There’s too many variables for there to be a definitive answer. Here’s what I’ve spent in 2.5 years and 15,000 miles.
Sprocket removal tool £20
Torx screwdriver £5
Half liter flushing oil £15
Half liter hub oil £15
Hub grub screw £1.50
Oil changing syringe £6
Hub gear cable £5
Shifter gear cable £7
Chain £9
Chain oil £1
Total £84.50
If I consider the tools to be part of the bike price, they added £31 and shouldn’t need replacing.
The investment in the oil was worthwhile, I bought a liter of each and sold some on, the savings over buying small quantities are vast. £1.70 per oil change against £8 plus postage.
I’ve just turned the sprocket and chainring round and expect to do another 15,000 miles before they need replacing at a cost of £45.
The numbers on the twist shifter have long worn off the rubber is looking a little rough. At some point I will replace this at a cost of £8. The shifter itself is working fine, it’s so simple I doubt it will ever need replacing.
The only expense I haven’t included was a replacement bayonet fitting, if you don’t keep these clean or covered they can seize.
And of course I haven’t included the stuff that needs replacing on any bike, tyres, rims, brakes…
So taking out the tools and the oil I have left, adding in cost of wear to the sprocket, chainring and shifter rubber and budgeting to replace all cables every two years, the running costs per year or 6,000 miles comes too almost £30.
I’ve tried to work out how much of a saving over running a derailleur, again there are too many variables, mainly what quality of kit, how well you look after it and where you ride. I estimate I save around £50 a year. My Raven cost £350 (inc tools) more than an equivalent Thorn bike, like a Sherpa with decent components. So 7 years before that’s recouped. It isn’t on it’s own enough of a difference to sway me one way or the other.
The biggest saving is in time, some people love maintenance, for me it’s a chore. I used to spend about an hour a week keeping my commuting bike running smoothly, I hardly touch the Raven. Even if there was no financial saving, this would be enough.