Hi Matt!
You asked a very good question...
any thoughts on how much 'extra' the coupling adds to a bikes 'worth'?
I can offer an opinion based on my own needs and perspectives; others will likely have differing and equally valid views based on thier own needs.
Just as Andy Blance has mentioned in the brochures, the S&S couplings do allow one to reduce the bicycle for transport inside a car trunk or on a bus or farm truck in rural areas when touring. S&S' couplings are above reproach and are an adaptation of a coupling method well-known to engineers and proven in a variety of fields over time (Campagnolo's split-shaft crankset uses a similar design). Because of the way the couplings wedge together and S&S' requirements for installation, I agree with claims the frame is as strong or stronger than one without the couplers, so long as the fittings are properly tight.
So, from a utility standpoint, if you need to transport the bike by car or taxi (and are realistically willing to spend the small amount of time and effort to un/couple it), then it would add greatly to the value of the bicycle. If you prefer to tour with a mix of transport solutions (say, riding some legs and then using taxis, buses and hitching rides with passing farmers), then couplers are a great solution and value. JimK produced a wonderful photo-essay showing the process of un/coupling his Nomad for transport in the trunk of his Toyota here:
http://www.thorncycles.co.uk/forums/index.php?topic=3035.msg16585#msg16585http://www.thorncycles.co.uk/forums/index.php?topic=3035.msg16606#msg16606On the other hand, they're not so useful on a daily basis for most riders...
You're really "supposed" to check the tightness of the couplers daily, and it really
would be a good idea to do so, especially on-tour when a load and rough roads would add to the usual stresses. Realistically, I've never known anyone with S&S couplers who checked them in, well...pretty much
ever. I do know of one instance where a lower (1 of 3) coupling on a tandem either worked loose or was not tightened (I suspect the latter) and the coupling teeth were slightly damaged. I do know (have seen) two instances of damage where a disassembled S&S bike was damaged in transit (tubes slightly bent) such that the couplers didn't want to align for recoupling. I'm pretty sure similar forces would have bent a frame without couplers.
The couplers make it very difficult to lock the entire bike securely. Any bike that comes apart can have the halves stolen, and while each is only half a bike, the thief sees it as a nice way to make away with a half-bike's worth of components that can be stripped at his leisure and resold on eBay (the used bike parts market is lucrative for thieves 'cos parts have no serial numbering and are virtually untraceable). I have seen several S&S "half-bikes" remaining locked to posts in the uni area of my town over the years, the couplers showing clear marks where they were undone using a common ratchet-head pipe wrench (not pretty, but the thieves really don't have to deal with the results).
Couplers do add considerably to the overall cost of the bike, and they add weight. The first can be addressed by getting them aready installed when you buy a bike; retrofitting is considerably more expensive and involves a respray as well. The added weight is insignificant on a touring bike and of little consequence on nearly any bike that would qualify to have couplers installed.
The big draw of couplers for me would be to reduce the bike to airline-legal luggage requirements so I could avoid the outrageous costs of transport a whole bike even on domestic (US) flights. A person could soon buy a bike on the difference saved, and local manufacturer Bike Friday have built an entire business on this very idea. Sadly, even the magic 26inx26inx20in luggage-fee-avoidance dimensions are going by the board, and costs are rising daily (now, the weight charges will get you if the dimensions don't). Still, shipping a bike in a suitcase or small box doesn't cost near what it does in a cardboard carton or dedicated hardshell box.
Unfortunately, this virtue of couplings is also the big stopper for me when it comes to coupled
Thorns. Thorn have been so generous with their steerer lengths (a great virtue and benefit for me...take a look at how I had the Sherpa setup and now the Nomad as well). The trouble is...a 400mm steerer atop a fork intended to fit a 26" wheel is too long to fit in an "airline-legal" container, offsetting all advantages for that purpose. Unless you packed the fork separately, there's no
way the entirebike can be reduced enough to help...
...unless...
...a person cuts the steerer off shortly above the headset *and* uses a riser or adjustable stem *and* something like Comfort 'bars that also rise, giving you the riding position you need while allowing a relatively short steerer. Then, that'll work fine to pack the bike small (though the extremely long stays on a Nomad can make it a bit problematic). If that sort of setup meets your needs (true minimal-size packing is made so much easier with something other than drop handlebars), then I think S&S couplers make a great deal of sense on a Thorn.
In summary, I think the value couplers add to a Thorn depends on how you plan to use the bike, and if you're willing or able to setup the bike with couplers in mind to take full advantage of the huge benefit they potentially offer to save on air travel. Otherwise, I think they represent an expense and a potential bother that is avoided for most of the bike's regular use.
All the best,
Dan.
