You might have seen or heard about convertible Novatec hubs supporting multi-axle system, often called 4in1 or 3in1 system, depending on how many variations they can be turned into.
So yes, apart from standard hubs meant for one axle size only (single purpose hubs or also known as single-axle system), Novatec has quite a few convertible models in its portfolio, which are very popular hubs amongst customers.
Most worldwide known models are D771SB/D772SB (front/rear hub) also D881SB/D882SB, D541SB/D542SB, XD611SB/XD612SB or newest models like D791SB/D792SB etc.
More models you can find in download section at the bottom of this page called Documents; there is a pdf file with a list of most popular convertible hubs so you can check it out.
Let's see how it works:
1. Front hub:
As you can see from the pictures above, front hubs only require to exchange the side caps (some people call them adapters) according to desired axle size and that's it, conversion is done.
For the front hub there are following possibilities available: standard QR, 9mm, 12mm, 15mm and 20mm through axle.
It's obvious that we have 5 options to go for, since 12mm side caps were introduced, so we can call it now 5in1 system, but we at Novatec prefer to call it simply multi-axle system.
Please note that not all 5 options must be available for each convertible hub, it depends on the construction of hubs. For example hub D771SB can't be converted into 20mm TA.
2. Rear hub:
Convertible rear hub requires the inner axle + side cap to be exchanged according to desired size of through axle (TA).
There are 4 options available: standard QR, 10x135mm, 12x135mm and 12x142mm TA also called X12 axle.
As you've probably noticed, the conversion feature applies to Disc hubs, mostly MTB, so you won't find this same option for Track, Dirt jump or BMX hubs.
I'd like to mention also very unique hubs which can be converted into different axle size just by exchanging the side caps on both front and rear hub (no conversion axle is needed).
These are being used on Novatec MTB wheels (hubs XD641SB/XD642SB) and recently they were released for sale so they are not dedicated anymore for Novatec wheels only.
There are some other systems like 2in1 for Dirt Jump hubs and Left-Right drive for BMX hubs but this is explained in different section of FAQ.
Please check the links and video below supporting this topic so that you get more details and can better understand the hub conversion.