Friday, November 11, 2011

Q&A: Sew-up tire reader tips and visiting Vittoria

Clement's 1977 line-up
Thanks for the emails about my sew-up tire repair and gluing piece. I received some reader tips that I'm sharing here at the end, and I found a good how-to-glue sew-up tires on rims article by While it focuses on gluing cyclocross tires, it's the same steps for road rubber. I like their roll-the-just-glued-on-tire-over-a-broomstick trick.

Just for fun, on the right is an illustration of Clement's tires offered circa 1977. Be sure to zoom it to see the detail. If you know who drew this, I'd love to give them credit here. In case sew-ups are new to you, it's the full, round shape so clearly shown in the illustrations that provides the supple road feel and superb cornering grip.

Visiting Vittoria
Thinking about tubular tires, always reminds me of a visit to the Vittoria factory in Terno d'Isola, Italy in July of 1990. I was in Italy with a group of bicycle and motorcycle journalists to visit their many factories and write about the famous products so popular in the USA at the time.

The companies we visited included Campagnolo, Castelli, Casati, Regina, 3T, Bottecchia, Columbus, Cinelli, Bianchi and Vittoria (I know I'm forgetting a few others we made it to). Keep in mind that this was over 20 years ago and things have changed.

I remember how Campagnolo was spotless, right down to the restaurant in the factory that served us on Campagnolo china. Also, I noticed that many of their machine tools had been made in the USA. Visiting Bottecchia (Carnielli) only days after Greg LeMond had cinched his 3rd Tour victory on one of their bikes gave us a chance to celebrate the victory with them, which was cool.

A trip highlight was Antonio Colombo at Cinelli giving me a spectacular cloisonné Cinelli stem badge. And, at Regina, I watched mesmerized as their Rube Golbergesque freewheel builder - a giant circular table with every body and cog on spools in the middle, and articulated, moving arms that reached for, grabbed and installed the cogs - actually worked.

Making sew-up tires
But I think the biggest surprise was seeing the amount of hand labor that went into making Vittoria tires at the time, because I assumed it was a fully automated process. While we were there we received a promotional book about the company, which has some photos in it that I've scanned and pasted below to give you an idea how they're made. The photos are by Ruggero Giuliani.

They actually make the casing by feeding a single thread from a spool like the ones shown below, onto a long, horizontal, spinning metal cylinder. As the thread is wound onto the cylinder it gets woven and the casing material is formed. A worker walks the length of the cylinder, brushing the fabric with liquid latex (I believe) to bond it. Then the finished material is cut off with a knife and put aside to be formed into a tire shape (you can see the finished casing fabric at the bottom of this photo).

It all starts with a single thread
 In another room the rubber that will comprise the tubes and tread is made from natural rubber that's mixed and formed with a machine that to me looked like the taffy-pulling machines you see at candy stores. I thought the rubber would come ready-formed and they would simply cut and apply it. But they started with the raw material and made it themselves.

Right off the rubber tree

You can just see the woman's hand feeding the casing through the sewing machine as it's sewn around the tube. More hand labor.

Sewing the sew-up
Perhaps so that workers don't have to breathe and handle glues, which can be dangerous, this machine applies the glue that holds the tread.

Applying glue to the casing before the tread goes on

I believe the last photo (below) shows the inverted tread strips ready to be attached. I remember they were heated for vulcanizing the tread to the tire too, and formed on rim-like holders. Watching the process made me realize why the tires were so precious both in price and value. And, today I still race on Vittoria tires and feel they are superior.

Tread strips ready to be attached
Reader tubular repair and gluing tips and tricks
Hope you enjoy the photos. Now here's some helpful sew-up input from reader David Heilbrun. He writes: "I used to repair sew-ups and have some tips people might like."
  • I learned to take J&J adhesive tape and cut a strip and round the corners, then apply it to the hole in the casing. That ended any problems with the tube popping out of the hole and exploding.
  • I found that you have to cut open the tire enough to get the tube out because if you don't and pull hard to try to get it through too-small of a hole, you can rip the tube and you don't want to do that!
  • Your suggestion to mark the original holes and then sew through the same holes is an important rule to make it easy and avoid a twisted tire.
  • I just loop the new stitches in a spiral pattern and overlap the end stitches.
  • I use a seamstress seam cutter to open the casing.
  • Regular rubber cement, like Carter's, works for gluing the cloth protector strip inside the tire.
  • On gluing the tires to the rims, I clean the rim with alcohol to remove any oils from your fingers.
  • If there's old glue on the rim, I soften it with mineral spirits or, if it's heavy, remove it altogether.
  • If the rim has ferrules on the gluing surface, I use a file to smooth and roughen them so they'll hold the glue and the tire will lay flat on the rim (the ferrules can lift the tire).
  • I only use one good coat of glue on the rim and none on the tire and that always works for me.
  • I apply the glue with my index finger making sure to coat all surfaces.
  • You can get glue off tire sidewalls with mineral spirits but watch out for silk sidewalls, which are fragile. 
Thanks, David!

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