Before my recent Australia tour, I took Tom’s Expedition Bike back to its birthplace in the UK for a tune-up and a few experimental upgrades.
This post details what’s changed, explores the thinking behind the upgrades, and goes deep into the specifics of why they were made.
(Warning: it’s a 5,000-word long read, so maybe put the kettle on.)
For those unfamiliar with the provenance of the bike, let me summarise the origin story in one paragraph:
In 2007 I built my first custom touring bike. While it took me halfway round the planet, the problematic design reflected my initial lack of experience. Years later, I created new design, and found a partner to build it in Richard Delacour, who had recently started a custom bike-building business. The prototype, named “Tom’s Expedition Bike” by my readers, is the bike we’ll be discussing in this post. Meanwhile, the concept has evolved into Oxford Bike Works’ flagship custom-built touring bike, the Expedition, with more than a hundred specimens circling the globe.
Pictured above: the prototype Expedition in 2015 (left) and 2023 (right).
I had a list of modifications I wanted to make to my bike. With some time in the UK over the festive season before starting my latest bike tour in Australia, I got in touch with Richard and arranged a trip down to his workshop. These were my requests:
- A new Brooks saddle to replace my stolen B17 Special,
- New flat pedals suitable for use with Crocs, flip-flops, wedding shoes, etc,
- A new front wheel dynamo hub paired with a USB transformer, and
- A shiny new Oxford Bike Works head-tube badge (since they didn’t exist when the prototype was built).
I also said I’d be happy to try out any experimental new components he wanted road-tested in the near future. Richard wrote back saying he’d had an idea for a new drivetrain concept and was looking for a guinea pig; would I be interested? Absolutely, I wrote back, intrigued.
One of the reasons I originally reached out to Richard – and why I’m still working with him eight years down the line – is that he isn’t interested in churning out copy-pasted bikes en masse.
Sure, there are plenty of “standard” components that feature in most new Expedition builds (current baseline spec here). After all, the original design was conceived to be simple, solid and timeless.
But he occasionally sends customers off on transcontinental rides having incorporated new and experimental features into the build, with the understanding that if it doesn’t work out there are fallback options.
In this way, Richard maintains close relations with the riders of the many Expeditions now out there plying the world’s roads and trails, collecting feedback on what works and what doesn’t, and incorporating the lessons into new iterations of the bike.
The result is that the current process of specifying and delivering a new Expedition draws on a much broader body of knowledge than I brought to the original prototype. Anyone in the market for a “forever touring bike”, to paraphrase various fashionable terms, really should check it out.
The new drivetrain concept was an interesting one, for it addressed a general inefficiency in touring bike design that’s been staring us in the face for decades.
Your typical mainstream, do-everything touring bike will most likely have been built using drivetrain components – that is, everything between the pedals and the rear hub, including cranks and chainrings, derailleurs/derailers, sprocket cassettes, and associated systems like gear shifters and bottom brackets – from the middle of Shimano’s mountain bike ranges.
A decade ago, that would have meant XT, LX or Deore-branded models. Today the functional equivalents are Acera, Alivio, and perhaps plain Deore, the premium lines having spiralled off into the black hole of planned obsolescence at absurd prices. (In a couple of years you’ll probably find the next-generation Cues groupset on most new bikes.)
Regardless of product line, you’ll usually find touring bikes built with triple chainrings up front and between 8 and 10 sprockets at the back. The reasoning for this has to do with achieving the wide range of gear ratios needed for common touring scenarios, using readily-available parts, at a price point befitting the not-very-glamorous nature of cycle touring, and acknowledging the conservative nature of the niche. Low- to mid-range mountain bike drivetrains have traditionally fitted these criteria pretty well.
But there’s a problem.
Most of the gear combinations on a typical derailleur-operated touring bike are redundant.
(Cue smug laughter from Rohloff owners.)
If you’ve got a bit of touring experience, you’ll probably be aware that you typically spend your days using a very small selection of gear combinations.
There’s the ultra-low hill-climbing gear, which you’ll frantically crunch into at the bottom of more or less any uphill segment, regardless of grade.
There’s the next gear up, which you briefly switch into as you crest the top of the hill, feeling like a legend.
Then, a few notches up the right-hand shifter and into the middle ring on the left, there are the two cruising gears, which you’ll alternate between depending on the smoothness of the road or trail, how energetic you’re feeling, which way the wind’s blowing, and a couple of other minor factors.
Finally, there’s the tailwind gear, for those rare days when you’re blasting along perfect asphalt with the wind at your back (or, alternatively, for when you’re freewheeling down a long descent and you want to look like you’re still pedalling, you absolute legend).
Reading through that list, you will notice that the biggest of the three chainrings almost never gets used. Conversely, the middle ring gets a disproportionate amount of (ab)use.
The result of this imbalance can sometimes be found in the stories that come back from riders who’ve been on tour for months or years. It starts with excessively worn chains, moves on to uneven chainring and sprocket wear, and ends with the expensive replacement of the entire drivetrain.
What exactly is drivetrain wear, though?
All else equal, a chain meshed with a greater number of sprocket and chainring teeth at any given moment will experience less force per chain link. If this scenario is prolonged over time, the components will wear at a slower rate.
Chain wear usually refers to the illusion of stretching as the individual pins and links that comprise the whole chain ever-so-slightly deform with use.
Indeed, every professional bike mechanic will have in their toolkit a chain wear measuring device which can be used to measure the length of a set number of chain links compared to the length when the chain was new.
(Special tools are used because the increase in length is actually very small: common wisdom holds that a quantifiably worn chain of the type likely to be used on a derailleur-geared touring bike is one which is more than 0.75% longer than it was when new.)
Chainrings and sprockets, manufactured to mesh perfectly with a new, unworn chain, can only tolerate a certain amount of chain wear before it begins to have an adverse effect. As the links in a chain stretch, each pedal rotation will start to put disproportionate force on the pins that have most recently engaged with the currently-selected chainring and sprocket. Consequently, the links that precede the ‘driving’ link go ever so slightly slack. The result is an uneven meshing of chain and teeth.
This brief concentration of force on individual chainring teeth and sprocket teeth will, over time, erode the driving face of each tooth. The effect is more pronounced when certain gears are used disproportionately more often than others.
Once a chainring’s teeth are worn beyond a certain point (you’ll see this as a hooked shape; run an image search for “worn chainring” to see what this looks like), a new chain will tend to get sucked back up into the derailleur in a phenomenon imaginatively known to bicycle mechanics as “chain suck”. The rider experiences this as a horrific metallic crunch as the pedal rotation stops dead (that’s the voice of experience right there, by the way).
At that point, since you can no longer fit a new chain at all, the whole lot goes in the scrap bin and it’s new components all round.
Cycle tourists rack up more miles in less time than almost any other cycling discipline, save perhaps for couriers (by the way, next time you roll up behind a bicycle messenger at the traffic lights, have a look at how heavy-duty their chain is and how few sprockets they bother with).
Given all of this, it’s easy to imagine how disproportionate the wear on the middle chainring and the couple of cruising sprockets on a fully-loaded touring bike in constant daily use might be.
Throw into the mix the entirely understandable observation that most tourers are not checking their chains for wear and replacing them as often as perhaps they should, and you have a fundamental weakness in the design of a typical touring bike with no obvious solution – at least, not from mainstream manufacturers of traditional derailleur drivetrains.
Being dedicated to the improvement of his bikes, Richard thinks he can solve – or at least alleviate – the niche problem of drivetrain longevity and redundant gearing on fully-loaded touring bikes like the Expedition.
And he wanted to test the theory on my bike, with the addition of four steel washers and a couple of new parts from Shimano.
The hack – for that is what it is – took about half an hour to implement with the bike on the stand.
The result? A 2×8 drivetrain that matched the range of the previous setup: 42–26 front chainrings paired with an 11–40 cassette, for gear ratios of 0.650–3.82 across 16 speeds.
Since we’re now in full nerd mode, let’s visualise that using Dirk Feeken’s extremely cool Bicycle Gear Calculator:
(Open the above visualisation in interactive mode here.)
This configuration is not commercially available, at least as a complete groupset.
What Richard did was to replace the previous 22-tooth small front chainring with a 26-tooth ring, and then install a 42-tooth ring – intended for use as the larger of three chainrings – in place of the former 32-tooth middle chainring, all on the original triple crankset.
The space normally occupied by the third and biggest ring of the triple was left empty, with 4 stainless steel washers acting as spacers for the original chainring bolts to be refitted (slimline two-piece chainring bolts do exist but we didn’t have any to hand).
The 16-tooth difference was the maximum possible with this approach if the combination was to remain compatible with standard Shimano front derailleurs. 44–28 and 46–30 could also work for light touring, but fully-loaded riders need that ultra-low bottom gear.
At the back, the new Shimano Altus CS-HG400‑8 11–40T 8‑speed sprocket cassette was a straight swap for the previous CS-HG41‑8 11–34T 8‑speed unit, slotting onto the standard splined freehub body of the Shimano rear hub.
The rear derailleur – a Deore model from the original build in 2015 – didn’t quite have the tooth capacity for the new ranges, so an extra-long-cage Shimano Acera RD-M3020 unit with a 45T capacity went on instead.
Chain length was adjusted, the front derailleur limiting screws reset, and the whole lot wired back up to the original cables and shifters. It ran like a dream.
And that’s the beauty of a custom-built bike: you can set it up precisely as you like!
(For clarity, the Expedition’s friction-based thumbshifter setup was chosen in the first place for its cross-compatibility with the varying components one might be obliged to fit over the course of an ultra-long tour. It’ll work with double or triple chainrings, and – in friction mode – pull any rear derailleur compatible with a cassette that sits on a Shimano freehub body, regardless of sprocket count.)
You might be asking how exactly this helps reduce drivetrain wear over time. Well, the theory was that the new system would achieve a couple of things:
Firstly, the range of typical chain angles would be reduced due to the smaller distance between small and large chainrings.
Secondly, the new ratios should result in the chain meshing with more teeth.
Together, these two effects should result in a slower rate of chain wear, meaning less frequent chain replacement and longer-lasting drivetrains.
These are benefits that people who are cycling round the world – and who potentially have large distances to cover between servicing stops – tend to like the sound of.
It may not be obvious why this is the case, so let’s get into some examples. (That gear calculator may help again here.)
Were I to be climbing a big hill with the new system, I would do so in 40/26 for a ratio of 0.650, with 66 teeth in rotation. With the previous drivetrain, I’d be in 34/22 for a ratio of 0.647 (an imperceptible difference) but using only 56 teeth.
More commonly, were I cruising along in, say, 42/22 at a ratio of 1.91, there’d be 64 teeth in play. Before, in the closest equivalent of 17/32 at a 1.88 ratio, there’d be 49 teeth going round.
(Of course, at any given moment, a maximum of 50% of the teeth would be meshed with the chain, but the relative ratios still stand.)
In the first scenario, and under controlled conditions, I might expect drivetrain wear from the normal rotation of the chain to occur at something like 85% the rate of before. In the second scenario, partly by encouraging me to cruise in the big ring (which rarely happened with the triple), my new setup might wear at 77% of the previous rate.
Richard previously recommended new riders who haven’t yet learned how their particular setup performs to routinely replace their chains at 5,000km. The new setup might conservatively get someone another 500–1,000 kilometres down the road – or, in many parts of the world, to the next big city and the next half-decent bike shop.
It is critical to state that this ultra-simplistic scenario does not take into account any of the other reasons for drivetrain wear rates to vary.
In Richard’s experience, now having built over a hundred Expeditions, excessive chain wear might occur at anywhere from 3,000–8,000km, depending on factors such as riding style (hard cranking versus smooth spinning), maintenance regime (how frequently the drivetrain is cleaned and lubricated), even riding environment (seaside humidity eats steel, desert dust plus chain lube equals grinding paste, etc). Some of these variables are within the rider’s control; others are not.
But all else being equal, there are potential benefits in Richard’s experimental new drivetrain that would improve the ability of a long-term cycle tourer to keep their bike in good working order for longer periods of time.
What I particularly liked about the change was that it did not involve spending large amounts of money on expensive proprietary technology.
In fact, this new and improved 2× drivetrain was innovated by combining low- to mid-range Shimano components at a comparable cost to the previous setup.
(Take that, smug Rohloff owners!)
In the meantime, my job was to take the upgraded bike on tour and report back on whether it actually worked for day-to-day. It did. (Read the full trip blog, starting here.)
In fact, the theory worked on all counts: I spent far more time in the big ring, felt less anxious about chain angles, and found I had all the ratios I needed (especially in the middle of the range where the ratio differences need to be a little finer).
Beyond that, I also realised I just liked the simplicity of the double chainring – one less variable to be concerned with while riding.
Full disclosure: I have not yet ridden enough miles to be able to report back on the longevity increase. But as soon as I do have that data, you’ll be the first to know…
Richard also wanted to see how I got on with a new heavy-duty kickstand he wanted testing.
Looking for all the world like it had come straight off a motorbike, the Italian-engineered Ursus Power somehow managed to fold elegantly alongside the non-driveside chainstay, well out of heel-striking distance.
Rated to 55kg (for reference, an unloaded standard-spec Expedition weighs around 16kg) but in reality strong enough to support a fully-loaded bike with luggage and rider (we tested it!), the Ursus Power is one of the few commercially-available kickstands built for the weight of a fully-loaded touring bike.
Richard had specified these stands on a couple of recent builds and had received positive feedback from his customers, but he wanted my thoughts on the new unit anyway, especially when compared with the double-legged stand that it replaced.
Cutting to the chase, I absolutely loved the new kickstand, and soon adopted a cool-casual manner of extending it with an outstretched foot whilst gazing thoughtfully in another direction, which I’m sure impressed no end of random bystanders.
With a relatively broad rubber foot, I had no issues resting it on grass and gravel as well as concrete and asphalt. The fact that it was a side-stand, designed to support an off-balance bike, meant that uneven and slightly sloping ground presented no issues, given a little care in positioning the bike – something the previous double-legged stand could never achieve. Unsurprisingly, it wasn’t entirely happy in soft sand, but then this is hardly the natural domain of the touring bike anyway.
On my particular bike, there was a little wiggle room between the edges of the frame mounting plate and the body of the stand mount. The current frameset used for the Expedition, which is now hand-built in the UK by Lee Cooper, has a much tighter interface and the stand is a very snug fit.
Richard had been concerned that the tensioning spring that held the stand in its stowed position wasn’t quite strong enough to stop it rattling on bumpy roads. Since so many such noises crop up when you hit the gravel with panniers and a bar-bag, I can’t say I noticed, even on the worst the Old Gibber Trail could throw at me.
One thing that did soon make itself apparent was that the mounting bolt, which threaded through into the unit from the top-side of the frame plate, really needed its thread locking. We’d had neither threadlocking compound nor lock-washer to hand on the day the kickstand was fitted, and I’d forgotten to install either before setting off.
By lunchtime on Day One, the unit was wobbling around and making a right racket in the process, all from routine road vibrations. In a masterstroke of bad planning, I then found my multitool’s 10mm hex key too short to reach the recessed bolt, so I kept having to stop in at bike shops to tighten it.
I later dropped in on Derek at BikeFix in Port Macquarie, and we refitted the stand with both threadlocker (Loctite 263, aka: red Loctite) and a spring washer for good measure. And that was the end of my mounting-bolt issues.
Short version: I love this stand!
The third major change that Richard made to the prototype Expedition was in fact my main personal request:
I wanted to experiment with using a dynamo hub (aka: generator hub) to keep my smartphone charged.
This would involve building a new front wheel and adding a transformer and current regulator to convert the output of the hub to a USB supply.
I had no particular preferences on the components involved; just that the resulting wheel be functionally the same as the one it would replace, so I asked Richard for his recommendations.
For the hub itself, Richard had in stock the Schmidt SON 28 or the Shimano DH-3N72. Both had similar specifications on paper, outputting a 6V / 3A alternating current, but at very different price points: the SON 28 currently retails at €269 while the Shimano DH-3N72 (sold as part of the Deore LX line) is a third of the price at €88.
With the SON having been thoroughly tour-tested over several decades (it’s been in production since 1995), there seemed little to add to the conversation, so instead I opted for the less-commonly suggested Shimano equivalent. As well as being significantly more affordable, I also felt a road-test and a review of the DH-3N72 in a touring context would be more useful to the touring community than yet another rider talking about how great the Schmidt unit was.
The wheel build itself matched the baseline Expedition spec in every other way: a Ryde Sputnik rim (559mm, aka: 26″) with 36 eyelet-reinforced spoke holes and a Schrader valve drilling, laced with Sapim spokes in a 3‑cross pattern.
(Since Ross Spiers retired, Richard has moved his wheel-building in-house, meaning each new Expedition now has its wheels custom-built to order as an integral part of the build.)
We refitted the Schwalbe Marathon Plus 47–559 (26×1.75″) wired tyre and matching inner-tube from the original wheel, which after almost a decade still had plenty of life left in them. These have been the standard long-distance touring tyre for the Expedition since the first prototype; even after almost 10 years of tyre development, nothing else comes close in terms of puncture resistance and longevity. One of Richard’s customers rode from Singapore to the UK on one pair of Schwalbe Marathon Plus tyres without a single puncture.
Plugging a 6‑volt, 3‑amp alternating current into your smartphone would be a terrible idea, and for that reason there is a growing range of transformer-regulators available that will convert the generator hub’s output into a USB-friendly 5V DC current. While there are many such devices available, I took Richard’s recommendation and went with a VeloCharger.
The VeloCharger is made by Adept Electronics, a small UK-based company who started producing transformers for bottle dynamos in 2015. Their products are now distributed through long-time UK cycle touring specialists Spa Cycles, as well as on new Oxford Bike Works bikes across the range.
Outputting a maximum of 1.5 amps at 5 volts DC to conform with the USB standard, and with a cut-out feature should the incoming current be too high (fast descents) or too low (slow climbs), the VeloCharger sounded on paper to fit the bill perfectly.
The VeloCharger is designed to be attached to the frame tubing, being supplied with self-adhesive velcro patches and a velcro strap for easy removal. For the same purpose, there’s an inline connector to easily unplug the unit from the supply cable coming from the hub.
What it doesn’t offer – and this is the main division in the arcane world of pedal-powered device charging solutions – is a cache battery, which can be thought of as an intermediary power bank that receives and stores a fluctuating charge as the speed of the bike varies during the course of daily touring, yet can always output a stable current while it holds charge. The benefit is self-explanatory, but oft-cited negatives include additional weight, another device to monitor/break/lose, added expense, the lost efficiency of another stage of power transfer, and (some claim) the fact that they aren’t actually necessary anyway.
Having used a cache battery (the long-obsolete Biologic Reecharge) paired with a generator hub in the past – part of the year I spent hopping around the UK on tour with a folding bike – I was eager to understand if the absence of an intermediary storage battery would prove problematic. I assumed not, since the VeloCharger was produced and sold on that basis – but only an actual tour would prove the theory.
Specifically, I wanted to know whether the DH-3N72 hub and VeloCharger combination could keep a modern smartphone sufficiently charged to navigate a pre-planned route with an app like komoot on a multi-day tour.
And the answer to that, dear reader, is a topic for another long and nerdy future post…
As for the other tweaks and upgrades:
To meet my request for a pair of flat pedals I could use while wearing Crocs or flip-flops (Aussies: thongs, Kiwis: jandals), Richard fitted a pair of Shimano PD-EF202s.
At first glance, these bore more than a passing resemblance to the classic mountain-biking flat pedal, the much-imitated DMR V8, which has long been a favourite for its broad platform, aggressive grip, renowned build quality, and simplicity (if not exactly ease) of servicing, running as it does on 3/32″ loose ball bearings.
The PD-EF202s are similar in many ways, also running on loose bearings and with a similar overall shape and size. Shimano market them for “casual” leisure riding and trekking (aka: light touring), but the word really refers more to footwear than frequency of use.
Richard picked out these pedals for me over the DMRs because – as anyone who’s used them in anger will know – the grip is rather aggressive. Specifically, the replaceable pins have a tendency to take chunks out of your shins if you slip (some riders have been known to file them round for this reason!) and equally make mincemeat of soft foam-rubber soles. Although the calculation may well be different for certain bikepacking use cases, fierce grip for technical riding isn’t on the priority list for most tourers, so the gentler profile and grip pattern of the PD-EF202s was welcome.
Other plus points on paper included 6mm hex key (Allen key) fittings at the inboard end of the axles, eliminating the need to carry a standard 15mm pedal spanner; and the price point, which at £40 a pair (trade price) should be a reasonable indication of above-average build quality. They don’t come with reflectors, but they are compatible (SM-PD69 is the product code for these), should you want the extra visibility in unlit tunnels and at night.
I’m not sure if or when I’ll write a standalone review, so I’ll interject here with my first impressions of the Shimano PD-EF202 pedals after a few hundred kilometres of riding:
On the positive side, they’re certainly the most comfortable pedals I’ve used on any tour, thanks to their generous size and shape and to the aforementioned grip profile, which I found perfectly adequate for my riding style without being overaggressive: at no point did I slip off the pedals, struggle for traction, or dither over foot placement (and yes, I was indeed wearing Crocs for the entire duration of the tour).
On the negative side, after just 700km of riding I would not expect a brand new pair of pedals at this price point to exhibit play in the bearings, nor to find the egress of grease through the inboard rubber dust cap, creating a sticky, sandy mess (this happened equally on both sides) – not a particularly good sign of longevity.
Had I continued riding, I wouldn’t have wanted to go much further without adjusting the bearings, which as anyone who has done it will tell you is a rather fiddly job. The ball bearings you’ll find supporting pedal axles are by far the smallest on most bikes, yet they frequently get slammed by the full weight of the rider freewheeling over bumps and along rough roads, and occasionally slammed into kerbstones by clumsy riders trying to haul fully-loaded bikes onto sidewalks. All of this means they’re usually the first to need servicing – although not normally after only a few hundred kilometres!
All that said, I feel it’s still too early to call this one, which is why I’ll be holding off on the review for a while. It would be interesting to hear other tour reports on the Shimano PD-EF202s – perhaps I just got a bad batch.
There’s little to be said about buying a new Brooks saddle, other than to repeat an oft-stated sentiment that most touring cyclists will find it to be the last saddle they ever need to buy, and the rest will spend a disproportionate amount of time seeking an alternative.
For the sake of interest, and because this is a long-running sore point – no pun intended – Richard has for several years been keeping count of the “Brooks Acceptance Rate”, and has found it to be around 80% for riders with male physiology and 55% for female.
(For that same reason, he now offers free saddle replacements for those who don’t get on with their Brooks.)
And finally, after working my way through a series of flat and riser bars and an equal number of stems, I finally decided to try butterfly bars for this ride.
I fitted them prior to my visit to Richard; this isn’t an “authorised” option for new Expedition builds, but every rider is different, and even after several years I was still not entirely happy with my cockpit setup. Once again, my thoughts on the pros and cons of butterfly bars on tour will be up on the blog in the coming weeks.
(And I did indeed get my shiny new head tube badge, in case you were wondering.)
Okay – at just under 5,000 words, or half the length of a novella, that’s probably enough for one post. Comments and questions about anything covered here are more than welcome. Thanks for reading!