Source: Bike Bound
From SLR650 to “SCR720R” with Finland’s KMPH…
Introduced in 1996, the Honda SLR650 was designed as an affordable, road-oriented city bike based on the same 644cc RFVC single-cylinder engine as the NX650 Dominator. For decades, this engine has been thumping along strong in the Honda XR650L, with a reputation for solid power and bulletproof longevity. In the SLR’s case, a different cam favored torque over maximum horsepower, translating to 39 bhp and 40 foot-pounds of torque, and the bike was produced in the Montesa plant in Barcelona.
Despite the enduro aesthetics, the bike’s off-road prowess didn’t extend far beyond gravel and dirt roads. However, with the bike’s chassis and suspension designed to be more road-oriented than other Honda 650 models, it was perfect for urban traffic and winding country roads.
Our friend Panu Laakkonen of Tampere, Finland, has been riding and wrenching on bikes since he was 15. For more than 15 years now, he’s run his own workshop: Kalevan MP-Huolto Oy. While service and repair are the mainstay of the business, custom bike-building is Panu’s passion and ultimate aim.
The Finn seems to have a soft sport for single-cylinder machines, as evidenced by the two past builds of his we’ve featured: a Husky SMR510 Scrambler and a Honda SLR650 “Gravel Eater” — both built for running the dirt roads and trails of the Land of the Thousand Lakes. Now Panu has returned with another SLR650, and this one is a ripper.
The donor — a ’98 model, sometimes known as the Honda Vigor — came from a friend who was moving abroad and couldn’t bring the bike along…so he gave Panu free rein to customize it according to his own vision. Panu looked from the big-single donor to the Honda VFR750 superbike suspension he had lying around in the shop, and the idea of a super single hot rod was born.
Up front, Panu combined the VFR fork lowers with the SLR fork tubes for additional ground clearance, mounted with custom triple trees and 3D-designed and printed headlight cover and front fender.
Out back, Panu modified the single-sided VFR750 swingarm to work with the SLR, complete with a custom adjustable linkage and frame modifications. The subframe is a real work of art, milled from solid in a similar style as the triple clamps and designed with a cutout for the big K&N air filter.
Other highlights include a custom seat, handlebar switches, foot pegs, license plate holder, complete rewire with twin LiFePo4 (lithium iron phosphate) batteries, some trick frame mods, and a stainless steel exhaust with an aftermarket NX650 silencer.
North Kustom Fab handled the laser-cut and water-cut parts, AkvaBlast Suomi Oy the vapor blasting and chemical treatment of the aluminum parts, and Panu’s friend and neighbor Suvi (@suvi.ahonen / @paintings_suvi) laid down the paint.
Some custom builders choose to leave the engine alone, but not Panu. This RFVC single was completely rebuilt with a 720cc big bore kit, Hot Cams Stage 1 camshaft, ported head (with smaller sparkplug hole), and all new bearings / valves / seals, with the engine breathing through a Mikuni TM carb.
The bike is now ~50 pounds lighter than standard — 158 kilos (348 pounds) versus 180 kilos (397 pounds) wet, and with that 720cc big-bore motor, this is one hell of a thumper:
“It feels a very mean version of the Honda RFVC engine with a really snappy throttle response :)”
Panu calls it the “SCR720R,” as it was originally going to be built as more of a scrambler with knobby tires, but he ultimately opted for 17-inch Dunlop Mutants, giving the bike more of a supermoto character and stance. This is one of those builds that the longer you look, the more you see to appreciate. And as lovers of highly tuned monos, we can’t help but wish to twist the throttle on this big-piston brute.
Below you’ll find our full uncut interview with Panu, along with a build sheet and other information. Credit to Tuomo Kallonen (@korpipiilo / @tkfotografi) for the photography.
Builder Interview
• Please tell us a bit about yourself, your history with motorcycles, and your workshop.
Motorcycle enthusiast by nature and profession. Started when I was 15 and got my first Honda Monkey. Ever since 2-wheelers have been a huge part of my life, and when I was in my early 20s in the mid 2000s it also became my profession.
Couple years in just working as a mechanic I bought the service shop I worked for and have been running it ever since. Mainly servicing and repairing motorcycles, but bike building is the end goal that I aim to do.
• What’s the make, model, and year of the donor bike?
Honda SLR650 From 1998.
• Why was this bike built?
A friend of mine moved out of the country and told me that if I have some good ideas for the bike I could carry out my vision of it as he’s not able to take it with him at that moment.
• What was the design concept and what influenced the build?
H-Profile, that was the only design feature I wanted to implement on the bike.
Rest of it just came along. Also I had this suspension from a VFR750 that I’ve always wanted to use on some project.
• What custom work was done to the bike?
- Custom triple trees*
- Custom subframe* with “airbox” implemented in the design
- Custom license plate holder*
- Custom seat
- Modified eBay fuel tank with ignition switch embedded
- Custom switches on the handlebar
- Custom footrests* — the left side is combined with a support bearing for the front sprocket and drive shaft
- Custom exhaust built from stainless steel with an aftermarket silencer left from a Honda NX650
- Modified VFR750 swingarm to fit the SLR
- Modified VFR750 lower front forks combined with SLR inner tubes to gain ground clearance
- Custom adjustable linkage*
- 3D-designed and printed headlight cover
- 3D-designed and printed front fender
- Frame mods to incorporate the inlet tube inside the frame. Frame acting also as a crankcase breather tank
- Frame mods for rear shock and linkage mounts and subframe mounts
- Customs electrics with all sealed connectors and two self made 4 cell LiFePo4 batteries
*Parts have been designed by me with laser/water-cut and lathed parts welded together.
Engine mods:
- Big bore kit 720cc
- Ported cylinder head with smaller sparkplug hole 12mm -> 10mm
- Hot Cams stage1
- All new bearings, valves, etc. Full engine work
- Mikuni TM carburetor
There are so many things on the bike that I probably forgot something 😀
• Does the bike have a nickname?
Unfortunately she doesn’t have a name, but I made up the model SCR720R.
• Any idea of horsepower, weight, and/or performance numbers?
Wet weight is 158kg but the power and performance is yet to be figured out.
• Can you tell us what it’s like to ride this bike?
It feels a very mean version of the Honda RFVC engine with a really snappy throttle response 🙂
• Was there anything done during this build that you are particularly proud of?
I would say that the way everything designed and modified parts fit together and the aspect of keeping it still very easy to service and use.
• Is there anyone you’d like to thank?
- North Kustom Fab for all the laser- and water-cut parts
- AkvaBlast Suomi Oy (@akvablast_suomi) for vapor blasting and chemical treating all of the aluminium parts including the engine.
- My friend and neighbour Suvi (@suvi.ahonen / @paintings_suvi) for the paint job.
- My friend Tuomo (@korpipiilo / @tkfotografi) for photographing
Follow the Builder
Website: www.kmph.fi
Instagram: @invert.moto
Facebook: @kmphoy
Photographer: @korpipiilo | @tkfotografi
Painter: @suvi.ahonen | @paintings_suvi
More KMPH
Very Mean RFVC: Honda “SCR720R” Supermoto – From SLR650 to “SCR720R” with Finland’s KMPH… Introduced in 1996, the Honda SLR650 was designed as an affordable, road-oriented city bike based on the same 644cc RFVC single-cylinder engine as the NX650 Dominator. For decades, […]
Finnish Gravel Eater: Honda SLR650 Adventure Scrambler – Finland’s Panu Laakkonen builds a Honda adventure machine… The Honda SLR650 was a streamlined, more street-oriented version of the popular NX650 Dominator, geared more for commuters and couriers than dual-sport riders. The SLR’s seat height […]
Husqvarna SMR 510 Scrambler by KMPH OY – The Husqvarna SMR 510 was a replica of the Swedish company’s championship-winning supermoto race machines — a lightweight (240-lb), high-powered (60-hp), water-cooled street weapon with top-notch build quality. Enter Panu Laakkonen of KMPH Oy (Kalevan […]
