I'm trying to determine what is the safest and longest length for an iPad sync cable. On Amazon, there are several long dock cables but according to some reviewers some of this cables have trouble syncing due to the length. I need to get a dock cable that's longer than what Apple gave.

You can use any male-to-female USB extension cable, as long as the total length does not exceed 5m.

In case, you are interested in the reason

The cable length was limited by a cable delay spec of 26ns to allow for reflections to settle at the transmitter before the next bit was sent. Since USB uses source termination and voltage-mode drivers, this has to be the case, otherwise reflections can pile up and blow the driver. This does not mean the line voltage has fully settled by the end of the bit; with worst-case undertermination. However, there's been enough damping by the end of the bit that the reflection amplitude has been reduced to manageable levels. The low speed cable length was limited to 18ns to keep transmission line effects from impacting low speed signals.
http://www.usb.org/developers/usbfaq/#cab1

You could use longer cables,but would need a powered hub, every 5m.

Thanks for the info. Yeah, i don't want to use a USB extension cable. I actually need another dock cable. The one Aople gave me is already being used with a USB extension cable in my bedroom. I need a dock cable for the office.

I'm surprised then that the long cables I saw on Amazon having trouble were the 6 feet kind. 5m is about 16 feet so 6 foot cable is well under that.

Worst case scenario would be to buy another official ipad charging cable cable plus an extension.

VERY helpful, DUMIP! I've wondered about how long a USB extension could get.

Originally Posted by richgalen

VERY helpful, DUMIP! I've wondered about how long a USB extension could get.

If you'll note the total length is limited to 5 meter or approx 16 feet.
If you go to Best Buy for instance you will find a 16' USB extension cable might be in the $30-40 range. I can't remember. Or just go to bestbuy.com
Check out mazon.com

I think the idea of just getting another charger with cable from apple for $15 makes for the best deal. Then you have another charger as well. IMO

Originally Posted by madhatter61

Originally Posted by richgalen

VERY helpful, DUMIP! I've wondered about how long a USB extension could get.

If you'll note the total length is limited to 5 meter or approx 16 feet.
If you go to Best Buy for instance you will find a 16' USB extension cable might be in the $30-40 range. I can't remember. Or just go to bestbuy.com
Check out mazon.com

I think the idea of just getting another charger with cable from apple for $15 makes for the best deal. Then you have another charger as well. IMO

Hmm....I don't know where you're getting a charger with USB to Dock cable for $15. I couldn't find any on Amazon or Best Buy. If it were at that price range, it would be good!

Originally Posted by thibaulthalpern

I'm trying to determine what is the safest and longest length for an iPad sync cable. On Amazon, there are several long dock cables but according to some reviewers some of this cables have trouble syncing due to the length. I need to get a dock cable that's longer than what Apple gave.

I used the Apple Keyboard extender cable. It works perfectly and looks great as well.

Sent from my interestingcompanionPad using iPF!

Griffin makes a 3 meter usb to dock connecter cable and they have it at Target for like $29 or $39.

eBay 5 ft one works but charges iPad VERY slowly...