Gone Racing: The Kramer HKR Evo2 S

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For those that haven’t been keeping track on Asphalt & Rubber, the Brap Talk podcast, and on social media, we are spending more than a little bit of time at the track this year, racing with the Oregon Motorcycle Road Racing Association (OMRRA) to chronicle what it means to become an amateur racer.

I have already outlined my reasons for wanting to go racing, but I wanted to spend the next two article mentioning what I am racing with, both in terms of machinery and gear. First up is an introduction to our racing platform, which for this season is a Kramer HRK Evo2 S.

We have already talked about Kramer’s ready-to-race single-cylinder motorcycles, and in fact our race bike for this series is the same bike featured in that article’s story.

Previously a demo bike for Kramer in the Pacific Northwest, this “S” model machine found its home in my garage, and as you can see from the photo above, it has been on quite the journey since.

Kramer HKR Evo2 S Overview

This is where it all started, with a photoshoot in 2018.

First off, it is important to note that the Kramer HKR Evo2 S is the track day model from the German brand, whereas the “R” models are meant to be the turnkey racers in the lineup. This creates some interesting challenges for those that want to go racing with the Kramer HKR Evo2 S, but I will get to that in a minute.

For now, the basic lay of the land is that the Kramer HKR Evo2 S is a 75hp supermono, which uses a 693cc single-cylinder four-stroke engine from KTM. Found in the Duke, Enduro, and Supermoto lines, as well as the Husqvarna 701 machines, the Austrian powerplant is the most powerful street-legal single-cylinder engine ever produced.

Kramer uses the current-generation version of the engine, which means dual-balancing shafts, and thus more power, smoother delivery, and better table manners.

Those with more technical knowledge than me praise the design and build-quality on the KTM motor, and it is of note that KTM will only produce this engine in Austria, because of the complexity and metallurgy required to build and design it.

All of this is wrapped into a steel trellis frame, of Kramer’s own design, along with a bevy of other parts designed by the German brand.

Fairings removed, which requires unscrewing 12 fasteners.

In fact, most of the HKR Evo2 S comes from Kramer, aside from the WP Suspension pieces, Brembo brakes, and cast aluminum wheels. This means that the tail section fuel tank, bodywork, and swingarm are all bespoke to Kramer, and come with some very clever touches (check out the gallery below for some close-up shots of these).

The total package weighs 280 lbs, according to Kramer. For those interested, the race-focused Kramer HKR Evo2 R weighs 276 lbs, with 80hp on tap thanks to different engine mapping.

The Kramer HKR Evo2 R also features dual 290mm brake discs at the front, higher-spec WP suspension, forged aluminum wheels from Dymag, a quickshifter, along with an adjustable ride height linkage.

While the Kramer HKR Evo2 S only breaks that bank for $17,000, the Kramer HKR Evo2 R costs a cool $22,500. Both are a princely sum, but not unreasonable by the time you start factoring the costs to build a Suzuki SV650 or Yamaha MT-07 to similar spec.

Why the Kramer?

Garden shot, not garden variety.

Though crunching the numbers helps justify the cost of the Kramer to some extent, the real selling point of the HKR Evo2 lineup is the no-compromises approach to these racing machines. These are bikes designed for the track – they are not adaptions from road-legal motorcycles – and it shows in their design.

I have already explained my reason for racing this season, and picking the Kramer as a racing platform very much fits into those stated goals.

I wanted a bike that would force me to ride with racecraft, not something that would spoil me with electronics and horsepower. The middleweight category fits the bill too from a costs perspective, with tires last over the race weekend, if not longer.

This two-piston rear brake caliper is from Formula and looks super trick. Works pretty good too.

Looking at the options, the usual suspects are all there. The Suzuki SV650 is the venerable club racing machine, with a plethora of used models available to buy, along with plenty of bolt-on go-fast parts already developed. For bonus points too, a completely competent SV650 can be built for half the price of the Kramer.

Another popular choice is the Yamaha MT-07 (nee Yamaha FZ-07), which has begun to take over the SV650’s mantle as the budget race bike. Very convincing race models have been made from this platform, though the price tag of a “Yamaha FZ-07R” stretch into Kramer territory pretty quick.

Somewhere in the middle of these two options is a third choice, which happens to be quite popular in our local club: the cripple triple. A four-cylinder 600cc motorcycle with a cylinder disabled, these 450cc race bikes are based off supersport machines with track-proven chassis and components, and they still make considerable horsepower.

With our home track of Portland International Raceway featuring two very long straight sections, connected with a handful of turns, the high-horsepower potential of a “cripple triple” Yamaha YZF-R6 et al is hard to ignore, especially when the flick of a switch can mean the bike is supersport legal again.

Finding a used R6 for racing use is easy enough, and depending on how you want to disable a cylinder, the modifications can be very straight forward. Bang for the buck, this is perhaps the easiest way to be competitive at road racing in OMRRA, and the number of cripple triples on the grid shows it.

But now, there is a fourth option – thanks largely to four intrepid racers who wanted something different…and fast.

The Kramers at OMRRA

Speed patina.

Last season, four Kramers took the OMRRA grid in the Lightweight and Middleweight classes, along with another rider with his own KTM 690 frankenbike.

In OMRRA, the Lightweight class features an unlimited single-cylinder motorcycle provision, which makes this class the “home” class for the Kramer HKR Evo2, which then races “up a class” in the Middleweight category. Make no mistake though, the Kramer is a class-killer as a Lightweight, and very competitive as a Middleweight.

Other clubs handle the Kramer in their own ways, but you will almost certainly see Kramers battling with SV650s and MT-07s, and often getting the better of those machines.

Over the course of the 2018 season, I watched with eager intent how the club’s four Kramers fared in OMRRA – and I largely attribute this article series to their progress. I will be honest, the bike intrigued me as the perfect mix of weird, different, and fast.

Some readers will note the number change, since 7## numbers in the club are for novices only.

But, I have seen single-cylinders pop on the race track before too…and PIR is a race track that is not kind to these often dirt bike sourced engines.

As such, I was very keen to see how the Kramers would hold up over the course of a season of racing, with some track days sprinkled in. While I generally have a high pain tolerance for fickle motorcycles, replacing engines was not something I wanted in my racing pursuits.

The KTM 690 engine was built as a street bike motor though, and it shows in its ruggedness. As such, all five (four race bikes and the demo) of our local examples made it through the season with aplomb, and looked no worse for the wear when taken apart.

That being said, there would still be a challenge getting the Kramer HKR Evo2 S demo bike up to the racing-spec found on the other four Kramer HKR Evo2 R bikes on the grid.

JB’s Modifications

Left side.

Often overlooked, one the most important components on a motorcycle are the tires. Watching the Kramer riders struggle on several brands of tires (namely on Dunlop tires), it took close to most of the 2018 season for them to come to the conclusion I had reached quite early – the OEM-fitted Pirelli slicks were pretty much the only choice.

This isn’t a dig at Dunlop or the other brands, but the rigid race chassis of the Kramer, tied to its featherlight weight and big thumper power meant the softer carcass found on the Pirelli’s proved to be the winning combination.

This makes sense, as tires on the Kramer can be ranked on effectiveness with a direct correlation on that brand’s tire construction rigidity, with Pirelli and Dunlop coming in as complete polar opposites on that spectrum.

Tire size was also an issue, though for a different reason. The “S” bikes come with a 5″ width rear wheel, while the “R” bikes feature a 5.5″ width rear wheel. Since it rains quite often, needing a wet and dry setup for wheels was a racing must for me.

The Kramer is basically a KTM 1290 Super Duke R on the front end, while the rear is close to a KTM 690 Duke. This makes it slightly challenging buying wheels that aren’t OEM spec pieces from Dymag, but it is not impossible.

The folks at Rotobox were up to task in this regard, providing their carbon fiber Boost wheels for the project. The KTM 1290 Super Duke R front wheel was a direct bolt-on modification for the Kramer, while the KTM 690 Duke rear wheel needed a new spacer made for the brake side of the wheel.

Pirelli slicks and carbon fiber Rotobox Boost wheels go together quite well.

Hidden from view is the fact that the Kramer swingarm has built-in ledges near the axle, which provide a sort of quick-change ability for the Kramer rear wheel. This allows the wheel to stay in place, even when the rear axle is pulled.

Since the Kramer sprockets are counter-sunk for the mounting bolt holes, the sprocket bolts clear this ledge with ease, but it does mean sorting button-head bolts to make the Rotobox wheels have the correct clearance with their different sprocket design.

This whole process proved to be easier than expected, which left the bulk of my attention to the single-disc brake setup.

With the dual-discs being a bit overkill, I had a thought that the single-disc setup would be the best option still – it just needed a bit of an upgrade.

This is a topic worthy of its own story, but so far the process has found me switching the 19mm Accossato master cylinder for a Brembo 15mm RCS pump, while the Brembo M50 street caliper has been swapped out for a race-only Brembo P.4 30/34 unit. The pads have been upgraded too for Brembo’s very grippy, but short-lasting, Z04 compound.

This combination has been a huge improvement over what comes stock from Kramer on the HKR Evo2 S, though I am not completely convinced yet. And…there are certainly days where I think it would have been easier to just mill the brake mounts on the fork legs down, and mount a second caliper to them, along with another brake disc to the wheels.

This Brembo P4 30/34 isn’t stock, and replaces the Brembo M50 that comes with the bike. The jury is still out on this choice.

Other changes to the “S” bike include a number of parts from Kramer to make it on-par with the “R” model. This means the addition of the adjustable ride height linkage, a quickshifter (up-shift only), adjustable engine maps, and a carbon fiber front fender.

The black-option fuel tank was also added to the package, though that comes mostly as a design choice. There is some benefit in the black tank, primarily when using UV-sensitive race fuel, but one can debate that against the ability to see the fuel level on the “clear” tank option it replaces.

If I am being honest though, the switch was made for aesthetic reasons. I owe the overall design package on this Kramer to ex-KISKA design Stephane Marty, now with Marty Designs.

The last addition is an AiM Solo2 GPS lap timer, which is a very powerful piece of equipment that I will spend some words on at another time, when we get to data analysis and progress measuring.

I found out after the fact of buying the timer that the Kramer already comes built with the mounting points for an AiM timer, which was a pleasant surprise, and a nod at its popularity.

With the half-pound lap timer installed, our Kramer HKR Evo2 tips the scales at 269 lbs, with a 54% front-wheel weight bias, according to our Intercomp two-wheel scales.

That’s an 11 pound weight savings so far off the quoted 280 lbs by Kramer, and most of that comes from the carbon fiber wheels.

With 80hp estimated on tap, the only depressing part about those figures is how uncomfortably close it gets to this 6’2″ rider, once he is in race leathers, boots, gloves, and a helmet…

269 lbs ready to race, sans fuel. Note the front/rear bias. It’s tricky to measure with one person, but I’m curious what this looks like when a rider climbs onboard.

The “Gone Racing” series is supported by the following brands: Kramer Motorcycles USA, Pirelli, Dainese, and Racer Gloves USA. Asphalt & Rubber would like to thank them for their support during my racing efforts, and for their support for other racers around the country.

Photos: © 2019 Jensen Beeler / Asphalt & Rubber – All Rights Reserved