I can’t figure out how to mount bb cable guides. Both of the examples below the cable is just going to scratch all over the frame. Can anyone explain it to a dummy please?

CABLE MOUNT FAIL

No 1 answer: get a cable guide specific for the bike.
the rear mech looks like it will be fine, the front mech is conflicting with that weld, indeed.
You could fashion a continuation of the runner.
your best bet is to use a nylon block of some sort.

no cable guides at all i guess?

personally ide use a full outer for the rear mech, and zip it to the frame as normal i think (on the top tube)
but without stops, the front mech is a bit of a problem….

The black frame (Trek XO) has cable stops for top tube and bottom tube front mech cable routing. However i want to run a normal bottom pull road front mech without a cable pulley thing, so down tube it is. Deffo don’t want full length outers as in my experience the less outer you can use the nicer the gears work. I thought about making the runner longer (maybe cutting a bit of tubing in half), but i can’t find anything suitable.

Any other ideas?

Nb i’ve contaced both manufacturers (trek and Planet X for the pink frame) and neither said anything about a frame-specific guide. In fact they weren’t any help at all…

The front mech cable on my Scott cross bike has a little plastic sheath on it where it fouls the frame on the way up from the BB. It’s not as ‘big’ a contact as you’ll have, but it should be fairly easy to sort something neat through the hole/over the weld using a bit of, for instance, Gore cable inner liner stuff?

Nb i’ve contaced both manufacturers (trek and Planet X for the pink frame) and neither said anything about a frame-specific guide. In fact they weren’t any help at all…

So the manufacturers build top pull bikes with the cable stops in all the right places but you’re not happy so you try to change it…

And then said manufacturers won’t help???

What ever next?

Actually, looking at it again, the XO looks like it’d be fine with a bit of a sheath on the cable, and the planet-x might be the same with the guide on the right way around 😉

So the manufacturers build top pull bikes with the cable stops in all the right places but you’re not happy so you try to change it…

And then said manufacturers won’t help???

What ever next?

Eh? Maybe i haven’t explained myself very well, but they both have cable stops on the downtube – which to me suggests that using them and routing the cable via the downtube should be perfectly fine.

Thanks Jonathan – the PX one is indeed fine if i turn it round. I said it was a dumb question! And i’ll try and find some sort of suitable sheath *fnar fnar* for the Trek one.