smontanaro 

I picked up an early 70s RRB last night. Component-wise it's a bit of a hodge-podge. For example, while spending a little time on it this evening, I discovered that it appears to have about 126mm rear spacing (definitely wider than 120mm) but it has a 5-speed Shimano SIS 14-28 freewheel attached to high flange Campy Record hubs. I pulled the Shimano freewheel and tried a 6-speed Sachs I have, but the small cog hit the frame. For the time being I'll live with the Shimano freewheel.

My question, though, is this. It clearly says "Shimano SIS" on the freewheel body. It seems nearly new, spins freely. I saw no freewheels which looked like it on Velobase. Did Shimano really make a 5-speed SIS system at some point?

T-Mar

Yes, they did and still do. In fact, you can buy 5 speed HyperGlide freewheels.

smontanaro 

Thanks. While this one still looks new, maybe I should take some photos and submit to Velobase.

ColonelJLloyd 

I recently bought a Sunrace 5 speed freewheel with chromed, HG cogs. I've been impressed with the quality for the price of their 7 speed freewheels, but this 5 speed freewheel is not of the same quality. It was dry right out of the box so I filled it with lightweight oil.

due ruote 

The 7 speed I bought recently was like that. It made some really funky sounds but the copious amount of oil I put in it seems to have done the trick. It does shift nicely.

OP, is your wheel centered in the frame? Seems like one would have to go out of the way to make a 6 speed not fit on a 126mm hub. If the rim is a bit off center, maybe someone serviced the bearings and didn't put the spacers back right.