Sorry, Alix, you really need to watch the Kassa review of cargo bikes.
There’s fundamental dynamic instabilities associated with three wheelers, which is why the Delft team only recommended using trikes at low speeds. Most people forget to take into account Newton’s Laws of Motion when evaluating trike against bike. And an additional factor in this country, which the Delft team didn’t need to take into account, is that our streets are more cambered than in the Netherlands.
The result of that instability is that the propensity of trikes to overturn is accentuated when negotiating right hand bends. In their test there was only one exception regarding tipping instability, a very expensive custom built trike with loadbase lowered below front axle height (by means of U-shaped subframe/axle carrier)…but that machine, at that time EU3500, was about the double the cost of any comparative two or three wheeler.
The other problem with load carrying bikes and trikes is braking. All too often they are fitted with drum brakes on the front axle. These are problematic enough on a conventional bikes as, on long descents, they tend to fade (in the same way as drum brakes on conventional motor vehicles did). I have a Trice recumbent trikes, which has Sturmey drum brakes fitted on the front, and I learnt very early on about their tendency to fade, even at fairly light touring loads. Most continental cargo bikes have the back pedal coaster brakes fitted at the rear which, because they use a completely different friction material, don’t tend to fade. These are not available for front brakes and, given the difference in load distribution between long john (central loading) vs trike (front end loading), trikes will be more likely to lose braking effort on the downhill gradients that feature in this country.
Whist I agree that it would be difficult to load a trike onto a train in the UK, the problem is less severe with the two wheeled Bakfiets, particularly the short wheelbased version. As regards access, life is very difficult even with a fully loaded two wheeled conventional bike, so I’d regard any station without level access or a large enough lift as problematic and plan accordingly. Whilst UK companies have banned trikes, a two wheeled bike similar in length and width to a tandem, shouldn’t be too much of a problem for many companies and/or rolling stock designed to take tandems. Well, that’s the excuse I’d use with the train manager.
As I said, I wouldn’t touch a trike with a bargepole for use in this country.
Cheers
John Meudell
C.Eng, MIMechE
From: Cycling and Society Research Group discussion list [mailto:[log in to unmask]] On Behalf Of Alix Stredwick
Sent: 24 June 2012 13:43
To: [log in to unmask]
Subject: Rent or Purchase Bicycle in Amsterdam? (cargo bikes)
Hello everyone,
Just had to respond to the thread appearing about cargo bikes in NL. Hugh of Cambridge Dutchbikes imports the Bakfiets brand but there are a number of dealers in the UK (me being one of them!) if you don't want to go all the way to NL to purchase one. I don't want this to be a message just promoting my selling of the bikes - indeed my social enterprise is about promoting practical cycling for its environmental & health benefits amongst many - but felt compelled to chip in, in case this advice may be helpful.
I am starting up my social enterprise Carry Me Bikes in London and there is also Practical Cycles in northern England and others too who sell Bakfiets and other brands.
I would agree that the two-wheeled cargo bikes (long johns) are definitely more nippy & maneoverable than the trikes. But the Bakfiets trike especially is good for very large loads and you can get electric assist for hills/large loads etc (as you can for 2-wheeled), although there is a bit of a 'grey area' about power limits in the UK. Some brands of trike may be a little prone to tipping and I would agree that the first choice for most loads would be a 2-wheeler. However, someone who recently borrowed my demo Bakfiets trike said that it was much more stable and smooth than the Christiania (trike) he was used to 'driving' so I would suggest that it is very much on a brand-by-brand basis (I think the Christiania is a great bike too for other reasons although I don't currently sell them).
People who haven't tried the 2-wheeled long-john type often start out wanting a trike but then when they try the 2-wheeler they often realise that it's a better choice for their needs and is in fact very stable (due to its low centre of gravity). It also has a super stand that keeps the bike entirely still when loading & unloading and kids getting in/out.
A big word of caution about cargo bikes on trains; I can't comment on the situation in NL but in the UK it is very unlikely that you will get a Bakfiets type cargo bike/trike on a train. Firstly there is the practical issue of getting a heavy and long/wide bike up stairs at the station or even fitting them in a lift, and then getting them to fit on a train; but also the issue that as far as I am aware most UK train companies do not allow over-size bikes such as tandems or cargo bikes on their services at all. Even adult tricycles as mobility aids are not allowed. As I understand it this is due to the demise of the much-missed guards' van and resultant modern rolling stock design.
I hope this helps
Alix Stredwick
----
Alix Stredwick
Founder, Carry Me Bikes
Skype: CarryMeBikes - tel 020 8525 4512 -07725 466 842 - [log in to unmask]
Twitter: @CarryMe_Bikes Facebook: http://www.facebook.com/CarryMeBikes
-------- Original Message --------
Subject: | Re: Rent or Purchase Bicycle in Amsterdam? |
Date: | Sun, 24 Jun 2012 11:17:55 +0100 |
From: | John Meudell <[log in to unmask]> |
Reply-To: | Cycling and Society Research Group discussion list <[log in to unmask]> |
To: |
Absolutely!