27" Panic Attack
 

So my 1982 Fuji is about to have it's first set of replacement tires. (It sat in a basement for thirty years....) I have the new tires in hand, a decent set of Vittoria Zaffiros (same size: 1 1/4). But I just had a moment of panic remembering something about old 27" rims. Weren't made differently some years ago? Like...they don't have a lip or something to hold bead? The old rims can't handle high-pressure tires? (The original tires were rated at 85 psi max.) So:
1. How can I tell what kind of rims I have?
2. Is there any danger in putting modern tires on the old rims?

Thanks for your help.

You're referring to "hook edge" rims vs......er, uh, well, "non-hook edge" rims:D , or straight walled rims. I had a concern about this not long ago myself, and did a little research on the various old wheels in my basement. First, a couple of guidelines: straight-walled rims, because they don't have a hook edge, won't hold the bead under very high pressures; for a 27 x 1 1/4" tire, the max. safe pressure will be about 75-80 psi. Hook edge rims will generally hold whatever the max pressure rating is on the tire. When I did my little research, I found that straight-walled rims are indeed that, there's absolutely no obvious bump along the edge for holding the tire's bead. I did find some slight variation between one "hook edge" and another, but what you're looking for is an obvious, well defined hump at the edge of the rim, which serves to keep the bead from climbing over the wall of the rim.........I had thought that I owned more straight-walled rims than I actually did, I found that the only rims I have that are straight-walled were on an '82 Schwinn Super le tour(27") and an '83 Schwinn le tour luxe(27"). I've long since replaced these OEM rims on the '83. I found hook-edge rims on my '83 Centurion Pro Tour (27"), '85 Centurion Accordo (27"), and all my mountain bikes, some of which go back to the late '80's. I did find that the hook edge is more pronounced on the modern 700c clincher rims (Sun M13II rims) I'm now using on the le tour luxe than it is on the various mountain bike rims and older 27" hook-edge road rims, including the most modern mountain bike rims I own (Mavic X517). It was rather interesting "research," I had even started a thread here asking about the various pressures, etc., because I knew that I had used straight-walled rims on my old road bikes, but I hadn't given all that much thought to it until I started building up the Centurion Pro Tour and I wanted to run pressures over 90psi. Interestingly, the stock tires that came on the '83 le tour luxe were 90psi tires, despite the straight-walled rims. I have no explanation for that. Given that your bike is an '82 Fuji, I'd say there's a fair chance for either type of rim, check closely to see what the inside wall of the rims looks like-

#1: Feel the inner edge of the rim. A hook edge rim will have a definite small ridge at the very edge of the rim, enough to hook your thumbnail into. A straight side rim will be just that, flat on the inner edge. 27"/630mm rims may be either or, contrary to what Well Biked has said.

#2: Most high-end modern tires are made for hooked bead rims only, as they have a "C" type fishook design on the bead, to catch the hooked edge. In practice, most of these will fit on a straight side rim with no problems, but I wouldn't advise pumping that tire up past 70PSI, which severely degrades the performance of a higher-end tire.

A cheap-o Kenda or Chen Shing tire made for straight side tires - although they admittedly have poor ride characteristics - will be better tires on straight side rims then a tire for hooked bead. These are designed to run in the 70-75 PSI range, and will perform accordingly.

-Kurt

[QUOTE=cudak88827"/630mm rims may be either or, contrary to what Well Biked has said[/QUOTE]

No, I said they can be either hook edge or not, as in I've got 27" rims from the '82 and '83 Schwinns that are straight-walled, and 27" rims on the '83 and '85 Centurions that are hook-edged. And I also advised checking the rim wall carefully, as it seems to me an '82 Fuji might be either type. Maybe you didn't read all of my post, I do tend to get wordy. :o

Bklyn, are your rims steel or alloy. I ask this because of the 6 sets of old 27" steel rims I have in the basement, none have a hooked ridge (rim?). Both of the alloy rims I had were "hooked". But like well biked says, the hook was not pronounced. In fact, I once thought they did not have a hook, but later, upon close examination, I realized it's there, but not as pronounced as my 700c rims.

Bklyn, as for tires, an LBS sold me two pairs of 27" Kenda tires, rated at 90PSI that they said would work fine on steel, non-hooked rims. Well, they do work fine in that I've never had a problem holding 90PSI. But the set I have on my 82 Fuji Monterey do not handle real well.
(I think slow so I need two posts:D )

Not sure whether they're alloy or steel. I can tell you that engraved near the valve is this:

UKAI 27 x 1 1/4 w/o LA Made in Japan.

Does that mean anything to you?

The "w/o" means "wire on", meaning it's a clincher, and "LA" likely means "light alloy", i.e. aluminum. You'll have to examine the rim walls to determine for sure if they're hook-edge or not. Since they're a quality aluminum rim, my guess is that they are-

edit: gotta give credit where it's due: the info regarding "w/o" and "LA" comes from Sheldon.

A refrigerator magnet will provide the answer. I'm sure cudak888 or well biked know what that means, but I don't. There was a thread about 2 months ago where one of the C&V posters explained all those terms. I knew I should have printed it out!:rolleyes:
EDIT, thanks for the answer well biked.

It was Sheldon in the Mechanics forum, I asked him. :D

You know, in the rest of my life, I'm the smart guy. Then I post to the C&V forums, and I'm like Pauley Walnuts or something, just amazed at the knowledge being tossed around. Thanks. (And "panic" is a bit of an overstatement. I only spent $30 on these Zaffiros, so if they wouldn't work, no great loss.)

Looks like I skipped over something that Well Biked said, but nevertheless, 27"/630mm rims can be either/or - that is, provided they are aluminum rims. I've yet to find a hooked bead steel rim.

Sounds as if your rims may be steel Ukais (but they could just as well be alloy - can't say for sure until you check them). The Vittorias will fit, but you might find that they perform a little bit substandard at the 70PSI setting.

Might be worth it to go hunting about for another 27" wheeled donor machine for a pair of hooked-edge alloy 27" wheels, if your rims turn out to be steel.

-Kurt

As we all seem to learn (over and over, in my case): wheels are the limiting factor when trying to bring an older bike back on the road. Everything else can be had for cheap, or scrounged, or easily salvaged. But a good set of older wheels makes my heart sing. jim

So if it turns out that I do have even a slightly hooked bead, can I inflate the tires to their full maximum? I've been running the gumwalls at their maximum, 85 psi, without incident.

When you say "slightly" hook edge, I assume you mean there is a definite bump or ridge at the edge of the rim on the inside (again, straight-walled rims have no ridge whatsoever). If that's the case, then yes, you should be fine running higher pressures-

Next question, are the tires folding or metal wire bead? If you bought them in an already circular state (as opposed to folded up in a box) they are probably wire bead which is good. 27 X 1 1/4 can safely sit on a straight wall rim up to about 80 psi and this is the normal pressure for that size tire if you weigh less than 220 lbs. 70 psi isn't a bad pressure either. I currently run straight wall rims with no problem but have pumped them harder than 80 and had the tire blow off. Have a spare tube handy before trying that experiment.

Keep in mind back in the 70's bikes were ridden on any kind of road and so tires were bigger and lower pressure to better fit the rugged lifestyles of hairy chested He-Wheelmen that dominated the roadways then.

:D

East Hill

...and now we know what you're looking for... ;) ;) Which would be your preference, the fellow sporting the '70s hat and bike kit? Or the Captain and his Racer?

I've revealed myself as a complete novice already, so why stop there? The tires came in a box (via USPS), but were not folded in on themselves. Rather they were crossed and tied in smaller loops. These are wire-bead tires, right?

Yes. Some afternoon after you and your buds have had a few beers try getting a wire bead tire to fold back up into those three loops. Do not attempt near furniture with sharp edges.

Ok. Here's a picture of the rim, which is definitely not steel.
This is not a hooked bead rim, correct? Someone had a diagram around this forum somewhere, but I can't imagine this is hooked in any way. (That whitish crud on the rim tape is the remnants of flaking gumwall from 1982 -- so you see why I wanted to change my tires.)

It's difficult to tell from the photo. Run your finger up and over the wall of the rim. Does it feel like there's a rounded bump at the very edge?..............."Hook edge" is a bit of a misnomer in some cases, I believe, as sometimes the "hook" is not much of a "hook" at all. But if it's a straight-walled rim, it will indeed be flat, with no bump at all-

I feel as if I'm in some cheap C.S.I. knockoff. "Can you enhance the image?" Hmm. Let me try.... clack clack klik clack
Yes. The killer was a straight-walled rim.

Yep, I believe you've nailed it. The sentence: 75psi, no chance of high pressure. :D

^
+1. Alloy, straight-side, no 100 PSI tires on this rim.

Might be worth it to nab a pair of hooked aluminum 27"s if you ever find a pair cheap, or a bike equipped with them at a good price. High pressure tires are one of the most determining factors whether your machine rides nicely or a tad sluggish.

Take care,

-Kurt