Thorn Raven Twin vs. CoMotion Mocha

[Cave]

Hi all,

I'm in the market for a light touring and day-ride tandem. The Thorn Rohloff hub equipped tandems fascinate me, the problems I've had with our (old, cheap, 2nd hand) bike have been with the rear hub and the front derailleur and the Rohloff hub eliminates both of these problems.

A Comotion Mocha is the other machine I'm considering.

Does anyone have any experience with the Thorn tandems? The reviews I've seen are all very favourable.

Does anyone have a different Rohloff-equipped tandem?

[rjberner]

I'm in the market for a light touring and day-ride tandem.

The Thorn may be a great tandem, but a light touring and day-ride machine it's not. At 48lb (with racks and fenders), it will sit there at over 50lb with pedals and water bottle cages. It looks like it would be suited for combat messenger duty in Afghanistan.

But, as they will all tell you, weight isn't everything (until you go to hoist it on or into your car).

Good luck in your search.

[Xanti Andia]

The Ronholff was used in a round the world tandem trip described here:
http://www.karennben.com/
It was the only part of the bike that never failed and did not need maintenance.

That said I ordered a Mocha last week, for loaded touring and unloaded local rides.

[zonatandem]

Co-Mocha is a light touring (heavy touring too) and dayride tandem. If you want a Rohloff rear hub, am sure that Co-Motion can accomodate you for a bit more $$. As you know Rohloffs are pricey/heavy/ durable.
Pedal on TWOgether!
Rudy and Kay/zonatandem

[Cave]

The Thorn may be a great tandem, but a light touring and day-ride machine it's not.

Clarification - I'm after a bike for light touring, not a light bike for touring (although lighter is better, all other things being equal, which they're not).

I'm not keen to add a rohloff to a bike not designed with one in mind, the decision is between a stock comotion (or possibly cannondale) or a stock Thorn Adventure. I'm leaning towards the Thorn, but haven't heard much about them on this forum.

I might need to look for a more European forum!;)

[zonatandem]

Try tandem-club.org.uk for more folks who do ride Thorns and there has been some discussion there re Rohloffs.

[geoffs]

We'll be on the Big NSW bike ride if your up this way in a couple of weeks and you could take ours for a test ride. We've now done 9,000kms on our Mocha doing everything from CC touring to fully loaded touring to an MTB race.
A bare Thorn is nearly 7kg heavier than a Mocha. That is a good portion of the weight we carry for CC touring.
If you want more info send me an email

Cheers

Geoff
Sydney

Co-motion Mocha Co-Pilot
Santana Sovereign

[stapfam]

Thorn are a good bike manufacture in the UK and they make good solid bikes in the UK. Never heard of a problem with their bikes and they do design it with the rolloff hub as part of the equipment. It is that solid bit that worries me, even though I ride a Heavy offroad machine. For what they are- They are expensive over here, but if you want a reliable machine then this is one of them.

[Cave]

Thanks for the replies, folks.

It's reassuring to hear the Comotion is up to touring.

I think our next step will be to try a Cannondale road tandem and compare it to the flat-bar 26" bikes we have ridden so far.

It really is a challenge finding test rides, but at least Melbourne has a dedicated tandem shop and a few other shops carry tandems; very few high-end bikes, though.

[Sammyboy]

I'm not keen to add a rohloff to a bike not designed with one in mind

Why? I'm not critiscizing, just asking. In a solo bike, there's no reason I know of not to do this. Are tandems different in that respect?

[Cave]

Only because, if I am going to get a Rohloff equipped bike, I would prefer to get one without a torque arm and with no hassles in terms of getting the wheel on and off and fitting racks and mudguards to the bike. Given that the whole bike will be new, it makes more sense to me to buy everything ready-to-go from a reputable manufacturer, rather than building a new wheel, routing and fixing cables, and making sure everything fits.

So no, tandems are no different in this respect!

[mrfish]

Re. whether the bike is heavy, the rohloff weight is comparable to the derailleurs etc. that it replaces, so it's the Thorns that are heavy. The Thorn bikes are built in the town where I grew up, so I should like them, yet I don't as I don't fit their target market. Basically Thorn markets their bikes at people who are the opposite of weightweenies, i.e. those interested in long-term reliability, practicality and like traditional approaches to bike design all at a fair price. They are still in business after 25 years or so, and provide excellent service for difficult to find bits, so they definitely know their market and based on their ebay feedback serve it very well. (I just bought a helmet from them).

For light touring as a person with weightweenie leanings I think an off the peg Cannondale or Trek would do fine, I think with the Cannondale having the edge as it comes with disc brakes as standard (Trek's standard brakes aren't that hot on my T2000). For a few more $s I would be tempted to get your local builder to copy the geometry of single bikes you are comfortable on (but with tandem steering geometry of course) but use Rohloff dropouts etc. so you can use the hub, get a go-faster paint job etc. If you buy mid-range parts off ebay to complete the bike, this could be quite reasonable.. Alternatively a Co-Motion would also be nice, and could be a bit more credit-card touring oriented.

...lots of choice...Final recommendation is to buy one and ride it!

[stapfam]

Re. whether the bike is heavy, the rohloff weight is comparable to the derailleurs etc. that it replaces, so it's the Thorns that are heavy. The Thorn bikes are built in the town where I grew up, so I should like them, yet I don't as I don't fit their target market. Basically Thorn markets their bikes at people who are the opposite of weightweenies, i.e. those interested in long-term reliability, practicality and like traditional approaches to bike design all at a fair price. They are still in business after 25 years or so, and provide excellent service for difficult to find bits, so they definitely know their market and based on their ebay feedback serve it very well. (I just bought a helmet from them).

For light touring as a person with weightweenie leanings I think an off the peg Cannondale or Trek would do fine, I think with the Cannondale having the edge as it comes with disc brakes as standard (Trek's standard brakes aren't that hot on my T2000). For a few more $s I would be tempted to get your local builder to copy the geometry of single bikes you are comfortable on (but with tandem steering geometry of course) but use Rohloff dropouts etc. so you can use the hub, get a go-faster paint job etc. If you buy mid-range parts off ebay to complete the bike, this could be quite reasonable.. Alternatively a Co-Motion would also be nice, and could be a bit more credit-card touring oriented.

...lots of choice...Final recommendation is to buy one and ride it!

+1 on this. Thorn bikes are aimed at the long term reliability and although you have to build reliability into a Tandem, I get the feeling that these are overbuilt. I can remember a few years ago where a Cannondale and Thorn Tandem were tested up against a couple of other tandems. The Thorn came out as good and solid wheras the cannondale came out as exceptional. The other two did not get good reviews.

[TheBrick]

A custum frame would be expensive but you would beable to save money on the fact that you would not need tandem cranks. I don't know how much more expensive tandem cranks are as I am only just learning about tandems but I would guess quite a bit as it is a specialised part. Plus a single side drive puts less stress on the bb accroding to Mr Brown. It make sense when you consider the force and torque involved.

[mrfish]

A custum frame would be expensive but you would beable to save money on the fact that you would not need tandem cranks. I don't know how much more expensive tandem cranks are as I am only just learning about tandems but I would guess quite a bit as it is a specialised part. Plus a single side drive puts less stress on the bb accroding to Mr Brown. It make sense when you consider the force and torque involved.

Good point to save money by using non-custom cranks. Yes they are expensive. You can do this on any frame - I guess what you meant was versus buying a full bike.

To my mind the main options are:
1) Cross over cranks but with swapped (and loctited) pedal spindles
+ Looks and works like a cross over drive
+ Any cranks possible, apart from those 2 piece ones with integrated b/b
- Loctite on pedals - may work loose
- Need 3 sets of pedal axles (swap pilot's axles plus extra RHS for stoker's LHS pedal)

2) Cross over cranks with helicoiled crank threads
+ Looks and works like a cross over drive
+ Helicoil strong if done by a professional (eggrings)
+ Any cranks possible, apart from those 2 piece ones with integrated b/b
- Helicoil is permanent and means your cranks won't work on a single again

3) Single sided gearing with third chainring used for connecting drive
+ Elegant solution and more efficient
+ No mucking about with swapping threads etc. and only 2 cranksets needed so cheaper
- Requires different chainrings
- No 3rd ring to get over hills

If I were you I would try option 3, then if you need the extra gears you can buy another set of cranks and try either options 1 or 2. If you're buying 3-piece Mid level campag / 105 / Ultegra level cranks (a few years old) you can get these for peanuts on ebay as everyone nowadays is 'upgrading' to compact / carbon or to get the Dura Ace / Record name (I am as guilty as anyone here!).

[TheBrick]

I ment if he was going for a Rohloff hub. I suppose if you had horizontal dropouts with a gear hanger you could install the Rohloff hub, install a short rear derailleur, set the limit screws, set up your chinline so that it is and have two rings up front, set up your chinline so that it is between the two rings, then the derailleur whould take up any slack chain. Result 28 speed.

[Michel Gagnon]

Good point to save money by using non-custom cranks. Yes they are expensive. You can do this on any frame - I guess what you meant was versus buying a full bike.

To my mind the main options are:
...
3) Single sided gearing with third chainring used for connecting drive
+ Elegant solution and more efficient
+ No mucking about with swapping threads etc. and only 2 cranksets needed so cheaper
- Requires different chainrings
- No 3rd ring to get over hills ...

According to John Allen, you could have your cake and eat it too. Just install a fourth chainring outside, between the large ring and the right crank as show here (http://bikexprt.com/bicycle/tancrank.htm).

[mrfish]

[QUOTE=Michel Gagnon]According to John Allen, you could have your cake and eat it too. Just install a fourth chainring outside, between the large ring and the right crank as shownQUOTE]

Yes, is is possible but you need to choose the crankset carefully. I think older or lower quality cranksets are needed. The Suntour crankset I think is about 15 years old. On more modern stuff like my 7 yr old Record road crank, the chain is about 2mm from the crank arm, with zero room for even a cadence magnet on the crank arm, let alone another chain ring. Similarly with the more recent centaur and Ultegra stuff we have. I imagine designers have minimised the space here to get minimum Q-factors.

[Cave]

Thanks for all the input.

We've looked at the costs involved and my original choices are looking like costing AUD$7000+ for a full set up, which is getting out of our price range.

Hopefully testriding a Cannondale next week.

Also, seriously considering a conversion on our current frame - not light, but stiff and solid; am looking at 2 options:

(1) Brazing on a derailleur hanger (easy) or new vertical dropouts (not sure), then upgrading drivetrain to Tiagra or XT front (not sure which) and XT rear

(2) Rohloff conversion with single-side drive and eccentric BB chain tensioning.

Thanks for the idea, Sammyboy - not keen on converting a new frame, but converting the old might save me $5000.

I think I'll start a new thread with the above.

[pands]

Where can I find the tandem shop in Melbourne? I will be in Melbourne next month and would like to have a look.
We are also looking at Thorn Raven Discovery to do a cycle camping tour in Europe next year for 5 months. However we have not owned a tandem before or ridden one any great distance. We did a four month cycle camping tour on single Gazelle bikes in 2002. They were not the lightest bikes but we found them very comfortable and reliable. No major breakdowns!!
Will be interested to hear what you choose.
Good luck