How does this rack fitting work?

[swee'pea99]

Looking to get a new rack, and quite a lot of the ones I've been looking at seem to have fittings like these:

How do they actually work? All the racks I've used in the past have a single bracket that goes on the back brake bolt - what do these two struts attach to? Can something like this be used on an old steel-framed racer? Baffled, me...

 

[adscrim]

They would fit to two bolt fixings at the top of the seat stays - if your frame doesn't have them you can buy p clips.

 

[shouldbeinbed]

You should have holes near the joint with the seat post on the rear triangle seat stays (diagonal struts) to bolt the silver arms onto, or you will need P clips to put around these struts to do the same

 

[Tim Hall]

You can also get seat post clamps that have threaded holes incorporated for the same purpose.

Evans, for example do this one.

 

[swee'pea99]

Right. Got it. Thanks. (You learn something new every day!)

 

[Yellow Saddle]

You can also get seat post clamps that have threaded holes incorporated for the same purpose.

Evans, for example do this one.

Now that looks like a much more elegant solution that those fugly P-clips. I like.

 

[DRHysted]

You can also get seat post clamps that have threaded holes incorporated for the same purpose.

Evans, for example do this one.

I'm using something similar to that along with an axle adaptor to mount a rack on my Allez which has no rack mounts at all.
It works very well, and looks quite neat.

 

[shouldbeinbed]

I'm using something similar to that along with an axle adaptor to mount a rack on my Allez which has no rack mounts at all.
It works very well, and looks quite neat.

I have a similar Bontrager one that uses a top arm that attaches via the brake caplier bolt & a slightly wider QR skewer to accommodate the rack feet.