Originally Posted by
3alarmer
...if you already know all this, I apologize, but "generally" the bigger you go in tyre size, the heavier your rotating weight gets. So there's a point at which the comfort and stability provided by a larger, fatter tyre starts to act a cross purposes to riding pleasure. For me, that's usually in the 700x28-32 range as a practical maximum, and I do have some wheels I built with newer lightweight rims that roll OK with Panaracer 27x1 1/4 tyres on them.
I have my most pleasing results with tyres like the old Rivendell Ruffy Tuffy, or some of the newer versions of them (also made by Panaracer). They're relatively puncture resistant, capable of holding high pressures with a modern hook bead rim, and mostly average in the 28-32 mm widths I prefer. they seem to do pretty well in the rolling resistance department. Anyway, this has been my experience after a lot of experimentation.
Originally Posted by
no67el
Unless the wheels and tires are fancy-light, 700x32c is about the upper limit for me.... bigger than that and the rotating weight of the tires starts to feel pretty sluggish. Even then, tire choice can make a difference: I had 700x32xc Continental Gatorskins on my Centurion Semi-Pro and the bike felt _terrible_ to ride..... then I switched to 700x32c Panaracer Gravel King slicks and they feel great..... a little bit less weight, a bit more "souplesse" in the sidewall, and the feel of the ride was totally transformed.
I wonder how much of how our bikes feel really comes down to wheels and tires....
Originally Posted by
bnewberry
This past year I ran Vittoria Zafirro 32’s on a similar vintage 620. They fit with good clearance and these are wider than you would expect for 32’s.
They provide good comfort but when riding a hilly century I noticed the extra mass. I am going to run 28’s next year.
I find it interesting that people bring up "sluggish" feeling wheels on a bike that was built for touring... so a 720 at a relatively weight conscious vintage touring build and still with racks... figure about 25 pounds (if not more). Add on to that the chainstays are 47cm- with a total of a 106.2 wheelbase... The extra mass of 32/35mm tires is making the bike sluggish? The bike was designed for the stock wheels to fit 27 x 1 1/4" tires- which is larger than 700c x 32 (especially as a 630mm 27" wheel is larger than a 622mm 700C wheel, and 1 1/4" is *nominally* 32mm). Wouldn't the rotational mass be more evident with an extra 4mm from the hub, and larger tires (larger circumference means more rubber, meaning more weight). Specialized's 27" touring tire offerings of the mid 80s were the Touring at 1 1/4" and the Expedition at 1 3/8" which is *nominally* 35mm.
My 1985 Trek 620 is currently wearing Sand Canyon 27 x 1 3/8" tires, but that bike doesn't have fenders. I do have plans to change this bike over to 700c x 35 tires with Honjo fenders- I'm fairly confident it'll all fit safely.
Again, my 1985 Trek 720 is currently wearing 700 x 35 Compass Bon Jon Pass tires with SKS Chromoplastic fenders.
IMG_1724 by
Dave The Golden Boy, on Flickr
Additionally, to get the full benefit of higher volume tires- one would not be riding them at high pressures- When someone suggested that I run the Compass tires at 35, I thought they were joking- or on crack. But sure enough, they rolled really nice at 35- I usually ride both the Compass and Sand Canyons somewhere south of 50PSI- and I'm more comfortable at running the Compass tires lower. This has also carried over onto the Paselas I use on my other bikes where I'm running 1 1/8" and 28mm tires- I'm cool with running them around 80 or so- whereas I used to feel I needed to be within 10PSI of the limit.