UNITED STATES QUAD RUGBY ASSOCIATION

February 2006

Chair Tune-up Tips
by Bob Crandall
 

Post season play is just around the corner and now is the time to tune up your rugby chairs. I expect that most players do some of this on a regular basis, but I do know that many players pay little attention to their rigs when they are not strapped in. If you regularly care for your chair, please read through this anyway and add things which I forgot or neglected. If some of this seems remedial, it is, but not everyone has the same experience.

1. Alignment
Our chairs take and give big hits. These aluminum frames do bend and the big wheels develop a toe in or out, i.e. - they are no longer parallel front to back, causing rolling friction. Toe in/out can be difficult to measure. Basically you choose a height from the floor, say 12 inches, to measure the distance between the two large wheels on the front and on the back of each wheel. Make sure you measure at exactly the same height and at the same points across the tire for each measurement. This measurement between wheels should be exactly the same front and back.
Note: When you do this measurement, ensure that the tire pressure is at your game pressure and for better accuracy, put 150 to 200 lbs in the chair, as if you were in it.

There are various causes for misalignment:

• a.) bent axles

• b.) loose axle sleeves. Most chairs have a sleeve threaded into the main cross tube. Each sleeve has a lock nut to keep it in position. That nut must be tight. Furthermore, each sleeve should extend beyond the lock nut the same distance for each wheel.
  Note: On offensive chairs these axle sleeves, sometimes in combination with spacers, are used to align the midline of the wheel with the arc of the wing.

• c.) worn casters. As casters wear down, the front of the chair drops and the wheels toe in. New casters or spacers will address this problem.

• d.) a bent frame. Once you’ve checked all of the above factors, it might come down to the frame. At this point, my advice is to contact the manufacturer about the best way to proceed.

Remember, every adjustment you make in one place will affect some other part of the chair.
Note: On offensive chairs there is a critical adjustment to get the minimum space between wheel and wing, without rubbing.  Being a low pointer, I haven't dealt with that here  because I don't know about it.  If you have that problem, contact the manufacturer or a high point veteran for advise.

2. Broken and worn parts
Pull the main wheels, remove the axles, checking for bent axles. If you have trouble pulling an axle through the wheel bearings, then it is probably bent.

Check your main bearings. Turn each bearing with your finger feeling for signs of a broken ball bearing or dirt behind the seals. Ensure the bearings are seated properly in the hubs.

Check your wheels for loose or broken spokes. Take this time to true your wheels.
[Author's note: This is the biggest advantage I have seen in using Spinergy wheels. They seldom need truing or spoke replacement.]
Check the wheel rims for dings that might leave sharp edges. Take this time to check your tires for signs of failure. Deflate the tubes and check for wire coming through the bead.

Flip your tires on the rims if they are showing signs of wear. The cambered tire can be used twice.
Note: some tires have a recommended direction of rotation and can not be flipped.

Adjust your axles to ensure they lock, but minimize play. You should also do this with spare wheels and axles, so you don’t have to mess with it on the court.

Remove your casters for cleaning and the same type of axle and bearing check that you did on your main wheels.

Check for cracked or failing casters. It’s not a one minute fix on the court if you have a caster break.

Examine your upholstery, taking care of worn areas and do a final adjustment to ensure you are seated the way you want. Check all strapping to ensure it’s adjusted properly and clean that Velcro so it holds properly.

After you’ve done all of this just strap in the chair like you would for a game and do some test time. Make sure the chair is working with you.

3.) LEGAL CHAIR
Finally and importantly check for the legality of your chair.  During regular season few teams protested a chair, unless it was dangerous. Post season will be different.

Reference the commissioner’s statement regarding contact bars on rugby talk
contact bars

ANTI-TIP DEVICES: Anti-tip devices attached to the rear of the chair are compulsory. If they are fixed in position, any part of the wheels cannot project past the rear wheels. If they are of the swivel caster type, then the housing cannot extend past the furthest point of the rear wheels. The maximum distance of the bottom of the anti-tip wheels from the floor is 2 cm. (See diagram B).
[Authors note: Loosening of the tip caster spindle nuts so that the tip casters hang to meet the 2 cm requirement and yet can be pushed up above the 2 cm limit is considered to be an attempt to circumvent the intent of the rule]

f) BUMPER:
i) Tubing or solid rod used for the bumper of the chair must be rounded and have no edges or protrusions that could give a player an unfair mechanical advantage. All tubing should be bent on a bender and be consistently round in nature. The bend shall not cause the tube to wrinkle, flatten, or flare from an excessive bend. The
tube/rod used must be a minimum of .635 cm or 6.35 mm or ¼ inch in diameter. All bends used in the construction of the bumper must have a minimum inside arc of 2 cm in diameter. Therefore, using these two requirements, the total minimum outside measurement, from edge to edge including the thickness of the tube/rod will be 3.27 cm. (See diagram C)

Note: The minimum outside arc can only be achieved by using the minimum size tubing/rod.

[Authors note: There are some bumpers which I have observed over the last two seasons which are built of tubing less than 1/4 inch. Some players are aware that their bumpers are illegal and other players are not. I suggest you measure your front tubing if you have any doubt.]

ii) The front-most part of the bumper, measured at the midpoint of the tubing/rod, must be exactly eleven (11) cm from the ground and span straight across. This measurement must be made with the front casters in a forward rolling position.
iii) The minimum length of the bumper is 20 cm measured at the furthest outside edges. The maximum length of the bumper will vary but cannot extend more than 2 cm past the outside edge of each caster housing. (See diagram A) Note: The length of the bumper corresponds to the width of the chair.
iv) Connections for the bumper to the main frame of the chair must include one on either side of the bumper, at the widest point. These side connections must be straight and cannot be made at less than 45' from the bumper and to the main frame, in the horizontal plane. (See diagram D) The angle will be viewed and judged from the top view.
v) The bottom edge of the bumper cannot be any lower than 3 cm from the floor. The top edge cannot be any higher than 20 cm from the floor. (See diagram B) vi) The maximum forward projection of the bumper is 20 cm from the front-most part (outside) of the caster housing. (See diagram B) g) WINGS: The wing-type addition to the frame, to protect the space between the bumper and the back wheel, is permitted but must be uniformly 11 cm in height at all points of contact (as is the bumper). This applies to open-frame construction of wings ONLY. For Safety to other chairs, the wings cannot extend laterally beyond the centre of the rear tires. Also, all wings stopping at the edge of the rear tire must be rounded without any sharp edges. Wings that stop at the rear wheel and/or are welded at an angle to the frame must be within 1 cm. of the rear wheel. This 1 cm restriction does not apply to wings that are rounded and continue past the rear wheel to the frame. Any tubing/rod used to reinforce the wing must have a minimum diameter of .635 cm or 6.35 mm or ¼ inch like the bumper; but the diameter of the tube/rod used for the bumper and/or wing need not be the same. 9 Like the bumper, the bottom edge of the wing cannot be any lower than 3 cm from the floor and the top edge cannot be any higher than 20 cm from the floor. (See diagram B) The space (10 cm above the top edge of the wing, from the front of the wing to 1 cm behind the tire of the rear wheel) must be obstacle free.

h) COMFORT AND SAFETY:
i) All protrusions such as handles, push-bars, crossbars, hooks, etc., having an element of danger but judged acceptable by the officials, must however be safely padded.
ii) Only one cushion, with a maximum thickness of ten (10) cm, is permitted on the seat of the chair. (Also see Art.16)
iii) Padding between the knees is permitted. However, this padding must not protrude above the level of the knees. (Also see h - ii) above)
iv) A strap or elastic must be attached firmly behind the calf if there exists the possibility of the feet slipping off the footrest. Strapping of the body to the chair is permitted.

As a final preparation for the post season, check your equipment. Spare wheels, marked with your name, tire size, air pressure. Maybe even which side, if it matters. Have spare tubes, tires, axles even a spare caster.

Everybody have a good time in post season, good luck to all and may no game be won or lost due to a preventable equipment problem.

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