Llewellyn cable Stop model Limpet for 28.6mm Top Tube in Stainless Steel
This is a beautiful investment cast top tube guide that elevates the cable and has many useful features.
Here is Darrell Mc McCulloch's (the designer) notes about this part:
1) I wanted a fair amount of surface area and a round shoreline to remove stress risers from the .40mm mid-section of tubes (I have seen a couple of marques of frames with .35 and .40mm top tubes fail next to cable stoppers)
2) I wanted ease of brazing, so a preload filler slot to be included.
3) Direct fitting of the brake outer casing without silly ferrules to freeze in with corrosion and reduced kinking of the casing.
4) The gear outer casing ferrule to fit nicely into the CS stopper (a compression-less gear casing must use a ferrule)
5) I wanted a smooth rounded appearance, so the stopper looks like it belongs being part of the tube, not like a plonked-on afterthought.
6) It must be stainless steel to remove corrosion issues due to perspiration or collection of road grime or paint will be the only protection
7) It needed to cause no extra hassle time to be added to the construction process
Note: I personally see no need for a slot in a road bike cable stopper because if the cabling is done correctly during assembly such as lubrication with “Slick Honey” or such, then there is no need to touch a cable until replacement is due. So, the inevitable paint chip from maintenance lubrication around the slot area is avoided.