Hello List ,
Seeing the inquiry about the Velox Flyer , a racing bicycle , probably from the late 1930's , featuring parts ( especially rims and tires ) which were made in the U.S.A. - well , it made me want to explain .
A bit of history - I will TRY to be brief :
If you think sew-up tires are expensive , try buying a brand new pair of single-tube tires , for your circa 1885 - 1935 "safety" bicycle .
"View Our Products"
"Scooter And Bicycle Tires"
" 28 x 2 1/2 $ 285.00 "
" 28 x 1 1/2 $ 124.00 "
each - yes for each tire
They were called "safety" bicycles because they were NOT "high-wheeled" bicycles . With both wheels of approximately the same diameter ( less than two and a half feet in diameter ! ) , they were much safer in case the rider should happen to fall .
The very first safety bicycles didn't use pneumatic tires . Today , these are called "hard tire safety bicycles" .
O.K. , so along came pneumatic tires for safety bicycles . Safety bicycles with pneumatic tires became outrageously popular . The end of the high-wheeled "ordinary" bicycle came quickly .
How should these new pneumatic tires be measured ? Rim diameter ? Overall outside diameter ? There were several sizes early on . Eventually , it all settled down to one standard size for adult-sized bicycles ; the so-called 28-inch single-tube tire .
Single tube tires are REAL "tubular" tires . They are NOT sewn up ! The tire cords are actually wrapped around the tube , during the making of the tire . And remember , this is all circa 1885 technology !
O.K. , so time passed . Eventually the serious bicycle racing passed away from the U.S.A. , but lived on in Europe . ( why do you suppose they still call it "Madison" racing , even today ? ) Tires got skinnier . Sewn-up tires , on tubular aluminum rims , became the standard for racing bicycles .
But ,
Today you can still buy "sew-up" tires , for tubular rims , which are STILL clearly marked , 28" , or 28-inch .
Of course , for a while there , you could buy "sew-up" tires , for tubular rims , which were clearly marked , 27" , or 27-inch .
But the 28-inch size is the ORIGINAL size !
And , shockingly , it is STILL the same size !
Yes , we all know that 700 c tires have a smaller diameter than 27-inch tires . And we all know that 700 c rims are the same diameter as tubular rims for sew-up tires . But , did you know that what is called "700 size" is the same diameter as what is still sometimes called "28-inch size" ??? Huh ? Yes !
700 is equal to 28-inch , but is smaller than 27-inch
And of course , 700 has an ACTUAL bead diameter of 622 mm , which is equal to an actual 24.488 inches .
But , it all began with those late 1800's tires , which were roughly 28 inches in OUTER diameter , for the whole tire , not just the rim or the bead .
O.K. , back to year 2003 , versus year 1893 .
Leaning against my leg , as I write these words , I have a rear wheel which is probably from approximately 1925 . Although it could easily be from 1890 - 1940 . ( It once belonged to a nice man named Claude West . ) It has a genuine Morrow coaster brake , with a one-inch-pitch , "skip-tooth" , rear cog ( 10 teeth by the way ) . It has 36 extremely skinny , small-diameter spokes ( with a faint X on the head of each ) . Perhaps these spokes are roughly 1.75 mm ? They are skinny-skinny spokes . Oh , and they are double butted too . The rim is a "clad" or "armored" 28-inch rim . It is a wide , heavy , solid-wood rim , with sheet-steel formed around the wood . It is not likely to break any time soon . It's tough . The "bed" where the tire goes is smooth wood . But , when a tire is mounted , all you see is the sheet-steel of the rim . Oh , and the spoke holes are drilled asymmetrically . That's right , it's a wide & heavy rim for a coaster brake , from approximately 75 years ago , and the spoke holes are staggered to minimize wheel dishing , just like Bontrager does today . And being made in the U.S.A. , it has a hole for a Schrader valve .
Also leaning against my leg is a brand new , never been on a rim , Tufo sew-up tire . I bought this tire a few months ago from a major retailer of new Tufo sew-up tires . It's a cyclo-cross tire . But other than being wide for a modern sew-up ( 34 mm ) , and not having average tread ( little knobs ) , it is a regular - standard - modern sew-up tire .
If I take just a moment to wipe the dust off of the approximately 75 year old , 28-inch wheel . . .
The new Tufo tire is now mounted up . And , it's a perfectly good fit ! Although , it is slightly narrow for that rim . With my handy metric ruler , I'd say if this tire is 34 mm , then about 38 mm would really be about the correct minimum for this rim . And it could certainly fit a tire wider than 38 mm . Hey ! As a matter of fact , 38 mm = 1 1/4 inches . That's probably just right for minimum size on one of these !
And just to be sure ( because there is no school of engineering quite like the Empirical School ) , I slipped the tire off , and grabbed a new , modern , tubular rim for sew-up tires . All right , this rim isn't all that new . It's a slightly used Fiamme "red label" . But , at least we certainly know what size it is . Yes , the two rims are almost exactly the same size . Yes , the new Tufo tire fits similarly onto both .
Actually , I've never conducted a side by side comparison before . The bed of the wooden rim is clean and dry . The tire slides on it easily . The Fiamme rim has a small amount of old dried glue on the bed . The tire tends to grip a bit more , and requires a bit more persuasion . The sides of the old steel-clad wooden rim are perhaps a millimeter higher . Make that a measured 2 millimeters more in total diameter , for the old antique "28-inch" rim . So , to be absolutely certain , I just grabbed a used Nisi Sludi rim . Yes , the sides of the antique rim are slightly higher . And they are higher by just about the same thickness as the sheet steel cladding . I won't draw any conclusions . I don't have an all-wood rim , totally bare , ready to compare . Perhaps an all-wood rim is a couple of millimeters smaller in diameter than a steel-clad rim ?
The sides of the antique rim are a tiny bit higher . But the center of the bed on which the tire rests , is just a tiny bit lower . So , when fully "seated" or fully "bedded" the tire is just the TINIEST bit more loose , on the old antique "28-inch" rim . With a total of about 10 p.s.i. in the tire , any difference in fit has totally vanished .
So , on the antique rim , the sides are very slightly taller , but the center is very slightly lower . If the bed of a modern tubular rim , for sew-up tires , is perhaps approximately 3 mm deep - then I would say that the bed of this particular steel-clad wooden rim is more like approximately 6 mm deep .
Final note about this little experiment - this new , 21st Century , Tufo tire states clearly on the label , and I quote , Diam. 28" , which of course means it is the equivalent of a tire with a bead diameter of 24.488 inches . Sure , it's as clear as mud .
Now , about rims , and tires , and terminology .
Commonly , bicycle tires for high-performance adult-sized bicycles fall into two groups :
Sew-up / tubular
or
Wired-on / clincher
O.K. , and if you want to mix and match your terms , I am NOT going to argue .
**TIRES**
But , sewn-up tires are not truly "tubular" are they ? They begin life as strips , formed into hoops with one open side , and are finally sewn into tubular shapes . Single-tube tires on the other hand really ARE tubular ! They are formed AROUND the tube , seamlessly .
And of course , today , we are starting to see some new "seamless" tubular tire designs !
Right back around to true tubular tires ! Just as modern as 1885 ! Wouldn't the good Dr. John B. Dunlop be proud !
:^)
So , right now today , if you are looking for tires which are held to the rim with adhesive , instead of being held to the rim with beads of steel or Kevlar - you can buy your choice of ; antique-style single-tube , or traditional sew-up , or the very latest genuine seamless tubular !
But , if you think you have ever actually changed a "clincher" tire . . .
Well , I have a Model T Ford out in the garage . And I welcome you to come over and change a real clincher tire some time . Really , I have my grandfather's 1915 Model T Ford out in the garage . And it really does have real clincher tires . And they are NOT like modern wired-on tires !! They are not at all like modern wired-on tires !!
Take a look at the real genuine clincher tires on that Coker Tire web site .
So , I won't argue . But I doubt that most folks have ever SEEN a real clincher tire , let alone actually tried to work on one . Modern wired-on tires are a HUGE advance over genuine clincher tires for genuine clincher rims .
**RIMS**
Rims for antique single-tube tires come in one of three ( 3 ) basic designs :
Single piece of wood
Laminated strips of wood
Steel-clad "armored" wood
All of those rims are solid , all the way through .
Aluminum rims for sew-up tires are all , with no exceptions I've ever heard of , hollow and tubular .
( Of course , we now have rims made of carbon-fiber-and-plastic , which are not necessarily tubular . )
So , I'm not going to argue with anybody . But , I don't own any "sew-up rims" . None of my rims have sewn seams . All of my aluminum rims for sewn-up tires are in fact , totally tubular ( dude ! ) .
Cheers ,
Raoul Delmare
Marysville Kansas