Lightweight front wheel raising questions

[pritchet74]

Tape is safe, but the rolling resistance is worse than using Mastik 1. Get rid of the tape and use glue.

[elfuinha]

i'm using Magic Mastik from Vittoria...

very light but you have to take all the old glue from the rims.

they have to be very clean.

[Devon]

25mm isn't a very aero option

Incorrect. 25mm in some cases has been proven to be more aerodynamic. Yes, drag is a function of Cd; however the profile of the rim plays into it equally.

You also need to consider that decreased rolling resistance, in some cases, trumps a slight degrease in aerodynamics.

A final note would be that any minor difference between a 23 and 25mm tyre could be made mostly redundant by fitting it to any regular (non-aero) road bike.

[Grill]

Errr... no dude. The Ventoux is a narrow rim and any tub that is wider will be detrimental to CdA by a wider margin than the Crr decrease.

Some wide rims were designed with wider tubs in mind (Hed GT3), but they're still slower than the narrow options at the yaws that matters (H3 is still faster where it counts and has lower watts to spin). Zipp, Enve, Reynolds all recommend going narrow for the best performance, it's just that pro teams generally ride the same tubs for everything (cobbles being the exception). No tester in the right mind would actually run Comps over Podiums given the choice.

Saying tyre width doesn't matter if you're not on an aero frame is silly. Not like Wilko's bike can be described as 'aero'.

[Devon]

in some cases

the profile of the rim plays into it equally

So you're basically saying the same thing. I didn't specify a specific rim.




Anyway, the topic is about weight, not aerodynamics.

[Grill]

This thread is about the Lightweight Ventoux, which is what my post was referencing. Regardless, my 28mm RZR's test faster with 20mm than 25mm, and Zipps, Enve's, and Reynolds Aeros all test faster with 22/23mm than 25.

[muntos]

Hi 2old4this, can you please post a picture with the wheel + tire ? I'm looking also for 25mm Competition but I saw several model on net, I presume that some are older...

[sawyer]

This got me thinking too:

Although thousands of people have ridden taped tubbies for hundreds of thousands of miles, how many and what fraction race 4-corner criteriums ?

Just wondering. I have seen quite a few glued tubs rolled off. Nowadays I use clinchers and don't race. But I always used to make sure to use Conti cement.

On the first point, a lot. Many people only use tubs for racing

On the second point, I've never seen a tub roll. There are a tiny handful of well publicised examples from the pro peloton

I suspect all the amateur examples, and may of the pro ones for that matter, are in truth just mis-application

And then there are the tens of millions of miles ridden without problems ...

Correctly glued tubs don't roll

Conti or Mastik One will do the job

Tufo tape is also secure

Jantex - not so good ...

[sawyer]

We had a customer who came into the shop for years, who insisted that you didn't need glue (or tape) at all! He ran tubulars with no glue or tape, just a dry tire on a dry rim, and I would see him a few times a year without ever a report of a problem. It's always possible that he wasn't doing more than riding around the block, I just wanted to include that as an example of the "it must work because it has been done for years" argument.
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Indeed. I would never do this in a group ride or down a mountain, but if the tyre / rim is reasonably tight and the tub is at 100psi+ then the attachment is secure for sedate riding IME

Old glue underneath helps though - on a clean surface there would be a higher chance of the tub slipping off

[2old4this]

Hi 2old4this, can you please post a picture with the wheel + tire ? I'm looking also for 25mm Competition but I saw several model on net, I presume that some are older...

Here you go : http://1drv.ms/1m93Fe7

I think they are just competitions, with lightweight stamped on them. I've taken its picture next to an off the shelf (albeit 22mm) front tire, for comparison.

I still think 25mm for the front is just too wide on the gipfelsturm (19 mm) front wheels...

[muntos]

Here you go : http://1drv.ms/1m93Fe7

I think they are just competitions, with lightweight stamped on them. I've taken its picture next to an off the shelf (albeit 22mm) front tire, for comparison.

I still think 25mm for the front is just too wide on the gipfelsturm (19 mm) front wheels...

Thank you, looks like I expect to look !