Climbing on 35's
 

I have 1976 Raleigh Competition that will clear 35 mm tires, so I have been doing some rides in the mountains on some nice Panaracer 35's (I normally run 23's), I have ridden several times in the mountains using this setup, and I find the comfort is good, and the cornering grip is very much improved.

But wide tires seem noticeably slower going uphill, at least on climbs over a mile or so. I'm a terrible climber, so I need all the help I can get in the hills, and these honestly seem like a step backwards to me.

The 35's seem great for flat or rolling terrain, and riding in dirt and gravel, but I'm thinking twice about using them again on very hilly or mountainous paved roads (pretty much all of my riding these days). Anyone else notice slower climbing speeds on wide tires?

With chunkier, heavier tires in general, yes.

Last year, I had to send one of my road wheels off for repair so I threw on the gravel wheels (heavier wheels with 35mm G-One Allrounds - a reasonably fast rolling tire on pavement). They were on for a couple weeks, for both solo and group rides - very noticeable difference. I think that a large part of if it for me is the more ponderous feeling when out of the saddle - those heavier wheels really resist changing orientation, so the bike swaying side to side under me feels like a lot more work. To a lesser extent, in-the-saddle climbing efforts feel less smooth, like there's a slow-down between each down-stroke. Regardless, my climbing relative to my group ride peers was definitely impacted and, even solo, it just felt like more work, though teasing that out of the numbers isn't always easy.

So not to be obvious, but if you're riding paved roads, I'd hazard a guess that 35s would generally always be slower whether climbing, descending or going flat (albeit less so here) than some narrower tire. Maybe look for a happy medium somewhere between your 23s and 35s ?

Seem slower ? You should time it.

There are many different tyres out there and your 35 may be slower than your 23, but are you comparing apples to apples? The weight penalty only accounts for a few seconds on a 2 km climb. Hardly perceptible without a stopwatch.

'76 Raleigh Competition is 27" not 700C isn't it? or 630 x nn as opposed to 622 x nn

The slowdown could be because of the knobs on the tire verses slick tires.

30mm Schwalbe G-One Speed tires would be a great compromise.

https://www.merlincycles.com/schwalb...00c-98628.html

https://www.merlincycles.com/schwalb...re-129402.html

He may have replaced the wheels. 27's usually only come up to a 1 1/4" or 32c.

Panaracer makes the RibMo in 35c.

Not sure, the original 1976 Raleigh catalogue said it came stock with 700c wheels, but the amount of clearance suggests it could possibly use either size wheel.


https://cimg1.ibsrv.net/gimg/bikefor...9ad352d594.jpg

Those sure look like 27's though, would not be surprised.

https://sheldonbrown.com/retroraleig...ompetition.jpg

I was thinking that 77 was the first year that 700C's appeared on the Raleigh Comp. But I now see that it's some of the lesser model Raleighs that still had 27" tires.

Curious what rim you are running those on? Do you know what the internal width is on the rims?

I know it's in the picture, but........

They're some Shimano 500's, 21 mm OD, so the inside diameter is probably ~17-19 mm.

I haven't carefully tested different tires widths on the same bike, but across bikes I haven't noticed anything that's easily-distinguishable.

Even on my gravel bike with its 2.1" tires, my paved climbing speeds tend to be about 5-6% slower than what I get on my Emonda, which is mostly explained by its 10lb weight penalty: for me that's a bike+rider difference of about 5%, nearly all of which is coming from things other than the tires. That's on top of a silly high-trail steering geometry which makes the gravel bike feel very floppy out of the saddle at low speeds.

I notice the tire squish when standing climbing.

Like on a mtn bike with the fork not locked- that's got to slow one down up the hills relative to a higher tire pressure.

I have a theory...

I've found that narrower tires (or higher pressures) provide better acceleration than wider tires (or lower pressure).

Well, if that's true, then narrower tires (higher pressure) should climb better since you're effectively accelerating when countering the effects of gravity (after all, g is measured in m/s^2).

It seems rolling resistance increases with the load. So perhaps the same is true for hill climbing. If thats the case, and rolling resistance makes up a much higher proportion of power required to climb, then it stands to reason tires with less rolling resistance might climb faster.

That said some 50 mm tires have no more rolling resistance then some much smaller ones (28 mm). So if we use them the difference should be negligible when both tires are inflated to the correct pressure (15%drop). But often the wider tires have more tread, and if the casing is less supple they will require more power to motivate.

Also perception plays an important role. Unless we do controled trials it's hard to say for sure.