Back Support in Sports Car Seats

The prominent side bolsters in some performance cars can make the seat-back quite narrow. BackShape is 350 mm wide (to suit the majority of seats and drivers) and if it does not fit between strong bolsters it folds round inside the bolsters and can make the seat too narrow.

The sales volumes involved are too small for us to make a BackShape for each width, but if you find this is happening to you, you can alter your BackShape yourself...

1. Measure the seat back width between the bolsters.
   
2. Unzip the BackShape cover and remove the foam core.
   
3. On the curved surface of the core, draw a straight line along a ruler in felt-tip pen, at one end, to the measurement you took.

Then...

1. Lay the core curved side up on a work table, and align the line with the edge of the table.
2. Using an electric carving knife, cut along the line.
3. Reassemble the core centrally into the cover, taking care to fit it the right way up - the sharper taper goes at the top.

Refit the back support into the car, folding the excess fabric at each end.

This may be fine, but if you are dissatisfied with the appearance of the fabric folds, you can try sewing the cover narrower to fit. To do this...

1. You should sew it inside-out, with the zip side down and the zip 3/4 closed.
   
2. Measure very carefully, and mark with chalk to take an equal amount off each end. Small errors will have a surprisingly big effect on the end result.
   
3. Trim and then refit the loop Velcro pieces by the seams, so that you do not have to sew through them (but leave them on or you will get plucks in the fabric).
   
4. Gather the loose material away from the seam and sew exactly parallel to the original seam.
   
5. An experienced machinist will get a better result than a first-timer.
   
6. Cut off the surplus fabric at the same distance from the sewing line as the original..

• You have to expect a less than perfect finish. However this is probably the only way for you to get correct and comfortable back support in a sports seat, if it is not right to start with.
  
• With your lower back being further out you will have less lateral support from the bolsters, so there is that trade-off. There is no way to avoid this, since any separate lumbar support that appears shaped to provide lateral support will just move sideways on the seat under load. The low-profile design and soft texture of BackShape means that this effect is at least minimised.