Hugo, thinking a bit more about your problem, I'm wondering about the role of excess or repeated cable flex at or near the grub screw causing metal fatigue.

Of course, the rear splitter allows for actual un/screwing, as it is basically just a seat for the leaded end of the cable and this tolerates some "slop". The front splitter half is secured rigidly to the cable so any movement will be concentrated at the screw.

Besides reinforcing the stranded wire as I suggested earlier, is there something causing the front run of cable to bend and flex unduly? Something like a nearby cable stop or frame boss? Maybe a clamped-on accessory band? Is the anti-scratch o-ring still intact on the front half of the splitter? Is the cable end getting bent overmuch while the bike is disassembled or put into a case?

Just trying to think of possible contributors.

If your splitters have hex flats, it might be worth holding the front half stationary from twisting with a small wrench while you spin the freely turning rear half. I modified a small, automotive ignition points wrench for a friend's similar need and it seemed to do the trick for him.

EDIT 1: If you are using the J-TEK cable splitters without wrench flats, they're available in different lengths and for gear vs brake cables. I presume the difference is related to the size of the leaded cable end? Perhaps fitting a longer or shorter example -- if possible -- would ease stress on the cable. See...
https://www.sjscycles.co.uk/search/?term=j-tek%20cable%20splitter&geoc=US

EDIT 2: Is the cable splitter fitted midway in the open run of cable between stops? If the splitter is too close to the front stop, the cable will flex at greater angularity, right where it is clamped by the grub screw(s), resulting in metal fatigue and snapped cables.

Best, Dan.

Greetings all,

My Raven Twin tandem has S&S couplings and hence cable splitters for gear and rear brake cables fitted as standard. This allows me to dismantle the bike to get it in the car, in a bike box for air travel etc. So far, so good.

During uncoupling and reassembly of the bike, I take great care to minimise twisting the part of the cable splitter that fixes the cable with a grub screw, and I do not over tighten the grub screw in the splitter when replacing cables.

Despite these precautions, I find that the cable that is fixed to the splitter by the grub screw snaps too often. In 43000kms of riding the bike since new, the "front" cables, i.e., those connected to the Rohloff gear selector on the handlebar, have snapped a total of 4 times (always at the grub screw) whereas the "rear" cables have not yet snapped.

There must be a better way of using cable splitters to reduce the frequency of cables snapping. I'm trying to figure out how to add a nipple to the end of the cable after it has been fitted, and doing away with the grub screw altogether.

Has anyone any bright ideas?

George,
There are a lot of interesting places to see between London and Edinburgh, and some great scenery.
...
...
If I wanted to shorten the journey I would take a train to Cambridge from London and start riding from there.

UK has lots of shops.  Petrol stations are usually open and sell food so no need to carry too much.  If you need something you will probably be able to buy it.

Google maps tells me that London to Cambridge is roughly 60 miles (sorry, I am still thinking miles, not km), that is a semi-long day on a bike.  I think I will pass on the train, as the train adds enough complications as as luggage, etc.  but thanks for the suggestion.  Being in USA, I am not used to convenient train travel, as our network of trains is quite poor.  So, if I planned to do very much train travel, I would have to spend a lot of time on education.

Perhaps your petrol stations have more normal foods than USA petrol stations have, ours rarely have much nutritious foods to eat.  I have diabetes, I have to limit my carbohydrates and that means minimizing overly processed convenient foods.  On bike tours, I often stop at restaurants when I see them so that I can eat nutritious food.  And after my Iceland tour, my doctor diagnosed a severe protein deficiency, so I have to make sure I am getting plenty of protein every day.  So, I anticipate looking for well stocked grocery stores.  A few days ago I put together a list of your main grocery stores and their internet sites so I can look for locations of them when I need to.  And my GPS is usually pretty good at finding grocery stores.  I usually carry several 20 gram protein bars so that I can have one a day for the extra protein.

Attached photos, two of my suppers on my last bike tour, a canned soup and a canned stew.  My stove can use both the long skinny butane cartridges like in those photos or shorter wider cartridges that you thread the stove onto, that threaded type canister is in the third photo.  I did not plan to bring a stove that goes on the unthreaded French canisters, but if those are common I could bring that stove along too.  Fourth photo is that type of stove and the French canister.  So warn me now if I need to also bring the French stove as that was not in my plans.

My last bike tour was a bit over two weeks, I rode a distance of 662 miles, or a bit over 1,000 km.  But that was mostly on reasonably flat ground, and I plan to ride shorter daily distances on this trip.  This trip as planned is about 50 percent longer, but I can easily adjust the latter routing to shorten it if I have to.  And thanks for the many suggestions here for Scotland routing, I plan to completely change my Scotland routing.

East Coast:
- Cambridge
- Lincoln
- York
- North York Moors
- Durham
- Newcastle
- Northumberland coast

That's a good itinerary for a first tour of the UK. So is Andy's west coast ride, especially the Lake District if you're a city dweller.

But a second tour could specialize. For instance one could visit the smaller cities with cathedrals. (Actually they're towns, jumped up to being formally cities because they have a cathedral, which on the whole makes them better places to cycle in as many of them have narrow streets e.) Academics and other friends from all over the world came to stay with us in Cambridge and a universal demand, after tours of Cambridge colleges, and a scull on the river, was for a half-day trip to Ely Cathedral, which accounts for how many people have photos of themselves in the Bishop's Door at the Cathedral. Pronounced not E-lie but E-lih as in 'lick'.

Or a tour of fishing ports like Whitby.

If I wanted to shorten the journey I would take a train to Cambridge from London and start riding from there.

Absolutely. London, except the City (meaning the financial district, like Wall Street), which is architecturally interesting, and the bicycle path beside the Thames, is dangerous for cyclists. Cambridge is a good place to start cycling without being stressed out for no good reason.

Hi folks. I've been a bit slow to catch up on this thread.

If any of you pass through or near Aberdeen, please contact me for support or accommodation.
Aberdeen has the ferry/ship to Orkney/Shetland. I have been to both several times and can highly recommend them.

A few years ago I rode from the top of Scotland/Shetland, down to the Southern most tip, Mull of Galloway, via the Outer Hebrides and islands.
So can offer advice/thoughts of the West side of Scotland.

Best wishes