I see no reason to drag around a boat anchor. And I second the use of a band to keep a brake lever depressed. I use one of those velcro tie downs; an 8" one works perfect.
On the MTB, it can catch on whatever you are riding through, and on the road bike, it's several pounds of no purpose what so ever.
Now if the bike is a heavy commuter, I might see it, but frankly, as you are likely to be carrying a lock/chain of some sort anyway to lock the bike to something, you are going to lean it on that something anyway...
Tzvia- rollin' slow...
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