Re: [CR] A single sew-up among many clinchers

(Example: Framebuilders:Masi)

From: "ternst" <ternst1@cox.net>
To: "P.C. Kohler" <kohl57@starpower.net>, <classicrendezvous@bikelist.org>
References: <200502120412.UAA23490@cascade.cs.ubc.ca> <005701c51228$e6005360$22e0fea9@man>
Subject: Re: [CR] A single sew-up among many clinchers
Date: Sun, 13 Feb 2005 22:09:33 -0800
reply-type=original

Peter and All: In my post on 2-12 05 where I listed a few tire related items for sale, I mentioned that I had been riding sewups since 1947. Except for test rides on clients' bikes I've never owned or ridden wired -ons(clinchers).

I'm going to give you my thoughts on sewups. If anyone can add something I didn't mention please follow up.

FIRST OFF: The industry standard by legitimate distributors is that they will replace a defective sewup for a legitimate dealer if has not been glued on. If a dealer exchanges a glued tire he usually will have to eat it, and does it to show his appreciation for your continued business. If he's big enough and does big business with a distributor, he may get it exchanged once in a while, depending on defect.

When buying on the "BAY" remember the tide does come in and maybe you got soaked. I would never buy a sewup in the bay unless it comes from a real shop that I know would stand behind the product.

There are a few rules with sewups that have to be done if not by the dealer then buy the buyer EVERY sewup should be aged at least 6 months. Gently inflated to shape, but not twisting. In a dark room , under bed in black plastic bag sealed from too much air exchange is just fine. Not in a hot dry attic.

Better yet is on a spare sewup rim inflated round maybe 30/40 lbs air to keep shape. Depending on tube check air and keep round. Before you store them they should be put on a rim, no glue, fully inflated. Checked for defects, straight strip, sewing, leaks, base tape, etc. In general, is this tire a keeper, or do I give it back. In my shop I did this. We had lots of used rims to store, age, and check tires before we put them out to sell.

This also stretched the tire so that when it was glued on the rim it was sound, round, and stretched so it went on without have to get a hernia.

We always tell our riders to get two spares to start. Ride their new tires several weeks to get them seated and shaped while riding. Then take them off and put the new spares on. This gives the rider two beautifully stretched and shaped sound tires as spares with some tacky glue on the base tape. When it gets installed it sticks quickly to the mastik bed that's on the rim. When on the road, and maybe get a flat, in a hurry, cold stiff fingers you will appreciate the prep and take a piccolo over to your favorite dealer as a thank you, unless of course you have done this yourself. Then YOU have the piccolo when you get home.

Remember to build the bed of glue with about two or three layers of glue. Let dry a day between coats. The glue should cover the ferrule ridges so it's a nice smooth base. If the sewup has a rubberized base tape then no glue is necessary on the tire. Put your final coat on the rim, depending on type of glue, let dry a little until tacky, have about twenty pounds or so in tire so it is round to hold and put valve in straight, hold tire tight with rim on floor for holding pressure. Let your hands slide equally down along the rim while holding tire tite so it stretches downward toward the middle and doesn't back off. As you are doing this keep adjusting either hand pulling pressure to keep valve straight.With your prepared pre-stretched tire you should be able to pop it over at the bottom without smearing the glue all over the sidewall. Just before you reach the bottom, lean / rest your forearms on top of bent knees and the tire will / should set into place. If your tire has an untreated cloth strip, then coat the base tape with one coat of rim glue to seal the tape before installing so it win't absorb your final rim glue coat and not stick tight enough. It's like a seal coat on wood. It's not necessary to put a wet coat on tire before mounting.

I always leave about a 2-1/2" section of rim dry or put a piece of masking tape between the two spokes opposite the valve. This allows you to get a start on removing the tire in case of puncture. The new glues are so tight that it's hard to get a tire off sometimes and it helps to know the starting spot. The tire can't roll off when properly glued and inflated, hasn't happened to me ever. If you don't trust that then by all means glue it all, but remember to take a tire iron or some kind of thin prying tool along to get your tire removal started.

With your tire stretched over and on the rim, inflate to about 75lbs. +/- so the tire is good and firm. Spin wheel and set base tape and rubber tread nice and even. Round the tire out so it runs nice and straight as you spin wheel. What you see spinning is what you will feel when you are riding. That's why I did what I did in my shop to give the rider his money's worth. Inflate to about 90% and let set overnight. Then get out and ride the next day and watch those hills flatten out.

This seems a lot, but it's really quite basic. After a few it's just part of the real bike atmophere. I'm getting writer's instead of rider's cramp so that's all she rode er wrote tonight. Ted Ernst Palos Verdes Estates, CA


----- Original Message -----
From: "P.C. Kohler"
To: classicrendezvous@bikelist.org
Sent: Sunday, February 13, 2005 4:05 PM
Subject: Re: [CR] A single sew-up among many clinchers



> Folks, I am a newcomer to sew-ups for about a year now. After some trial
> and
> error, I settled on Vittoria Rallys. But everyone told me to get Veloflex
> Criteriums. So splurge on a pair sold on eBay. New. $120 for a pair.
> Cheap.
> I put them on my TI Raleigh Team Pro. Guess what? Both are defective! The
> tread is warped or out of round near the labels on each. So they go squish
> squish squish as I ride. Useless. And the chances of getting my money
> back..
> well, I don't rate them any high. So much for "handmade in Italy"! I
> suspect
> this seller who has been flogging these for several months bought seconds
> or
> something. But that's enough "high end" sew-ups for me... I am sticking to
> my cheapo Rallys and happy to do so.
>
> Peter Kohler
> Washington DC USA