Why do we still have brake adaptors on bikes manufactured in the last few years. Why isn’t everything post mount?

BTW I’m looking at the back of my orange five as I type this.

Most are PM unless you buy a 15 year old design 😉

Adapters F&R on my 2015 eunduro.

Adapters allow different rotor sizes should you want to change so they are fine by me.

Adapters allow different rotor sizes should you want to change so they are fine by me.

PM-PM adapters would still allow this though.

PM-PM adapters would still allow this though.

True, maybe I have misunderstood the original question.

Edit, Ignore my ramblings I really have misunderstood!!

Yea rear is is to pm

no one?

Guessing PM is a pain on some read stay designs, easier to do an IS and them convert.

I’d say the main reason was that IS mount can be cut from sheet so it can be easily fabricated as a plate to weld on or integrated into the dropout. Fork legs tend to be cast so post mount is easier at that end.

Plus, if you strip/wear the PM threads you might as well bin the frame.

Post mount more difficult/expensive to fabricate

Also wouldn’t surprise me if many companies made/fabricated/bought tens of thousands of pieces of metal for IS mounts and were surprised when the industry settled on PM calipers, leaving them with lots to use up!

180 post mount on my rallon

Most are PM unless you buy a 15 year old design

Mates 2015 Nomad is IS mount 😉

Plus, if you strip/wear the PM threads you might as well bin the frame.

Turner have a very simple soloution for this.

You will always need some form of adaptor to accommodate for various disc sizes.
Post mount on my Spicy Team

Fitting an IS adaptor isn’t exactly hard and you don’t get that worry of stripping threads
Had both PM rear and back on IS rear now. Both work

just curious really.

turner seems to have actually thought about it.

It really depends on the diameter of the cylindrical inserts, if they are anything like the ones on the Planet-X Dirty Harry, you won’t have that many threads to work with.

Seem to remember from my Five Spot that they are 10mm, so plenty.