Slightly off the topic, but the topic isn't real clear in the other posts.
I actually "prefer" the look of threaded presta stems. That's what presta valve stems looked like when I first started using them in the early 70s. A few cheap sewups and cheap tubes had smooth stems at the time so smooth became equated to cheap!
If I remember correctly in 1975 Michelin introduced tubes with smooth stems that were vulcanized in place. They were designed to go along with their then new Elan tires. We had a lot of problems with the stems on these tubes leaking at the joint. Several other companies offered similar tubes with the same kinds of problems surrounding the stems.
Jump ahead...
Michelin AirSTOP A1 700x18/23 tubes come with 36mm, 40mm and 52mm presta valve lengths.
Michelin AirSTOP A2 700x25/32 (27x 1/14") tubes come with 36mm and 40mm presta valve lengths.
These tubes have smooth stems but not replaceable valves.
I buy them in boxes of 20 for ~$5.00 each.
Last year I bought some Continental tubes that had replaceable valves. On a group ride, one tire kept going flat near the end of the ride. Turns out, the replaceable valve was leaking and noting I did would correct the problem except to chuck it.
I've been lucky over the past 40 years and have had very few flat tires, even in the 70s when I rode sewups much of the time.
A flat tire is always embarrassing for me so I like to make sure I've done everything I can to prevent them from checking the the tire casing to making sure there's nothing inside the rim that might cause a flat. Five minutes in the shop is well worth 20 minutes on the road!
The 20 or so grams that I might save with Michelin's AirComp Ultra Light and Latex or similar tubes is not the potential for a ride stopping flat.
Chas. Colerich Oakland, CA USA
Harry Travis wrote:
> What OP might have also been concerned for, for this forum, is that some,
> the "classic", have smooth stems but for the last 5mm. Most, however are
> threaded for the entire length. Ugly.
>
> Someone else may know, for further authenticity, whose presta valves are
> removable --weren't they all, in the day? -- and whose snap off if you try
> to find out.
>
> Anyone still hot-vulcanizing patches to repair their tubes should also
> report where they stash their flammables and the clamps that fix them to the
> tube during vulcanization.
>
> Harry Travis
> Pine Barrens of New Jersey
> USA
> On Sat, May 8, 2010 at 1:18 AM, M-gineering <info@m-gineering.nl> wrote:
>
>> Andrew R Stewart wrote:
>>
>>> Marten- Actually the wholesale cost of like tubed but different length
>>> presta valves is not different by much. Now the longer PV tubes were more
>>> initially expensive (at the wholesale level) a while ago. But what things
>>> cost at retail levels is often about economics of scale at the manufacturing
>>> stage, managing inventory cost and the competition throughout the supply
>>> chain.
>>>
>> here
>> conti charges the same for 42 or 60mm
>> Schalbe's 60 are 25% more expensive, and a lot more if you take into
>> account I can't get them in boxes of 50
>> Vittoria charges 53% extra for a 51 over a 42
>>
>> Marten Gerritsen
>> Kiel Windeweer
>> Netherlands