Pulse Swing Cranks

 swing crank fitted on bike  Pulse swing crank animation path of foot with
normal crank
path of foot with
Swing Crank

Use a Pulse Swing Crank when one of your knees doesn’t bend as much as it should. This adaptation will let you generate as much power as possible without the foot and knee being lifted so high.

  • For use on upright bicycles and tricycles
  • No need to raise your saddle or alter your riding position
  • Uses your existing crank and pedal (suitable for all adult pedals with standard 9/16″ threads)
  • A Swing Crank will let you set the knee bend that is comfortable for you
  • A Swing Crank will let your leg straighten at the bottom of the stroke (unlike a shorter crank)
  • Includes a Pulse Crank Shortener which may also be used on its own

Can be used on three wheeled recumbents, and two wheel recumbents with caution (see note below)

Adjustable for different degrees of ability

A standard Swing Crank and Crank Shortener each have three pedal holes. These allow you to adjust the effect to suit your particular needs. You can even reduce the effect in stages as you recover from a leg injury:

Standard Swing Crank normal setup: If you need to bend your leg less: If you can bend your leg more:
Crank Shortener: middle position
Swing Crank: middle position
Crank Shortener: short position
Swing Crank: long position
Crank Shortener: long position
Swing Crank: short position
swing crank standard position Pulse Swing Crank Swing Crank: short position

There are other possibilities if you have difficulty straightening your leg completely at the bottom of the pedal stroke. For example, you can use just the Crank Shortener on its own:

Crank Shortener: middle position Crank Shortener: short position Crank Shortener: long position
Crank Shortener: middle position Crank Shortener: short position Crank Shortener: long position

Or you can use one of these intermediate setups:

Crank Shortener: middle position
Swing Crank: short position
Crank Shortener: short position
Swing Crank: middle position
Crank Shortener: short position
Swing Crank: short position
swing crank and shortener Pulse swing crank in intermediate position Pulse Swing Crank

(These lengths assume your cranks are 170mm long. Increase them by 10mm for 175mm cranks and reduce them by 10mm for 165mm cranks.)


How to check if a Swing Crank is suitable for you

Ask a friend to measure how high you can raise your foot – it is important you make this measurement while sitting on a bicycle

 1. Raise your saddle so your leg is almost straight at the bottom. Measure height A. 2. Lift your pedal and foot as high as you can. Measure height B. 3. The height you can raise your foot is B – A.
swing crank measuring
Choose a Standard Swing Crank if you can raise your foot 200mm (8″) or more.(or 190mm if you use 165mm cranks,
 or 210mm if you use 175mm cranks)
Choose a Long Swing Crank if you can only manage 164mm (6½”) or more – see below.(or 154mm if you use 165mm cranks,
 or 174mm if you use 175mm cranks)

Long Swing Crank for riders with more severe restriction

Long Swing Cranks are only recommended for riders who can’t raise their foot 200mm (8″) but can still manage at least 164mm (6½”). They are available in 2 different types and offer the following possibilities, plus various intermediate setups:

  Long Swing Crank normal setup:   If you need to bend your leg less:   If you can bend your leg more:
  Crank Shortener: middle position
Swing Crank: middle position
  Crank Shortener: short position
Swing Crank: long position
  Crank Shortener: long position
Swing Crank: short position
Long swing crank Bike swing crank for bad knees swing crank for partially able

3-hole Long Swing Crank for bicycles

The Crank Shortener has 3 pedal holes, allowing the 3 basic setups illustrated above (164mm, 200mm, and 240mm pedal circle diameter). This is suitable for all types of cycle including bicycles, tricycles and exercise bikes. The Swing Crank arm has 4 holes for added flexibility in setting up in intermediate positions.

4-hole Long Swing Crank for exercise bikes

The Swing Crank and the Crank Shortener each have 4 pedal holes, allowing 4 basic setups (164mm, 200mm, 240mm and 286mm pedal circle diameter). This is suitable for tricycles and exercise bikes. It is unsuitable for bicycles in the ‘A’ (286mm) position as there would be a danger of grounding the Swing Crank arm as you lean to turn corners.

(These lengths assume your cranks are 170mm long. Increase them by 10mm for 175mm cranks and reduce them by 10mm for 165mm cranks.)


Please note:

Pulse Swing Cranks can be used on most upright bicycles and tricycles, and on three wheel recumbents. They can be used on two-wheel recumbents, but since these bikes are intrinsically harder to balance you may find that using a Swing Crank on one side only troublesome.

A Pulse Swing Crank is machined from high grade aluminium alloy and incorporates sealed bearings and stainless fasteners. It is supplied with a selection of fittings, allowing it to be fitted to most cycles:

  • Left cranks up to 41mm wide (*)
  • Right cranks up to 41mm wide (*), with removeable chainrings
  • All standard adult pedals (you can re-use your existing one)

(*) please request ‘fat cams’ if your cranks are VERY narrow (less than 21mm)

Available in machined or polished finish (extra charge)

Order Online – only for UK/EU residents who pay 20% VAT or Rest of World residents who pay no VAT.

We can supply at zero VAT for eligible UK/EU customers – please see here

 

Pulse Swing Cranks complete with Crank Shorteners
GB pounds
Standard 3-hole Swing Crank  (for all cycles)

£235 + VAT

£282 including VAT


Choose Side


Long 3-hole Swing Crank  (for bicycles)

£265 + VAT

£318 including VAT


Choose Side


Long 4-hole Swing Crank  (for trikes + exercise bikes)

£265 + VAT

£318 including VAT


Choose Side


Spare parts

Click here to order Swing Cranks without Crank Shorteners, and other spare parts

Shipping: £ 6.99 to any part of the World. Free on orders over £160.00

Fitting

Easy to fit using hand tools, though if you have any doubts get them fitted by your local cycle shop, or a fitting service is available by post.

Free fitting

Fitting Instructions for Pulse ProductsPrinted instructions are enclosed with every Swing Crank, or you can download a copy here.

Important : Your safety depends on the correct fitting of these items. SEEK PROFESSIONAL HELP IF NECESSARY, or send your crank(s) to us if you’d like your Crank Shortener(s) fitted for you.

Trial period

We want all our customers to be absolutely happy with our products. If, within 14 days of receiving any Pulse Product, you find it unsuitable for your needs you may return it in as new condition, using the original packing, for a full refund. Please use a trackable delivery service, at your own expense.

If the Pulse Shortener/Swing Crank has been fitted, a nominal deduction will be made for the ‘consumable’ items used in fitting – namely the straps, star washers, packing strip, the Torx screws and driver – and the reduction in value of the item due to fitting marks, our postage costs etc. This ‘restocking fee’ will be a maximum of 25% of the purchase price, subject to condition.

We reserve the right to make a further deduction from the refund if any item is returned in less than saleable condition or with items missing.

If you have any concerns about our refund policy, please contact us.


Is there a cheaper option?

If price is a concern, you could try a single Crank Shortener instead. You may upgrade to a full Swing Crank later as required (see Spare parts). However, we firmly believe a Swing Crank is the best solution from the start :-

Using one Crank Shortener (or one short crank)

  • The only way that each leg could straighten at the bottom of its pedal stroke would be to have a different saddle height for each leg – which, of course, is impossible.
  • Leaving the saddle at the right height for your good leg would mean that your damaged knee would always be bent, even at the bottom of its pedal stroke. See the diagram on the left below.

Using 2 Crank Shorteners (or 2 short cranks)

  • Your saddle would need to be higher. This might make it difficult, and possibly dangerous, to put a foot down when you stop.

Using a Swing Crank

  • This allows your saddle to be at the correct height for both legs.
  • Each leg straightens at the bottom of their pedal strokes, without your damaged knee having to bend so much at the top. This is shown in the diagram on the right below.
One Crank Shortener Swing Crank
its pedal is raised at the bottom, so your damaged knee remains bent all the time  short crank both pedals reach the bottom, so both legs straighten at the bottom  Pulse swing crank animation

What if I have 2 damaged knees?

Upright Bicycles

The best solution is to fit two Swing Cranks. You could use two Crank Shorteners (or two short cranks) but you would need to raise the saddle to a height that may make it difficult to reach the ground when stopped. This is unnerving for many riders, and may be dangerous.

Tricycles and Recumbents

You can use just two Shorteners, though your saddle or seat should be set so that your legs can make a full pedal stroke at the bottom or furthest point of the pedal travel.

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