Dirtitis XL500R
Intro: Gary Inman
Photos: @storiesbydominique
Luuc Muis is a 28-year-old, custom bike builder from Groningen in the Netherlands. His business, LM Creations, has fans in high places, including Indian Motorcycle, who commissioned him to build a custom Indian Scout board tracker. Not just a bike builder, the college-trained Industrial Product Engineering, is growing his business into the design and creation of off-the-shelf products and kits for custom bikes. Here he tells us about the 1982 Honda XL500R, he built into a dirt track bike to learn and practice new skills.
‘I bought this Honda in early 2019 in -6˚C weather, collecting it from a remote farm in the north Netherlands. It was in a pretty bad state. It needed a full engine rebuild and the suspension was toast. It would stall at idle, the bitter cold made it really hard to ride it back and it leaked petrol all over the place.
'I planned to learn new skills, experimenting with a few things on my own bike, instead of on an expensive customer’s project. My brief was: more torque and build it into a flat tracker. That was ‘phase one’ of the build before I put the Honda up for sale. A customer came knocking and requested a few things changing: a more traditional seat and since he was a bit smaller, I swapped the front fork and suspension for a second time.
But I’m getting ahead of myself. I started off by stripping the bike, having a set of 19in rims were laced to the original hubs then fitted with Shinko race tyres. I fabricated a new rear section for the bike that could hold a street type monoshock instead of the bouncy MX style. I could have just gone for a harder shock setup but I had some shocks laying around, so this was the cheaper option.
'The engine needed a full rebuild after the cases were soda blasted. The cylinder was honed and fitted with a new piston; the top end got new valves, timing chain, gaskets... I flowed the exhaust ports since they can be way bigger than they were cast, then swapped the carb for a Mikuni BST 40, from a 2006 KTM LC4. I need to design a new intake manifold that I 3D printed out of carbon-nylon. It works really well. The engine now has 15% more horsepower and 35% more torque than original.
'I actually hadn't welded that much alloy before I started this, my first aluminium gas tank, and never had done any aluminium sheet fabrication. That was something I wanted to challenge myself with. The inspiration came from the small, slim tanks of vintage flat trackers and old dirt bikes. I also wanted to create something industrial and raw, so I left the exposed welds and added the indentation of the X to make it a bit cooler while referencing the X in XL. The tank is asymmetrical because I wasn’t that confident in my aluminium welding skills that I would be able to make a symmetrical one. Every centimetre of welding I did, the welds got better.
'I also wanted to experiment more with 3D printing so I engineered the complete seat unit using the Fusion 360 programme and printed it in two pieces myself. It’s an example and experiment to show what can be done with 3D prints for motorcycles. I want to make the seat available for purchase and add a bunch more 3D-printed parts. I can easily adjust the seat unit to fit someone else’s frame. I recently engineered a full body, vintage-style dirt track kit for the 2010 KX250F and want to make it available as an off-the-shelf product, as well as a kits for more bikes like the Yamaha XSR700.
'I learned what I wanted to during this project so it was a success.'
Thanks Luuc, we love it.
