Re-Re 870c motor mount vintage chassis fitment
Posted: Sat Apr 20, 2024 3:51 am
I originally posted this on one of the Yokomo Facebook groups but I thought I would also post it here as, quite frankly facebook is absolute trash for anything other than posting pictures and asking for parts.
Having had a look at the re-re motor mount I thought it looked broadly in spec with an original motor mount so I purchased one to check fitment on an original chassis. The mount in its standard form will fit an original chassis on the two forward and middle screw holes, however the rear most hole does not line up and is about 6mm further back than the original screw hole position. So for it to fit you would either have to drill a new hole in a vintage chassis about 6mm further back ot drill and tap a new m3 hole about 6mm further forward of the rear most mounting screw hole.
I choose to drill a new hole and tap it to m3 and as you can see from the pictures below it now fits the chassis. You could drill the chassis for a new hole but I would rather not drill out a vintage chassis.
The second question was to examine if an original layshaft would fit and there seems to be no issues there. An original cap will also fit but you will need to enlarge the holes as the new mount takes a m2.5 retaining screw as opposed to the m2 used in the original. I would probably purchase a re-re or FAN-RC cap rather than drilling out an original cap.
As the part is only about £16 it is a very cost effective option for a vintage build and is relatively easy to modify - I used a centre punch a few varying size drill bits, an Dewalt drill and m3 tap. If you want to drill a new hole in the re-re motor mount you can use a vintage chassis as a guide but a centre punch will make your life a lot easier.
Having had a look at the re-re motor mount I thought it looked broadly in spec with an original motor mount so I purchased one to check fitment on an original chassis. The mount in its standard form will fit an original chassis on the two forward and middle screw holes, however the rear most hole does not line up and is about 6mm further back than the original screw hole position. So for it to fit you would either have to drill a new hole in a vintage chassis about 6mm further back ot drill and tap a new m3 hole about 6mm further forward of the rear most mounting screw hole.
I choose to drill a new hole and tap it to m3 and as you can see from the pictures below it now fits the chassis. You could drill the chassis for a new hole but I would rather not drill out a vintage chassis.
The second question was to examine if an original layshaft would fit and there seems to be no issues there. An original cap will also fit but you will need to enlarge the holes as the new mount takes a m2.5 retaining screw as opposed to the m2 used in the original. I would probably purchase a re-re or FAN-RC cap rather than drilling out an original cap.
As the part is only about £16 it is a very cost effective option for a vintage build and is relatively easy to modify - I used a centre punch a few varying size drill bits, an Dewalt drill and m3 tap. If you want to drill a new hole in the re-re motor mount you can use a vintage chassis as a guide but a centre punch will make your life a lot easier.