YAMAHA YFZ450R PROJECT: LTR SPINDLE GEOMETRY?

YAMAHA YFZ450R PROJECT: LTR SPINDLE GEOMETRY?

Stage 3: WORCS pro-level racing suspension By the staff of Dirt Wheels

When asked, “How do I make my sport quad faster?,” we always suggest upgrading the suspension to start.  The stock YFZ450R suspension is pretty good if your off-road rips consist mainly of MX tracks and dunes. However, it’s on the stiff side, so you’ll want to substantially soften up the compression and rebound settings for cross-country racing and trails. All the power in the world won’t matter if you can’t keep the wheels on the ground. 

You could say we went against our own advice with this build. We’re at part three of the project, which began months ago, and we’re just getting around to the suspension. In our defense, we ordered shocks and arms first, but as usual in today’s world, some parts were backordered! That said, the best things in life often take a little longer. Rather than being satisfied with OEM suspension tweaks, we changed everything with help from Roll Design, Elka Suspension and Duncan Racing.

MAXIMUM CONTROL FROM DOUG ROLL

“The Suzuki LTR geometry is the cat’s meow regarding motocross racing, because positive steering kingpin inclination is preferable,” claims Jed Bunch. Bunch is Doug Roll’s right-hand man at Roll Design. Bunch continued, “In the past, we had to change out the tie-rod ends and ball joints completely, and the steering stem had to be changed on the Honda 450 to get the taper right for the tie-rod ends. A lot more expense went into it. So, what we did is take it to the next level, where you can use all of the Yamaha ball joints and tie-rod ends so that a customer doesn’t have to go through the expense of buying all those Suzuki parts to gain the advantage of Suzuki spindle geometry.” The spindle change allows more responsive turning, so it doesn’t push as much in the corners under hard acceleration. It’s so good that we had to adjust to the changes mentally; just thinking about turning the bars invokes a change of direction. 

Another benefit to LTR geometry is slightly increased wheel travel. “With standard YFZ450R spindles, wheel travel is 10.79 inches. We gained a quarter-inch of shaft travel with the LTR spindles, so we are sitting at about 11.40 inches at the wheels,” said Bunch. That’s an increase of 1.6 inches over the stock suspension, allowing for a longer shock shaft without increasing stock width or relocating the shock mounts.  

NATIONAL-LEVEL ELKA SHOCK TREATMENT

The Elka Stage 5 shocks we got through Roll Design are far from standard. “Above and beyond the valving, the spring rates and the length that we change on the shocks, Doug also goes inside to blueprint and balance the Stage 5 cartridges. Doug matches the springs and backup plates, so when you set your clickers to zero, all three shocks are at true zero. So now we can adjust the clickers with confidence [knowing they are the same],” claimed Bunch. The front and rear springs are tension-tested with a scale for accuracy, so Roll Design nails the setup to a single pound rather than being off by 3 or 4 pounds when adjusting for rider weight.

With the customer’s weight and riding-style information, preload, high- and low-speed compression, and rebound are set by Roll Design. All you must do is bolt them on, and then you have a solid baseline should you decide to make any incremental adjustments. On the YFZ450R, Roll Design also likes to change ride height to what Jed refers to as a Honda-like stagger. “A Yamaha chassis is very flat. If you look at a Honda chassis, it has a rake in the front. When you hit a deadhead with a Honda, it wants to naturally walk over the obstacle, whereas a Yamaha tends to pop the front end up,” claimed Bunch. In short, the Honda TRX450R has a better attack angle, and that’s why it’s the preferred machine for desert racing. Bunch continued, “So, we like a 3/4-inch stagger front to back on average, with the rider on the machine and the arms scrubbed out.” Now, the YFZ450R reacts to hits more like a Honda.

The rear shock linkage that Roll Design currently uses is from Teixeira Tech. “This is a very developed package, and we’ve been working with the Teixeira linkage for about four or five years. We could have duplicated it, but as an industry courtesy, we went ahead and used what Ed Teixeira already had developed,” said Bunch. This suspension package is identical to the setup pro ATV racer Travis Damon used to win the 2024 WORCS Championship.

SETUP WITH ATV-TALK/DUNCAN RACING

With our new suspension boxed up, along with a 1-inch-taller Roll Design steering stem and bar clamp, we loaded the truck and headed to Duncan Racing for installation, which included a few additional parts we’d find there. The shop manager and host of the ATV-Talk podcast, Leonard Duncan, was instrumental in the performance upgrades in part one of this build. While most motor-heads have no problem installing bolt-on suspension parts, searching how to set up toe and camber correctly will get you dozens of answers—and arguments. The job also requires at least two people, as you’ll want a rider on the seat holding the bars straight with the suspension scrubbed out, while another takes measurements and makes adjustments. 

Various styles of riding/racing require different measurements. “For this off-road WORCS-style setup, setting camber for the most ground contact is desired for better braking control and setting up corners, so I only set camber at 1/4 inch on each side,” said Duncan. This puts the angle of the wheels at nearly 90 degrees to the ground. 

While WORCS has some motocross elements, it has more high-speed desert sections where you want steering to track better. Duncan continued, “Too much toe-in will cause the rear end to wander at higher speeds, so I only set toe-in at 1/8 inch.” This is also a better setup for dune riders, while motocross riders will prefer extra toe-in for more responsive turning. 

If you’re not heavily experienced with suspension setup, it’s always better to let the experts do it. Aside from the crew at Roll Design, Duncan has probably completed more Roll/Elka suspension swaps and adjustments than anyone.

BETTER CONTROL AND BRAKING 

With our new Roll Design suspension and steering stem installed, Duncan swapped out the stock brake lines with Crown Series front and rear steel-braided brake lines, which resist expansion for a more robust braking response. The lines are also longer to accommodate our 1-inch-taller Roll Design steering stem.

Duncan also installed a Works Connection clutch perch and lever for quick clutch adjustments in the pits and on the fly. And last, we swapped out the standard handlebar grips with ODI Ruffian 2.1 ATV grips, which clamp onto the bars using an Allen wrench rather than messing with glue.

VERDICT – IT’S LIKE CHEATING!

Our YFZ450R is an entirely different animal! The changes are most noticeable off-road and in the desert at higher speeds. While we didn’t set it up for motocross, knowing we can now change the settings for track riding and different terrains is a luxury. That said, it still corners better than stock on trails, and the hits from rocks and square edges are buffered without any abrupt surprises. Compared to stock, the new Elka shocks prepped by Doug Roll are far softer for off-road use, but give us an infinite amount of adjustability for track use and anywhere else we want to ride.

As taller riders, we also appreciate the extended steering-stem height teamed with the lower pegs built into our DBR nerf bars, which we covered in the November 2023 issue. The changes make seating and standing much more comfortable for off-road races lasting over an hour. We said it once, and we’ll repeat it: when it comes to performance modifications, nothing will make you faster than better suspension.

PARTS & PRICING

ROLL DESIGN/ELKA SUSPENSION

Lobo II MX/DZ/DN A-arms $1795

LTR Geometry Spindle Kit $1495

Elka Stage 5 Front Shocks $2190

Elka Stage 5 Rear Shock $1625

Blueprint Stage 5 Cartridge $195 per shock

Teixeira Tech MX Linkage $160

Roll Design Steering Stem Extended Black $329.95

Roll Design Bar Mount 1 1/8” $174.95

DUNCAN RACING

Crown Front Brake-Line Set $149.95

Crown Rear Brake Line $49.95

Brake-Line Holders $79.95 for 2 pairs

Works Connection Clutch Perch $189.95

ODI Grips $29.95

CONTACTS:

Roll Design/Elka Service: www.rolldesign.com, (760) 731-592

Elka Suspension: www.elkasuspension.com, (450) 655-4855 (Canada)

Duncan Racing: www.duncanracing.com, (619) 258-6306