Round plug, square hole: Axle converter 20 to 15mm

I just rebuilt a front wheel (29″ into 27.5″) because I didn’t like mulleting my trail bike. The front hub is a Koozer BM540, 20×110 boost.

Koozer sell several axle converters. So I decided I could use one wheel and two forks on two of my bikes depending on what I was riding using the 20×110 to 15x100mm adapter. Tubeless Assegai fitted, maybe have to adjust the brake caliper when swapping wheel between bikes.

But then I hit a conundrum. My first fork is a 20x110mm boost 200mm Killah DH fork, one dropout side is threaded for the 20mm maxle. The second a 15x110mm 160mm boost Durolux Enduro fork with their snazzy titanium flower headed QR axle .

The hub end caps diameter only fit onto the DH fork. I have no way of using my Suntour axle in the dropout hole.

I just don’t see the point of the axle converter right now, for my forks. I assume I need to build another 15x120mm boost wheel.

What is the point of these adapters? Am I missing something? I couldn’t even use it between a 20x110mm and 15x110mm Durolux because of the end cap issue.

It should fit if you have a fork that takes torque caps.

Ah, I see “Rockshox torque caps” for sale for this hub. There’s a geometry drawing for it but couldn’t figure how it’s fit my Durilux. Don’t have one of those forks and definitely not buying one to make a wheel fit.

Got a spare 15x110mm boost front hub (ARC MT009 £12.50). Due to insane pricing where I am, it’s only £19 for a Duroc 30 27.5″ pinned/sleeved rim, 2.0 stainless spokes and brass nipples. The rubber I need costs more than the new front wheel!

Might use the converter in a DIY fitting so I can wheel my bike behind my moped. It doesn’t make a good paperweight. Keeps rolling off my desk.

Another thing to consider is caliper alignment. I may be making this up, but iirc there’s 20×110 and 20×110 boost, and the disc is in a different place. So if yours are 20×110 boost, it wouldn’t even work if the axle and end caps fitted.