good bike to convert with disc brakes under £400?

[Stu33]

kiwi, thats cool, I like decathlon bikes.you dont think it will cause problems using a 26" wheel on a bike that usually uses 27.5" ? I don`t have any experience of that! i decided to keep my 26" motor wheel, goes like a rocket

 

[anotherkiwi]

It might look silly with a 24" wheel on the back. With the bigger tyre the difference in diameter is minimal it won't look too funky and the bike is a disk brake bike. A rim brake bike doesn't work with smaller or larger wheels.

You can (could?) actually buy bikes that are set up like this as standard. The rear wheel is more dynamic and the steering more stable or so the marketing spiel goes.