NextRightThing

So I get done cleaning/repacking the hubs and bottom bracket on my 83 Raleigh Super Course that I picked up recently. Stayed up late last night cleaning and polishing the crank-set, deraileurs, and wheels. And I mounted new forte road tires on it last night as well with new tubes. I only used a portable hand-pump, as to not wake up the house with my compressor. So today I'm all excited about going to the local metropark to ride for an hour or so; my first real ride on the bike Of course something had to go wrong. I go to pump the tires up all the way. The first one pumped up fine to 100psi. The second one blew up right in my face, seriously only 2 feet away I start taking the blown tube out of that one and the other one goes

What happened? Well, I guess my 27 x 1 1/4 tires were too wide for my original Araya wheels. The bead blew and so went the tubes, damnit. The ones that came off were marked the exact same size; while the old tires didn't, these tires hit the brakes when I installed them (yes the calipers were in the released position). The inner diameter of the rim is 15mm, and I guess that just wasn't wide enough. I'm going to go to the LBS where I get my discount and pick up these Continental Ultra Sports in the 1 1/8" size. I think 1" would work best, right? but I don't want to pay full price somewhere else, nor wait for something to be shipped.

An hour later and I'm still all stressed about this... serenity now!

cudak888 

No hooked bead = 80 PSI max. Your existing tires should fit with not problem.

-Kurt

Little Darwin

According to a tire width chart on Sheldon Brown's site, https://www.sheldonbrown.com/tire-sizing.html a 1.25 inch (32 mm) tire should be the largest allowable tire for a 15 mm wide rim. So, it should be no problem with width.

Do your Araya rims have hooked beads? If not, then 100 PSI is too much pressure regardless of size.

In fact, I think 100 PSI is higher than the embossed ratings for any of my 27 X 1 & 1/4 tires. I believe they are labeled as 85 or 90 PSI. They could probably handle 100, but it is above the rated pressure.

EDIT: By the way, I have a pair of those Continental Ultra Sports in 1 & 1/4 width, and I like them. They are nice riding tires.

cudak888 

IRC Roadwinner II's claim 105 PSI max on hooked bead rims - the way they have a tendency to blow off, I question anything over 90.

-Kurt

Oldpeddaller

+1! 80 PSI is more than plenty hard enough with parallel rims.

tolfan

I think you need the right sized tube also.

CACycling

I run 27 x 1 1/8 (Forte GT2/k) on both of my vintage Schwinns that have the original, chrome Araya rims (straight sided). Max pressure on sidewall states 105 psi and I usually run them at 100 psi without incident. Just use a lot of caution when inflating to make sure everything seats well.

We are running the Continental Ultra Sports on one of my wife's other bikes (700Cs) and they are very nice tires for the price.

NextRightThing

I used the proper tubes, these, and I never knew about the whole 'hooked' bead thing.

So it got even more frustrating. I figured I'd mount up a pair of 26x1.25 slicks I recently got on my extra MTB wheel set to do some road riding on my mountain bike today. I had been waiting for the proper tubes, but somewhere I had read that a larger tube would work well enough so I figured I'd give it a go. Well, go figure, more issues. The tubes had so much extra material my plastic tire irons pinched holes in each of the tubes, so I had to patch both of them That wasn't so bad, but getting those tires mounted was one hell of a chore. I had to use numerous zip-ties to keep the bead from popping out as I got the last 1/3 of the bead on. Today is not my day with bikes... Time for a run...

Little Darwin

I can't speak for everybody, but I know many of us have had days like that.

Hopefully the worst is behind you!

Citoyen du Monde

The tube size has very little if any impact. The tire is what constrains the expansion of the tube. If you inflate a tube on its own, you will see that it will inflate to a size far greater than the size of your tire, so you can generally get away with a tube rated for narrower tires without any major negative impact. The fact that you are getting both pinch flats and blowing tires off the rims indicates that you do not yet know how to install a tire properly. There is a proper methodology to installing a tire that should be followed. Once you master that, you should no longer have either problems with pinch flats or beads being blown.

due ruote 

+1

Try to keep the bead in the center of the rim as you go - you'll buy yourself a bit more room that way.

OP, are you saying you used the 27" tubes with the 26" tires? You can get away with fudging the cross-section, but you should really use the correct circumference.

btw, I really like the IRC Roadwinner tires, and have never had the trouble Kurt mentioned.

sekaijin

Something has to go wrong on the first real ride on a new-to-you vintage bike. For me, the RD cage came apart and left a trail of bushings and pulley wheels behind me. Fixed that and the bike has been a riding pleasure for many miles since then. Hopefully same for you.

cudak888 

I must agree - they ride beautifully, but I just do not have confidence in the beads anymore.

P.S.: Got any spares in 630mm?

-Kurt

NextRightThing

No, I was certainly using the right circumference tube on the wheels. I was working on both 27" and 26" wheels with the proper tubes on each. I went to the LBS, bought another set of tires, Bontrager Sport gumwalls, and tubes and went at it again. Same result, LOL. I took it back to the LBS and paid them to do it; it was my birthday today and I didn't feel like getting all frustrated again. It turns out I was getting part of the tube stuck under the bead, which lifted the bead off the rim and allowed the tube to expand and blow. Lesson learned.

As far as things breaking on my first new-to-me ride on my bike, not anything catastrophic, but the right pedal is all tweaked. It's rebuildable, so I'll take a look at that tomorrow.

I put 12 miles on the bike at the local metropark and she rode beautifully. I need to put some clipless pedals on though; I'm just used to being able to pull up so much harder on my MTB that the toe clips just don't cut it.