rpenmanparker 

Wider rims have become all the rage lately because of the advantages they offer when equipped with 23 mm tires as compared to more traditional 21mm rims with the same width tires. As I understand it, the wider rim is stiffer and also flattens the tire and provides better traction, lower rolling resistance and the ability to run lower pressures without the risk of pinch flats. It occurs to me that just increasing the tire width on the standard narrower rim to 25mm would provide some of these same improvements at a lower weight penalty. Can anyone comment on the relative magnitude of these and other beneficial effects of these two approaches. There are not many rims that have similar depth to the wider rims (24, 25), but some approximations of weight penalty can be made vs. the narrower rims. If rims of the same depth are considered, the weight penalty would be perhaps 60 g for both wheels together. The weight penalty for just mounting 25mm tires on the narrower rims is only 20 g for the two wheels (Continental GP 4000 tires in 23 and 25 mm sizes). How would the riding characteristics of the two approaches compare? Would the permissible reduction in inflation pressure be similar. Would the effect of the lower inflation pressure on comfort and traction be similar. Your comments will be appreciated.

Robert

BoSoxYacht

Don't tell me what to do. You aren't my boss, and I can't remember the last time we had sex.

Christobevii3

I ride Grand Prix 700x24's on all my wheelsets typically. I have put a 25mm lithium 2 on 19mm wide rims and fide they ride sorta similar to the 23mm rim with the 24mm tire. The 23mm's still have a more sure foot in turns though and roll in and out of turns smoother.

I will probably only ever buy 23mm rims again (have 3 sets: velocity a23 and two h+sons). I'm actually considering getting a set of 25mm michelin service courses to try on the 23mm rims.

xjustice09x

Up until recently I was riding reynolds carbon clinchers with 25 GP4KS in the rear and GP 24's in the front (would have used 25's but the tire rubs at the top of the fork). Due to a brake track failure I decided to get some aluminum clinchers for rides with steep fast descents. Reynolds did replace my rim for free, and I do think they make quality wheels, but for some situations aluminum is just safer.

I got a good deal on some HED Ardennes which have wider rims. They came with free tires which happen to be 23's. I find the 23's on the wider rim do have much of the comfort the larger tires gave me on the narrower rims. Since they are different than the normal tires I am used to I dont know how much is due to the rim and how much is the tire. At some point I will switch to my normal tires, and can get a better idea of how much of a difference the rims make. Since my bike has always handled very well I didn't notice a big difference in handling.

So far I really like the wider rims.

rpenmanparker 

Thanks for those responses. They are very helpful and pretty much along the lines I was expecting. I have four sets of 19mm clincher wheels, three of which are built on Kinlin XR200 shallow rims, so they are very light (1,250-1,290 g). I would like to experience the benefits of the wider rims, but they are also all(?) deeper and consequently considerably heavier. I run exclusively 23mm GP4Ks now and am wondering how the 25mm ones would feel relative what folks report for the 23mm rims/23mm tires combination. That is the point of my question.

By the way, two folks above mentioned 24mm tires. Color me crazy but I didn't know they existed. I thought GP4Ks only came 21, 23, 25. Certainly that is all I see when I go looking to buy online. No?

Thanks again.

Robert

WhyFi

One thing that hasn't been mentioned is the cross section of a 23mm tire on a 23mm rim - it's less bulbous than a 23mm tire on a 21mm rim (25mm tire/21mm rim would be even more bulbous). If marketing literature is to be believed, this improves both handling (less roll over) and aerodynamics; neither of these attributes would be gained with simply moving to a 25mm tire.

clausen

Last year weighing in the 155-160 range, I trained on 25mm Vittoria Rubino Pro 90/95 psi and raced on 22mm Vittoria Diamante Pro Radial 105/110 psi identical rim/spoke wheels Mavic open pro. 40g difference per tire. The ride quality was similar edge to 22mm but that's TPI and construction. Rolling down the road I found them equal. Cornering goes to the 25mm. The 22mm where nicer on hills, sprints and coming out of corners any time you where accelerating. From my experience putting extra weight at the rim is the last place you want it.

rpenmanparker 

Yeah, you're right, and doesn't rolling resistance increase with wall height also? So the lower rolling resistance benefits shouldn't be felt either. Okay, that is the kind of stuff I was looking for. Thanks.

rpenmanparker 

Sounds like the comfort of wider tire and lower PSI is the main improvement, but other improvements of the wider rim can't be gained just with the wider tire. But I agree with you about not increasing weight at the rim and tire. It's just that sometimes the benefits outweigh disadvantages. I will think on all this and see what makes sense for me to do.

Robert

squatchy

I have played a lot in this arena. I have had a few different 21cm wheelsets and used 23 and 25 rubber on them. I then bought some Hed Belgiums in 23 and used 23/25 rubber. I am 6'3" and weigh 240 lbs.

There is no comparisons and only one way I will ever ride again now that I have played with all the combinations. Wth 21/23 combinations I have to fill the tires so much to not pinch flat that it makes my ride quality super rough and I still feel like I could pinch flat pretty easy.

Going up to 23/23 is a pretty significant improvement in several ways. Less air pressure gives a more pleasant ride (less harsh), corners way better, and it seems like I can feel the rolling resistance is better.

My final resting place is 25 Conti 4 seasons on my Hed Belgiums in 23. THE tpi on the rubber makes them very compliant and grippy. I feel like I'm super connected to the road surface. I don't get any sense of roll over, my air pressure is 20-25 psi less and I don't feel like I am subject to pinch flats at all. It might be all in my head but I think I can feel a rolling resistance difference. The tiny weight difference for me is something I just laugh at. I'll never race so the difference is something I can easily afford. The confidence and improved handeling are worth way more than the little bit of added weight IMO

I just cant think there could ever be anything better for me

canam73

GP4000s don't come in 24mm, but some other Conti GP models do.

I used to ride some 25mm tires and 23mm tires on 19-20mm rims and found I preferred the ride at the slightly lower PSI I could run with the 25s. I now use the 23/23 combo pretty much all the time because I can run the pressure I want and tire choice & availability is better with the 23s. I would also give a cornering edge to the 23/23, but that is highly subjective and a subtle difference at best.

For what it's worth, I have built wheels with the A23, Kinlin 279 (BHS 472) and HED C2. The A23 is the shallowest and lightest at 19mm deep and around 445g. The Kinlin was basically a cheaper copy of the HED at 28mm and 470g. I don't worry about the weight so much and going forward I would build with the Kinlin again as the 4 rims I built were all good out of the box and are holding up well.

WhyFi

The H Plus Son Archetype can be found online for about $60 shipped. From what it sounds like, it's similar to the Kinlin but with a welded instead of pinned joint (haven't laid hands on a Kinlin myself, so this is hearsay). Weight in the 450-480 range, depending on variance and whether or not you get the anodized ones.

rpenmanparker 

It is a bit off topic, but I will agree with you that Kinlins are very impressive, especially in their flatness and roundness. They seem to just fall into true with little effort. I have never needed to over tension spokes on one or both sides of the joint to get lateral or radial trueness, respectively, with Kinlin rims. On the contrary that was a constant problem when I was building with Velocity Aeroheads. For aluminum rims Kinlin wins, hands down.

canam73

The Kinlin is not welded, but all 4 of rims I had were quite smooth at the joint. Smoother than my 2 A23s, although they felt fine too after a few hundred miles of riding (and braking).

One other thing that I like about the Kinlin wide is that unlike the XR300 and IRD Cadence that I have built with the 279 has a much taller brake track.

hueyhoolihan

this has been my experience too.

very round, little fuss when truing. light and inexpensive.

OTOH, the silver ones have a dull finish and look to be non-anodized, and the non-braking surface is very, very thin and easily dented, but i guess that goes with the territory, no?

two sets 4,000 miles and no problems. oh, and they are XR-200's.