Touring frame differences

Cycle-touring, Expeditions, Adventures, Major cycle routes NOT LeJoG (see other special board)
22camels
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Touring frame differences

Post by 22camels »

Alright, I suspect there are going to be a lot of opinions on this.

I've been thinking about getting my first proper touring bike for well over a year now and this process will likely soon come to an end.

I've studied in detail the specs of a number of alternatives and test ridden a few, being mathematically inclined I recently made myself a spreadsheet comparing the geometries of different frames in my size, also looked at weights.. Some numbers were hard to find so I had to guess or imply them.. And the exercise got me wondering.

I looked solely at steel derailleur bikes, both in 26inch and 700c, some of them are generally known as heavy or expedition grade tourers (LHT, Thorn Sherpa) others are supposedly more light and sporty tourers mainly for road (Kona Sutra, Salsa Vaya, Surly Straggler/xCheck) then there are the ones that look more like mountain bikes (Surly Troll, Salsa Fargo, Specialized Awol maybe), and a few others (Ridgeback Expedition, Oxford Bike Works, Vivente) that are either medium or "expedition" tourers I guess, whatever those terms mean. I am being vague grouping them this way but that's not the point..

The gist of my question is: how much of the distinctions between these frames are based on solid, rock hard science, and how much of it is marketing (people following the use mode prescribed by the manufacturer) and fashion (people following the use mode set by other people)?

Firstly, weight. I know manufacturers don't like to publicise it but it's possible to get an idea, I looked at a few steel frames and they are all 2.1-2.5kg, then the fork is about 1kg. So all this stuff you hear about say the Thorn Sherpa being a tank, is to me a load of nonsense, sure if you put on bomb-proof rims and tyres and racks that will add a lot to the weight and high rolling resistance tyres will make it sluggish, but as far as just the frame goes, 200g difference between an expedition tourer such as the Sherpa and a supposedly sportier tourer like the Vaya is nothing.

Secondly, geometries. I know differences between bike geometries are already quite subtle for the non-experts and one degree of angle here or there can make a huge difference, but nonetheless here I have a number of bikes that the manufacturer says are good for road touring, with varying off-road capacities and luggage-handling characteristics. I condensed out the main numbers of interest: trail, wheelbase, bottom bracket height. They are all in the same ball park, with a few notable exceptions e.g. the Kona Sutra and the Salsa Fargo (which is really more MTB) seem to have a longer trail than most at over 70mm - though perhaps my trigonometry is wrong..!

I am not an engineer or a frame builder and I'm sure I'm being naive and a lot of thought goes into how wide to make each section of each tube and the types of steel and how they are joined up. But I wonder, when you only have 200-300g differences between the frames, and half a degree to play with here and there, how much can you really do to make one bike more an expedition tourer for 40kg loads (say the Thorn Sherpa) and another a more sporty all-surface "fun" tourer for max 20kg loads (take the Salsa Vaya)? How much of it is solid fact and how much is hype?

Clearly it's in the interest of the manufacturers to differentiate their products from the rest of the field (read a Thorn brochure say and the Surly spiel).. at least to some extent.. obviously saying a bike is good for everything is a good sales strategy.. consumers also contribute to the differentiation (maybe everybody wants to feel their bike is unique).. bike shops I've observed often like to blur the lines (one recently told me the Salsa Vaya and the Surly LHT are basically the same bike - they only had one of them in stock..).

I've been tossing it up between an LHT and a Sherpa (cos I want to do a long tour in countries where 26inch wheels are standard) and will probably end up going for the Sherpa, though I recently had a phase of seeing if there was something more 'fun' out there and I started looking at 700c options (cos they might be faster and you have so much more choice!) and in particular got intrigued by the Salsa Vaya cos you see people harp on about its lively and snappy feel etc, but then realised its frame weight is not really that different to the so-called tanks and the geometry is similar and what am I really buying into except what the marketing departments tell you the bikes should be used for? And what other owners have used them for? Where are the actual differences at? And is Thorn heat-treated chromoly really better than regular Surly 4130?

I realise that this may be a bit vague but hopefully you got a sense of what I am asking :).

P.S. please note I am not looking for recommendations or help in choosing. I am just wondering what people think about where the differences are at. Is it in the distribution of weight across the tubes, the tube thicknesses/widths, the welds, the steel types, and how much of it is marketing and fashion driven?
Last edited by 22camels on 29 Mar 2015, 5:33pm, edited 1 time in total.
pwa
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Re: Touring frame differences

Post by pwa »

200g is certainly not a big deal. And neither is the difference between 4130 and Thorn's version. Either of your front runners would serve you well for rough tracks. No bike can do everything, and if you want a fast, exciting ride you will sacrifice robustness, and I don't think you want to do that.
22camels
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Re: Touring frame differences

Post by 22camels »

Thanks, yeah, I'm sure they'll be fine too,I'm just trying to get a better understanding of the differences between frames and where my money would be going, and how the market works. I've read tonnes of stuff comparing this bike to that over the past eighteen months but coming from a scientific background a lot of it seems pretty woolly.
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531colin
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Re: Touring frame differences

Post by 531colin »

Not everything is what it seems.
Why the long trail on bike "X"? well, if you want to use an existing manufactured fork, it will usually have 45mm offset. With straight bars, you can have an acceptable reach and toe clearance. Fit drop bars, and you can get some rather stark choices.....what do you want, of a choice between too long reach, or toe overlap?....or shall we partner the fork with a shallow head angle that will give excess trail, but a bearable reach with toe clearance?
The numbers hide more than they reveal.....you have to ride the things.
Elsewhere, you tell us you are tall. Most manufacturers use the same size tubes for the big frames as for the small frames, so the big frames will be more flexible than the small (the tubes are longer) when really the big frames should be stiffer, because the rider is likely to be heavier, and his weight will certainly be higher up, and his luggage may well be further back (although maybe not if the chainstays are the same length on all sizes)
I'm 5' 10" and weigh 11 stone....the current fashion for oversize steel tubes means that fashionable bikes are all over-engineered for me, and stiffer than comfortable.
If you are 6' 4", twenty stone and carry survival gear, you should look for a stiff bike.
Ditch the spreadsheet, get out and ride some test bikes.
22camels
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Re: Touring frame differences

Post by 22camels »

"Ditch the spreadsheet, get out and ride some test bikes." I've test ridden a few but none have yet felt like my destiny, maybe cos it just takes time to get used to a new bike. It's hard to tell, there are too many variables at play to compare test rides side by side, and in my opinion you need at least a few hours, better a day, and preferably two days, to get a good idea of what the bike is about, which is hard to arrange and time consuming.
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531colin
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Re: Touring frame differences

Post by 531colin »

22camels wrote:"Ditch the spreadsheet, get out and ride some test bikes." I've test ridden a few but none have yet felt like my destiny, maybe cos it just takes time to get used to a new bike. It's hard to tell, there are too many variables at play to compare test rides side by side, and in my opinion you need at least a few hours, better a day, and preferably two days, to get a good idea of what the bike is about, which is hard to arrange and time consuming.


I'm not just being argumentative for the sake of it, there isn't another option. The numbers don't tell you how the bikes ride, however hard you look, however much experience you have.
Somewhere on these 2 threads you mention "high stack to reach ratio". If a bike has a high stack, it necessarily has a short reach, because reach is measured vertically above the BB, but in the plane of the head tube.
effective top tube varies much less with height, as seat and head tubes are nearly parallel.....but top tube length needs to be considered in parallel with seat tube angle, otherwise its near meaningless.
Its pretty quick to set up a bike to your accustomed position, if that's what you want. Take your saddle, set it at the right height above and horizontal distance behind the BB, use a plumb line for the latter. get the shop to swap the stem for the right reach and height, and you have replicated your position for a test ride.
BTW, I don't think you have long legs either, I'm 5' 10", crotch to floor about 33"
22camels
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Re: Touring frame differences

Post by 22camels »

Really appreciate your input though these are two completely separate threads, maybe I should have delayed one of them so as not to cause confusion :). Re the test rides, no I've so far found it impossible to set up my desired position on any test ride bikes, because the bars always end up at least a couple of inches too low due to my high saddle height.
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531colin
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Re: Touring frame differences

Post by 531colin »

22camels wrote:Really appreciate your input though these are two completely separate threads, maybe I should have delayed one of them so as not to cause confusion :). Re the test rides, no I've so far found it impossible to set up my desired position on any test ride bikes, because the bars always end up at least a couple of inches too low due to my high saddle height.


On the other thread I have suggested getting comfortable on your existing bike before you go shopping.
A steerer extender, a few stems, and maybe some headset spacers is a lot cheaper than buying the wrong bike.
I don't think you should be difficult to fit, have a look here.....http://www.spacycles.co.uk/info/pedaltosaddle.php...all the pictures have standard forks, you should be able to reproduce any of them on your existing bike using a steerer extender if the forks have been cut short.
Spa have test bikes, but I still think you need to get comfortable on your existing bike before you do any more shopping.

edit.. this pattern of extender...http://www.highonbikes.com/controls/handlebar-stems-road/bbb-extender-quill-to-ahead-bike-handlebar-stem-adapter.html?gclid=CJTW0ZDOz8QCFYnHtAodTUkA4g...needs more spacers, but gives continually-adjustable bar height. I have happily used them with steel steerers.
mercalia
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Re: Touring frame differences

Post by mercalia »

if its a matter of A head extenders Rose Cycles in Germany have some of the longest I have seen - 120mm - I have one and does a great job & dont cost the earth


http://www.rosebikes.com/article/rose-steerer-tube-extension/aid:721075
pwa
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Re: Touring frame differences

Post by pwa »

531colin is clearly right to say that you need to find a good set-up on your existing bike so that you have something to duplicate with a new one. That is how I measure up on the rare occasion that I go buying.

My touring bike has been much mucked about to get it right. It now has a very short upward angled stem to get the reach right and the bars at the right height. It now feels perfect, and when I built up a new bike a couple of years ago I carefully reproduced the same position, to within a few mm, and it felt right as soon as I sat on it.

Even a good bike will feel wrong of you are too stretched out or the saddle is not quite in the right position.
22camels
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Re: Touring frame differences

Post by 22camels »

Apologies for my poor communication skills. I really should not have started these two threads at the same time! If you read carefully, I am asking a very different question in this thread. It is about what makes two steel touring frames, of similar weight, and geometry, one rated for expedition touring (e.g. a Thorn Sherpa) , the other for light/medium and more sporty touring (e.g. a Salsa Vaya), different. How much of it is to do with weight distribution between tubes, tube thicknesses. And how much of it is it to do with image/hype/marketing/fashion/trend.
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531colin
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Re: Touring frame differences

Post by 531colin »

22camels wrote:Apologies for my poor communication skills. I really should not have started these two threads at the same time! If you read carefully, I am asking a very different question in this thread. It is about what makes two steel touring frames, of similar weight, and geometry, one rated for expedition touring (e.g. a Thorn Sherpa) , the other for light/medium and more sporty touring (e.g. a Salsa Vaya), different. How much of it is to do with weight distribution between tubes, tube thicknesses. And how much of it is it to do with image/hype/marketing/fashion/trend.


A great deal of "marketing", a little substance would be my first reply. If you are just looking at "categories" of frames its almost pointless.
If you have 2 specific frames in mind, there are some things to look at which might be important.....
disc forks need to be stiffer (heavier?) than forks for rim brakes, particularly long (suspension corrected) forks.
An expedition bike needs long chainstays to clear heels and big panniers, stable steering also.(maybe!) A long wheelbase is considered detrimental to ability to do quick turns (for "sportier" bikes), but for a touring bike I like the feel of a stable, long wheelbase rig, and I like sometimes to ride in boots with big tyres and mudguards without toe overlap.
If you want to compare Thorns in any detail, you are hampered by their "secret" geometry.
Just to take your "Fargo" example, with a long trail.....that would normally rule it out as a "fun" bike, (because the steering will be "slow") and place it in the stable/expedition category. .....but does it have long chainstays and lots of toe clearance to go with it, or would you risk kicking the panniers and front tyre/mudguard?
jags
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Re: Touring frame differences

Post by jags »

That SPA tourer looks a cracking bike.
colin on the 51cm frame is the top tube 51cm.just curious.



jags.
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gaz
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Re: Touring frame differences

Post by gaz »

jags wrote:That SPA tourer looks a cracking bike.
colin on the 51cm frame is the top tube 51cm.just curious.

Top tube is 54.4cm, effective top tube 56.4cm
Spa publish the frame geometry: http://www.spacycles.co.uk/smsimg/uploa ... ometry.jpg
High on a cocktail of flossy teacakes and marmalade
jags
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Re: Touring frame differences

Post by jags »

Thanks for that Gaz to long for me so.looking for 53 cm or 52 i reckon.height would be good tho..
very confusing these frame geometry .
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