Author Topic: Rolhoff's on tandems  (Read 19968 times)

leechy

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Rolhoff's on tandems
« on: August 20, 2004, 12:24:43 pm »
Sounds like the opening line of a Julie Andrews song.

Well, like peaches and cream, assault and battery, etc, Rolhoffs and Tandems seem like perfect partners, so how come I've not read anything about them anywhere other than Rolhoff reckon that they'll shrug off the best efforts of two well honed athletes and their 32 spoke wheels with no dishing will be stronger than a 9 speed.

My current well used voyager is now feeling rather small for my wife and I - now the cherubs are self propelled on solos. It will be most interesting to hear people's views and experience as I contemplate a replacement.

Not sure which section this should be in...
 

Team Triplet

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Re: Rolhoff's on tandems
« Reply #1 on: August 22, 2004, 09:28:27 pm »
Strangley enough - when we visited SJS in May and June, they had a Rolhoff tandem on display.  It had a 3.5K price tag.  I gather it was not shown at Tandem 2004 on Friday, which I presumme means its been sold.

The only downsides I see on the Rolhoff tandem are:

1. the only third brake option is a disc or additional rim brakes.  It depends on the intended use if that would be a problem.
2. Whilst I believe what Rolhoff says for 32 spokes being suitable for a tandem, I am only convienced that would be the case on smooth road surfaces only.  I like to take the tandem over the same rough terrain I ride my half bikes, and have taken the tandem loaded for cycle camping over such tracks as well.

On the positive front having got a half bike with Rolhoff hub, I wonder why they concept wasn't thought of years ago.  
 

leechy

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Re: Rolhoff's on tandems
« Reply #2 on: August 23, 2004, 10:00:38 am »
Interesting, wonder where that one went, need to owner to get typing...

I doubt we'd be hitting any rough stuff on a tandem, though it would be nice to think we'll do a big tour on it some day, sticking mainly to day rides. Its the maintenance aspect and not needing to pratt about with front and back changers which appeals to me. 3.5 smackers doesn't appeal, though!

Previous Majestic Two had a drum break,  which I liked, but find the Voyager with Vs plenty powerful for all but the steepest of downhills, and certainly better for emergencies. Block life is frustrating so maybe a disc up front would be better, though no experience of discs. I've heard pad life is quite good...
 

chrispayne

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Re: Rolhoff's on tandems
« Reply #3 on: September 01, 2004, 09:59:59 pm »
Apparently SJS are going to release a Rohloff tandem for approx £1600 in January, I cant wait...... Robin Thorn told me this when I was on the phone to him a week ago - discussing how the heck I can get a 650B tandem wheel rebuilt................

I think the Rohloff will be excellent on a Tandem - the only planning I can see I would need to get right is the gear range. My Raven is fractionally undergeared (my own fault I specified the chainwheel and sprockets 38x17). I find I spend most time in gear 12 - it should be gear 11 (the most efficient gear) - so at the next opportunity will switch probably to 40x16 to move the range up a notch. I remember from a 3000K tandem tour we did 20 years ago how useful a high gear can be on long descents, or even on the flat with a following wind. I need for us to get out on our tandem and note our fast "comfort gear" and pick the ratios to place that at 11. Even so I suspect we wont get an upper gear much above 100 inches.

Does anybody have any observation about whether a tandem cruising gear tends to be higher than a solo?

 

marcg

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Re: Rolhoff's on tandems
« Reply #4 on: September 04, 2004, 06:54:53 am »
OK, now the Rohloff tandem story is out, what is going to be the spec of it.  Does anyone know anything about it?
 

MattHodges

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Re: Rolhoff's on tandems
« Reply #5 on: September 19, 2004, 11:44:59 pm »
I would certainly like to try a Rohloff hub on a tandem but I would want the disc brake version. I would not be happy with rim brakes only. I would also want a frame built for it with the special adjustable dropouts so the chain tensioner was not required.

Regarding the number of spokes, certainly tandems have traditionally used 40 or 48 spokes but years ago solos often used 40 for rear wheels and 32 for front. 36 all round was a compromise and initially was blamed for many spoke breakages. Now there are many quality bikes with far fewer spokes and they don’t suffer lots of breakages. One friend was touring on a bike with a very low number of paired spokes. I think it was twenty or less and had no breakages. This seems to be due to better rims, better spokes and better wheel building.

I have used one of the early Rohloff hubs on a Greenspeed Recumbent Tandem Trike (GTT). This is of course a very different position from a normal tandem as the 20 inch wheel is intrinsically stronger but the back of a GTT subjects the rear wheel to massive sideways forces on cornering. Also my wheel was built with standard 14 gauge spokes not the thicker ones possible with the tandem version of the hub. Surfice it to say that the wheel performed very well. I took it off partly because I wasn’t happy without the rear brake. (It was the early version without the disc carrier and the GTT was fitted for a Hayes disc brake). Also the cables kept working slack as my cable stop mounting was not very firm. Finally I wanted to use the hub on my Moulton where it is now doing a grand job.

Somewhere recently I read about someone (or sometwo) touring South America on a Rohloff equipped tandem very sucessfully. (Was it the TC magazine or Velovision?)
 

graham

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Re: Rolhoff's on tandems
« Reply #6 on: September 20, 2004, 07:13:30 pm »
We took delivery of our 'Raven Vitesse' late May, since when we have travelled 1450 miles.

Ours is in Small size, all up weight under 125 Kg. Used on tiny country lanes wherever possible, with plenty of broken tarmac and sunken badly filled services trenches. We have hit big feeling bumps at more than 30mph.  No wheel trouble at all. We have the Mavic X618 ceramic (lightweight) rims with the 1.5" tyres and tandem carbon fork. The leaflet that came with the rims seemed to imply that a big bump might cause cracking in the coating (not detrimental), but we have seen no sign of that happening, so I suppose the spokes are supporting the rim adequately.
The Rohloff manual compares their 32 spoke wheels with 48 spoke dished wheels, and the spoke tension is allegedly less on the Rohloff. I'm inclined to believe them.

Our machine is geared 44 x 16, 71 inches or so in 11th gear. We cruise at 17 to 20mph in this gear. I was wondering about getting the 15 tooth sprocket (76 inches in 11th, or half a gear up on what we have now), but probably won't. Not before we wear the original out, anyway.

I haven't ridden a Rohloff solo, but suspect that on a tandem the shifter might feel a bit 'woolier' owing to the increased cable lengths.
We are delighted with the Vitesse and the Rohloff Hub. The next bikes we buy will be Rohloff solo's (the train companies won't take the tandem on anything other than the main line).

On solo's we would average 12-13 mph (the wife's speed). On my own on a solo I could average about 15mph. On the Vitesse we average up to 18mph over 20 miles or so, 16-17 over anything up to 80 miles and when we tried the 100 we still averaged 15.5. This is across east anglia, which has undulations but no mountains. So yes, a tandem is definately quicker than a solo.

 

marcg

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Re: Rolhoff's on tandems
« Reply #7 on: September 20, 2004, 08:09:01 pm »
What is a Raven Vitesse?  No mention on the Thorn website.
 

LowFlyingHawk

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Re: Rolhoff's on tandems
« Reply #8 on: September 21, 2004, 10:49:28 am »
 

graham

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Re: Rolhoff's on tandems
« Reply #9 on: September 21, 2004, 06:59:06 pm »
It's a bit special (well, we think so, anyway).

It's a lightweight 725 tubed double marathon. Except all the tubes radiate out from the head tube, unlike the Discovery where the second marathon tube springs from the front seat tube.

There is passing mention of it in the paper Thorn brochure. We saw a picture of a couple of stock ones on the website, which have probably now been sold.
Normally comes with loads of chainrings and sprockets, but if you ask nicely, it seems Mr. Thorn will sell you anything with a Rohloff hub in it.
 

Team Triplet

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Re: Rolhoff's on tandems
« Reply #10 on: September 22, 2004, 08:15:30 pm »
quote:
Originally posted by graham

It's a bit special (well, we think so, anyway).

 but if you ask nicely, it seems Mr. Thorn will sell you anything with a Rohloff hub in it.


Yes that is waht I have found.  The Rohloff hub options are so sexy and desirable, the only way you can get them is to ask Robin under  the counter for them, and then it is delivered in a very large plain brown box!
 

Joth

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Re: Rolhoff's on tandems
« Reply #11 on: December 02, 2004, 12:39:48 am »
Out of interest, does anyone know if the Raven Tandem have Rohloff specific dropouts? If so, how does it get tension on the drive chain?
I can't see making both BBs eccentric working... so does it use a tension arm?
« Last Edit: December 02, 2004, 12:40:08 am by Joth »
 

graham

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Re: Rolhoff's on tandems
« Reply #12 on: December 02, 2004, 07:18:15 pm »
Yes, Thorn use their own Rohloff specific dropouts. No Torque arm to be seen.

Yes, they use two EBB's. And it does work. Obviously as the rear one takes up the slack in the rear chain, you have to adjust the front one too, so there may be effectively less range of movement in the front one.
My experience is that the rear chain wears most, because it carries more load. So you may well replace the rear chain well before the timing chain. I would suspect that if you run out of adjustment on the front EBB, you may feel ready to replace a chain anyway. I suppose in an extreme case of short arms & long pockets, you could take a link out to get a bit more service life, but I think I probably wouldn't bother.
 

Joth

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Re: Rolhoff's on tandems
« Reply #13 on: December 02, 2004, 07:24:23 pm »
quote:
Originally posted by graham

Yes, Thorn use their own Rohloff specific dropouts. No Torque arm to be seen.

Yes, they use two EBB's. And it does work.



Cool, well I never. Blows my theory of them using a Sheldon style ghost chain-ring out of the water anyway [;)][:o)][:D]
Thanks for the answer!