General Cycling Discussion - Yet another pedal question

Bear w/ me guys,

I think I have decided to get Shimano M520's. But I dont know if I should get the regular M520's or the PD-M520's. I think the only difference is the the PD one is dual sided? Meaning it doesnt matter which side of the pedal I clip into? The diff. is only $8, but is the PD-M520 as good as i've heard the reg. 520's are? I will run these on my hardtail. I will ride mailnly on street, some trails, no realy hardcore stuff. I might start commuting to a job soon, so I would use these.

So should I get single or dual sided? I like the idea of the dual sided one, but is it still decent?

Thanks
Matt

Dual sided. Just a mechanism on both sides. For commuting on a hardtail I'd suggest what I've got on my commuter hardtail: Shimano PD m-424 which is a dual sided 'huck' friendly pedal. You never have to flip 'em and you can wear just about any shoe, anytime. See here. (https://shop.sunrisecyclery.com/item/308/)

Dual sided. Just a mechanism on both sides. For commuting on a hardtail I'd suggest what I've got on my commuter hardtail: Shimano PD m-424 which is a dual sided 'huck' friendly pedal. You never have to flip 'em and you can wear just about any shoe, anytime. See here. (https://shop.sunrisecyclery.com/item/308/)

I've looked as those. So it doesnt matter what side I clip in on? How are they holding up? I dont in any way intend to "thrash" them.... I like those, cause I wuldnt have to wear my bike shoes all the time, like when im ust biking to somewhere close.

They work great. Regular shoes or cleats. If I had a little more to spend and were doint it all over again I'd look at the Time Z-controlhttp://www.performancebike.com/shop/profile.cfm?SKU=16362#

Kinda lost at the moment. I plan to buy the pedals off of ebay. I am having trouble telling whether the pedals are dual sided or single sided. Like here:

Here (http://cgi.ebay.com/NEW-Shimano-SPD-PD-M520-dual-sided-clipless-pedal_W0QQitemZ7105998873QQcategoryZ36138QQssPageNameZWD1VQQrdZ1QQcmdZViewItem) these say they are dual sided on the description.
But here (http://cgi.ebay.com/Shimano-SPD-PD-M520-Clipless-Mountain-Bike-Pedals-4S-H_W0QQitemZ7176927476QQcategoryZ36137QQssPageNameZWDVWQQrdZ1QQcmdZViewItem) same looking box, but it doesnt say they are dual sided. are they? why do they have the same box?

I'm kind of lost :)

And I have noticed, so 520's come w/ SM-PD22 removable platforms. Is it possible to buy a set of 520's then seperatly buy those platforms somewhere else? if so, would the platform work on the dual sided 520's?

Thanks for keeping up w/ my "noobness" when it comes to clipless :)

Also, is it bad for your cranks or pedals if you change them often? cause i would still use my platforms at times. Would that wear on your threads a lot faster?