A road to Damascus kind of week

I have held off from posting this for almost a month until today.  Now, I can’t wait any longer!!  I am now the proud owner of a lovely Thorn Raven Sport Tour, with an equally wonderful 14-geared Rohloff Speedhub.  There, I’ve said it.

Readers of the blog will know of my interest in the Thorn/Rohloff combination, an interest garnered first by my visionary cycling buddy, Mark, whose Raven Sport Tour I have posted on this blog (spookily, I posted his first comments and pictures on exactly the same date a year ago….July 24th!!!).  It remained a pipe dream until recently when I happened upon an advertisement on the Thorn owners’ forum, for an RST in the frame size 561L (which was around the size I was interested in).

I’m probably being presumptuous if I assume that all my readers know what is so special about either a Thorn bike or indeed a Rohloff Speedhub, so I’ll begin from the basics.  Thorn have been producing steel-framed ‘Traditional Touring Bikes’ from their shop in Bridgwater for many years.  They tend to operate in a slightly different universe to the majority of cycle brands, and whilst the frames are no longer actually made in their shop (they outsource the production of their designs to one of the top Taiwanese firms, as do the likes of Koga), they are all designed and the actual bikes built there prior to shipping.

The Thorn Raven, itself a descendent from the legendary Nomad (the kind of bike which can be, and frequently is, ridden literally around the world), is a solid, slow and heavy bike that is built for durability and comfort.  My bike, the Raven Tour Sport, is its flashier, slicker cousin – less weight, slightly tighter geometry.  But all of the bikes I have mentioned share one unique attribute – their gearing is not the common deraillieur mechanism, dangling from the rear axle and exposed to the elements.  No.  The gear shifting (all 14 of them, with over 500% range) all happens inside the rear hub, sealed from the elements and facilitated by a series of ‘planetary’ gears moving around the ‘sun’ central geared axle.

It is not an exaggeration to state that the Rohloff Speedhub 500/14 is perhaps one of the most over-engineered components that money can buy – it’s made in Kassel in Germany, of course.  It’s a bit like a Swiss watch on the inside, and the real beauty is the range.  It covers the same set of ratios, broadly speaking, as a mountain bike with three front chainrings and a 7 ring rear cassette.  Indeed, Bernhard Rohloff designed it for mountain biking in northern Europe – it is sealed against the elements so effectively that, suffice to say, all of the recent ’round the world’ cyclists of note have used bikes with Rohloff hubs.

I hope that my digression has proved interesting – and so, I pondered the spec in the advert – it seemed right.  Lots of upgrades.  Black anodised Rohloff hub.  Little use.  A few emails were exchanged, and the deal was sealed.  I travelled up to the far North-Western reaches of the country at a ridiculously early hour, seeing the sun rise as I sped northward.  After a test ride, some conversation and a decent cup of coffee, I was on my way home and peeling off the A66 onto the A1 southbound by breakfast time.  And, stunned by the intensity of the journey I had just undertaken, I arrived home at lunchtime with a gleaming Raven Tour Sport in my car.

My RST (that’s what we geeky Thorn aficionados call them!) arrived with a specification relevant to the area it was ridden in – which is to say the Pennines.  The tyres were wide (1.75), the gears were low (a 42 tooth chainring) – the other big area in which the Rohloff excels is that by selecting the number of teeth on the front chainring and rear sprocket, you can set the range of the gears – every Rohloff hub is the same, you see.  What suits hilly Yorkshire is not at its best in flattish East Anglia, and so some discussion ensued with Mark to see what would produce a favourable ratio.

Now Mark runs a 16 tooth rear sprocket with a massive 48 tooth chainring – whereas I plumped for a 46 tooth as a replacement.  This was duly ordered from SJS Cycles (Thorn’s bike shop), and arrived a couple of days later in the post.  You see, the Rohloff, despite being ostensibly a 14-speed hub gear, is actually two 7 speed boxes between which the gears can shift – low ratio and high ratio.  Gear 11 is the one that is effectively ‘direct drive’ – the gears are not stepping your pedal power down, nor are you stepping the gearing up, as it were.  Thus, the combination of chainring and sprocket is crucial in getting your own perfect gear 11, in which you can ride for as long as you like with complete efficiency.

But then I encountered a problem I hadn’t anticipated.  The bike, amongst its many upgrades, enjoys a Rohloff SRT-99 chain (which, believe me, is a good thing).  This chain, unlike its run-of-the-mill Chinese made siblings, is another solid Teutonic piece of engineering and retails for what you might politely call ‘a few quid’.  But, if you replace a small diameter chainring with a bigger diameter chainring, the laws of engineering tell you that the chain ain’t going to fit anymore!!  Luckily, a quick post on the Thorn forum led to a very kindly fellow Thorn owner from Scotland offering to send me some spare links from his own Rohloff chain, and this became a reality, prompting me to spend a very, shall we say, interesting morning breaking and lengthening a bicycle chain which I’m pleased to report has now stretched nicely.

The problem of having a single sprocket (and thus no chain tensioning of the like you get on your primitive, crappy derailleur) has been overcome by Thorn with the addition of what is known as an ‘eccentric bottom bracket’.  I know, cue ‘Carry-On’ style jokes aplenty.  What this gives you though is a bottom bracket that can be loosened via two screws, rotated, to lengthen or shorten the chain, and then tightened up again – the rotation possible is greater than a full chain link, meaning that the chain should rarely need any links taken out.

How does it ride?

Well, thus far, with the driveline modifications described above, and with a pair of 1.25 inch Panaracer Pasela TG tyres (much narrower), as well as the trusty Brooks saddle and a pair of Ergon handlebar grips, the RST is little short of a revelaton.  It has a longer wheelbase that my Audax bike, giving utterly predictable riding.  I love the upright position – the stack of spacers on the fork and the Thorn Comfort bars give a great riding position.  But it’s the gears that really do it for me.  Oh, and the brakes.

My buddy Mark said last year that once you’ve ridden a Rohloff geared bike, you’ll never want to go back to the derailleur way of changing gears again.  In engineering terms it’s inherently superior – a fixed chainline with no lateral stresses placed on the chain – gearing of a wide range protected totally from the elements, running in an oil bath to eliminate wear.  Rohloff still do not actually know the service life of one of their hubs – they have never had one fail due to wear.  Braking is taken care of by Shimano XTR V-brakes, the front one placed sensibly behind the fork crown.  These are the best rim brakes you can get and are designed for competition level mountainbiking – they provide total confidence.

I’m in the early days at the moment, and will post again soon about some rides with the RST.  But for now, suffice to say, it has not disappointed!


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