Post vs flat mount disc brakes. MTB

[stackie]

Im definitely a roadie at heart. Some I'm going to ask some questions that are probably pretty dumb to the MTB savvy people.

But, considering a Ti 29er, just for something different. I'm looking at a used Ti MTB frame. It has the disc brake tabs off the back of dropout so that's post mount, right? Seems like most modern disc road frames have the flat mount discs where the caliper sits inside the rear triangle. Would I have trouble with component selection in the future?

Any other things I should worry about?

Thx

Jon

[ColonelJLloyd]

You are trying to correlate caliper location to mount type. It doesn't work like that.

You can find both ISO and post mount that are attached to the outside of the seat stay. You can find ISO, post and flat mount that are mounted to the chainstay.

I'm not sure why it matters because all MTBs that I'm aware of will use a post mount caliper because all current MTBs use ISO or post mounts.

The MTB you are looking at probably has an ISO tab welded to the outside of the seat stay. This would require a post mount caliper and ISO-to-post mount adapter (which is sometimes included with the calipers).

[p nut]

Here is a quick overview of post and IS mounts:
https://www.bikeman.com/bicycle-repair-tech-info/bikeman-tech-info/1638-51mm-international-standard-74mm-post-mount

I have both and don't see advantages either way. Most new bikes are post mount, though.

[stackie]

Perfect. That answers my question.

Thanks!

Jon