Author Topic: Tandem decisions - Rohloffs and is there anything wrong with dérailleur systems?  (Read 13035 times)

marcusjb

  • Full of bon courage.
So, new tandem.  Primary focus is touring (on mainly paved roads, towing our trailer), but a secondary focus will be some Audax riding, hopefully including PBP.

Subject to them not riding like an oil tanker on a test ride (and reviews and personal recommendations suggest that it won't), we're almost sold on it being a Co-Motion Speedster Co-Pilot (we want the Co-Pilot bit to open up easier travelling options and storage as well) - http://www.co-motion.com/index.php/tandems/speedster

There is one big decision I thought I had made - but I've got cold feet at the moment.

Rohloff versus dérailleurs

I started off thinking I really wanted a Rohloff - all sealed away and nice. 

But, as I have thought more about it - does it really make sense?  I have dérailleurs on many other bikes, and they work just fine thank you.

Weighs lots, costs lots, seems to need quite a bit of maintenance (oil changes etc.), limit us to one set of wheels (whereas there's a possibility that, with a dérailleur setup, we could have a set of touring wheels and a set of lighter Audax wheels, for instance). 

Within reason, it's not a cost thing - this bike is going to cost a lot - the uplift to a Rohloff isn't ever so huge in percentage terms.

A Rohloff on drop bars is always going to be a bit funny - Co-Motion make their own grip shifter, which is apparently, very good indeed.

After always thinking I wanted a Rohloff system, I'm suddenly sat there thinking what's wrong with dérailleurs?


As I said, our primary focus is always likely to be touring - this bike's going to spend it's first tour in Thailand next Christmas.  Audax is secondary.  We've toured with our dérailleur equipped tandem and I know how these things work - I can fix them, keep them running well etc. - a Rohloff is all new to me.  Our touring is more likely to be Western Europe (this trip to Thailand aside), Northern America and not ever so far from the beaten track (i.e. primarily on paved roads). 

I've just suddenly lost my bottle a little on the whole concept of hub gears - it just seems that I am trying to solve a problem that isn't really there. 

Forget the money - what would you do?
Right! What's next?

Ooooh. That sounds like a daft idea.  I am in!

LittleWheelsandBig

  • Whimsy Rider
Derailleurs for an Audax tandem. Lots more maintenance than a Rohloff though.

The Rohloff doesn't have enough range for a fast tandem team. Back in the old days, I ran 54x12 top and down to 26x32 low. The gaps between the big gears are a bit far apart on a Rohloff and too close for the low gears.
Wheel meet again, don't know where, don't know when...

marcusjb

  • Full of bon courage.
Audax is definitely secondary in our considerations.  It'll probably be used for an SR and PBP and that's about it.

So really it's working out what is the best solution for touring and we'll make it work for Audax.
Right! What's next?

Ooooh. That sounds like a daft idea.  I am in!

Rohloffs have a decent range for touring.  They're pretty bullet proof and maintenance is very low.   Deraillers are pretty low maint also though, and more fixable, and better range which would make them the winner in a "whats best for touring" line up.

I got a rohloff and looked forward to the low maintenance benefits, then I realised I do easily enough maintenance/tweaking to have kept the deraillers clean and adjusted in any case. 

I like them for cleanliness (esp in the salty winters) and the ability to change when stationary. (oh, and the silent running)

I do agree they're a solution looking for a (real) problem. 

Kim

  • Timelord
    • Fediverse
I do agree they're a solution looking for a (real) problem.

Touring cycles with small rear wheels.  Perfectly real.

Rohloff on my Moulton tandem conversion, which I also use in solo mode as my off-road bike. 20" wheels, with a 58t chainwheel and 16t sprocket, gives 20" bottom and 106" top gears.

Pros: pretty bulletproof, less vulnerable, change gear any time, 11th is direct and our usual cruising gear

Cons: feels heavy due to all weight in one place unlike distributed weight of derailleur, 7th is the least efficient gear.

I prefer the derailleur on my Moulton road bike, but wouldn't go back to derailleur for the tandem/off-road bike.

and the ability to change when stationary. (oh, and the silent running)

Agreed the stationary changing is good but that would have only helped us out a couple of times in 6+ years of tandemming.  Silent running? Not sure about this one, I think our derailleur system is as quiet as a Rohloff esp in some gears (that's probably 7th).

Caveat - we don't tour, we only day ride.

Kim

  • Timelord
    • Fediverse
Stationary shifting is a definite advantage for recumbents (means you don't have to do so many anticipatory downshifts).  Probably not so much for upright tandems.

marcusjb

  • Full of bon courage.
I am intrigued by the silent running - I haven't ridden on a Rohloff bike for a few years, but I do remember it being fairly noisy (no better or worse than the average dérailleur system).

There's loads about the Rohloff that makes sense, but I just can't quite make the leap yet as to what doesn't make sense about dérailleurs. 

It's all just fear of the unknown (there's belt drives in the mix as well with Co-Motion) I think.

I know where I am at with dérailleur, I know I can change things easily (a closer ratio cassette for Audax or whatever).

We're not super hardcore, we're unlikely to tour the world for months on end in terrible conditions.  Barring a trip to the far-east, it'll mostly be touring in Spain, France etc.

It's just weighing up the advantages and seeing if they out-weigh the disadvantages at the moment.
Right! What's next?

Ooooh. That sounds like a daft idea.  I am in!

Kim

  • Timelord
    • Fediverse
Yeah, belt drive is one of the other killer apps for hub gears.

Which seems like an excellent choice on, say, a commuter bike where not having oily bits is a significant advantage.  Not so sure about a tourer - I'd be concerned about having a gap in the seatstay.

I've not owned a Rohloff, but my experience of riding alongside them is that, once worn in, they're noisy in some gears but mostly not significantly worse than dérailleurs.  They shift more quietly, of course.

We have also asked ourselves the same questions, without finding a definitive answer.

Forget the money - what would you do?

Yebbut the money man sayd: the Rohloff might even  be cheaper on the long run. Each year, we do wear out 4 chains, 2 cassettes, and a set of chainrings, on our derailleur tandem.

At 15€ per chain, 45€ each cassette, and, say, 80€ for the three rings, that makes a maintenance cost of 210€ each year. After 5 years, the Rohloff pays for itself...
My calculation is perhaps a bit simplistic, but I think the idea is here.

Each year, we do wear out 4 chains, 2 cassettes, and a set of chainrings, on our derailleur tandem.
As have we.
The mechanisms need more fecking about with (technical term) than I've ever done on a solo with similar(ish) milage, the wear is so much greater. Fit & forget is tempting.

I just don't really like hub gears. If I rode a recumbent I'd swap like a shot, but as I don't... Plus I don't think you can get a Rohloff with a wide enough range (happy to be proved wrong)- you'd have to pick one end or the other, and we certainly use both ends of ours.

We have Alfine 8 with Versa shifters on our Circe. Changing gear whilst stationary is a big plus for us. However, I would happily trade it for a load more range. Having ridden LEL behind with boab and chris, you need to be able to crawl up hills, spin along at 50kph on the flat, and do about 80kph at the whiff of a hill. To make our Circe cope with the Dales, we're spun out at about 35kph with Alfine 8. boab and chris do that into a headwind.

marcusjb

  • Full of bon courage.
If it were for pure Audax, then dérailleur all the way I am sure. 

I'm yet to find a truly compelling positive for the Rohloff - other than a tandem with dual belts and a Rohloff looks well sleek:



There seems to be lots saying that they aren't as fit and forget as you'd hope.
Right! What's next?

Ooooh. That sounds like a daft idea.  I am in!

Plus I don't think you can get a Rohloff with a wide enough range

I'm sure Chris & yourself are strong enough, so this should not be an issue  ;)

There seems to be lots saying that they aren't as fit and forget as you'd hope.

I tend to see belt drives like the way  I see proprietary wheels:
they don't let you down very often, but when they let you down in the middle of nowhere, you are in really serious trouble.

marcusjb

  • Full of bon courage.

There seems to be lots saying that they aren't as fit and forget as you'd hope.

I tend to see belt drives like the way  I see proprietary wheels:
they don't let you down very often, but when they let you down in the middle of nowhere, you are in really serious trouble.

Well Rohloff = belt drive in Co-Motion world, so I wouldn't have an option.  Belts weigh around 75g, so carrying 2 spare belts wouldn't be a big deal for touring.
Right! What's next?

Ooooh. That sounds like a daft idea.  I am in!

That's fine as long as you can open up the seat stay by the roadside. Make sure you don't need a special tool for that!

On the other hand, it's probably none of my business, but why would you buy a Usanian mass product when you can buy, for about the same price, a finely
hand crafted tandem made in England? We are really happy with our Bob Jackson tandem, and they can make for you exactly what you want, Rohloff or not Rohloff.

LittleWheelsandBig

  • Whimsy Rider
A friend of mine has been running a belt-drive solo for a decade. No belt failures since swapping to a Gates system but he used to fail belts annually. Easy enough to swap roadside.
Wheel meet again, don't know where, don't know when...

marcusjb

  • Full of bon courage.
On the other hand, it's probably none of my business, but why would you buy a Usanian mass product when you can buy, for about the same price, a finely
hand crafted tandem made in England? We are really happy with our Bob Jackson tandem, and they can make for you exactly what you want, Rohloff or not Rohloff.

Because my previous interactions with manufacturers of hand-crafted bicycles in England have made me want to stab myself in the testicles with blunt lugs.
Right! What's next?

Ooooh. That sounds like a daft idea.  I am in!

I'd also say that USAnian tandems are made for USAnian roads and handle like supertankers. This probably makes less difference if your team is as light as yours is, Marcus.
(Peter & Amanda have a Co-Motion as do the undulates and I believe both pairings are very happy with their choice).

Kim

  • Timelord
    • Fediverse
they don't let you down very often, but when they let you down in the middle of nowhere, you are in really serious trouble.

My take on that is that it's orders of magnitude easier to ensure reliability from any half-decent bike component than it is for my body.  Not that they aren't going to fail, but that you need some sort of plan for when it happens anyway.  YMMV.

According to Gates belts require very precise aligning or they go ping prematurely. For this reason I would always want vertical drop-outs and an eccentric bottom bracket on a belt-drive solo to keep the alignment right when removing and replacing the wheel. This isn't an option on a tandem because the eccentric is already being used to tension the relay chain belt. So a potentially interesting option is, for me at any rate, still needing one or two problems solved.
This doesn't mean that belts don't work on tandems just that for now I don't think the ideal set-up has been designed (and that's only me)

Because my previous interactions with manufacturers of hand-crafted bicycles in England have made me want to stab myself in the testicles with blunt lugs.

Sorry to hear about such a bad experience! In our case, we ruled out all the makers that were not within a day of driving from home, because we wanted a really customized thing.
The choice was then restricted to french and english makers, and it happened that our english maker was infinitely more open-minded than all the french makers I got in touch with...

This isn't an option on a tandem because the eccentric is already being used to tension the relay chain belt.

It might be possible to solve this problem with TWO eccentrics on a tandem frame. Never tried. Just a suggestion.

marcusjb

  • Full of bon courage.
This might give some ideas of how Co-Motion deal with dual belts and Rohloffs:

http://www.omagdigital.com/display_article.php?id=1070856

And some info on how they make their dropout arrangement (photo is of a solo, but same principles applied onto tandems):



Another very attractive feature of dealing with someone like Co-Motion, rather than a UK builder, is this is what they do - they build significant numbers of tandems every year and have the skills and experience in house to develop technology that just isn't possible for a small UK builder who might build a double-digit number of tandems a year if they are doing well. 

All of that said, I am not 100% on the Rohloff yet.  An option I will question is to look at two sets of drive cranks/belts (a 50T and a 55T) - it should be relatively painless to swap them over for touring or Audax usage (18.8"-99" for touring and 20.7"-108.9" for Audax). 
Right! What's next?

Ooooh. That sounds like a daft idea.  I am in!

I have considered a belt for the timing 'chain' on our proposed new custom tandem (that one day we will order) and found that there seems to be limited lengths available.  From memory it was one bottom bracket to bottom bracket dimension (24" possibly) with the choice of two chainring sizes.  So only two lengths available.  We want a shorter stokers top tube so belts are not an option.

I don't know what lengths are available for final drive.