Thorn Tandem

[NZPeterG]

Well I would like to know if Thorn/Rohloff Tandem's are a good Tandem to start off with?

How do they go offroad? like a Nomad?

How do you work out which size to order when I have no co-Pilot/Stoker?

I'm just thinking about it at this time, but would like to Know Please.

Pete............
 

[il padrone]

I have no expertise with Thorn/Rohloff tandems at all. However as an experienced tandem cycle-tourist I do have one or two concerns with the basic concept.

1. The Rohloff has a more limiting gear range for tandem use, along with concerns about the low gear limit.
2. Using a Rohloff hub prevents the use of a third brake - a rear drum. This is something that is of great value for a tandem in hill country touring, preventing rim overheating. And while discs remove the rim brakes, they have their own issues with overheating on long steep descents. A disc brake is no substitute for an Arai drum with cooling fins.

Re touring off-road* with tandems, I would advise against it. Tandems are faster on descents and slower on climbs than single bikes. They do not handle technical trails well, steer like you're closing a barn door, and are enormously hard work on short steep hill work. Tandems are best as open road vehicles, flying along flat-undulating terrain, with advantages in headwind conditions and rocketing on a flat road with a tailwind as long as the gear is high enough.

If you are buying a tandem for the generic stoker I would get a frame size that is close to your own seat tube height, maybe with a slightly lower seat tube height for the stoker. You really need to make sure you get the rear top tube as long as possible - most stoker's cockpits are too cramped on cheaper tandems. Our Trek T100 has a quite long stoker top tube length which provides a less cramped space for the stoker.


Our tandem, fully-loaded in western Tasmania



* By 'off road' I'm talking about MTB singletrack and 4WD tracks, not domestic gravel roads and forest roads

[Mike Ayling]

I have no expertise with Thorn/Rohloff tandems at all. However as an experienced tandem cycle-tourist I do have one or two concerns with the basic concept.

1. The Rohloff has a more limiting gear range for tandem use, along with concerns about the low gear limit.

I believe that Rohloff may have revised the low gear limit for tandems - see elsewhere on this Board.

2. Using a Rohloff hub prevents the use of a third brake - a rear drum. This is something that is of great value for a tandem in hill country touring, preventing rim overheating. And while discs remove the rim brakes, they have their own issues with overheating on long steep descents. A disc brake is no substitute for an Arai drum with cooling fins.

Thorn will not fit a front disc brake on their forks. You can fit a disc as a drag on the Rohloff hub but as Il Padrone wrote it is no match for the old fashioned drum brake.
Thorn offer XT V brakes with blue pads to work on the CSS coated rims and these brakes are good and the CSS coating prolongs rim life. There is a bloke called Dave Whitney who posts on the Crazy Guy site who has toured on most continents with his wife on their Thorn tandem and he is very bullish about the V brakes and CSS coated rims and manages without a drag brake.

Re touring off-road* with tandems, I would advise against it. Tandems are faster on descents and slower on climbs than single bikes. They do not handle technical trails well, steer like you're closing a barn door, and are enormously hard work on short steep hill work. Tandems are best as open road vehicles, flying along flat-undulating terrain, with advantages in headwind conditions and rocketing on a flat road with a tailwind as long as the gear is high enough.

100% in agreement with Pete here.

If you are buying a tandem for the generic stoker I would get a frame size that is close to your own seat tube height, maybe with a slightly lower seat tube height for the stoker. You really need to make sure you get the rear top tube as long as possible - most stoker's cockpits are too cramped on cheaper tandems. Our Trek T100 has a quite long stoker top tube length which provides a less cramped space for the stoker.

+1 here again.

If it is fast riding that you are considering the Rohloff is probably not the best choice because the gears are quite widely spaced whereas a close ratio cassette would be a better proposition. If you are considering a 11to34 cassette then a Rohloff may be a good choice for you.


Mike (who has just purchased a Thorn tandem.)

[brummie]

I've owned a couple of Thorn Derailleur geared tandems in the past - every bit as good as their solo bikes, rock steady handling when fully laden too !  - Sadly I never had a Rohloff version ( maybe one day? ) The Rohloff system would definately be more beneficial on a tandem for making multiple shifts when climbing the hills...

[lewis noble]

I agree with il padrone's comments about off-road / poor road use.  We have a Thorn Voyager tandem, the most basic of the Thorn models, and anything other than reasonably surfaced roads and trackes / trails are quite difficult with it.  Avoiding boulders and other obstructions is difficult in a hurry, and when we went on some trails in the Lake District / Cumbria (UK) we had to push on terrain that we managed easily on solo bikes (including my wife's upright Dawes with 7 speed hub) a few days later.  We also went on some gravel roads in Finland, which were quite hard work on the tandem.

Our favourite rides and on quiet paved lanes, without too many potholes or obstructions.  And yes, they can go fast!!  We have Deore brakes, fine for us, but long mountain rides would get rims pretty hot and a lot of care would be needed.

But we enjoy riding it, and despite being the most basic Thorn model, it is good to ride and well designed.  No problems with it.

Ours is a dérailleur model - all we could afford.  And I would prefer the Rohloff, as it is very easy to get caught out in the wrong gear on lanes with sudden steep gradients - and the Rohloff would give us enough range for our purposes.  And gears and other components wear quickly on a tandem, in our experience - anything to cut down fiddling and adjustments while on tour would be good.

[Danneaux]

I agree with pretty much all of the above wrt my own tandem and its suitability for use.

It runs 26x1.5 tires and does wonderfully solo or loaded to the guards and pulling a trailer -- on smooth pavement, even on very rough gravel (the sus seatpost eases things a *little* for the stoker in such use).

It just would not do, however, on really rough or uneven tracks. The long wheelbase coupled with the low ground clearance caused by the timing chain would make it a disaster in that environment. It wouldn't take much to high-center if one or both wheels fell into a hole while off-road.

And yes, the Arai drum brake is worth its (considerable) weight in gold as a drag brake. I actuate mine with a bar-con and it keeps downhill speeds to 80-100kph; Scott/Pedersen and SunTour SE cantis with Kool-Stop Salmon pads nicely haul it down from there. Thanks to really low gearing, it climbs pretty well, but requires a lot of foresight to avoid being caught-out if a hill inclines more quickly than anticipated.

There are purpose-built off-road tandems with long-travel suspension front and rear -- I believe at least one of our Forum members owns one. They are an awesome sight to behold, especially on downhills. However, they are still not ideally suited for use on tight, forested tracks, due to the long wheelbase.

Tandem and Family Cycling magazine (later, Tandem: http://www.tandemmag.com/tmban.shtml ) was published locally for many years and one day, the editor headed out to the local BMX track with a partner to try a new off-road DaVinci tandem with independent drive ( http://www.davincitandems.com/sy.html ). The pair got pretty enthusiastic as I watched from a distance and the bike flew, literally; there's a photo on the DaVinci homepage of it taken while airborne ( http://www.davincitandems.com/images/jump1.jpg Editor is the stoker). The landing was not pretty, and said editor broke a collarbone. It was a terrible sight to behold and took months for the poor guy to heal. So yes, offroading a tandem is possible if one throws enough money at it, but it is not necessarily a good idea.

Best,

Dan. (...unless prepared-for in advance, some activities on a bike-for-two make it a tandumb)

[NZPeterG]

Hi Thanks all for the in put so for..
Its sounding like it's like riding a Tandem Unicycle just not fun!
I may look out for a full on Offroad Tandem.

Pete...
 
Yes there are Tandem Unicycles!. . . . .

[il padrone]

Yes there are Tandem Unicycles!. . . . .

OK, I had to go looking for that one. Yes there are such beasts.... not sure why though




Re tandems and 'fun', not sure if you may thnk tandems are not fun. I can assure you they are heaps of fun. But like all bikes, most fun if you ride them in the conditions they are designed for. Like track bikes are fun on the track, much less so if you want to load up some panniers for a hill country camping tour (don't laugh, I have seen people try to do such thing - track bike converted to 5-speed   )  As I said earlier tandems fairly rocket along in the right conditions, like flat open roads and long descents. You'll have all your friends sucking wheel. They are great as a social cycling event. Riding with fellow tandemists is a great experience and you're lucky if you have a local tandem club. We had one in Melbourne but it has sadly folded - it's difficult to get all the scattered tandem riders together for an event.

[Danneaux]

I may look out for a full on Offroad Tandem.

Here ya go, Pete; I knew I remembered seeing it here...
http://www.thorncycles.co.uk/forums/index.php?topic=701.msg10489#msg10489

Annnnnd, a forum for off-road tandem enthusiasts:
http://sports.groups.yahoo.com/group/DOUBLE_FORTE/
http://www.thetandemlink.com/Double_Forte.html
http://www.thetandemlink.com/DF/dffaqs.html

Hope this helps. There are some very serious and expensive machines on there.

Pete...if you get one, please tell me how you go about finding a partner to ride it with you!

Best,

Dan. (...who thinks it looks like lots of fun...the first time)

[swc7916]

I have no expertise with Thorn/Rohloff tandems at all. However as an experienced tandem cycle-tourist I do have one or two concerns with the basic concept.

1. The Rohloff has a more limiting gear range for tandem use, along with concerns about the low gear limit.

Our Rodriguez/Rohloff tandem has a gear range of 23.25 to 122.25 gear-inches (50X15, 26" wheels.)  That seems plenty to me.  If you don't want/need such a high-end gear ratio, you can lower the whole range by selecting a smaller chainring or larger cog.

2. Using a Rohloff hub prevents the use of a third brake - a rear drum. This is something that is of great value for a tandem in hill country touring, preventing rim overheating. And while discs remove the rim brakes, they have their own issues with overheating on long steep descents. A disc brake is no substitute for an Arai drum with cooling fins.

We have 2 brakes on the rear, a disc and a cantilever rim brake.  The disc is set up as a drag brake.  I know that discs don't have the heat-dissipating capacity of the the Arai drum, but the drum doesn't fit on the Roholff hub and Arai drums are not made anymore anyway.  I haven't had a need to use the disc as a drag brake yet, but should the need arise I intend to alternate between the rim and disc brakes to prevent either one of them from heating up excessively.

[NZPeterG]

Well how about this  
http://www.ventanausa.com/bikes/el-conquistador-de-montanas-s-and-s/
With Std Gear's or Rohloff  

Pete..
 

Tandem Unicycle? Why? Because when you Got Married you have too ride only One   meet them at Unicon XV in New Zealand (Unicycle World's)

[benstevens]

We have owned both Rohloff and non-Rohloff Thorn tandems - the Rohloff tandems have had much nicer frames (more expensive) and as a result carry big loads far better and are more tolerant of the stoker wiggling. We have ridden on tracks with Marathon Mondial 26x2.15 tyres and the tandem has coped - it is difficult to avoid some rocks on the way though.  I'd agree that something purpose made is going to be far better.

Never found the lack of the third brake an issue (including hilly touring with 30kg+ on the bike).  I am quite happy to let the bike run though.

Cycling with a Rohloff is different to standard gears - I personally love ours but know that some people do not get on with them.  Rohloffs will not shift under a high load so it requires easing off the pedals which requires a bit of coordination (would be difficult if your stoker was trying to rip the pedals off).

[il padrone]

Our Rodriguez/Rohloff tandem has a gear range of 23.25 to 122.25 gear-inches (50X15, 26" wheels.)  That seems plenty to me.  

A few years back on our tour of the Western Explorer* in Tasmania we had a 19" bottom gear on our tandem. It was significantly NOT enough with me and my teenage daughter. 17" is about the standard sort of bottom gear required for fully-loaded mountain and backtrack touring. With the Rohloff this will give you a top gear of about 94" - fine for me on the single Thorn Nomad, but on a tandem on a good road I reckon we would rapidly spin out of gears.

On the Western Explorer, approaching Mt Longback


Sealed road made us worried


* Read Day 5 and 6

[fleur]

We own a Hase Pino half recumbent tandem equipped with a Rohloff.  This bike has a shorter wheel base than a classic upright tandem and has a suspension fork.  It is more maneuverable than an upright tandem and works pretty well on gravel and dirt roads.

For the Rohloff range, it is true that it is a little limited on a tandem that can go very fast on the flat and also need short gears to go uphill (we use our Pino for travel where it is loaded but also for day ride without load).    Our Pino was factory equipped with a triple dérailleur system and we mounted the Rohloff later (it is cheaper to buy a Pino with dérailleur system and adapt the Rohloff later than buying the Rohloff option from Hase !  Installation of the Rohloff is easy since the Pino frame has the Rohloff compatible dropoff).  So what we did is to keep the front dérailleur with two chainrings, the big and middle one (the small one cannot be used due to the torque limitation of the Rohloff) so we have now a front O.Symetric double 50/38 with a rear 15t (16t gives too much torque on a tandem with a front 38t).  We normally use the 50t chainring, the 38t is only used for steep hills.  To give an idea of what is possible with this combination, using the 38t front, we for instance climbed the well known Kapelmuur http://www.climbbybike.com/climb.asp?Col=Kapelmuur---Muur-van-Geraardsbergen&qryMountainID=701 followed by the Bosberg http://www.climbbybike.com/climb.asp?qryMountainID=146.  At the other extremity, we really use the 14th gear together with the 50t front on fast flat roads.

For the brake, the Pino is a difficult case: the front wheel is a 20" meaning that a rim brake cannot be used (small rims become very warm with rim brakes so warm that tire explosion may happen, even on a solo bike and it is of course much worse on a tandem), so we have a Hope 203mm ventilated disk on the front and the factory SRAM Code R 160mm disk on the rear.  When we moved to the Rohloff, we took a Rigida Andra 30 rim (designed for Rohloff) also designed for rim brake and added a rear rim brake.  But in practice, we never really needed the rear rim brake, the front Hope disk never got too hot.

[swc7916]

So what we did is to keep the front dérailleur with two chainrings, the big and middle one

What do you use for a chain tensioner?  Will the Rohloff one take up enough chain slack or did you leave the derailleur on?