Author Topic: What does your Thorn Audax weigh?  (Read 237 times)

Danneaux

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What does your Thorn Audax weigh?
« on: June 11, 2019, 08:59:52 AM »
Hi All!

I've got that early summer go-fast bike bug in the back of my mind and am wondering...."What does your Thorn Audax weigh?" as-configured and by size, so I can get some idea as to weight. It is probably the first question people here ask me when I mention Thorn's Audax and they see what kind of bike it is. Remember, my Nomad weighs in at 20kg appropriately outfitted for my intended use, so anything lighter is "light" to me. ;D The majority of my randonneur and road touring bikes weigh in between 14.5-15kg/32-33lb built up as I like them.

It seems a majority of the current mass-produced go-fast bikes on this side of the Pond have carbon or aluminum frames/forks or carbon forks if they have steel frames. I'd prefer an all-steel ride out of familiarity and comfort, so I've been looking at older models on Craigslist (our version of Gumtree) for comparison. It seems a bike of this sort with a horizontal top tube in my size (58cm c-t seat tube. ~57cm c-c top tube) weighs just under 10kg/~22lb as an unadorned bike with light saddle and pedals included if it is made with 0.8/0.5/0.8 main frame tubes and rides on 25mm tires (for a general apples-to-apples comparison). I would prefer slightly wider tires and would of course have to adapt such a bike to local conditions. For example, this week's local temperatures are expected to hit close to 37.7C and desert temps even higher, so I'd be hauling at least three full 1l bottles of water with me on the 300+km day rides I take, throwing ultimate "lightness" right out the window.

So, just curious. Could you please give the size and a brief general description of how your Audax is appointed (i.e. mudguards, bottles, frame pump, lighting/tires) in your replies?

Thanks in advance.

Best,

Dan.

leftpoole

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Re: What does your Thorn Audax weigh?
« Reply #1 on: June 11, 2019, 11:06:32 AM »
 ;D I have and have owned a number of Audax bikes.
Weight matters not.
How does a person weigh their own bike?
The frames built with Carbon forks and no mudguards (fenders) weigh the least. Indeed feel very light and as light as this writer is happy
to go with.
But those frames with Reynolds 853 forks, whilst slightly heavier , are the best to ride for comfort and agility.
Weight as mentioned, matters not. It is for those with 20 kg bicycles that weight does matter!
Best,
John
« Last Edit: June 11, 2019, 11:09:40 AM by leftpoole »

geocycle

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Re: What does your Thorn Audax weigh?
« Reply #2 on: June 11, 2019, 04:29:56 PM »
According to the Thorn literature the 'A1 Thorn Special' weighs 10.5-10.9 kg depending on frame size, the A2 High End Spec 9.8kg including mudguards.

http://www.sjscycles.com/thornpdf/THORNOVERVIEW+RECIPES.pdf

 

Danneaux

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Re: What does your Thorn Audax weigh?
« Reply #3 on: June 11, 2019, 05:49:43 PM »
Thanks very, Geo'; a much appreciated baseline.  :)

Still kinda wondering also what individual bikes might weigh as setup for real-world use. I know it is easy to add "just one more" item to my underseat bag, making my lighter bikes that much heavier (more appropriate as a training aid/boat anchor), but I've got it pretty light for "shoulder season" changeable weather 'round here (pic).

All the best,

Dan.

lewis noble

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Re: What does your Thorn Audax weigh?
« Reply #4 on: June 11, 2019, 07:49:56 PM »
You are right, Dan, in real-world use bikes weigh more than even Thorn's generally realistic weighing . . . .

My audax is in 'dock' at the moment, having 165mm cranks fitted - but I expect that the LBS will have a decent set of scales so I will weigh when picking up; will post then.

Lewis
 

PH

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Re: What does your Thorn Audax weigh?
« Reply #5 on: June 11, 2019, 10:23:28 PM »
Iíve never had a Thorn Audax, but Iíve had a couple of others, most recently a SOMA ES.
With too many bikes it was getting the least use, with deteriorating roads and receding youth, 28 mm tyres no longer provide the comfort I desire. So (sorry this is already a longer post than intended) I sold the ES, but then had two similar bikes, Mercury and trad tourer, in order to put some differences between them I built the tourer up with audax type parts and wheels.
Which finally brings me too the point  - 400g is the difference between the ES and the tourer in similar spec, or it would be if I used the same tyres.  I donít believe there is ever much difference between decent quality steel frames unless you compare expedition with race.  Comparing tourer with audax is always going to be about the build.
Of course itís more about feel than the weight itself and that varies between riders.  Iím 100kg and 1.87m Iím more likely to find a frame too flexible than too stiff.  A 65kg short rider may well prefer to go the other way and tour on an audax bike.
Mercury, 610L, guards, rack, dynamo, lights, empty bottles, no luggage, 38/35 tyres, 13.6 kg
Tourer 58cm, no rack, Bagman, no other luggage, guards, empty bottles, 35/32 tyres 12.4 kg
« Last Edit: June 11, 2019, 10:37:20 PM by PH »

martinf

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Re: What does your Thorn Audax weigh?
« Reply #6 on: June 12, 2019, 11:54:26 AM »
I don't have an Audax, but did consider getting one a few years ago.

Instead I ended getting a Thorn Raven Sport Tour frame, which I built up using fairly light components, apart from the Rohloff hub. And although I no longer use my 1977 Woodrup 531-frame lightweight tourer very often I kept it, because it wouldn't be worth much if I tried to sell it.

Just been into the garage to weigh them both, after removing their saddlebags.

The Raven Sport Tour weighs about 14 Kg, the Woodrup about 13 Kg, on scales designed to weigh a person (I pick the bike up and substract my own weight).

Both bikes have full mudguards, SON hub generators, lights, bottle cages and lightweight saddlebag supports. Apart from the different frame geometries, the main differences between the two bikes are :

- the gearing systems. Triple crankset and 6-speed narrow freewheel, front and rear derailleurs, bar-end shifters versus Rohloff hub and twistgrip.
- the rims and tyres. 28 spoke wheels with Mavic Open Pro rims, Schwalbe One 28 mm tyres and latex tubes versus 32 spoke wheels with Mavic 717 rims and Kojak 35 mm tyres and latex tubes.

I don't think I could save much weight off my Woodrup bike without getting carbon-fibre bits, which I don't like, or removing things I consider essential (lighting, bottle cages, mudguards, etc). And there isn't very much difference in weight between the Audax frame and my old Woodrup frame. An Audax would, however, have different geometry and be designed for modern components.

My lightest bike is a 2-speed Brompton, this weighs about 9.7 Kg. On this I have titanium bars, forks, rear triangle, seatpost and have sacrificed gearing, saddle comfort and practical lighting for lightness. This bike is used for short trips using other transport where I have to carry the folded bike.

« Last Edit: June 12, 2019, 09:33:45 PM by martinf »

Danneaux

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Re: What does your Thorn Audax weigh?
« Reply #7 on: June 12, 2019, 06:26:47 PM »
Thanks All for your replies and the care, trouble, and thought you put into them; much appreciated and helpful!

Best,

Dan.

lewis noble

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Re: What does your Thorn Audax weigh?
« Reply #8 on: June 12, 2019, 09:14:39 PM »
Picked up bike and weighed it today.  I have had shorter cranks fitted, because of troublesome knee problems, and also reconsidered saddle height, position etc. etc.  My Sherpa, not ridden much since Audax arrived, had 165 cranks, which I find more comfortable - we'll see how it goes.

Weight of Audax - 12.2 kg.  In ready to go trim, see below.

Audax 555S. Merv 853 fork
Wheels & tyres - DT SWiss, lighter than standard but not ultra light, 700/28 Schwalbe One tyres.
Fizik Aliante saddle - pretty light.
Tubus Airey Ti rack.
Guards as fitted by Thorn, SKS I think.
Zefal pump up the seat stay.
2 x bottle cages, 1 bell, 1 Moon rear light on the rack. Light bracket at front

Interestingly, it has put on weight!  The Thorn 165 cranks, with cartridge bearing, are about 100 g heavier than the Deore / EBB set up they replace.  Not enough to worry about in the scheme of things.  It is now very difficult to source triple cranks at short lengths at the sort of price I was prepared to pay for a solution that I hope will help, but cannot be sure . . . Fitted by my trusted LBS.  I am delighted that Thorn is selling this kit.

There is a clear trend towards 11 sp compact double drivetrains, sometimes with very wide cassette range, which makes changing triple kit difficult. 

I will report later on how the new cranks feel.

I hope this helps.

Lewis
 

lewis noble

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Re: What does your Thorn Audax weigh?
« Reply #9 on: June 12, 2019, 09:20:12 PM »
Sorry, forgot pedals . . . . yes, I use pedals.  One on each side.

MKS Road pedals, toe clips and straps. 

Lewis
 

Danneaux

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Re: What does your Thorn Audax weigh?
« Reply #10 on: June 12, 2019, 10:08:30 PM »
Quote
I hope this helps.
It really does, Lewis (and John, Geo', PH, and Martin) and gets to the core of what was in my mind when I asked the question.

Here it is in a little more detail: I now have 15 active bikes in my fleet, most dating from about 1970 to the mid/late-1980s with one a 2007 and the latest being my 2012 Nomad. They range from folders to a tandem but in between their numbers run heavy to randonneurs and touring bikes. My heaviest is the expedition Nomad at 20kg and my lightest is a skinny-tired Fixie I ride surprisingly often. It is this last bike that got me thinking it would be nice to buy my first-ever "go-fast" bike -- and try really hard to keep it that way so the positive weight-saving difference and feel between it and my other bikes remains distinct. Based around a 1970 road racer, the Fixie has been nice up to 200kms but distances, hills and wind are eventually problematic

'Trouble is, my bike builds tend to converge over time. Brooks saddles aren't light but work best for me. It gets hot here in summer, so I add bottles and cages, then fill them with water for those long rides. Self-sufficiency is a requirement, so a multitool/tube/patch kits are added to an underseat bag. Farmers water their fields heavily which results in a lot of standing road water, so mudguards get added and of course day turns to night so there's lighting for seeing and being seen and pretty soon a lightweight bike becomes...heavier. Equipped with mudguards, three bottles/cages, a pump, underseat bag and clip-on battery lighting the Fixie now weighs 12.7kg dry as I ride it most often even with 25mm road slicks. Add a full derailleur drivetrain and I'm perilously close to the 14.5kg weight of my rando-tourers, so I'm not at all sure it is worth trying to pursue a go-fast bike if it becomes so heavy it isn't really fast/quick anymore.

I don't like the feel of aluminum and having evaluated a number of failed carbon frames for warranty coverage, I'm scared of its potential for sudden failure despite the zillions of people who have never had a problem. I prefer a frame made of nice, quality butted steel tubing, hence my focus on older/used road bikes here with Thorn's Audax as an option for new. I'm just not sure I'll see/feel much difference over what I already have by the time I finish personalizing it to my tastes and needs. By crowdsourcing the data collection, I was hoping to see how close a real-world Audax might come to what I already own.

Thanks again for the input; it did help!

All the best,

Dan.

« Last Edit: June 13, 2019, 03:17:36 AM by Danneaux »

PH

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Re: What does your Thorn Audax weigh?
« Reply #11 on: June 13, 2019, 11:28:58 AM »
[I'm just not sure I'll see/feel much difference over what I already have by the time I finish personalizing it to my tastes and needs. By crowdsourcing the data collection, I was hoping to see how close a real-world Audax might come to what I already own.
I've a feeling you were pretty sure of the answer before you asked, maybe hoping someone would tell you otherwise. but I don't think anyone can.  If you want a bike to feel substantially different, it need to start with a substantially different frameset and/or be built up in a different way.   Even on the Audax Spectrum that goes from Road>Touring the Thorn is way over towards the Touring side, not IMO a bad thing but becoming increasingly rare on the Audax I do. I think you'd get closer to what you're looking for with a steel road frame, though you might have to make some other compromises.  Or Ti - I had a Linskey Sportive for a while, absolute blast to go out on a sunny afternoon and thrash around 40-50 miles on decent roads, after a couple of years I had to confess that's not the cycling I actually do much of and it was a lot of bike to hang on to for the two or three times a year I did.


geocycle

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Re: What does your Thorn Audax weigh?
« Reply #12 on: June 13, 2019, 01:06:59 PM »
I hear what you mean about convergence Dan.  Last year I bought a second bike to be 'very different' to my RST.  It's an audax styled bike with a Ti frame.  The idea was light and fast for day rides while avoiding identikit carbon offerings.  But in the end I couldn't resist a leather saddle, mudguards and a dynohub!  Still it is nice to have some variety as well.
 

martinf

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Re: What does your Thorn Audax weigh?
« Reply #13 on: June 13, 2019, 08:41:13 PM »
With a large number of bikes to play with, it might be nearly as much fun to build a set of very light wheels for one of the existing bikes and fit them with state of the art lightweight (but not too narrow) tyres. This is what I did with my Woodrup a few years ago when I started getting other bikes to fulfill the loaded touring role. So far I have got away with using 28 spokes front and rear, but the bike is now used only occasionally and on good road surfaces.
 
The high performance tyres I know about are Schwalbe One in 700x28 mm, but I expect there are now others that are even better.

I have no experience of tubeless, which is supposed to be better than using conventional inner tubes for a "go faster" bike. Latex tubes, which I do have, also give a slight performance/comfort boost over standard butyl tubes. Downsides are that they don't last so long and need topping up frequently.