do I need the Presta valve nut?

It is not necessary.

All those nuts do is hold the valve stem steady when you do the initial inflation. After that, they are useless.

Real cyclists point and giggle if you have them on your bike. 

TW

sweet.  my carelessness will be rewarded by less people pointing and giggling at me.  Or at least they will now be pointing and giggling about something other than the fact that I have a Presta valve nut. 

thanks all. 

Real bike junkies also ditch the protective plastic dust caps too.  And if you want to be a tire changing speed freak, you can also save time by not even screwing in the valve stem after inflation, but that's getting a little anal! 

judging by the hour and 15 minutes it took me to do this for the first time, I'd say that I have other things to work on first. 

You did take the reflectors off, right?

It's okay...apparently I am the laughing stock of the cycling community with my nuts. I'd like to be a spider on the wall in the LBS after I walk out of there .

Yes, I did have the wherewithall to do that.

Excuse me?

It's "fly on the wall."

So THAT's what they were giggling at!    and I thought it was my chaps.

Heh. I guess you're right. But, the spiders would have heard too, I'm sure .

Yep, the fact that you have nuts makes the cycling community giggle.

C'mon folks, that's rotational weight. Don't you realize that's slowing you down? .

Guess after 15 years of cycling, 5 years of road racing, managing the service departments in 3 different shops and placing top 5% overall in most of my tris for cycling times I'm not a real cyclist then .........

I'd like to be a spider on the wall in the LBS after I walk out of there .

 

It's "fly on the wall."

Not after the spider gets through with it.

I put them back on since it's either that or put them in my jersey pocket (then you gotta fish them out before washing, etc etc) or toss them on the road (no one here does that, right???), and as mike says it can make inflation (espeically via CO2) easier, but if I happen to lose one, I don't worry about it.

Noticed in the original post a reference to "rotating the tires."  On a bicycle, this generally isn't a good idea, as it means you put the more worn tire (the rear) on the more important wheel (the front).

If the rear tire is worn, better to replace them both with new (unless you wore out the rear tire on a trainer without putting miles on the front tire).

This year I've done about 1/2 of my training on the road, 1/2 on the trainer.  I figured since I'll be indoors most of the time over the next few months, I'd switch the tires.  Thanks for the post... when spring rolls around I'll probably get a new set for the road. 

After watching someone else do this very thing (after he made fun of me for keeping those nuts), I just leave them in. 

I do take off the dork disk and reflectors though.   

x2, too often...they stay on....

yes, the added rotational mass slows you down, but more angular momentum=less tipping over....