Alex and Weinmann do make some decent and affordable 27" rims -- I'm using Weinmann LP18's on my old Peugeot -- but it's not quite that simple. You'd need to disassemble your current wheel, removing the spokes and nipples. You could then transplant a new rim, but you'd need to make sure the spokes are the correct length for the rim. Different rims, even if they're made for the same tire size, may require spokes of different length. You'd need to replace your current rim with one of equal ERD (effective rim diameter), otherwise you'll need new spokes in addition to a new rim. And by that point, if we're talking about budget rims, you might as well buy a new wheelset because rims plus spokes may not be that much less expensive than pre-assembled wheels, and that's before considering your time and aptitude.

A new alloy 27" wheelset with Weinmann LP-18 double-wall hooked rims and stainless spokes costs a little under $100 from Niagara Cycle (link HERE).

...or you can run tires that have sufficient width to be used with lower pressure, which should keep 'em from blowing off your straight-sided rims.

Flyboy suggested it above bu I'll state it directly - Tubes don't pop. In fact, tubes don't hold the pressure, the tire does. There is no way in the world that thin surface of butyl will hold any pressure. When the tube pops it is because the tire let go.

(Was there another thread on this subject just a month or two ago?)

In the old days a high-pressure clincher tire like Michelin or Hutchinson would be 1-1/4" (32mm) and rated at 70psi, a lesser one at 60. Some time in the late 80's IIRC Specialized came out with 1-1/8" tires rated at 90psi, and then 1" tires rated at 100. I and most of the other cyclists I knew upgraded to them and they were indeed the cat's meow (even on my UO8 with upgraded alloy wheels). But those rims were never meant to handle the >110psi we see today as commonplace markings on tire sidewalls. Of course, given how some people in C&V and elsewhere claim that wider with lower pressure is better, then you could just go that route.

You asked for tire recommendations. I'm a fan of the Panaracer Pasela for most use.

++ double check your job.. go around the tire after its on and make sure the tube is 100% between the tire beads ,

any left outside /under the tire bead will push the tire off the rim, when pumped Up.

Including a soft inflation bounce and tire massage before filling to spec. I've caught tires outside the bead clincher just in the nick of time.

Beads are not seated properly, you have to look at the tire while airing it up...to see if the bead is seating correctly. You should lube the beads with soap. Kenda tires for sure are not easy to seat. Sometimes takes a few times airing it up and letting it down to get it right.

Flyboy718 you're letting us down.

You're supposed to latch onto the most expensive option, (from Chrome Molly and ignore the rest of his advice), and buy more and more expensive tires. After spending 4-500 dollars on tires, (we won't talk about how many tubes you explode), you're supposed to decide that the solution is to change to 700c. After spending lots more money on wheels, chain, sprockets, cranks, chain rings, deraillers, cables, tires, etc you proudly show off your new pride and joy firm in the knowledge that you have solved the original problem and you're Man-Cred is intact.


Oh, and you hang on to all those expensive 27" road tires you bought even though you're other bike is a 26" mountain bike.



Just in case.



Very firmly tounge-in-cheek

I've had one Kenda 27" skinwall tire that had a slightly over sized wire bead, a quality control issue I assume. At first glance it seemed fine when mounted but on two occasions I heard this 'bang' from the basement and went down to find the tire flat and the tube split inside the tire. Should mention that these were two identical sized tires on identical wheels. The bead on one side of the tire turned out to be slightly too large in diameter so at high pressure it allowed the equivalent of a pinch flat to occur.

Thanks I needed that breath of fresh air!

Straight-seated tire beads are usually the key, even if it takes perhaps an extra wrap of rim tape laid wall-to-wall to take up any remaining unwanted slack (on certain specific rims only).

Many, many late-1970's bikes were sold with reliable 27" straight-sided rims wearing 27x1-1/8" tires reliably inflated to the sidewall-rated 100psi.

The biggest variable has been the rims in most cases, just a few bad (mostly Weinmann) rims seems to have discredited the majority of perfectly good, high-pressure, straight-sided clincher rims.

That's the spirit!

In my experience, it is a combination of rim, tire & tube that promote this issue. Change any one of the three (in a meaningful way), and it goes away (for very good, physical reasons, as excellently described by dddd, and others).

Without correlating any specific tires and sizes to actual observations in this regard, I will note that it is the tension in the tire casing that pulls a bead up and over the edge of the rim.
And the tension in the tire casing increases proportionally with tire pressure, but also increases proportional to the tire width or cross-section, such that a wider tire inflated to a lower pressure may have the very same tension force in the casing as a narrower tire inflated to a higher pressure.

And the root cause of the bead climbing up is the slack that exists between the bead diameter and the slightly-smaller "shoulder diameter" of the rim (measured at the base of the inside of the rim sidewall).
A deeper channel (smaller diameter) in the rim where the spokes are centered eases tire fitment, but should not affect the pressure at which the bead might lift off of the larger-diameter shoulder where the inside floor of the rim meets the sidewall.
Anything that increases the rim's shoulder diameter will increase the blow-off pressure of any tire that has been seated straight initially.

I am going to post this pic again to make sure I have the tire mounted/seated correctly? I am not sure where the bead is...this is area of the tire is sticking up all around the rim and will not go further into the rim when I press it down...is this an issue? Is this 'hash marked' area the bead?

The bead is the wire (or kevlar band) embedded in the very edge of the tire. Your tire looks OK but it's hard to say. Can we see the whole wheel, too? The sidewall of the tire should be embedded in the rim more-or-less evenly. A little inconsistency is tolerable, but not too much.

No, that's not the bead itself -- it's an indicator line. When the tire is centered (and the bead is seated in the channel of a hooked rim), that line should stay equidistant from the rim all the way around.

Hehe sure will when I get some more tubes! This was before the second cannon went off.

Yes, it is equidistant all the way around

So here is a picture of the rim...those raised areas on both sides of the inside of the rim...does the tire beads go in between those channels?

Those narrow, raised areas that run out to the rim sidewalls are the bead seat shoulders.

The shoulders are supposed to be of a very precise diameter, such as to take up any slack that might otherwise allow the tire's beads to lift up, and at some pressure climb over the top edges of the rim sidewalls.


it's very important that the tire's indicator line be at a uniform distance above the rim sidewall early in the inflation process.
If the indicator line rises up in one spot during inflation to higher pressures, then the rim's bead shoulder diameter is insufficient to control the pressure, and the inflation pressure will be limited to some pressure under the pressure where the bead starts lifting up.
Only an increased shoulder diameter or bead hook can retain the tire at higher pressures.

So does the beads sit on top or between those raised areas?

Going on ten days pretty soon...

The tire sits on top of the bead shoulder, not in between. Try inflating the tire very lightly after mounting, then pinch and work the tire around the rim to make sure the seating above the bead shoulder is very even before taking the pressure up. If you can't get it even, try a layer of tape on the rim (slightly wider than the normal rim tape you'd use, covering the bead shoulder, but not going up the sidewall). If your tire still blows off the rim at reasonably low psi, then you're back to tires, or possibly even the rim itself. Tire being the cheaper option to try to solve the original problem and preserve your man cred. Seriously though, if you're aiming to get over 90psi, you'll want a hooked rim. If you're OK with lower pressures, then a better tire will ride more nicerly on the rims you have. Good luck.

FIFY
Just a minor nitpick on your always excellent technical insights... allowing for the possibility of an out-of-round wheel, the measured diameter could vary somewhat from the precisely specified nominal, but hopefully the circumference at least, is both precise and invariant (temperature and hoop stress being held constant .

Ok well ten days equals...my tubes and rim tape just got here, plus family obligations and blah blah blah. Anyways I got the tire and tube on and inflated a little and went around the wheel making sure that the tube was in fact completely inside the tire then aired a little checked and repeated a few more times till is was aired to 75 psi. I really think what happened was I didn't go around the tire on both sides and check for a tube showing. So, I am new to this stuff...and I am trying to understand the mechanics and I just don't understand the beads of the tire sitting on top of some metal shoulders along the inside walls of a rim make a tire seat and not move or come off?

No worries, was just handing back some of that tongue-in-cheek razzing that I got above...

You are correct that it is the bead shoulders keep the tire from moving off. Having a really tight circle around a closely sized circle inside of it is intended to prevent movement. Therefore, having the tire centered when starting with inflation is key to keep problems from starting. The comment about "good tires" just means that given the tolerances of the two circles needs to be so close, having one of the two circles poorly spec'd will cause a problem. It's not always that tires improve the situation, some rims are better than others in terms of sizing (but most are more consistent than the sizing of tires). At the other end of sizing extremes, the tires can become hard to mount because they are "too tight" for that particular rim. It can go wrong both ways.

If you put 75 in, and it holds for a ride, then you are probably out of the woods. 85 is about the max for those rims though. Straight wall rims rely on the relative sizing of the tire to the rim (and not super high inflation) to hold together. A hooked rim wall, has a little "bead" toward the top of the rim wall that uses the pressure from the tube to hold the tire from blowing off. You have straight walls, so it's just more sensitive to pressures and the rim/tire relationship, whereas a hooked wall rim uses the pressure of the tube against the tire to keep the tire from blowing off the rim wall.

Again, no razzing you and your difficulties, just defending my man-cred (or trying anyway)...

Chrome Molly, I hope you were not offended by my using you as a 'straight man' and no razzing was intended your way. Although if you want I can email you some, it grows wild down here. I also appreciate Flyboy718 taking my post in the manner it was intended.

BTW, Chrome Molly, that is a most excellent online name!

I can sympathize with Flyboy718 as my Raleigh has the older non-hook rims. Mine are even marked H.P. for high pressure... Just not the high pressure our tires are made for today. One of the things I have learned from the VERY smart people on these forums is that good tires can make a 'gas-pipe' frame ride nice and cheap tires are.... well..... cheap. Very much you get what you pay for in more than mileage and puncture resistance but better ride quality as well.

What tires do you run on yours that have the non-hook rims and what pressure do you have in them?