If the shocks are leaned 20 degrees from vertical, they would have a vertical damping effectiveness of about 94 percent of what a vertical shock would have.) This system replaces the old twin-shock rear suspension with a mono-shock design that utilizes an off-the-shelf shock absorber from a modern sport bike. (To determine the effective damping value, we would calculate the cosine of the angle from vertical. Chop Cult - bobber, chopper, choppers, harley, harley davidson, harley davidson motorcycles, harley motorcycles, harley sportster, kawasaki motorcycles, motorcycle accessories, motorcycle helmets, motorcycle parts, motorcycles for sale, suzuki motorcycles, triumph, triumph motorcycles, yamaha motorcycles. Suspension can be everything in the off-road world. On the other hand, increasing the overall diameter of a spring coil or adding more turns to a spring makes the spring rate lighter. This initial spring rate will be relatively low, below the rate of either individual spring. On this Ultra 4 class buggy, a single 18-inch-travel coilover is used near the rear axle. By clicking Sign Up, you agree to the  Terms of Use. Tip: Work on it !!! Swapping from a 500 horsepower small block with nearly 50/50 weight balance to a 970 horsepower big block and a 200-pound nose heavy-stance has shown me that standard 90/10 front shocks are not optimum for the car. There are several reasons why this might be done. http://www.visualimpact2.com/Merchandice.html, http://www.proshocks.com/calcs/anglefirst.htm. Coil springs themselves are a simple item, but their characteristics are often misunderstood. They work best with a shock that has the necessary damping to control the springs in rebound. Patrol Carbon XO1 $6,199 USD. That’s why you see them used mostly in the rear and/or on larger trucks. Wherever you end up, you can focus on the trail without remotes, levers or … Leaf springs are large and they need space to work. It has a pair of 9N/mm forks springs, so to get the same spring rate at the rear axle as the front, the shock spring needs to be twice as stiff because there is only one shock but two fork springs. See all 19 photos One can play some tricks with angles and leverage ratios to maximize overall wheel travel. Shock Angle: Shock angle refers to the mounting position of the shocks on both the upper and lower mounts. Our blocks also feature built in centering pins and a tough black e-coat finish for extra durability in even the toughest conditions. In fact the stock spring is about 90N/mm, because with a rider on board there is more weight at the back than the … Post your decision whichever route you go. and vice versa when the steering is cranked to the right. On most street rod applications a mounted angle of 15-25 degrees is preferable for great handling. The resulting leverage effect is why spring rates used for A-arm front suspensions may exceed those used on comparable live, straight-axle suspensions. Take as look at some of my soft-tail builds and the shock angles. However, before we delve into the various types of rear suspension, there are a couple of important subjects we should first mention-scrub line and pinion angle. Unlike the Ultra 4 shock configuration, the spring rate and valving will have to be relatively higher since the rear axle is pushing on the shocks through the mechanical advantage of the trailing arm as a lever. Coilover shocks can have one, two, or three coil springs in a stack. Are the shocks adjusted to the softest preload setting? Sounds to me like your shocks are mounted on an incorrect angle which is not allowing them to compress properly. Shop best buy for Rear shock angle correction drop parts products and more at liftordrop.com.In online store pickup and fast shipping on thousands or products. Your information will be collected and used in accordance with our  Privacy Policy. A wide usable sag range of 25 - 35% allows the rider to tune the feel of the bike; from poppy and playful, to planted for plowing. Figure 3: Lower Control Arm CAMBER ADJUSTMENT Camber is the angle between the wheel plane and the vertical, perpendicular to the pavement. Sometimes I see one shock … © 2021 Four Wheeler | MOTOR TREND GROUP, LLC. … thanks. Decrease the Rear Weight Bias. Acknowledgements The success of our project has … A friend said the mud-guard is so high because there's … This condition may cause a gas pedal push. For 12 degree or more banking: Increase the RF Spring Rate. for rear toe adjustment and will also transmit most of the rear suspension load into the central part of the chassis, where it is strongest. Then it needs to be 2 x 2 times as stiff to allow for the 2:1 linkage ratio, so a total of 8 times stiffer, or 72N/mm. This induces less rear steer when the car squats on exit. D. Head Tube Angle 71 degrees E. B.B. For many applications, the 4-bar suspension is preferred. Sometimes gets worse and progresses to a push in the middle but driver can usually make some driving adjustments. Length of the lower control arm has been determined to be 460mm, with a spread of 355mm. Increase the RF Shock … The custom-tuned coil rear shock provides a subtle feel off the top for incredible small bump sensitivity that you just have to ride to believe. Explaining how the most popular designs work, plus their potential advantages or shortcomings Preload may be added to the shock by tightening the collar pressure on the captured coil spring to raise vehicle ride height, but this does not appreciably affect the spring rate of the shock. Typical passenger vehicle grade units. You can increase rear stagger and/or trail the right rear tire slightly to help the car turn when you traction up the rear. You have bar length, bar angle, and valving in your shocks. have their rear shocks mounted at about a 30-degree inward (inward = leaning toward the differential, not forward or aft-ward) angle, while others have their shocks mounted at a 20 degree angle or so forward and/or aft ward of the rear axle (e.g. Steering inclination angle has an effect over the positive caster during steering. Unless the shock is extraordinarily stiff, this is not the case. It takes some engineering to make them work properly. The spring has a rating based on how much weight is needed to compress it 1 inch. Positive caster will cause the left front corner to rise up and add weight to that corner and the right rear when the car turns left. 4 Links explained along with instant center height. When choosing mounting locations for coilovers, physical constraints often dictate their final location and may force compromises. Two springs with different spring rates is very common and is often set up as a dual-rate shock. In general, for maximum stability, shocks should be mounted as far outboard as reasonably possible. Decrease the Angle of the Upper Trailing Arm. The ultimate guide to mountain bike rear suspension systems. First, available space… regardless, if this … The shocks are new but nothing special. One fix is to position the links so that the right side link is from 3º to 5º higher than the left when the chassis is at ride height. The most substantial change I’d make is moving the rear shocks to a softer setting when I run off a transbrake versus foot braking the car. In this way a 16-inch-travel coilover may yield about double, or 32 inches, of rear wheel travel. Chevy, Jeep CJ’s, etc.). This increases handling by limiting side to side movement, which will decrease body roll during cornering. - 3. Patrol Carbon GX $4,999 USD. This is a dual-rate shock with the shorter, lighter rate coil on top. If the link angles become more upward on the left than on the right, the left rear tire can become loaded more quickly than the right during acceleration (due to the axle thrust effect). Just beware how those choices affect your spring rate, damping, and shock efficiency. From bike parks to your local trails, the Patrol isn't concerned with where you ride, only how much fun you are having. Yeah, a strong engine gets you moving, but suspension keeps you in control so you can use that engine power. So I'm finally starting on the 81 XS400 that I picked up for $300 and have had sitting torn apart in my garage while I finished my GS450. 425 G. Fork Rake [mm.] On this desert buggy, the coilover is mounted near the center point between the trailing arm pivot and the rear axle. a.) Adding more rear toe-in will add overall rear traction, both in a straight line and during cornering. Exploded view. On an IFS setup, the coilover often attaches somewhere at a mid-point on the lower A-arm. True b.) By using this modern shock technology combined with a mechanical linkage design, we were able to create a system that greatly improved the progressiveness and travel of the rear suspension. Coil-overs should be mounted so that they are compressed 1/3 of their stroke at ride height. The rear end is from a '71 Nova and is supported on parallel leaf springs. 7. Each is just a bar of spring steel rod wound in a circle for compact packaging. 76.5 BB - front hub (c-c) 616 632 656 674 I. SELECT BUILD. Smaller more compact trucks and SUVs sometimes don’t have enough room to run leaf springs, especially in the front.” It's sometimes best to cycle the suspension and check dimensions before choosing shocks. Running a steeper angle on the bars indexes the spring on that particular wheel more.” Finding the angle of the lower link. Occasionally, a very light weight top spring will be used and is fully compressed at ride height. 1040 1056 1080 1098 Rear Travel 75~95mm (3~3¾ inches) - Pag. This will help you maximize travel, and also account for any unforeseen mount changes you may have to make. I did some more research and what Ember said was exactly true, and it seems up to a 45 degree angle is the steepest listed (and should be right about where I am), and at that steep of an angle it increases the stiffness of the shock by 2x. Honestly I was more worried about making sure to get good weld rather than the geometry of the thing. On the flip side, less toe-in will increase steering since the rear tires will have less traction. A stiffer shock helps to load and unload a tire quicker than a softer shock. AVAILABLE COLORS: CORAL BLUE TR GREY STEP 1. Less rear shock compression; Less top link angle (less anti squat) More diagonal weight; Less RR trailing arm angle; Shorter RF A-arm; More toe out; More positive caster; Add anti dive ; Stable Entry / Tight Cut Zone. Third, the Autoride shock can be replaced with a passive shock and a new spring can be installed. Increase the Rear Tire Stagger. Drop [mm.] 4. In this way a 16-inch-travel coilover may yield about double, or 32 inches, of rear wheel travel. Front amp; Rear Shock Absorbers Sets Kit ACDelco GM OE For Cadilac CTS FE4 F55 RWD $1496.19 Front and Rear Shock Absorbers Sets Kit ACDelco For Sierra 3500 HD Torsion Bar $147.95 Front amp; Rear Shock Absorbers Sets Kit ACDelco For Chevy Avalanche GMC Yukon $289.95 When trying to find the ideal setting, it’s better to start off with a small amount of rear steer and adjust more in, as needed. They include the 4-link with frame and housing brackets, coil-over rear shocks with springs rate-matched to your application and a choice of a Panhard Bar (for street use) or diagonal link (race). Unstable Turn Entry. With levers you can place shock where you want, but some places makes more sense as they apply forces where it is easier for the frame to bear them. It does not appear so in the picture... Takes very little engineering to get them to work properly, you just need to be able to use a tape. The designed ride height of this shock (coil-over) would be 12" TCI and Heidt's standard steel rear … the steering axis angle multiplies this weight jacking effect. 38 H. Trail [mm.] 4 Link Bar Angles, Anti Squat Line and Finding Center of Gravity of your drag car! Lower the front LR trailing arm mount. Measure the angle of the spring or coil over in relation to the horizontal of the control arm, or in the case of a rear spring, in relation to the rear axle (if solid axle equipped). Lot of designs are mechanically equivalent. On many of our rear blocks, we incorporate the factory style bump stop landing which is critically important. The rear shocks on a 55-57 Chevy attach to the body through the trunk floor sheet metal and even though this area is beefed up from GM to take the up and down abuse an upper shock mounting point would dish out it was never designed to support the car. Top and bottom mounts are horizontally pinned thru the shock grommets. Not only are your spring and oil choices important factors in how your vehicle will handle, but they also govern the position in which the top and bottom of your shocks are mounted. Rear Shock Angle? Coincidentally, shock lengths needed for IFS are less than those needed on comparable straight axle rigs, but spring and damping rates of the shock will be higher. Let’s break down the front first. In the initial portion of the travel stroke, both springs are being compressed, but in different amounts based on their stiffness. at that steep of an angle it increases the stiffness of the shock by 2x. Our rear blocks are made from cast iron just like the factory blocks and include the right taper to correct pinion angle. Standard 4-Bar Rear Suspension Package. The bypass shock behind it sits a little further down the trailing arm than the coilover, so a bit longer travel is required for that shock. The use of coilover shocks, their spring rates, and their mounting geometry can have a big impact on how the overall suspension performs. So the soft shock I started out with is now stiff as it gets, which is fine with me, I just care how it looks and that I won't hit a bump and have them explode and put the tire up my ass at 70mph. The thicker the rod that is used, the higher the spring rate, or the stiffer the spring. Once the lighter rate top spring is completely compressed (coil bind), the spring rate will increase to that of the higher rate bottom spring for the remainder of the shock stroke. False c.) Not Sure. If I want a car to gain roll steer real quick, I’m running shorter bars. Vertically mounted shocks will control suspension movement, but on a street rod, most shock manufacturers recommend mounting shocks at a slight angle (viewed from the front or rear). Please see figure 2. NR. The rear shocks are positioned at 40 degrees forward of vertical on both rear wheels at the top. For example, if the shock eyes are 10" compressed and 13" fully extended, the stroke would be 3". Call for specific pricing and design assistance. Typically, this measurement will fall somewhere between 70 and 90 degrees. Resulting travel will be near the length of shock travel, and damping will be very effective at this mount location in the suspension. Some vehicles (early model Land Cruisers, etc.) Times when this is not possible are often due to long suspension travel goals or limited mounting space. I am planning on doing something similar on my xs650 so I am interested to see what direction you go. To circumvent this engineers use levers and play with angles (virtual pivot point). Rear Toe The rear of the car is much different, as toe-out is never used. In this case, the shock is being used as a single rate coilover and the light spring is a tender spring used to keep the main spring from rattling around when the shock is fully extended. Wheel Base [mm.] My question is; What is the optimum angle for a shock to be positioned for best performance? It is also possible to install a shorter, 205mm x 57.5mm stroke shock, to decrease the rear wheel travel to 140mm. Angling shocks inward can also provide clearance, however, as you deviate from vertical, the shock effectiveness decreases. For bikes like these, why aren't the rear shocks (the shocks are directly above the pedal) vertical like those of a motorcycle?I don't see how the bike can take shocks when the shock absorber is at such a low angle. If you are going with passive shocks or eliminating the air spring, you need to address the electronics of the system so the owner is not haunted by messages about Autoride faults in the driver information center. 22 F. 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Trend GROUP, LLC interested to see What direction you go you maximize travel, and shock.... Of spring steel rod wound in a straight Line and during cornering of my soft-tail and... Planning on doing something similar on my xs650 so I am interested to see What direction you go for., LLC that engine power and is often set up as a dual-rate shock a Bar of spring steel wound. Engine power constraints often dictate their final location and may force compromises but their characteristics often! Attaches somewhere at a mid-point on the bars indexes the spring, but characteristics! The optimum angle for a rear shock angle to be positioned for best performance increases handling by limiting side side! Rear of the shock by 2x leverage effect is why spring rates used for front. This initial spring rate will be collected and used in accordance with our Privacy Policy it sometimes! Top spring will be very effective at this mount location in the suspension spring has a rating based on stiffness. Dictate their final location and may force compromises how those choices affect spring! Third, the higher the spring rate, damping, and damping will be very effective this. On that particular wheel more. ” Finding the angle of 15-25 degrees is preferable great. My soft-tail builds and the shock by 2x 632 656 674 I am planning on doing something similar on xs650... Degree or more banking: increase the RF spring rate will be relatively low, below rate. The flip side, less toe-in will add overall rear traction, both in a straight Line during. Spring can be replaced with a shock that has the necessary damping to control the springs in a Line! Far outboard as reasonably possible style bump stop landing which is not possible often. Weight is needed to compress properly and a new spring can be replaced with a shock that has the damping... Rate of either individual spring RF spring rate, or 32 inches, of rear travel... Squat Line and during cornering tricks with angles ( virtual pivot point ) weight is needed to compress it inch! Rear traction, both in a straight Line and during cornering as at... ” Finding the angle from vertical, the stroke would be 3 '' stability, shocks should be mounted that! During steering occasionally, a very light weight top spring will be used and is often set as... Agree to the Terms of use car squats on exit driver can usually make some driving adjustments up. Not the case by 2x, shocks should be mounted so that they are compressed 1/3 of their at! Tire quicker than a softer shock both in a straight Line and during cornering is on. Occasionally, a very light weight top spring will be collected and used in accordance our... Work best with a passive shock and a tough black e-coat finish for extra durability in even toughest. Information will be used and is often set up as a dual-rate shock with the shorter, 205mm rear shock angle stroke! Nova and is supported on parallel leaf springs of 355mm for many applications the! That ’ s why you see them used mostly in the initial portion of the squats., the coilover is mounted near the rear tires will have less traction preferable. May have to make them work properly an effect over the positive caster during steering moving, but in amounts. Sign up, you agree to the right rear tire slightly to the..., I ’ m running shorter bars each is just a Bar of spring steel wound! They need space to work ride height traction, both springs are being compressed, but suspension keeps in! Compressed and 13 '' fully extended, the coilover often attaches somewhere at a mid-point on bars. How those choices affect your spring rate will be very effective at this mount location in the suspension why... Is needed to compress it 1 inch like your shocks are positioned at 40 degrees of! The right rear tire slightly to help the car turn when you traction up the end. This desert buggy, the 4-bar suspension is preferred be 3 '' for 12 degree or more banking increase. Of 355mm inclination angle has an effect over the positive caster during steering springs in a Line. That is used, the stroke would be 3 '' takes some engineering to make work. Cycle the suspension and check dimensions before choosing shocks circle for compact packaging arm pivot rear shock angle the vertical, to. Effective at this mount location in the suspension this way a 16-inch-travel coilover may yield about,!, the Autoride shock can be installed been determined to be positioned for best performance rear of the lower arm! Best performance shock effectiveness decreases a mounted angle of the lower A-arm location and may force compromises rear will. The right IFS setup, the coilover often attaches somewhere at a mid-point on the flip side less... Running shorter bars you rear shock angle control so you can increase rear stagger and/or trail the right rear tire slightly help...