Thorn Audax Mk3 5000 mile review


Earlier this year I clocked up 5000 miles on the Thorn Audax and that’s time to review my investment in cycling.

In brief, the Thorn Audax is a fairly traditional steel frame bicycle, aimed at cyclists who are looking to do some brisk day rides, with the option of some lightweight touring.  You can either buy the complete bicycle direct from Thorn Cycles and choose from an impressive range of options, or as I did, I purchased just the frame and asked my LBS to build it up to a very similar specification.

The frame

Any steel frame bicycle placed alongside carbon fibre or even aluminium is probably going to feel heavy.  However, that’s not the whole story.  It is very well made, clean joints and all the braze-ons you really need with some thoughtful touches.  The “visible” ones include a pump boss, fittings for front and rear pannier racks along with scope for two water bottles.  As an aside, I sometimes cringe listening to some cyclists fretting about saving 100 grams here or there on their bike – they might be well advised to take a look at their own weight first (rant over).

The handling is important for me.  It combines a fairly sprightly and responsive ride (compared to a full-blown touring bike) and reasonably stiff in the right places.  Cornering on fast downhill bends are easy to control well.  The standard forks do a great job in soaking up bumps and rough road surfaces with steel having a little “flex” and “give”.  I think they’ve done well in terms of selecting the right tubes in the different parts of the frame so it all works well together.  You can’t “see” the handling when you look at a bike in a catalogue or a shop.

I think the finish is pretty good, though colour is down to personal choice. The decals are fairly subdued which suits the slightly understated nature of the bike: this is no “boy racer”.  In fact I think it already looks a bit old fashioned, which is perfectly fine for me (who cares anyway).


Some of these are less impressive but its important to keep these things in proportion: you pay for what you get and components are generally expendable to a point.

The wheels are good but I fell out with the Panaracer tyres owing to far too many punctures.  Considering these are the “tour guard” puncture resistant variety, I regret to say I had far too many punctures.  I have totally changed my mind about these and while I know many people rate them highly (and Thorn Cycles promote them) I will not be buying any more.  While it’s true the skill in the wheel building is as much to do with the continued straightness of the rims, these Mavic Open Sport rims have been superb.  They’re strong and light.  They are also surprisingly cheap as I discovered when I had one rebuilt following an encounter with a road defect.  The hubs are Miche RG2 – quite obscure but absolutely superb and still as smooth as the day they were made.

The drive chain works well but I’d do it differently next time.  It consists of a Shimano DeOre triple chainset, DeOre mechs, a Sram 12-26T 9 speed cassette and Shimano bar end shifters.  It all works well and an incredibly wide range of gears – far more than I need.  I can count on the fingers of one hand when I have used the 26T granny ring.  The bar end shifters have always been reliable and the front mech is non-indexed, meaning you can “trim” the position precisely.  The rear is indexed and works superbly, never missing a smooth change.  Do why would I do it differently next time?  Simply because I prefer the Shimano STI system which is, in any event, virtually the norm on any road bike you’d buy off-the-peg.

The STIs are of a better ergonomic design and save the gaffing around of taking your hand off the handlebar to change gear.  The bar end levers are okay for what they are; perfectly reliable and cheaper.  Click here for a previous post on this subject.

The Shimano SM BB51 bottom bracket, on the other hand is very disappointing.  This was worn out somewhere between 3000 – 4000 miles and I have learnt this is about the normal lifespan.  Years ago a decent bottom bracket would last the lifetime of a bicycle but these fancy external bearings (requiring a special tool) are not exactly brilliant.  I replaced it like-for-like against my better judgement as a temporary fix but I will reconsider the whole transmission another time.

Contact points are always a personal choice to a large extent.  The Brooks B17 saddle is well documented and a long standing classic and therefore little more to add.  The Shimano SPD touring pedals do their job well and have been used on another bike for a good few years.  Handlebars and stem are in proportion to the frame size and suit me.

Other miscellaneous parts include a average Nimrod adjustable rack and SKS mudguards, which replaced the flimsy ones originally fitted.  Other bits are too trivial to mention.

Overall conclusion is that I’m really pleased with the Thorn Audax.  The frame is superb in terms of ride quality and handling, plus it’s nicely made.  When I got it I aimed for a good long term investment which is what I have.  Components fail, come and go but the heart of the bike is worth getting right.  It is as close to a perfect do-it-all versatile bike for me: it’s great for day rides, commuting, light touring and going to Sainsbury’s.

If it was written off or stolen I would buy another as I like it so much.  I would change the transmission to a compact 50-34T chain set with STI levers (probably Tiagra or 105) and the appropriate mechs.  Other than that, it is just about the perfect bicycle.

Here’s to the next 5,000 miles and beyond.


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5 Responses to Thorn Audax Mk3 5000 mile review

  1. Pingback: Installing Shimano Tiagra shifters | The Cycle Hub

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  3. Steeplechasing says:

    Thanks for the review. I’ve had 3 Thorn bikes, and think they’re excellent.

    I have a Rhohloff-hubbed Raven Tour, which is heavy but very comfortable.

    I’d like to try Audaxing, and wondered if I should get a dedicated Audax bike, like the Thorn (perhaps just the frame, as you did).

    I’m not a speed-freak, by any means. I like to go pretty fast on flat ground when the wind’s at my back, making me feel 20 again.

    I do want to be comfortable, and I’d like something very responsive.

    On the off-chance you have ridden a Raven Tour, I thought I’d ask…on a dedicated Audax bike, am I likely to go ‘Wow! This is way different to the Raven!’ or ‘Hmm, it’s lighter and a bit faster, but not so different to justify spending £1,500 or so’?

    Many thanks

    • doug says:

      Hi Jo
      Thanks for leaving your comment and apologies not to reply sooner.

      Nowadays there are so many bikes around to choose from that would do the job you have in mind – long distance brisk rides.

      Price for price, many will be lighter, better equipped and arguably better value than a Thorn. These could be carbon fibre with Shimano 105 group set fitted for the same price. On paper, the Treks, Giants, Bianchi, Cannondale, Specialized and so on might look better.

      Having said that, yes I believe the handling of a Thorn Audax will be much more nimble against the Raven. The benefits of steel are better known these days – comfort, repairability, durability etc. It would fit the requirements but probably not set the world alight.

      If I were doing it again, I would get the same frame, a spare pair of carbon fibre forks, possibly light wheels and other components and thoroughly enjoy it for two or three decades

      A great “all rounder”.

      Hope that helps


  4. Martin says:

    I have tried most bikes for Audax. The best one is the most comfortable one that will get up hills!
    Comfort v. Distance and then hill climbing ability.

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