fuseecyclist

I have an oval 40-50mm down tube with no cable stops. Im trying to fit road sti s . I can't seem to get a clamp anywhere that size and all the frame builders work in steel

mcoine

There have to be cable stops somewhere. You might be sol.

MichaelW

Clamp-on cable stops are for round, not oval tubes.
https://sheldonbrown.com/harris/cable...ecablehardware

You may want to consider positioning the stops at the base of the head tube rather than downtube. This prevents cable rub when you steer and is quite common on modern bikes.
Dont forget that a HT clamp will require the stop to be oriented differently than a DT clamp. You are unlikely to find such an accessory made commercially but you could probably fashion one yourself from a hunk of Al and a dremel.

fuseecyclist

thanks for that, its given me a whole new way of looking at it !

sch

You might consider drilling and tapping holes in the head tube to mount the bits you fabricate. The headtube is certainly strong enough that a few holes will make little difference and a bit of locktite and gasket cement will go a long way toward sealing the holes and reducing screw back out. Careful length measurements of the screws will prevent interference with the fork. Would be prudent to R&R fork to clean out any bits of shaving that might fall inside and get in headset bearings and the verify the screw clearance.
Steve

Little Darwin

I concur with the previous poster to an extent, but I wouldn't expect to be able to tap the thin walled aluminum, I would look for something like rivnuts to use in holding some sort of cable stop that could be fabricated to mount that way...

https://www.bikeforums.net/general-cycling-discussion/148651-how-mount-water-bottle-cage-no-threaded-posts.html

MichaelW

The only manufacturer who drills the HT for cables in this fashion is Principia. This is no hack job, few bikes are as well engineered or built.