I do indeed have the wrong brake/shifters on flat bars, they are Shimano ST-EF35-8 and ST-ET35L, the bike was converted from drops to flats by the previous owner. I gather my options are to change these levers, to something like Deore LX M567 combined shifter/levers or change the cantilevers to V brakes, but again told by the bike shop that this would not be possible, but feel I might do this at some point, just a case of finding suitable V brakes.

I don't have issues with cantilever brakes myself. Two of my own bikes still have them, as does one of my wife's bikes. One of my "visitor" bikes has a cantilever brake on the front. Braking is less fierce than with V or disc brakes, but I can still lock the wheels on all my bikes in heavy rain, even the Bromptons with calliper brakes, so the limiting factor for braking is tyre adherence.

Converting from cantilevers to V-brakes can be an issue with drop bars, as suitable levers are becoming harder to get. It is less of a problem with flat bars. I have done several conversions on flat bar bikes, the most recent being a fairly old Dawes (probably late 1980's or early 1990's). Not yet had any flat bar bike where it wasn't possible to fit V-brakes instead of cantilevers.

For these conversions I use inexpensive XLC BR-V03 110 mm V-brakes, these give good clearance on wide tyres with mudguards. I reckon they work as well as more expensive models so long as the original brake pads are replaced, and with their bronze pivot bushes they seem to last quite well. Paired with fairly inexpensive Shimano DEORE BL-T610 brake levers, good quality brake cables and housings and Kool Stop brake pads (there are other good brands), in my opinion they work better than cheap cable operated disc brakes and about as well as the entry level Shimano hydraulic disc brakes.

I only have one disc brake on my own bikes, it is a good quality cable-operated TRP Spyre on the rear of my "touring" Brompton, which is heavily modified from standard with a Rohloff hub. Braking is, as always, limited by tyre adherence. The disc has three advantages on this bike :

- transmission picks up less muck than with a rim brake. It isn't possible to fit a Chainglider on a Brompton.
- rim wear is eliminated. The 16" rims on Bromptons wear quicker than on a large wheel bike, this isn't much of an issue for me as the rims are reasonably inexpensive and I build my own wheels.
- rim heating on long descents is eliminated for the rear wheel. Small rims heat up quicker than large ones. The disc will heat and cause brake fade, but I reckon this is less dangerous than the tyre blowing off a hot rim. 

I would recommend you have a go at solving this problem yourself. It will teach you the finer points of setting up this type of brake and give you the confidence to keep them performing optimally as the pads wear. The Park Tools web site is an excellent source of bike maintenance information.

https://www.parktool.com/en-int/blog/repair-help

This video deals with cantilever brakes which are very similar to those on your Club Tour.

https://www.parktool.com/en-int/blog/repair-help/cantilever-smooth-post-brake-service

My only criticism would be that I’m not a great fan of straddle link wires. In theory the correct length link wire should help to optimise MA but in practice this doesn’t allow for variations in the distance between the mounting bosses nor their height above the axle. Their main advantage is when running without a front mudguard, where they eliminate the risk of a conventional straddle wire snagging the front tyre and pitching you over the bars if the main cable fails.

Back to the LBS today to explain my concerns, they're going to look again at simpler solutions.

I'm interested to hear the explanation!  The T261 was a popular touring rim about thirty years ago, it's 26mm width isn't in any way exceptional, it was the standard rim on many bikes including the Dawes Galaxy. There was some variation in brake boss widths until V brakes standardised it at 80mm, but forks designed for touring tyres wouldn't have been far off that.  Your canti brakes are pretty standard fare for the time period as well.  As said in your previous thread, those brakes work better the lower the straddle wire, as a consequence that also increases the distance from the rim.  I may be missing something, but I can't see why your brakes wouldn't work as well (Or as badly) as cantis have always worked.
If it were me and the bosses are wide enough and you're not concerned with keeping it original, I'd fit V brakes, there's good reason they replaced cantis, though they will also require different levers.

Hi,

I have bought two Thorns on this forum -- one Nomad a couple of years ago, and one Raven for a family member. Had good experiences both times -- honest, direct sellers, no faff.

I have sold non-Thorn bikes on Ebay and on another popular cycling forum. The forum sale the buyer was local so an easy transaction. Ebay sales involve a bit more effort responding to queries, some time wasters, but in the end no problem with the sale.

I would be potentially interested in the Mercury depending on size, price and location. After a long tour with a Rohloff I am trying to get a Rohloff equipped audax/ light tourer and Mercury fits the bill.

Good luck with the sale however you decide to proceed.

Thanks for the reply, and yes it is.  I've felt a bit caught between the advice here and the LBS.

Back to the LBS today to explain my concerns, they're going to look again at simpler solutions.

Thank you for the advice again, it is appreciated