The Art of Suspension
Front suspension is designed to dissipate road vibration so that it does not enter the frame of the chair and transfer it to the rider. It must also absorb the higher impact energy created when the front caster wheels encounter obstructions while rolling over every day surfaces.
A study conducted by the Department of Health & Human Performance, Iowa State University determined that 80% of all the vibration within the frame of a wheelchair originates from the front casters. Their studies showed that 76% of all the vibration in the frame of the chair is eliminated by the addition of (Frog Legs) front suspension.
Why Frog Legs Forks
In a rigid chair, as the small front caster wheel strikes an object, the wheel has to move up at least the height of the object carrying its own weight plus the entire weight of the system (chair and rider combined).
On a suspended caster fork, the wheel striking the same object only has its weight plus the weight of the bottom of the fork. The difference can be thousands of times. Also because a suspended fork and wheel has so little mass/weight it can move out of the way and return in a fraction of a second before the chair and rider even notice.
Combining quick motion with vibration absorbing materials is the best way to accomplish safe and comfortable transportation.
For front suspension it is important to allow the wheel not only to travel up but also to travel backward to give more time to respond to the obstacles. The Frog Legs forks have accomplished this by using a simple pivot so that the wheel would travel on an arc instead of along a line(straight up and down). The Frog Legs forks are designed out of aluminum and our caster wheels are as light weight as possible(approximately 160 grams for a 4 inch wheel and bottom fork tine plus axle bolt and fasteners) to give quicker response.
The Polymers
Combining quick motion with vibration absorbing materials is the best way to accomplish safe and comfortable transportation.
For front suspension it is important to allow the wheel not only to travel up but also to travel backward to give more time to respond to the obstacles. The Frog Legs forks have accomplished this by using a simple pivot so that the wheel would travel on an arc instead of along a line(straight up and down). The Frog Legs forks are designed out of aluminum and our caster wheels are as light weight as possible(approximately 160 grams for a 4 inch wheel and bottom fork tine plus axle bolt and fasteners) to give quicker response.
Within the hinge Frog Legs use a polyurethane dampener. Polyurethane is the primary material used to eliminate vibration in most industries. Urethane is similar to a spring in that is has shape memory – it can be compressed and then return quickly to its size/shape after being distorted. However, when a spring is compressed it retains energy and reflexes it back into the system. When a polymer is compressed, it dissipates the energy as heat thereby completely eliminating it from the system.
Areas that Frog Legs forks helps a wheelchair rider:
- Spasticity
- Secondary injuries
- Fatigue and muscle tightness
- Crystallization of body fluids (kidney stones)
- Neuropathy, predominately in the feet
- Pressure sores from sheering of seat
- Longevity of chair and other components
Specifications
- Black and silver forks are a standard option, all colour options are custom-made and cannot be refunded
- Fits 3, 4, 5, or 6" diameter casters
- Prior to ordering, please make sure you are aware of how your current caster forks are attached and you have the necessary tools in order to be able to remove and replace them. If you are unsure, please contact either your wheelchair supplier or the manufacturer for further details.
- Price is for a pair of forks without wheels.
Shipping & Returns
Here at Spokz our emphasis is on value for money and customer service. We now offer free tracked Express UK delivery with DHL on orders of over £50 to mainland UK. Any orders under £50 will be charged £6.25 for our DHL next day service or for smaller items you can choose £2.50 Royal Mail 48 Tracked which is a 2 working day service (not guaranteed).
All pre-order items are delivered free of charge to any destination apart from international orders.
Find our more about our delivery & returnsFrog Legs Phase 2 Hybrid Wheelchair Caster Forks
This fork has many advantages over the original aluminum. The Hybrid features a newly designed aluminum top, the wedge progressive polymer, and a carbon fiber lower swing arm.
The curved design creates an optimised absorption zone. The Hybrid is lighter weight and offers equivalent tensile strength of 6061-T6 aluminum.
The optimized absorption zone of the Phase 2 Wedge Polymer dramatically improves bump response providing a substantially smoother ride. The progressive wedge technology prevents bottoming out and biopacing by becoming more stiff as it compresses.
Price is per pair without wheels
PRE-ORDER ITEM - Each pair of forks need to be built to your chair specification. Please select your options below and press the pre-order button to add this to your basket and checkout as normal. We will notify you once the product/s are ready to ship. Express shipping is not available for this item.
Go to full description-
A big thanksGreat Forks of usual frogs legs quality. I can still feel uneven ground through them, but I can already feel that the vibrations up through the chair are a lot less than on my factory fitted forks. I am looking forward to putting them through their paces in the cobbled town near where I live once lockdown is over! The fork material will I reckon be less damaging on furniture around the house too. I was determined to use Spokz again though as the advice from them before ordering was great, and important to me when spending so much. They also got to me quicker than expected which was a bonus. Thanks again for great customer service!
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