Racing motorcycles makes about as much sense as customising them, which is what makes both pursuits so utterly enjoyable.
Club racer and fabricator Ian Davis founded ETTO motorcycles to indulge his passion and share a wealth of experience. ETTO’s first build is this TRX850, which was exhibited at Bike Shed London 2017, although back then the handmade fuel tank was raw aluminium to best display Ian’s talents.
Ian decided on using a TRX after spending the 2010 season battling his pal Mike who rode a fully sorted 850, the parallel twin offered great drive out the corners and sounds like something Hades would ride. The hunt for a donor led to a trip from Nottingham to Bournemouth where a chap was selling a pampered ’97 model. Ian recalls the moment when the TRX’s future was disclosed to the now former keeper “he made the school boy error of asking me what I was going to do with the bike, (after I’d given him the cash). I thought he was going to cry when I said the angle grinder was coming out and most of it would be junked!”
Being an ex-racer and suspension technician Ian knew exactly how he wanted this bike to handle and simply chucking an R1 front end in wasn’t going to cut it. Experience aboard a Ducati 749 race bike led to the decision to source an USD fork, four pot Brembos and lighter Marchesini wheels from a road going 749. The fork was rebuilt with linear springs, new seals and bushes, then mounted to a custom top yoke. The setup is a touch lower than the squidgy stock fork, steepening the rake and sharpening the handling. The rearsets are from LSL with the linkage reversed for a 1-up, 5-down race pattern.
A more aggressive approach was taken at the rear where Ian wielded an angle grinder chopped the subframe off completely, replacing it with a much lighter aluminium structure mounted to new tabs on the main frame. The height and angle are intentional to weight the now much more capable front end. An upgrade to a YZF750 swingarm is a common upgrade for the TRX but Ian went one step further and skinned the box section with aluminium to replicate a beefier MotoGP style. The shock is by British suspension experts Nitron, Ian chose a road biased NTR1 with a black rather than trademark turquoise spring.
A simple 2-pot caliper replaces the heavy YZF united and the agricultural torsion arm made the bin, superseded by a stainless, rose-jointed linkage. The Ducati’s rear wheel took some persuading to mate with this Yamaha concoction, 6mm was milled off the sprocket carrier to achieve perfect chain alignment. Avon AV79 Ultra Sports make sure none of this effort is wasted.
As the donor was a well cared for, low mileage example it didn’t need opening up, just a through service and valve adjustment before a few hours on the local dyno – run by TT and Macau racer Dan Hegarty. Ian wanted to eek usable mid-range punch from the gutsy twin rather than impress mates with big bhp figures. That said, after a few runs the new Mikuni 40mm flat slide carbs were up-jetted from 145 to 165 which equated to a hike from a stock 75 to 87bhp. Combined with a drop in gearing from 17/39 to 16/41 that new frontend should claw the air through the first couple of gears.
Despite clearly being an accomplished fabricator (making a fuel tank from scratch is no mean feat) Ian wanted a specific look for the exhaust and seeing as tubing with conical sections are notoriously tricky to get right an ex-Skorpion employee was enlisted to help. Nigel from NRP exhausts made a big-bore stainless system with no joints or obvious brackets and soda blasted the finished article for a near titanium appearance. These cross plane cranked twins sound wonderful from idle right up to the redline and this stubby system should really bark.
When exhibited at our show in May the unpainted tank certainly left Ian’s panel beating skills nowhere to hide but he fancied a touch more zing and had it painted in a retina searing orange by local firm Pro Bodywork. The seat and tail progressed through a few iterations, finally leading to this traditional café-humped unit which needed modifying and re-glassing to meet Ian’s high standards. Viking Seats in Kent delivered a simple cross stitched seat pad.
As this bike is to be enjoyed on the road rather than track a few concessions were made. A 5 ¾” Bates light up front, compact rear stop/tail lamp and LED indicators mounted to an ETTO tail tidy should keep the MOT man happy and an all-in-one KOSO CRD64 speedo will let Ian know when he’s having too much fun. And that’s exactly what the first test ride yielded, huge grins and an overwhelming sense of satisfaction, Ian told us “I opened the throttle and was met with a visceral roar from the engine and short shifted up through the box – barrp, barrp, barrp. I got back literally laughing my head off. The last time I felt like that on a bike was when I was a teenager and bought my first RD350LC.”
This article first appeared on The Bike Shed; It’s republished here with permission.