READER’S SPECIAL
Sarah Chapman is a turbo Slabby riding female who just loves embarrassing newer bikes (and blokes) on this beautiful beast.
Sarah Chapman’s cool GSX-R1100H Turbo.
They say you can’t beat cubes, but try telling that to Sarah Chapman as she reckons you can’t beat a turbo! It is funny how we end up not just riding a particular bike but also modifying it to suit our needs. Over several years this Slabby has gone from a tired and wobbly icon of yesteryear to something that’s more than capable of embarrassing bikes that are much newer than this 30-year-old Suzuki. Like all good stories there’s a start, middle and an ending that includes a happily ever after. Sarah explains: “I always wanted a Slingshot until I rode one! This Suzuki GSX-R1100H Slabside came along around five years ago. It was pretty stock and was showing 45,000 miles. Since I was a little girl I’ve always loved blue and white bikes and knew that one day I would own one. This one was originally black and red, but I managed to have a deal on this blue body set with someone who preferred the red and black colours.” Sarah’s garage is bulging with motorcycle parts as a result. It’s a jamboree of air-cooled and oil-cooled Suzuki parts with the odd dash of BSA projects thrown in for good measure. Since setting about this build, Sarah’s moved house and changed jobs a few times, each domestic change had a knock-on to the progress of the GSX-R build. Her partner is equally bike mad, so at least she hasn’t had the hassle of bribing him so she can play in the workshop! With a trip to the Isle of Man planned in 2015, it doubled up as a deadline for prioritising the completion of the bike, even if there isn’t too much of that original bike left now. The Slabside GSX-R1100H uses a 1052cc variation of the now-legendary oil-cooled powerplant. The later Slingshot models (so disliked by Sarah post-ride) may have had more cubic capacity and more outright power but Sarah avoided going down the engine swap route and instead opted for a turbo. Ahhh turbos, remember them? This was a mode of forced-induction so beloved of the 1980s.
It therefore kinda fits in with the very ethos of this Slab-sider special. During the mid-1980s the turbo road bike came and went. Historically speaking, it’s up for debate as to which of the offerings was the best as each of the big four Japanese manufacturers had a decent crack at the concept, so this is a real ‘what could have been’ from Suzuki. I wanted to know why Sarah opted to go for a turbocharged road bike and if it was a painless process fitting it to the GSX-R: “The turbo that’s on the bike now wasn’t the one first fitted,” admits Sarah. “The project kicked off as an early Fastbyme kit trial, they used my bike as a bit of a guinea pig. Neither me nor Dave Dunlop were in any rush to complete the project initially, but before we knew it, it had been about four years that the bike had been off the road. My first proper ride was to the Isle of Man but unfortunately the turbo bearing packed up so I had no boost and unwanted oil gave me a sticky rear tyre. Still, I made it around the mountain! “I arranged to drop it off to Dave at Fastbyme on the way back and he found another turbo unit in his workshop. I was back on the road within a week. It’s one of the risks you take with second-hand turbos.” By this time, turbo fever had taken grip in Rutland and surrounding counties and there were many ‘old skool’ Suzukis now boosting around. I asked Sarah what the used turbo unit was originally from and I did chuckle at her answer: “I’ve no idea what make the turbo is! I did ask; apparently it’s a ‘grey one.’” So there you have it! One change will often lead to another, so I wanted to know if there were any knock-on effects to the drivetrain once the bike was making boost? Sarah says: “That extra grunt punished the stock Slabby clutch so now the GSX-R runs an MTC lock-up spacer that I blagged from somewhere. I also dropped the compression with a spacer gasket, but other than that it’s a standard motor even running the standard carbs.” With everything in place at last the fun could begin, but Sarah put me in the picture of living with a turbo road bike. “It pretty much ran bob-on ‘out of the box’,” she says. “But a few hundred miles down the road and a dyno run said it was running real rich. Better fat than thin but this was pretty obese. Still, I got 150bhp at the rear wheel. Not a bad return for a bag of favours and broken biscuits!” So, is the bike finally finished? Course it isn’t and Sarah gave me her immediate plans for the Slabby. “I’m about to order some Wiseco 78mm forged pistons and will then go for a full engine refresh. Then it should be good until the bodywork gives up.” The chassis, meanwhile, is real mix of parts and Sarah talked me through the origins of some of them. She says: “The Ohlins forks came from a friend and they started life on an Aprilia Mille-r, and then ended up in his hands after that bike had a crash and they ended up bent. The original Aprilia fitment stanchions were replaced with some Ducati items, despite being told it wouldn’t work they turned out just fine. The wheels are also from an Aprilia Mille R. They are OZ forged items; the rear was fun to fit! It’s a 6in wide item: that’s a full inch and a half wider than the original GSX-R1100H one. After asking various people to machine the hub down, I eventually left it with a local farmer who did the job that nobody else wanted to do.” The wheels really stand out and make a change to the usual three spoke upgrade which often comes courtesy of later Slingshot models. The swingarm is a Metmachex deep-braced alloy model that Sarah happened to have in her stash of Suzuki parts, but it lost its trademark eccentric adjusters and they were replaced with drag slots. Not everything worked out well; Sarah gave me an example that’s all too familiar to those who set about building a special: “I found an Ohlins rear shock and was really chuffed with it. I sent it away to have it refurbished and re-gassed. It was only when I went to fit it that I realised the remote adjuster feed into the shock body would need moving to allow it to fit, only when I did this it let all of the gas out! I fitted a non-adjustable one in the end from an Aprilia Falco, it’s not like anyone can see it anyway!”
It’s the details that always get people talking. Sometimes special builders change things because they need to, mostly though it’s because they want to. Sarah’s Slabby is a perfect example of this. The top yoke is an adjustable item and the Koso clock is one of Sarah’s favourite details. It gives her all the info she requires and even incorporates a built-in neutral light. Both master cylinders are Brembo units and the screen is very orange. Her partner piped up to say, “She thinks she’s still in 1983!” Each part of this bike tells a tale, either in how it came to be fitted or from where it originated, but there’s one part that’s always been there since Sarah bought it and that’s the rack. There can’t be too many CMM Reader’s Specials that have had one fitted and probably fewer on turbo creations. Sarah uses her bike on a regular basis, so finds it a useful extra to have. She plainly rides it and doesn’t hide it so that’s to be applauded. Sarah hit her self-imposed deadline in 2015 and her and the GSX-R went to the Isle of Man. She was impressed with not just the extra power but also found an improvement in fuel efficiency, so it was win-win. Since then the GSX-R’S put plenty of miles under its belt but there’s now trouble at mill. Sarah explained: “As I mentioned, the engine is getting tired and it’s going to need some TLC. I was toying with going for a Slingshot engine and taking it out to 1216cc, but in a way that’s what everyone else does. I have grown to love the fact that my bike still uses a 1052cc motor, so I’m leaning more towards staying loyal to it and maybe getting some 1200 Bandit pistons or the Wisecos and re-boring it to 1109cc.” There’s a saying that project bikes are never finished. It’s pretty true from my experiences and Sarah’s GSX-R is a good example of this. The bodywork isn’t all perfect, it’s peppered with plenty of touch up and imperfections, but she likes it this way. She says: “When I ride it fast I can feel the fairing creaking and moving. That plastic is over 30 years old and quite often a fresh crack appears after a blast.” Riding this bike is what it was built for and Sarah gave me insight into what a turbocharged 1980s GSX-R feels like to ride. “It’s brought the performance into this millennium. There’s now 152bhp being put out at the back wheel and it’s priceless giving modern bikes a run for their money. I love Slabby GSX-RS and mine comes with an added spark. I sometimes wonder how much of the step-up in performance is psychological, because the turbo creates a gorgeous mechanical music when out on the road, the chassis upgrades and better brakes give me that confidence to explore the extra power.” So there you have it, the happy ending to the story of how this GSX-R1100H found its soul mate. The story might have reached an end but the fun is only just beginning.