Category: Technical Info

With a bunch of different hubs available for the Brompton, I thought a comparison would be a good idea:

	Kindernay	Rohloff	Alfine 11	Alfine 8	Enviolo NuVinci	Sturmey 8
Number of gears	14	14	11	8	n/a	8
Gear range	543%	525%	405%	307%	380%	325%
Weight	1.4kg	1.7kg	1.6kg	1.7kg	2.4kg	1.8kg
Gear ratios	18″-98″	19″-100″	24″-99″	24″-74″	25″-95″	29″-95″
Shifter	Thumb	Twist or Thumb	Lever*	Lever*	Twist	Twist or Thumb
Efficiency	Very good	Very good	Good	Medium	Good	Medium
Axle	Solid 10mm	Quick release	Solid 10mm	Solid 10mm	Solid 10mm	Solid 13/32″
Disc brake	Yes	Yes	Yes	Yes	Yes	No
Kit cost	£1795	£1595	£795	£725	£725	£395

Gear ratios are the most common possibilities – with the Rohloff and Kindernay, they are with the smallest possible rear cog and largest Brompton front ring (54t). With the Alfine and Enviolo, it’s 18t/50t. So getting higher gears is possible on the Alfine and Enviolo hubs, more difficult with the Kindernay and Rohloff.

I know it seems a bit odd that the Kindernay has a wider range than the Rohloff but has very similar gear ratios, but it’s because the difference between 18″ and 19″ at the bottom end is a much bigger difference than between 98″ and 100″ at the top end.

Other factors are harder to quantify in a table: In terms of fitting, the Rohloff is easiest – it’s a simple quick release hub (though I usually use an Allen key skewer) and cable fitting is very simple. The Alfine and Enviolo hubs are nutted, so need a spanner to fit, but cabling is pretty simple. The Kindernay is the most complex, with a nutted through axle, and hydraulic shifting that has to be cut and perhaps re-bled to fit.

*A rapid-fire shifter is available, but I strongly recommend the Jtek shifter for the Brompton handlebars.

Why Ride Recumbent?

 

There are some very good reasons for reclining. You rest on a supportive and comfortable seat, rather than perching on a saddle. Your diaphragm can expand freely, improving your breathing. Weight is taken off your wrists, your neck does not have to strain to see where you are going, and you have better all-round vision. Recumbents are quite often very beneficial to cyclists with back or knee problems, who would otherwise need to restrict or stop cycling altogether.

Recumbent bikes and trikes come in many flavours, and are often very fast machines, partly due to the improved aerodynamics of having your legs in front of you not below you. And with a firm supportive seat to push against, a recumbent cyclist produces just as much energy as an upright cyclist. It is also argued that recumbents are safer than upright cycles – for one thing, the first part of your body to hit an obstruction is your feet, not your head. Brakes can be pulled as hard as they will go with no fear of diving over the handlebars, and car drivers seem to be much more wary of recumbents. Read lots more on the General Info page….

Which Recumbent?

That all depends on what you intend to do with it 😉 Two-wheelers are generally lighter and faster, and happier in traffic. Three-wheelers are more stable, especially at very low speeds, and can be a lot of fun to play with as they’re like pedal-powered go-karts.

It’s a common question – which is the better kind of trike? The answer isn’t so easy – both configurations have their advantages and disadvantages:

Tadpole:

• Simple drive system – a normal chainset at the front with a chain leading through to normal rear wheel gearing.
• Very stable, you sit right in the middle of all three wheels.
• Can carry normal panniers alongside the rear wheel.
• You can see how wide it is when riding, for narrow gaps.

Delta:

• Very manoeuvrable – the front wheel can turn through about 80 degrees to either side, so it can almost turn in its own length.
• Very easy to get onto and off – you can sit down first, then swing your leg over. Access from a wheelchair is simple.
• More complex drive system, with single-sided drive to one rear wheel or a differential to drive both, sometimes with mid-mounted gearbox gearing.
• Less stable when cornering fast.

Heinzmann controllers are clever – they often use a half voltage tap from half- way along a battery pack to monitor the cells. This causes problems when you try to fit a new lithium battery to an old controller.

To disable the half voltage detection, simplest way is to bridge a diode on the circuit board. These pictures show you which one to bridge, depending on whether your control board is surface mount or not:

Advantages of recumbent bikes:

 

There are two main advantages of riding a recumbent bike – speed and comfort. Recumbents are more aerodynamic than any other bikes (your legs are in front of you, not below you), so you slip through the air with less effort. Touring recumbents are probably about 5-10% faster, racing recumbent bikes can be 30% faster – even before you start adding aerodynamic fairings.

With a recumbent, you don’t really sit on the bike, you sit in it. Your back is fully supported, and there is no strain on your neck, wrists or back. Almost all the power comes from your legs, so you don’t need a death grip on the handlebars. All of this means that on a recumbent you are a lot more comfortable – nice for everyone, but wonderful if you have a problem which makes it painful to ride an upright bike.

 

Disadvantages of recumbent bikes:

 

There aren’t many, but you should be aware of what differences a recumbent makes:

To start with, you won’t be faster – in fact, you’ll be slower. This is because recumbent riding uses different muscles to upright riding, and it will take 2 months at least of riding for your muscles to adapt.

You will attract attention – recumbents aren’t for the shy and retiring! 99% of comments you’ll get are good ones, but don’t expect to blend into the background. Of course, this also means you are more visible to car drivers, which is always good…

Some kinds of riding aren’t possible – serious off-road riding, for example. You can’t get out of the seat, so you can’t hop the front wheel over obstacles. With a full-suspension recumbent, you can just hit things at speed to get over them (within reason!) but it’s not as slick as hopping the front wheel on an upright.

 

Learning to ride a recumbent:

 

Most people take 5 minutes to get the basics – the real trick is to relax. You should always be back in the seat – don’t sit forwards to start. Your shoulders should always be hard back against the seat. If you need to push hard on the pedals, push with your shoulders, don’t pull on the bars. You should never need to put any force on the bars – your hands should just rest on teh bars. If you find this hard, try holding the bars just with your thumb and index finger – you can’t force the bars by accident that way.

Starting, especially up a hill, is the hardest thing to learn. The trick is to rotate your “good” pedal to vertical, or a bit closer to you. Give a very good push on that pedal, and that will give you enough momentum to get your other foot up.

 

Types of recumbent bike:

There are two main classifications for recumbent bikes – the wheelbase, and the handlebar position:

 

Wheelbase – can be short, medium or long. Short-wheelbases (SWB) have the front wheel behind the pedals, almost under the seat. This is compact and fast, and also amnouverable. It is a bit trickier to get used to, as you can’t directly see the front wheel, but SWB recumbents are the best performing types.

Medium-wheelbases are also called compact long wheelbases (CLWB) just to be confusing… The front wheel is small, and directly below the pedals. CLWB bikes are very easy to get used to, and still quite compact.

Long-wheelbases (LWB) are now rather rare – the front wheel is out in front of the cranks. This design is very stable, and good for serious touring – though there are now SWBs which are just as good for touring without the disadvantages. LWB recumbents are heavy, take up a lot of space, and not very fast.

 

Handlebar position – the bars can be either over the seat or under it. Overseat steering is very direct, manouverable, aerodynamic and easy to get used to. Underseat steering is very comfortable – a lot better for touring.

A collection of old articles I wrote about issues around disc brakes, weak quick releases and inadequate hubs: Continue reading “Disc Brake Safety Issues”