Swap 451 wheels with 406 wheels

[Peter.Bridge]

So I've run out of local second hand folding Carrera Intercity disc 8s to convert ! There are some very nice, very cheap Carrera Intercity disc 9s (with hydraulic disc brakes and 9 speed cassette) but they have 451 rim wheels (and a limited selection of very narrow tyres) Can I just buy a akm-75 406 front hub wheel and then buy a second hand 406 rear wheel that supports a 9 speed cassette and disc caliper and fit those instead ?

 

[Sturmey]

Disc brakes are great in that they make swapping around wheel sizes easy. I have rebuilt a Barracuda hydra that came with narrow 700 x 37 (622) with 27.5 x 2 (584) on front and 26 x 1.75 (559) on rear. Two things I think you need to watch out for.
Firstly, the forks and chain stays are probably narrower with the narrower 20 inch tyre size (451) so this may limit you from fitting a much larger and wider 406 tyre size that one might do to compensate for the smaller overall wheel size you get when changing from a 451 to a 406 rim.
Secondly, if you end up with an overall smaller wheel, your bottom bracket will end up lower. Sometimes, this is an advantage, as often bottom brackets are designed too high but at the same time, this needs to be considered as if it is too low, your can get 'pedal strikes'.

 

[Peter.Bridge]

Thanks, the 451 tyres seem to be 28 mm wide, hopefully the frame / forks will allow a little wider. Wondered about axles / dropout sizes, do they tend to be standard?