Wide rims versus wide tires?

[mhespenheide]

Forgive me if this has been discussed before -- if so, can you point me towards the appropriate thread(s)?

Has anyone ridden an A/B comparison of similar width comparisons between different sizes of tires and rims that ended up having the same final width? I'm wondering about something like comparing a 25mm tire on a wide rim versus the same tire in 28mm on a standard rim. To put it another way, is there something more to the ride of a wide rim than just the additional width of tire that it provides?

Second question: if there really is a benefit to the wide rim (beyond the extra width of the tire), as is talked about with the "bread-loaf" shape better than the "light-bulb" shape, do those benefits go away if a wide tire is used? Say, a 28mm (nominal) tire on a wide rim -- doesn't that get back to a "light-bulb" shape? If those benefits do go away, should we be looking at even wider rims? Should we be lacing up some 29'er rims for the road to go with 28mm or 30-35mm tires?

Thanks for any thoughts/input -- particularly on that hypothetical A/B comparison.

[Bruce K]

Some manufacturers already make 25mm rims (HED Plus).

Yes a 28 tire on a 23 rim just makes a larger "old" profile

BK

[Ralph]

Not everyone (me included) buys into the lastest fad of wide tires on wide rims. Especially for all uses, all riders, all body weights, all roads, etc. Agree the tire needs to fit the rim properly, and there are plenty of good uses for a wider tire. I even use a 700X25 on my daily rider. But my fastest wheels overall still have 700X23's. I might add I only weigh 155 and I ride on smooth roads.

[tigoat]

I have used ENVE 45 (traditional narrow rims) rims with 28c tires and ENVE 29XC rims (modern wider rims) with 25c tires. They do not feel the same way. The ENVE 29XC wheels feel much more smoother and faster and resemble more of a tubular feel. I have also used HED C2+ rims, which are probably widest road rims available right now. The HED C2+ wheels perform very similarly to the ENVE 29XC wheels. Bottom line is that don't fool yourself into slapping on some traditional narrow rims with wider tires and think they perform the same as modern wider rims do, as they are not the same.

[mhespenheide]

Originally Posted by tigoat

I have used ENVE 45 (traditional narrow rims) rims with 28c tires and ENVE 29XC rims (modern wider rims) with 25c tires. They do not feel the same way. The ENVE 29XC wheels feel much more smoother and faster and resemble more of a tubular feel.

Thanks for that, tigoat. Guess I'll have to at least sip some of the kool-aid and try out some wide rims... My budget may have to wait until more people are selling them used, but I guess they're starting to show up.

[RobJ]

Tigoat and Mark McM nailed it and my testing combos falls in line with Tigoat. The ride quality of the wide/wide combo vs. narrow rim/wider tire is very noticeable. Running latex tubes has also contributed to a nice improvement. One other point not discussed, but important too is the aero properties of the various combinations. Most of the wider rims paired with a 23mm tire are topping the charts for aero and rolling resistance. Obviously mostly a concern if time trialing or triathlon etc.

[professerr]

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[jamesutiopia]

Shifting from 23 to 25mm tires was a big improvement for me (190lbs, 63cm frame size). 28s have been even nicer, even on beautiful California roads. I've ridden 28s on Belgium+ rims, but not on narrow rims. They are nice for sure-footed descending.

I can see why this would be a less tangible benefit for more ideal-size riders.

[eippo1]

So to take this a bit further, I would like to fit a wider tire on my bike, but the limiter is the front brake having only 3mm clearance at the top with Conti 25's (that actually measure closer to a 28). If I went with a wider rim on this bike, would the tire, being less of a lightbulb, come down lower vertically since it is more spread out?

[druptight]

Originally Posted by eippo1

So to take this a bit further, I would like to fit a wider tire on my bike, but the limiter is the front brake having only 3mm clearance at the top with Conti 25's (that actually measure closer to a 28). If I went with a wider rim on this bike, would the tire, being less of a lightbulb, come down lower vertically since it is more spread out?

That depends. See the first post here: http://forums.mtbr.com/wheels-tires/...th-756818.html

[marciero]

Originally Posted by professerr

My only caveat to that conclusion is that there are big differences in the construction of the Ardennes and C24s that, for all I know, might outweigh the differences in rim widths.

I think there may be something to the difference in construction of rims. The Belgium+ seemed to me to ride noticeably better than the Dyad, more than just the 1 mm difference would seem to explain. And I only had it in the front. But I could not say it wasn't all in my head. I experienced the same thing when I built up a 650b Pacenti SL 23 (24 mm) to replace the Velocity A23, again only on the front.

[Neil]

I'm a convert to the new generation of wider rims, coming from tubs.

I've got HED Belgium rims on the CSi with 25c Corsa's, it's hugely sure-footed and very comfortable.

I've got FLO30's with 25c Conti GP4000-S II's, same thing - and they alternate with 25c Ultremo's on HED Stinger 4's.

[nbl78s]

I was thinking of joining the wider movement but I am running Dura Ace 7700 (just because I just really love the looks of it). Will I run into fit issues using A23's and 25mm tires with the older 7700 brakes?

[Davist]

I went from 19mm to Archetypes, been using 28mm tires for years. To me, the difference was subtle, though definitely faster and more comfortable overall. Ran too low a pressure (oops! in the 60's at 190lbs) got some pinch flats until I figured out that ~85 front/90 back works for me. Side benefit is the width of the rims, I wanted to build my own wheels, lighter and better than factory wheels I could afford.

[exapkib]

Originally Posted by nbl78s

I was thinking of joining the wider movement but I am running Dura Ace 7700 (just because I just really love the looks of it). Will I run into fit issues using A23's and 25mm tires with the older 7700 brakes?

No troubles here. I've been riding a 7700 equipped bike with 25mm Conti 4000s on Pacenti SL23 rims for a while now without any trouble.

It does require some adjustment of the brake calipers, but I found that I have plenty of room to work with.