MotoAmerica: Driving Harley-Davidson’s Street Glide 131R Bagger Racebike – Roadracing World Journal

Editorial Word: This text initially appeared within the March 2022 problem of Roadracing World & Motorbike Expertise journal.

Kyle Wyman’s Harley-Davidson Street Glide 131R Bagger

When Hogs Fly

By Chris Ulrich



Racing Is Leisure

A bagger and a racetrack are usually not two issues that basically appear to go along with a optimistic end result. Or at the very least not till 2020, when MotoAmerica hosted the King Of The Baggers invitational exhibition race at WeatherTech Raceway Laguna Seca. Purists scoffed on the idea and MotoAmerica took a variety of warmth, however they pulled it off, gaining an enormous quantity of publicity and extra importantly, attracting a brand new viewers to the game of highway racing. Even Superbike mechanics got here out to the pit wall to look at the race, and not one of the bikes oiled the observe.

That wildly profitable first occasion led to King Of The Baggers (KOTB) races being included in three rounds in the course of the 2021 MotoAmerica season, and all three of these races had been aired on FOX Sports activities TV. The rival Bagger Racing League held two occasions, and Baggers are beginning to achieve traction on the membership stage, too, with ahead considering membership racing organizations, just like the California Racing Affiliation (CRA), including a category for baggers, giving riders a chance to check and race exterior of the foremost sanctioned occasions.

My first on-track expertise with a bagger wasn’t using, however following, once I was requested by MotoAmerica to shoot some onboard footage at Laguna Seca (from my Suzuki GSX-R1000R 2-Seat Superbike) following Ben Bostrom on a Feuling Elements Harley-Davidson Street Glide. Bostrom was on the gasoline from pit out, regardless of the Large Twin bucking and wobbling everywhere in the racetrack. He was sooner than I anticipated and it was spectacular to look at. Large motion whereas pushing the boundaries at velocity on the racetrack is a part of the sport while you take a motorcycle that was initially designed to cruise down the freeway or meander by the canyons. That’s proper, meander.


MotoAmerica: Driving Harley-Davidson’s Street Glide 131R Bagger Racebike – Roadracing World Journal
Based mostly on a manufacturing Street Glide Particular, the bagger racebike weighs 631 kilos in race trim and is ready up very excessive to get cornering clearance out of a really broad bike. Seat Top is a tall 36.6-inches.


Whereas Harley-Davidson didn’t have an official crew within the exhibition races, the model clearly noticed worth in going racing and established a hyperlink between new mannequin improvement, the Screamin’ Eagle Efficiency division, and racing within the KOTB collection, which allowed the group to justify going racing. However there was a caveat for 2021: All members of the racing crew needed to proceed to do their day jobs at Harley-Davidson, which means anybody taking part the KOTB program could be volunteering on their very own time. Like most racing tasks, it was half advertising and marketing, half engineering, and all fueled by ardour.

Serving to justify the racing program was the truth that there was a shift out there, with extra riders wanting a extra purposeful avenue bike combining increased efficiency with the standard bagger feel and look. Going racing permits Harley-Davidson’s Screamin’ Eagle Efficiency components and accent division to develop components in racing and use the on-track success to bolster the motor firm’s high-performance credentials within the bagger enviornment. To Harley-Davidson’s credit score, new 2022 fashions carry styling cues and upgrades from the 2021 KOTB racebikes. Win on Sunday, promote on Monday nonetheless works when utilized appropriately.


The Harley-Davidson 131R (which stands for 131 cubic inches engine displacement) racebike. The left-side footpeg and shift lever are mounted to the CNC-machined billet cover of the primary drive case, which houses a chain running from the crankshaft to the separate transmission's input shaft.
The Harley-Davidson 131R (which stands for 131 cubic inches engine displacement) racebike. The left-side footpeg and shift lever are mounted to the CNC-machined billet cowl of the first drive case, which homes a series working from the crankshaft to the separate transmission’s enter shaft.


Zero To Racing In 4 Months

Harley-Davidson’s new official KOTB program kicked off in January 2021, with the primary race scheduled at Street Atlanta in April. A ton of labor needed to be executed to get the bikes on observe in such a brief period of time. The group selected Superbike race crew proprietor/rider Kyle Wyman because the lead rider for the venture together with his brother, Travis, filling a second spot on the crew beginning on the second spherical.

In 2021, Kyle received the KOTB Championship, taking wins at Street America and Laguna Seca. Travis completed fifth general with a greatest end of third. It’s clear Harley-Davidson confirmed as much as win.


The Harley-Davidson 131R (which stands for 131 cubic inches engine displacement) racebike. The right-side footpeg and brake lever mount on the CNC-machined billet transmission cover. Note trellis-style swingarm machined out of a 400-pound block of billet aluminum.
The Harley-Davidson 131R (which stands for 131 cubic inches engine displacement) racebike. The proper-side footpeg and brake lever mount on the CNC-machined billet transmission cowl. Word trellis-style swingarm machined out of a 400-pound block of billet aluminum.



High Secret Tech Particulars

Wyman’s 2021 Championship-winning Harley-Davidson Street Glide 131R is closely modified for KOTB racing. Given the rivalry between Indian and Harley-Davidson, engineers had been reluctant to present away very many particulars of their successful weapon.

Every part is massive on this bagger racebike from the large air-cooled engine to the 65-inch wheelbase and 631-pound race weight. The scale of the bike are excessive.

Electronics are restricted, so the baggers should run the inventory ECU and are usually not allowed to make use of information acquisition throughout race occasions. For testing, Harley-Davidson engineers run information by an AIM MXS 1.2 information logger sprint. Which means many of the efficiency modifications are old fashioned, i.e. mechanical. However simply trying on the components used and engineering time required, I’d estimate the construct value for a top-line bagger to be between $150,000 and $200,000 with out together with the price of the inventory bike.


With a 65-inch wheelbase, the Harley-Davidson Bagger needs a lot of lean angle to turn, which requires cornering clearance gained by raising the bike a bunch. Footpegs are 18.8 inches off the pavement and 17.7 inches below the seat. Few riders at Inde could touch down both feet at once, and dragging knees took an effort.
With a 65-inch wheelbase, the Harley-Davidson Bagger wants a variety of lean angle to show, which requires cornering clearance gained by elevating the bike a bunch. Footpegs are 18.8 inches off the pavement and 17.7 inches beneath the seat. Few riders at Inde might contact down each ft directly, and dragging knees took an effort.


On the coronary heart of the Street Glide is an air-cooled 45-degree V-Twin Milwaukee-Eight 131R engine. HD engineers used an upgraded model of the Screamin’ Eagle 131 cubic inch (2,151cc) crate engine provided as an aftermarket alternative engine for the highway. Upgraded camshafts are used and the form of the piston dome has been modified to extend compression, and better movement injectors are added to enhance efficiency. The tip result’s an engine that Harley-Davidson claims places out round 150 bhp and over 150 lbs.-ft. of torque on the rear wheel. Warmth dissipation is the limiting issue for the Milwaukee-Eight engine, so engineers added bigger fins to the cylinder heads and put the horn housing again onto the bike to push extra air to the rear cylinder. A big oil cooler is fitted within the opening within the carbon-fiber entrance fairing; engineers pay shut consideration to the oil temperature to steadiness warmth dissipation with out having to extend oil viscosity, which reduces energy output. On the racetrack the engine averages 6,000 rpm with redline set between 6,600 and 6,800 rpm, nicely above the inventory rev restrict.

On the chassis facet, the large problem is to create sufficient cornering clearance and nonetheless get the bike to go across the racetrack. There are some challenges to changing a bagger that comes with ground boards right into a racetrack-capable machine with footpegs. There isn’t a strategy to mount rearsets on the body, so the billet main drive and transmission covers are machined with peg mounts. The peg to floor peak is eighteen.8 inches (480 mm) and the seat peak is 36.6 inches (930mm), which is roughly 4 inches increased than a mean sportbike. The peg-to-seat distance is 17.7 inches (450mm), which is a bit cramped for me. For higher race ergonomics, the set-back inventory handlebars have been changed by a one-piece motocross/flatrack fashion bar. A big pommel was additionally added to the rear of the gasoline tank so the riders can really hold off, and the unit used on the bike I rode was model 4.0.


With a 65-inch wheelbase, the Harley-Davidson Bagger needs a lot of lean angle to turn, which requires cornering clearance gained by raising the bike a bunch. Footpegs are 18.8 inches off the pavement and 17.7 inches below the seat. Few riders at Inde could touch down both feet at once, and dragging knees took an effort.
Portrait of a championship-winning highway racing bike at velocity. The MotoAmerica King Of The Baggers Sequence has drawn new followers and groups, and opened new, paying gigs for riders, but additionally has polarized conventional followers. On the finish of the day, it’s a modified streetbike being raced, as was regular at first of U.S. racing.


The KOTB race spec Street Glide should use the inventory mild-steel, backbone-style body, however the remainder of the chassis is broad open. The rake is inventory, sitting round 25.5 levels, however the path is round 160mm, which is near the inventory path on the inventory Street Glide, however very excessive in comparison with a sportbike. The inventory triple clamps had been changed with customized made, totally adjustable items. Just like the inventory bike, the fork mounts on the triple clamps are additionally offset (pushed out ahead) from the steering stem, which will increase the wheelbase and path numbers. The standard forks have been changed by inverted 43mm Öhlins FGR 250 racing entrance forks. On the rear there’s a set of Öhlins-built Screamin’ Eagle Shocks. The customized swingarm is machined from a 400-pound piece of billet aluminum right down to the 18-pound unit used on the racebike. The swingarm mounts on to the engine utilizing rubber bushings, so there’s a little bit of motion when leaned over. Wheelbase on the bike examined was 65-inches (1651mm).

Stopping the Bagger is a set of radial-mount Accossato racing mono-bloc calipers with 34mm titanium pistons mixed with a Brembo RCS grasp cylinder. The large bagger makes use of a set of 300mm entrance brake rotors, which is on the small facet for such a heavy bike. Harley-Davison plans to improve the brake system to make use of Brembo mono-bloc calipers mixed with a set of 330mm entrance rotors.

On the rear, Harley-Davidson engineers used one other 34mm piston radial-mount entrance caliper with a 300mm single disc. Wyman, a former dust tracker, depends on the rear brake to get the Bagger to rotate across the center of the nook. The Street Glide rolls round on 17-inch Core Moto Apex 6 solid aluminum wheels.


Kyle (#1) and Travis (#10) Wyman's 2022 Harley-Davidson 131R Road Glide Special racebikes pose at Inde Motorsport Ranch. 
Kyle (#1) and Travis (#10) Wyman’s 2022 Harley-Davidson 131R Street Glide Particular racebikes pose at Inde Motorsport Ranch.


A Bagger On Monitor

I hate to confess it, however for the primary time in a very long time, I used to be nervous and possibly a bit intimidated to trip a bike. I feel the final time I’d had anxiousness (in addition to regular pre-race jitters) about using a bike on a racetrack was at Brno Circuit in 2004, however that was on a MotoGP bike on track with all of the MotoGP riders.

I used to be at Inde Motorsports Ranch within the Arizona’s excessive desert about to throw a leg over a 631-pound bagger. I don’t know why, however the bike simply seems to be intimidating. Possibly it was worry of the unknown. It could have additionally been as a result of as a consequence of scheduling conflicts, I hadn’t been on a motorcycle in a couple of months.


Another view of Kyle's upgraded 2022 bike in new graphics.
One other view of Kyle’s upgraded 2022 bike in new graphics.


However my nerves calmed as I obtained suited up and threw my leg excessive of the Street Glide KOTB particular. I might really feel the burden of the bike because the crew let it down off the stand, stabilizing it with each ft. The 36-inch seat peak mixed with the large cylinders mounted excessive within the body makes the bike a bit unwieldly till you get used to it. Wobbling barely, I clicked it into gear, opened the throttle whereas slipping the clutch and rolled out for my first laps behind 2021 KOTB Champion Kyle Wyman.

That unwieldy feeling carried onto the observe, however corner-by-corner, I began to know what I wanted to do to trip the Street Glide. With a 65-inch wheel base, there isn’t a lot pitch on the brakes so that you don’t get the identical sensations from the entrance tire on nook entry. Essentially the most tough half comes at turn-in, as the acute peak of the bike and excessive middle of gravity make it tough to provoke turn-in, however then the bike falls into the nook faster than anticipated with a ton of momentum heading to full lean. I struggled to get my knee on the bottom so it was tough to evaluate lean angle. On the apex the Street Glide was actually secure and gave nice suggestions. I pushed the entrance over one of many sealer patches, but it surely has a lot path that entrance got here again instantly. And, surprisingly, it nonetheless completed the nook nicely. There was traction on nook exit; I feel the burden of the bike helps drive the rear tire into the pavement. The shortage of pitch to the rear didn’t trigger any issues.

The Milwaukee-Eight engine was torquey, but additionally delivered clean, linear energy by the rev vary. I used to be a bit shocked how smooth the ability was within the decrease a part of the rev vary, from first contact to about 1/third throttle. Energy picked up because the revs climbed into the rev limiter which regarded prefer it was set round 6,500. The engine makes a ton of energy and torque on paper, however the sensation of energy and acceleration is diminished by the burden of the bike.


Remote Reservoir Screamin' Eagle by Öhlins 36mm dual shocks were developed by the Swedish suspension manufacturer with extensive testing and input from Kyle Wyman and his crew. Photo by Brian J. Nelson.
Distant Reservoir Screamin’ Eagle by Öhlins 36mm twin shocks had been developed by the Swedish suspension producer with intensive testing and enter from Kyle Wyman and his crew. Picture by Brian J. Nelson.


The transmission ratios are unfold out, so the throw between gears might be problematic. I needed to be very deliberate throughout upshifts and downshifts on the bike. I didn’t time a downshift proper on the primary lap and caught a impartial off the again straight. I made certain I gave the bike a correct two-stroke blip each time I downshifted after that second.

By the tip of the four-lap periods, I began to achieve some confidence on the bike and choose up the tempo. By this time, I found out the timing on turn-in; my inputs simply needed to be very clean and deliberate. I positively wanted to roll the bike into the nook. I might get my knee down in most corners, which was reassuring. And, as soon as I figured it out, the Street Glide typically felt like a standard bike; it stopped, turned, and accelerated, however with a personality distinctive to a customized bike doing one thing it wasn’t designed to do. Harley-Davidson’s Street Glide Bagger really will get across the racetrack fairly shortly, which is spectacular.


Specs: 2020 Harley-Davidson Street Glide Particular Racebike

Engine Configuration:             45-degree V-Twin

Engine Displacement:            131 cubic inches (2,152cc)

Engine Cooling:          Air

Combustion Chamber Design:           Screamin’ Eagle Stage IV Heads

Valves Per Cylinder:   4

Consumption Valves Per Cylinder (Materials):           2 (Stainless Metal)

Exhaust Valves Per Cylinder (Materials):        2 (Inconel)

Bore x Stroke:             4.31-inches x 4.5-inches (109.474mm x 114.3mm)

Connecting Rod Size (center-to-center):   8.015 inches (203.6mm)

Connecting Rod Materials:       Metal

Claimed Peak Rear-Wheel Horsepower:       150 bhp

Claimed Peak Rear-Wheel Torque:   150 lbs.-ft.

Engine Redline:          6,800 rpm

Valvetrain Kind:          Pushrod

Valve Adjustment Interval:     Self-adjusting Hydraulic Lifters

Consumption Valve Diameter:           41mm

Exhaust Valve Diameter:        34mm

Gas Supply System:            Digital Gas Injection

Throttle Physique Venturi Dimension:    64mm

Air Filter Kind:            Ok&N Oiled Pleated Material Factor

Exhaust System Kind (Materials):       2-1 (Stainless Metal)

Ignition System:          Digital (Inventory)

Lubrication System:    Dry Sump, Screamin’ Eagle Professional Excessive-Quantity Oil Pump

Oil Capability:   4-quarts Engine, 1-quart Transmission, 1-quart Major

Engine Oil:      Screamin’ Eagle SYN3 Full Artificial 20w50 Motorbike Oil

Gas Capability:             20 liters (5.3 gallons)

Transmission Kind:    6-speed, Fixed Mesh

Clutch Kind:   Multi-plate, Moist, Screamin’ Eagle Excessive Capability

Clutch Actuation System:       Cable

Clutch Spring Kind:    Coil

Quantity Of Clutch Springs:    3

Quantity Of Clutch Plates:      10

Drive Plates:   10

Pushed Plates: 10

Major Drive:             Hyperlink-Plate Chain

Major Drive Gear Tooth:     24-26

Remaining Drive Sprocket Tooth:    47-53

Body Design (Materials):        Inventory FL Spine (Metal)

Rake/Path:      25.5 levels/160mm

Measured Wheelbase:           65 inches (1,651mm)

Swingarm Kind:          Uneven Billet Aluminum Alloy

Seat Top:    36.6 inches (930mm)

Footpeg Top:          18.8 inches (480mm)

Footpeg to Seat:         17.7 inches (450mm)

Entrance Forks:    Inverted Öhlins FGR250 Racing

Fork Tube Diameter: 43mm

Fork Changes:

Rebound Damping:    30-Click on Vary

Compression Damping:          30-Click on Vary

Spring Preload:           18-Flip Vary

Entrance Wheel Journey:    130mm

Rear Wheel Journey:    81.5mm

Rear Suspension Kind:          Distant Reservoir Screamin’ Eagle by Öhlins 36mm Twin Shocks

Rear Shock Changes:

Rebound Damping:     36-Click on Vary

Compression Damping:          22-Click on Vary

Spring Preload:           25mm Vary

Entrance Brakes: 300mm (11.8-inch) Twin Discs, Radial-mount 4-piston Accossato PZ001 Calipers

Rear Brake:    300mm (11.8-inch) Disc, 4-piston Brembo Caliper

Entrance Wheel:   Core Moto Apex-6 17-inch x 3.50-inch Cast Aluminum Alloy

Rear Wheel:    Core Moto Apex-6 17-inch x 6.00-inch Cast Aluminum Alloy

Entrance Tire:       120/70-R17 Dunlop KR448

Rear Tire:        200/60-R17 Dunlop KR451

Claimed Racing Weight:         631 kilos

Weight Distribution, P.c: (46F/54R)

Estimated Construct Price:             $150,000 – $200,000




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