Hi folks
I'm heading over to Canada (from Scotland) this summer, to ride south for around 1000miles to Jackson, Wyoming on the Great Divide route with my son. Camping all the way. I'll be on my 6 year old  Mercury Mk3. My son on my old Sherpa.
A few adjustments to my Mercury for the ride will be dropping the gears from a 43 x 19 set up, to 39 x 19 and switching from slick 2.00 tyres to the largest gravel tyre I can fit. Guidance for largest tyres on the Mercury are 54 mm. The front fork looks like it has clearance for a larger tyre.
Can I ask? If it fits, Is it worth having a larger tyre up front? The route is predominantly tracks/ off road.
As an over 60, I have only ever used inner tubes. Is it worth switching to tubeless at this late stage? Or stick to what I know?
Any recommendations for tyres?
Thanks, as ever, for your comments and all round knowledge.
Eddie

The guy that put together this video has done a LOT of videos on bike touring and related equipment.  I trust his opinions highly.  And for touring, he likes belt drive.  He also mentions some efficiency stats.  This video is a few years old. 
https://www.youtube.com/watch?v=PhXTl7gApVA

He often runs his belt looser than the manufacturer recommendation.

Regarding chain drive efficiency on Rohloff bikes, I think that the Thorn bikes with an eccentric bottom bracket are more efficient than the bikes that use a spring loaded chain tightener with a jockey wheel.  And of course once you start talking about chain efficiency, then different lubes become a factor.

He is sponsored by Koga, but he does not specifically push them, unless you watch the review of his bike.

2 - If I ever get a purpose-built electric bike. But, when the time comes that I need assistance, at the moment my plan is to convert one of my existing bikes, or perhaps a second-hand mountain bike (available for about 50 euros), and use a chain, chainring and sprocket designed specifically for electric bikes together with a ChainGlider. These KMC transmission components cost significantly morer than standard ones, but still a lot less than belt drive components.

I agree with you, Martin. Having discovered the Chainglider and the KMC X8 chain, and steel chainrings, I have zero interest in the frame-weakening a belt drive brings with it. It may be that I'm biased by having been a motor racer as a young man, whose specialty was suspensions, which absolutely demand stiff frames. But I'm not convinced by the special electric bike components KMC are marketing.

I discovered steel chainrings serendipitously: I was ready to order a Utopia Kranich but hated the amorphous cranks that was their standard supply, and had been put off the aluminum chainrings that went with the ugly cranks when I used Nexus transmission from Shimano, which ate itself up pretty shortly; I never saw as much as thousand miles from a set. I thought about the Thorn default chainring which then as now had a pretty good reputation of longevity, until I discovered it wouldn't fit in Utopia's Country chain enclosure (same principle as the Hebie's Chainglider but much lighter build). Someone suggested I fit a temporary cheap steel crankset from India, Amar brand, until found a way to buy a set of the Japanese cranks I had my heart set on. It was many months before I found a way of actually having the cranks I wanted delivered to me, from Paris as it happened, and not too long after that a lot of things happened simultaneously: I moved up the steepest hill in town, the Country chain protector started falling apart, I discovered the Chainglider, I bought a not too outrageously expensive electric bike kit to educate myself, and I discovered that the only really satisfactory upmarket chainring inside a Chainglider is Surly's stainless steel model. After about 3500 miles the black paint on the Amar was still intact. When I went from a front-drive to a mid-drive electric motor the Surly chainring couldn't be made to fit, so I got a couple of sizes of 8Fun's standard steel chainrings, dished to fit over their motor to give the right tread width for the Rohloff, both in steel. The chainring that on test I found most suitable has since done 11000 miles inside a Chainglider without any sign of wear. It follows logically that I see zero reason to fit anything more expensive than steel on a utility or touring bike -- I presume a road bike someone intends to race would be built to a more weight-conscious decision pyramid.

Belt drive from my persepective :

I tend to keep my bikes for quite a long time. The last new bike frame I bought was an old stock Raven Tour step-through frame in 2018. All the bikes I use myself are more than 10 years old, so not worth spending about £400 to try and convert to belt drive. Instead, most of them now have ChainGliders, which prolong transmission life and reduce maintenance, perhaps not to the extent that a belt does.

Two exceptions though :

1 - If I ever replace one of the family Bromptons I would be quite interested in a belt drive. Since retiring I don't use a Brompton on a daily basis, but in bad weather conditions the chain needs cleaning very often - my "record" is just 40 kms between cleaning after 3 short rides in the recent storms. The chain on a Brompton picks up much more road muck in bad conditions.

2 - If I ever get a purpose-built electric bike. But, when the time comes that I need assistance, at the moment my plan is to convert one of my existing bikes, or perhaps a second-hand mountain bike (available for about 50 euros), and use a chain, chainring and sprocket designed specifically for electric bikes together with a ChainGlider. These KMC transmission components cost significantly more than standard ones, but still a lot less than belt drive components.

Very interesting and informative article; best read before you get the hacksaw out!

https://thorncycles.co.uk/blog/carbon-gates-belt-drive