured 28mm width, while the same tire on my 19mm wide rims measures around 26mm. What exactly is the problem with running a nominal 25mm wide tire on a 25mm rim?

FBinNY 

I guess if you want your tire to work like that, then your post makes sense. However I challenge the notion that tires with an inverted U shape are more desirable than the classic Omega profile.

If you look at any compatibility char it'll show ideal rim widths of about 1/2-2/3 the tire width, following the accepted concept of the omega profile. The reason is that this shape has the tire approximating a circular X-section, so the hoop stress of the air on the wall is uniform, and the wall is in a fairly uniform tension (like a garden hose). The inverted U profile introduces local stress differences as it tries to achieve the natural circular section.

Also, the curved walls of the Omega profile allow more vertical deflection with less wall distortion making for better traction and a more comfortable ride.

As I said, you started with a different premise of which was better, so starting from there you'd want the wider rim.

cyccommute 

Many road bikes can't take a taller tire. A 32mm tire might not fit depending the fork.

I agree. I doubt that it would make much difference but, as with the 32mm tire, there might be fit issue with a wider rim.

SethAZ 

Thanks FB, btw I asked the question out of curiosity and the desire to learn, not to be argumentative. As I researched components to use for my wheel build I read a lot about the wider rims, and the inverted U shape seemed to be seen as a big plus, for various reasons including the different shape of the contact patch and how it affected traction in turns, the wider base of the tire (between the sidewalls) allowing more air in the tire for a similar pressure (or the ability to run a little lower pressure for the same springiness), and some other claims.

I'm just trying to sort out the various claims and arguments and keep track of them in my own mind.

This isn't worth much even as an anecdote, but having ridden my completed wheelset now I'm really, really loving the feel of the two 25mm GP4Ks on the SL-23 rims.

FBinNY 

No worries, I didn't see it as argumentative, and tried to word my post in an non-advocate way.

There's lots of fashion and trendiness in the bike world, and you'll often see press touting this or that deviation from established norms as somehow superior. Sometimes there is a real reason, as when technology changes opening up new opportunities. However, in the absence of a technical change you have to ask yourself which is better new or old.

The tire/rim width ratio is a perfect example. Pneumatic tires have been around for over a century, and are very highly evolved. Over all that time there have been trends, such as to ever narrower tires, which later on trend back closer to the established (read evolved) norm. So who to believe, the new idea (which was always possible) or the old idea which has been proven and accepted after plenty of experimentation?

This isn't worth much even as an anecdote, but having ridden my completed wheelset now I'm really, really loving the feel of the two 25mm GP4Ks on the SL-23 rims.[/QUOTE]

Roadie1

FbinNY:

You seem to be a very knowledgeable member of this Forum and I see your posts on other Forums as well. I am curious as to why you, and others, seem to feel that I should go with a tire wider than 25mm. I do have the room in my frame.

My thinking is that I want a quasi sport/race type of tire which is why I am going with a 25mm tire as opposed to a 23mm or a 21mm tire. All I see in 28mm and 32mm tires are low end heavy tires and that is not what I want. I said my bike would be used for sport riding but there will be occassions when I have to climb with my bike or when I want to get out of the saddle and hammer the pedals.

Can you share your thoughts with me on this? Thanks.

rydabent

Wider tires have several advantages. With more air, with a small leak you might be able to get home and not have to repair the tire on the trail. Bigger wider tires are far less prone to snake bike flats.

FBinNY 

Optimal tire width is a balance between various benefits and drawbacks. If we consider only rolling resistance, wider tires and.or higher pressures win out because there's a shorter contact patch and less tire distortion at the pavement. Wider tires do a better job keeping rolling resistance down with better handling and traction than narrower tires at higher pressures.

If you look at the automotive world, you'll see that higher performance cars have wider tires in proportion to the car weight than family cars. So that's the plus side for wider tires in a very short simplified version.

OTOH, it's not all rosy. Wider tires mean more weight, and a broader profile cutting into the wind. So it's not that wider is better or worse, but finding the best balance based on rider weight.

What had me urging wider tires was your weight. With 160# pros gravitating toward 23-25mm tires, I figure you should be going wider. Of course that depends on what's available. If you can find a reasonably light 28mm smooth tread road tire, go for it. Otherwise go with the widest high performance road tire you can find.

HillRider

There is another factor in the current trend to wider tires and rims. Aerodynamics. A slightly wider tire on a wider rim can have less drag due to a smoother transition from the tire to the rim and this is particularly the case with deep section rims.

The "frontier of technology" for professional racers and bike manufacturers is now aerodynamics since the UCI's minimum weight spec has precluded further weight reductions and aero trumps weight for everything but steep climbs. Since the pros are doing it, every "serious" rider is too.

cny-bikeman

What is useable for sport riding is not the same in all areas and for all riders. If you have to contend with any significant stretch where pavement tends to be broken (whether by environmental damage, bridge joints, railroad tracks, etc. or is commonly littered then that situation added to your weight would weigh against 25mm. I don't think you need to go to 32 mm - 28 mm should be OK given good inflation and puncture protection.

Worrying about the extra weight is just plain silly - one flat will easily eliminate the fraction of a percent you would gain, let alone the need to go slower over bad sections of road.

cyccommute 

What you said in your first sentence is indeed true. However, your statement applies to pavement/road conditions, as well. A heavy rider can ride 23mm (or even 19mm) tires in normal to bad road conditions just as easily as a lightweight rider can. It all depends on how they ride. Sitting in the saddle like a sack of potatoes and slamming into road hazards will damage tires and wheels with either heavy or light riders, independent of tire width.

On the other hand, a rider who "rides light" by using their legs and arms to absorb road shock can easily ride on very narrow tires without issue. I'm in the same weight range as Roadie1 and I aggressively ride bikes that have tire ranges from 23mm to 2.1" width and seldom experience pinch flats. Even when riding loaded touring bikes on sketch roads or on race bikes with 19mm tires, I don't have pinch flat problems.

cny-bikeman

Yes, riding style is another consideration I did not mention, certainly valid. But for someone on a budget I think the 28 mm is a good compromise, as flats and rim damage cost both time and money. I would think the OP has enough info to make the decision taking his variables into account.,

Roadie1

My retro build project is coming along nicely. I pulled all the components off the frame, prepped it, and painted it and it looks good if I do say so myself. I thought about changing the color but I stayed with the original paint scheme which is a red to black fade. I was a little nervous as to whether of not I could pull the fade off but I did it and the frame looks good if I do say so myself.

I have all the parts back on the bike and have been out for a couple of rides and the steel (Reynolds 531) feels so good under me and I wonder how any thinking person can spend the outrageous prices for let along ride a carbon bike without throwing up. I guess the expression "A fool and his money are soon parted" applies to all of the clowns who go out and spend in the upper 5-digits on carbon bikes when there are incredible values in steel and aluminum just waiting to be had but there's no accounting for some people . . .

I currently have my bike set up in a 9-speed configuration and I am running friction down tube shifters because the 9-speed brifters I want are on backorder but I should have this soon enough and my retro build will be done. I have gotten so used to not taking my hands off the bars that reaching down to shift required a bit of relearning on my part.

I originally posted this thread to ask about tire widths and I got some good answers. I ran into a problem with the tires I originally ordered and had to exchange them. I decided on a 25mm tire and even though my original tires were marked 25mm they were in actuality only 22mm as measured with a Vernier calipre. I could tell when I took the tires out of the package that they were wrong so I took them back and got a set of 28mm tires which actually measure 26mm. I was at first little surprised that the advertised tire widths could be so far off from actual but on doing a little research is is actually quite common. The tire makers lie and spin their numbers a lot to try and gain a perceived advantage over their competitors. Brand "V" tire will market a tire with a claimed width of 23mm when it is actually only a 20mm tire but it weighs 5 grams less than the brand "C" tire which is a true 23mm so brand "V" can claim a weight advantage over brand "C". To me this is deceptive advertising and fraud because I like to know what I am dealing with but that might just be me.

Anyway, my bike is riding nicely on the 28mm (26mm actual) tires and once the warm weather gets here I plan to put in a lot of miles. Once I get the brifters and mount them I will post before and after photos of my project. Stay safe all and keep the rubber side down.

rpenmanparker 

Unless you are weight conscious, the wider rim is the one to choose. It will give you a better ride with the 25 mm tire, already comfortable even on a narrower rim.

bigfred 

Just an FYI on the tire width issue. Most light weight, folding, kevlar bead, tires will relax and stretch over the first week or so that they're inflated and grow by a couple millimeters. At least that's been my experience. So, the 25s that immediately measure only 22 may grow to 24 or more over their first several days.

Of course, inflatation pressure also plays a role.

nymtber

I'm 225lbs (working it down) and ride 25c tires. Never an issue. I did have 28c on my hybrid, and when I switched to 25c I gained a little over 1mph average on 15 mile rides, but being a better quality tire, it rode just as smooth.

I had 23c Michelin Krylion Carbon (oh whyyyy did they quit making those? ) on my Allez I had back in 2007. Never had a problem with those tires, fantastic ride. I was around 210-215 back then.

For what its worth, backroads (where I ride) have a lot of chip seal and potholes here. Not many are all that "smooth" so take that into consideration.

I'll be sticking to 25c now. Its a little smoother, but still fast rolling. Just got to find something equal to those Krylion Carbon tires...

Dfrost 

For really fantastic larger width tires, check out the several models and brands from Compass Cycles. Yes, they are expensive, but they ride soooo well. I'm using 32mm Grand Bois Cypres on the Rambouillet with Velocity Synergy 25mm wide rims, and 29mm GB Cerf on the Marinoni with 21mm Open Pro rims. Both are fabulous riding, low rolling resistance, and remarkably light weight for their respective sizes.

https://www.compasscycle.com/tires.html

Panaracer Paselas are frequently recommended, reasonably priced, readily available from many sources, roll and ride well, and can be moderate in weight if you pick a folding bead model. They also have models with flat protection.

Roadie1

DFrost:

I had pretty much forgotten about the Panaracer tires since they seem to have gotten so hard to find. A set of the best tires I ever owned were the Panaracer Stradius Pros which I had on my Colnago (what seems a lifetime ago) and rode until the cords showed. I could never find the Stradius Pros again and thought Panaracer had stopped making tires but I am glad to see they are still alive and kicking.

I will pick up a set and give them a try. Thanks.

Dfrost 

Panaracer makes the Grand Bois tires as well as several models that Rivendell sells. Harris Cyclery is also a good source for many tires including Grand Bois and Pasela. My local REI carries Paselas in both 27" and 700c sizes, so not sure about them being hard to find.