Hotrock Freewheel & Chain Swap

[coopdad]

When I recently measured the chain on my son's hand-me-down 2005 Hotrock 24 I found out it is time for a new chain and freewheel.

The original freewheel was a Shimano MF-HG37 (14-28T). I found another freewheel, a Shimano MF-TZ07, in my parts bin. 14-28T also.

Does anyone know what is the difference in the two?

[GMF]

I do not know what the difference between them is (HG = hyperglide, TZ = ?), but in general 7sp shimano freewheels are completely interchangeable. You should be able to swap, no problem.