KTM Cafe Racer project
Wanting to make a café racer, Nigel used the non-traditional base of a late model KTM 250. The result, as you can see for yourselves, is pretty impressive and certainly individual. But how did a near-stock motocrosser become a road burner? We'll let Nigel explain.
I think you have to ask yourself what motorcycling means to you. If someone asked me what motorcycling is to me, I would probably look back to my childhood. Our house backed on to empty paddocks. My dad and I restored a '70s model Honda XR75 and I loved nothing more than twisting that throttle and getting up as much speed as I could before I had to brake for the next fence. It was freedom, and it always has been freedom, from BMX to motocross to motorsport, it's that sense of getting on a bike and going anywhere you want to.
When the time came in 2008 to buy a new dirt bike, I chose a KTM 250 EXC-F, because it was road-registerable, which made it easy to head out to the bush for a quick blast. Some friends of mine were riding Supermoto bikes at the time, so I saved up some money for a 17 inch Excel rim and RAD hub wheel set from the US. When it arrived, I got some road tyres fitted, put on a smaller rear sprocket, made up a new chain and fitted a larger front brake. The first few rides were really good fun. . . until we started getting the wrong kind of attention. Stick a 60KPH sign in front of your nimble-handling, sticky-tyred, supermotard and the fun gets taken away quite quickly.
So, to save our licences, most of us quickly changed back to the dirt tyres and larger sprockets for the bush. However, I still wanted to ride on the road. The café racer-style of motorcycle really caught my eye, and I'd seen what others were doing, but the old bikes used for these just didn't suit my taste. Don't get me wrong, I'd love an old SR500 to restore and modify, but I just didn't have the money or time to do so.
About four months ago, I took my KTM dirt bike down into the Otways National Park for a blast. With the fresh morning air pumping through the vents in my helmet, it sparked something in me. I looked down at the EXC-F's triple clamps and envisaged a set of clip-ons around the KTM forks. Maybe, just maybe, the café racer idea could work on a late model dirt bike!
When I returned home, I quickly pulled the bike down to just the frame and motor. It only takes about an hour to do so, as everything on a dirt bike is simple and made to be removed and replaced regularly.
As most people acknowledge, the tank and tail units are a big part of the café racer look. At first, I intended to find an off-the-shelf tank, but found nothing except overpriced tanks that were going to need modifying to suit the KTM anyway. I thought, 'Bugger it, I'll build my own. How hard can it be? I have built an entire car from nothing so why not give it a go?!'
A trip to Metaland and a sheet of panel steel later I was starting to get the desired shape for my tank. I used a tig welder to weld all the seams and simple tools to get the shape. An English Wheel to roll the steel to shape would have been a good investment, but I decided to go with a square edged design. It was an intricate job because I made the decision not to cut a single thing on the factory frame.
Being water-cooled, the KTM's radiators presented a challenge, too. I had to partially cover them while still allowing air to enter and exit cleanly. I eventually came up with a design that made the tank look like it went right over them while actually allowing air to enter and then be scooped under the tank and across the motor. My good friend Luke from GWorks Custom Cycles in Geelong advised me on a few things re: the construction of the tank. Luke also hooked me up with a neat flush-mount filler and some tank sealer. After the final welds, I sealed the tank up and left it to focus on job 2 - the ride height.
Dirt bike height on a café racer-style roadster wouldn't work, so the KTM's ride height had to be altered to get the correct stance. I decided the front forks needed 120mm taken out of them. There was no production springs available at the height I wanted, so I got Chad from Chad's Off Road Setups to cut the springs down in my factory forks. I left the front forks with him and went on to the next job; the seat and tail.
I knew exactly what I wanted with the tail section before I even started - a nice "bullet" style rear section with a simple flat seat. I made the seat and tail base out of one piece of sheetmetal, with the top section being bolt-on and off. This allowed access to the battery and fuse panel that the factory KTM has under its seat. All I had to do was relocate it further back in the frame and extend the main power cable to the starter motor. I ordered some race foam online for comfort and then went on to the next job.
To match the dropped front end, the rear subframe needed to drop down around 50mm. Determined not to cut up the factory KTM item, I found a solution by fabricating an alloy extension link that pushed the top mounting holes out 30mm. This in turn dropped the rear of the subframe around 60mm - perfect!
Soon after I finished this, Chad said the forks were ready. He advised that they'd be stiffer than factory, but I expected this and was happy with the finished product. Once I slid them back in, I had to work out what clip-ons I could fit. It just wouldn't be a café racer without clip-on bars, right? The KTM forks are 54mm OD, so after some quick internet research, I found Ducatis ran a 53mm fork. $200 later and I had a set of DRIVEN branded CNC alloy clip-ons on their way from WA.
The headlight I sourced online was a chrome ADR-approved 7-inch item that has parkers, low beam and high beam. Would you believe it even plugged into the factory KTM electrics? Speaking of electrics, I really didn't need to do anything. The KTM controls are so simple, I just moved them to a neater position, lowered the factory speedo 25mm and made a new panel to mount the factory wiring loom that now sits behind the headlight.
So, with the forks in, the tank done, and tail section all finished, it was starting to look like what I had originally imagined. I had wound down the factory rear spring to match the front, and the headlight was looking spot on after I made some neat brackets. Next things on the list were the induction and exhaust.
I had been running an FMF Ti aftermarket exhaust on this bike since I bought it. The factory KTM pipe was sitting there unused, so I pulled it apart to get the baffle tube and the matting. I then went to my local REECE Plumbing Supplies to get the rest, I used some 3-inch stainless tube, a pair of stainless reducers from 3-inch to 2-inch and then cut down the factory baffle tube to slot inside. With everything together and looking good, I stuffed the silencer packing inside and tacked it closed.
How do you do perfect cylindrical welds? Well, I made up a pair of rollers on my bench and made a drill spigot to fit inside the pipe, I zip tied the trigger on the drill to get it to spin at the right speed and then welded the pipe as it rolled around. I also purged the pipe with ARGON to make sure the weld was as good on the inside as the outside. The inlet side of things was a little easier, with a neat little stainless pod filter bought from the UK providing the finishing touch.
So, after three weeks, everything was complete, and it was time for some test rides. I had left the bike in raw steel, so it would be easier to identify and fix any issues with the ergonomics, suspension and handling before I painted it. Aside from the custom-built muffler, the engine was untouched, so performance wasn't going to be a problem, the real question was how all the modifications I made would impact on that performance. That first ride around the block was like no other! The long nights and eBay bills paid off; the bike handled really well, was a blast to ride and the new seating position made me feel as cool as James Dean!
The reaction from the public was something I didn't expect, though. People from all walks of life would look twice, comment, or even take photos of my custom bike. The starting point of a KTM made it unusual, and the fact that it was still raw steel made it stand out like no other, too. I would pull up at the traffic and see smiles and thumbs up. With that in mind, the idea of painting all that hand-fabricated metalwork just went out the window! So, all I did was give everything a coat of clear to protect it from the elements.
In less than a month, I had transformed my 2008 KTM 250 EXC-F into something totally different, something with style, a hint of the “older generation” of bike, but with reliability, light weight, and smart engineering.