> Mike Jacoubowsky wrote:
>> It's really dumb to have high PSI ratings on 27" tires, because there are
>> *very* few 27" rims that have the required "hook" for higher pressures.
>> In virtually every application (old bikes), 60-70 PSI is about the max
>> you can safely inflate to.
>
> Huh? Just about all the aluminum 27" rims sold in the 80s had the hooks.
> I know, now I'm stuck with a garage full of 'em and slim pickings for
> tires. Even the straight-side (hookless) rims worked nicely with the 85
> psi "HP" tires of the 70's - though those had wire beads; perhaps you're
> thinking of folding-bead tires. The hookless Araya steel rim was a staple
> in entry-level 70's bikes, standard with those 85 psi tires. IIRC, the
> Arayas fit tires far better than the Schwinn steel rims of the era.
Oh sure, SuperChampion had some very nice rims that were available in 27"
(the Mod 58, for example). But for every 25 27" tires we sell, perhaps ONE
(and probably less) goes to a customer with a nice rim. The rest are all
going onto really junky stuff (old Firenzes and such).
> Any more, you're right, though, that there are few 27" rims with hooks,
> b/c there are few 27" rims. At the rate the industry is going, I
> sometimes worry that soon there will be very few /rims/ at all available
> for purchase without a goofy hub already laced to them.
We're pretty much already there. Not too many choices these days. Simply a
matter of the small size of that market.
> And even then you have
>> to be careful about how they're mounted since, without a hook, the tire
>> can mis-position itself fairly easily.
>
> Agreed, esp. those Schwinn steel rims, which always seemed to have sizing
> issues.
>
> Sometimes they got around that by having
>> a very tight fit. Tire "irons" weren't just for motorcycle and car tires;
>> you sometimes needed something quite gnarly for older 27" steel rim. And
>> then you'd have an impossible time trying to get it to mount correctly
>> without a sunken spot that you couldn't get out.
>
> With many brands of the era, yup. Though I recall the Japanese steel,
> matched to Japanese rubber, fit quite nicely. I wrenched briefly in a
> Raleigh shop at the time and hated trying to seat the stuff they sold, but
> the Japanese stuff I grew up with didn't seem to have that problem.
My first impression of a japanese bike was extremely favorable. The Cal
Clipper. I'd been trying to make entry-level ($130 at the time) Gitanes &
Merciers build up OK, having nightmares with chainrings (pretty much had to
"true" every single one, and look for bent teeth too), wheel issues and
frame alignment. Then we bring in this $90 Cal Clipper from a local
distributor. My gosh, the darned thing built in half the time and shifted &
braked twice as well! And the frame was perfect.
>> Anyway, many bike shops can confirm the meaninglessness of tire pressure
>> limits on 27" tires, based upon the large number that come back with a
>> customer claiming the tire defective because it blew off the rim at the
>> pressure listed on the sidewall. It's something that I try to tell
>> everyone buying 27" tires.
>
> It's bizarre (IMHO) to see this attributed to the size. Cheap rims or
> cheap rubber, which 27" now tends to be, but it ain't the size that's the
> problem.
Well, it's the size that makes it the problem. 27" lost out in the
marketplace, so what you come across, as a bike shop owner, are nearly
always problems. But I do understand your point.
>
> Mark J.
--Mike-- Chain Reaction Bicycles
www.ChainReactionBicycles.com
