I'll have a go at those:

There are no cable guides along the left hand (non-drive side) chainstay.
You can get purpose made fittings that stick and zip tie on, but standard zip ties are fine.  There's no indexing to worry about, but a smoother cable run gives a smoother shift.

From what I see I'd need a 'regular' 135mm hub with either the disc brake cap (for any future changes) or smooth cap.
If buying new there's no disadvantage to getting the disc hub, unless it's dearer.  If buying secondhand, non disc models fetch a good bit less.

Also, would either the QR or threaded axle work - is there any preference?
I have both, they work the same in a vertical dropout, the nutted axle is better in a horizontal.  Wheel in and out takes a bit more time with a nutted axle and of course you need a decent spanner.  By default I'd choose QR, but it's no big deal.

I'm not sure about the internal or external gear mech.  Which would work best on a bike which wasn't built with Rohloffs in mind?
Again both work fine, the internal is a bit crisper.  You have to have the external with discs, you can have either with rim brakes. The external is easier to detach, it's also easier when you replace cables.

I expect I'd also need the 'standard' hub which uses a separate torque arm.  Is this likely to cause any problems?
There's no issue.  The torque arm is a bit ugly, you have to detach it to remove the wheel, that's simple enough. You don't have to line anything up when refitting the wheel, which is an advantage over some methods.

There's various chain tensioners, chainline is easy to adjust on the Rohloff one, it's well built and parts replaceable. I have one on my folder, it isn't as big a disadvantage as some think.

I tried uploading more photos but no go. The red in the above is a tad brighter than in reality! Here is a better gallery: https://www.flickr.com/photos/steveparry/albums/72177720329159894

Your going out the same way you came in.
Honestly ive gotten lazy o  the bije wbat really putting me off is the amountvof cars
So far 7000 housrs built all where i ljve s.and everone drives.

Quote from: mickeg on October 28, 2025, 01:32:55 AM

Is it a Checkpoint?
I know about five or six people with the Checkpoint, two of them had to replace their bottom brackets.  But the bottom bracket problem might be limited to the carbon frame models.

Domane AL. Not sure which number. A midrange model. Funnily enough, I had asked her if there had been any bottom bracket problems. She said apart from normal wear items, everything was original.

The people that I know that have Trek bikes, the only ones that had bottom bracket problems had the Checkpoint, I think both of them were carbon frames but maybe only one is carbon?  The people I know with aluminum frame Checkpoints, no problems other than one gal has had some defective tires, I think her bike is now two years old. 

I have never thought of the Domane as a gravel bike, I think of that as a road bike.  And it does not surprise me that it has 24 spokes.

There are lots of Trek bikes in my area, the CEO lives about 10 miles from my home, their headquarters about 30 miles.  But I have never owned one.  I considered a 520 about a decade and a half ago, but got something else.

thanks for replys folks .y bike frame is aCX cross bike ultegra groupset .
i have an electric front wheel on 250 watt get my aching bones up the hills.
but makes the bike HEAVY  .

all the camping is brand new really nice gear Kilos brand
panniers are ortlieb classic
tent is really nice 2 man looks pure quality but sure wont know
how it holds up in storms until i try it lol.
ya know being old 72 is not a lotta fun thats a fact
broke a bloody tooth last night aint got to many left who invented teeth
my poor back is still knackered and eye sight is getting a bit on the dodgy side.

But saying all that im determined to get a few good over nighters before i totally seize up,
hence the reason i asked about alu frames lol

cheers
jags