Bob the Mech

Here's two senarios for you to make sence of.

1) THE COSTS OF CONVERSION.

Shimano 105 R7020 Hydraulic Disc STI Levers & R7070 Flat Mount Disc Calipers - 11 Speed $600
Mavic Allroad 700 Disc CL Wheelset $300
Axle adapter fit form thru axle 12-15mm (142mm OLND) to 9mm QR (135mm OLND) £25
Shimano 105 CS-R7000 11-speed cassette $50
Frame repspray $250
Labour to fit disc mount plate, plate NOT included (steel frames only) $90. Alloy or carbon frame, well you are plum out of luck. And most light weight steel frames are too thin to weld lumps of metal onto. Frames not designed for disc brakes have no way of resiting the applied / transfered kentic forces of the disc brake...it leads to accelerated structural fatigue and
Disc mount plate £60 (custom made, speced stainless A2) $80
Carbon forks, flat mount disc fitting (thru axle only) $330
CX tyres (Continental Cross King CX Folding) and tubes x 2 $95

Cost of conversion: $1820
Cost of conversion without cassette and tyres: $ 1675

Now factor in the time of taking all the hydraulic system off the bike, removing bar tape, hoses, refitting mechanical STI units, brake and gear cables, refit cantis, removing the forks and refitting the canti compatible forks, refit bar tape, adjust brakes and gears, swap over tyres and cassette (if you aren't getting a second set of the disc wheels)...then you are ready to ride.

Do the reverse if you want it back to disc brake format. Just remember that in removing the hydraulic system the hoses have been detached from the disc calipers, so now you have to refill the fluid lost when they were removed in the first place.

2) STRUCTURAL FATIGUE.

Alloy or carbon frame, well you are plum out of luck. And most light weight steel frames are too thin to weld lumps of metal onto. Frames not designed for disc brakes have no way of resisting the applied / transfered kentic forces of the disc brake in actuation...adapting such frames will lead to accelerated structural fatigue and / or catastrophic structural failure.

Yeah I know N+1 has an intial cost out lay, but that cost is retured in hassle free convenience.

Kapusta

There use to be a product called Therapy Disc Brake Adaptor (or something like that) which let you run a rear disc on a non-disc frame. It apparently worked fine.

The company was Therapy Components.

Not sure if it is still sold.

Bob the Mech

Or something like this...and that looks super reliable...it couldn't possibly fail

msu2001la

I'm not saying it's impossible. I just mean that you can't buy an off-the-shelf/prebuilt or used wheelset unless you're willing to buy mismatched front/rear wheels individually or have a shop (or manufacturer) do a custom build, or order individual parts and build your own.

I would imagine most people might find this annoying, but I guess if you're this far down the "disc conversion" rabbit hole, it's likely not a dealbreaker.