[SpiderNhan]

Or you could wait a month for the V-MODA M-100.

 

[warrenpchi]

Quote:

Imo it is too dangerous to use a closed headphone when bicycling. It is also dangerous to use a closed headphone while walking through traffic intersections.

 
+1.  However, your enemy will then be the wind noise.  And BTW, how are you gonna get around the helmet issue?

 

[JK1]

The PX100II won't fit under a helmet? The PX100 and PX100II are very comfortable and have plenty of bass.

 

[warrenpchi]

I'm not saying that it won't spatially fit underneath a helmet.  But the hard polystyrene foam liner of the helmet is usually pressing on the top of your skull.  It's supposed to fit snugly for safety reasons and not slide around loosely.  So whatever cans you decide to insert between the liner and your cranial mass better be pliable enough and comfortable enough or else you're gonna be peeved.  Plus, depending on how much the helmet's hard foam liner bends or warps the headband, you may or may not be able to get a good seal. 
 
Just speaking from personal experience here, it's not always as easy as we imagine ahead of time.  IMO (and experience) IEMs + good tips + securing hooks tend to work the best as far as comfort and SQ go.  And of course, you're gonna want to stay sharp.  You'll probably hear trucks, busses, muscle cars, etc., but those damn Priuses can EASILY sneak up on you and get you where the sun don't shine.  And you'd never know it until it was too late.

 

[JK1]

Perhaps the headband of a headphone worn under a helmet might be an issue if one gets into an accident? So I guess something like the JVC HA-EB75 or the Koss KSC75 might be much safer to use while bicycling? Traditional earbuds without earhooks would probably fall out of the ears soon enough.