I have a very cheap, yet very old, 26" Chinese rear wheel with a freewheel hub mounted on my MTB. The hub, bearings and cones are shot, but the rim is still good.
I have two Shimano cassette hubs FH-RM20 and FH-RM50, that I got very cheaply on eBay. I was hoping to get the freewheel hub swapped for one of the cassette hubs at a local shop for 160 baht (~£3) - labour is cheap in Thailand.
However, after originally having said that the hubs could be swapped, once I had taken the cassette hubs to the shop to show them, the lady in the shop has now told me that the hubs could not be fitted. Due to language issues, I wasn't given any explanation as to why.
I am not sure whether the shop was expecting me to want to swap the existing freewheel hub for another freewheel hub - maybe having the cassette hub instead was the problem.
The number of spokes is the same (36) and the spoke holes diameter is 45 mm in both the freewheel hub and the cassette hub, and the spoke bases (i.e. the holes for the spokes) are 67 mm wide (or rather, apart) on both types of hub. So, the fit (i.e. dimensions) would appear to be the same.
So, my questions(s) are:
- Is it possible to swap the hub types, or
- Does it lead to other issues, such as offset issues? Can the same spokes not be used?
I am tempted to just try to swap the hubs myself and then go back to the shop to get the spokes tightened properly, but I don't want to mess up my current wheel if it is not possible - the bearings may be shot but it can still get me around (just about).
Keeping costs to a minimum is a priority, hence why I am not going for a new set of Formula hubs, AlexRims RM19 rims and Pilar spokes for ~3000-4000 baht (~£70-100), However, I don't want another cheap Chinese hub, so that is why I am attempting this hybrid solution of a good cheap second hand Shimano hub and the existing cheap rim.
Please note that this is a different question to Can I convert freewheel hub to use cassette?, as I actually want to swap hubs and not convert them.
FWIW, I currently have a 7 speed freewheel gearset (Shimano MF-TZ07), and I have a Shimano CS-HG41-7ac to use for the cassette.