Hi. I have an old style Cannondale M500, the one where the seat stays meet up with the chain stays, like this one:

Will this cause me difficulty mounting racks or fenders?

Most racks and fenders will fit fine. You will find two sets of threaded holes at the drop outs, one for rack, one for fenders. There are threaded holes for a rack on the sides of the bridge that serves as brake cable hanger. There is another bridge connecting the seat stays below that one which has a hole for mounting a fender.

Thanks. I'm building this bike up and haven't any racks or fenders to mock-up on it. I know that the hoes are there but the frame is such an odd design I was afraid that it was one of those deals where there were a "Wide range of genuine accessories" when they made the bike 15 years ago, but that nothing modern or uiversal would fit on today! The last thing I wanted to do is sink a lot of time and oney into building this only to find out it couldn't do it's job!

THe points of attachment are pretty typical. The rack mounts on the brake cable hanger are a little closer together than normal, but most racks have adjustable arms to fit a range of width and length requirements. I have a Cannondale with this style rear end and fitted a Blackburn rack easily with the standard parts that came with the rack.

Post pics of your new bike when you get it set up!

My Cannondale T700 has a similar setup. Normal racks should work fine.

Now on my F500 - that is a different issue. Attaching a rack to the mono-seat stay (with no brazons) took some ingenuity.

It likely has 130mm spacing for the rear hub, so you won't be able to use the modern standard 135mm hubs without some extra stress on the frame.