I wasn’t decided until the last minute about whether or not to go with a bag seat and, if so, when might be best to fit it. The Tillett wasn’t too bad for me and I’m not tall enough to have to worry about scruteneering clearance under the roll cage. However, there were a couple of factors that made my decision.
- I was sensible enough to pick up a HANS device and I can’t use it until I’ve had some modifications done to the harness mount points of the car. These can’t be made until you have your final seat in the car, as the harness holes are positioned based on your position in the car. Having a HANS device and then not using it is asking for trouble and so not a sensible choice.
- The bag seat is lighter. A Tillett weighs about 4kg and a bag seat more like 1kg. So, removal of the passenger seat and getting a driver bag seat should see a saving of 7kg. For someone who’s car + driver combo is 20kg over weight, this is not insignificant!
However, there is a slight trade off. Firstly, I’m used to the Tillett and it’s driving position. I could have taken a step backwards by making the car more uncomfortable or awkward to drive and now that I’ve done a fair number of track days with the Tillett, that change shouldn’t be underestimated.
With the sprints coming up and only 2 track days to go, it was now or never. Luckily Caterham were extremely flexible and, thanks to Mark and Lee, they fitted me in on Saturday morning.
I had to go to a wedding reception that evening and also had a track day at Silverstone the following day, so I arrived in the Caterham fully loaded up with all my racing and wedding gear. It JUST fit into the passenger footwell.
The Tillett put up a struggle to the last and was very reluctant to come out of the car. It did eventually comply but it hung on in there for grim death. Once the seat was out, we made an initial assessment of where I’d sit in the car to check I could see OK and also that I complied with being under the roll cage. The latter was never going to be a problem. The former, more so.
A small pancake of foam was made for me to sit on and get raised up by an inch or so off the floor of the car before we went on to create the bottom half of the seat. It’s unnerving having the estimate your driving position, knowing that, if you get it wrong, you’re stuck with it. But in the end it wasn’t too far off. It needed another slight filling at the rear off the seat to fill out the back of the floor area and offer some lower back support.
Each application of foam to the bag takes around 15 minutes to expand and then go off sufficiently that it will hold it’s shape. It gets nice and warm as the chemicals do their thing and on a cold morning, it was really quite nice!
When I finally jumped out of the car, the pancake I had been sat on had disappeared, so I was sat on the floor. I could still see OK though and so we left it and started on the back rest.
Again, you have to guestimate your driving position in the car and hold yourself in place until the foam has had a chance to expand around you. Being of slightly short stature, I had a fair whack of foam behind me, so it took a while to go off.
Mark trimmed down the excess on the edges of the new seat. We ran out of time to tape the backrest but he left me with the tape and good instructions on how to go about it.
It’s great chatting to Mark and Lee and their friendly approach is always appreciated. Mark has the bag seat process down to a great level of expertise and the seat I’ve ended up with is very nearly perfect.
It would be nice to have a tiny bit more lateral support and it would be nice to be around 1inch further away from the pedals, but having now taken it out on track, so long as you really pull those belts down tight, it doesn’t give me any problems.
Sitting so low in the car should also be good for centre of gravity of the car. Now I just need to continue to eat salad leaves until the first event and I might even lose a few more of those excess KGs.