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PostPosted: Wed Feb 03, 2010 11:12 am 
Old School Grand Master

Joined: Tue Oct 09, 2007 1:55 pm
Posts: 8212
Location: New Forest, UK
Independent freewheeling is very unusual - the problem is that you then get out of sync and this can cause all kinds of strange wobbling, especially if you have a fairly flexy frame.

You rightly identify the issue of one person feeling that they are barely on top of a gear while the other feels that pedal pressure is too light. The best solution is different crank lengths, but this doesn't come cheap. Highpath Engineering are your friends here - they will re-machine cranks for around £50. They made up a set of 120mm cranks for the back of No.2 tandem for my 6 year old from some old 300LX.

No.1 tandem has a Kiddycrank setup, with a THIRD chain from the left-hand rear up to an extra bolt-on bottom bracket on the stoker seat tube, with dinky cranks. It's possible to fit a freewheel here, but some linkage in the cranks works well to allow younger (4) son to climb on and off.

I think you are doing the right thing, with plenty of communication. The main thing is for the stoker to feel totally confident and relaxed. Keep talking, the rest will follow, and soon you will just know by feeling through the chain. It's really important that the stoker doesn't try to balance the bike - usually you end up getting out of sync and over-correcting for each other. The stoker should usually do signalling for turns etc, as our tandems with two adults aboard certainly need a fair bit of muscling around - lots of steering!

Last one - get a "Yes I AM pedalling" T shirt made up for the stoker...there is a load of people who think it is a hilarious and incredibly original joke. :roll:


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PostPosted: Sun Feb 14, 2010 11:45 pm 
rider | rBoTM Winner
rider | rBoTM Winner
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Joined: Fri Jan 25, 2008 1:42 pm
Posts: 5132
Location: Wakefield, Yorkshire
That's really cool, a street cruiser for two! It's come up really well. The brakes worry me though - Weimann 730's aren't that good on a solo never mind a tandem so don't get up to much speed!

Regarding crank settings, when I raced tandems in time trials regularly in the '80's we generally had the cranks in parallel but one evening I had to do some quick fettling before the race and just 'threw' it back together. We did storming ride that evening in a '25', everything felt really smooth, and when we finished we noticed that the cranks were around 30 degrees out. I therefore reckon that doing this means that the 'top dead centre' effect is sort of nullified.


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PostPosted: Mon Feb 15, 2010 12:49 am 
Gold Trader
Gold Trader
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Joined: Wed May 20, 2009 1:29 pm
Posts: 10798
Location: Manchester, UK
Dead Rats wrote:
apart from finding a location for the stroker's gear lever that doesn't touch the captain's bottom :lol:



stoker / stroker? dunno but latter seems more appropriate for 14th Feb :P


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PostPosted: Tue Nov 16, 2010 10:43 am 
Gold Trader
Gold Trader
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Joined: Wed May 20, 2009 1:29 pm
Posts: 10798
Location: Manchester, UK
a few rubbish updated photos now that the Miller dynamo is almost up & running (just needs a longer wire for the front) and the mudguards, rack, Brooks saddles and bags have been fitted:

Image

Image

Image


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