March 4: Tyre selection
This week's drama topic is tyres. The bike came with WTB Ranger TCS Light / Fast Rolling 29" x 2" tyres. These are mountainbike tyres, knobby and grippy, which means they're slower on smooth surfaces like asphalt, hardpacked gravel or dirt.
I've been tracing the trail on Google Maps and an awful lot of the route is fit for cars. There's a few sections where it goes fully offroad, and from the satellite photos it looks like there is no track whatsoever: but that's a tiny minority. So something a bit slicker seemed wise.
I was in the bikeshop getting pannier racks and bags, and we talked about tyres. Their recommendation was to get the Schwalbe Marathon Almotion. They're REALLY slick, so I have some reservations, but they seem like a good place to start.
But the tyres the bike came with are 29" tyres, and according to Schwalbe the Almotion tyres are only available in 28". So presumably they won't fit...
... and at that point I'd fallen into one of the traps for new players.
But I didn't realize that yet. So I spent a bunch of time researching 29" tubeless tyres that are slick but not too slick, and there aren't that many options.
Google has an option to shop for 29" tyres but - perhaps because there's so few options? - it throws in a lot of 28" options and I wasted a lot of time looking into options that turned out to be the wrong size.
After looking at a lot of contradictory info, the light finally dawned: the listed sizes in inches were utterly untrustworthy. It turns out ‘29" wheels’ is jargon for wheels that aren't actually 29 inches.
(Deep sigh.)
Wiki page with confirmation: https://en.wikipedia.org/wiki/29er_(bicycle). Fave quote: "For example, at least 6 different "26 inch" sizes exist (just by American notation), and "27 inch" wheels have a larger diameter than American "28 inch" wheels."
I was pretty annoyed by this. I'm no stranger to annoyance; I often encounter things that irk me enough to fix them (eg doors left open, mistreated tools). But I can't even imagine annoyance (rage? indignation?) so immense yet focussed that that it motivated someone to form a committee and get an ISO standard approved to fix it. Because that’s what seems to have happened.
I find it a bit disturbing. Do people genuinely rage-start committees? It sounds so alien to me I worry I'm personally inadequate in some way.
Anyway, the committee is ETRTO: "European Tyre and Rim Technical Organization", an acronym so unpronouncable it can only have been produced by engineers. They defined ISO 5775, for labelling bicycle tyres and rims. And for their work, I am genuinely grateful.
An ETRTO measurement is two numbers: the first is the rim width in mm, the second is rim diameter. My tyres had "50-622" printed on them. (50mm across! They are chonky.) And it means I could be sure that a tyre I saw online would actually fit my bike.
I also noticed that a lot of the tyres Google found for me actually fitted: maybe Google knew some things I didn't?
The next problem is getting a reliable recommendation. Tyre reviews and forum posts seem good, but are often contradictory. bicyclerollingresistance.com not only has a really great name, but has (seemingly) objective numbers for the energy loss rolling on a smooth surface, among lots of other stats. Unfortunately they often haven't tested the tyre I'm interested in: tyres seem to be updated regularly like bikes are, and it's not obvious how similar the Continental Cross King Protection 29" Folding Tyre is to the (not making this up) Continental Cross King Protection 29" Folding Tyre Bernstein Edition.
I'll skip over the next round of fruitless research, to the part where I had the idea to see what tyres the European Divide finishers used. They don't list that info, but many of the people had photos including their bikes. With a bit of zooming and Googling I was able to figure out a few. One in particular is the "Continental Race King Protection" tyre, and bicyclerollingresistance.com has tested it and thinks it's really fast. It's got a slick center and features on the sides, so it's got grip if you use that part of the tyre. Looking good!
Until I found a Canadian bikepacker who used them long-term and complained about tubeless sealant seeping through the tread, and it losing pressure so fast it needed to be pumped up every day. Nope.
At that point I thought I should check if the Schwalbe Marathon Almotion came in my size. Turns out it does! And bicyclerollingresistance.com thinks it's even faster than the Continental. And it has much better puncture protection too. Would like some more grip … but I didn't see any other good options so I'll just have to make it work.
In summary: multiple hours of research. Much drama, including a stupid plot twist. End result is back where I started. Could have avoided it all if I'd gone with the first recommendation and didn’t try to do things properly.
