Key new features
Michael Salven as chief designer, developed this successor of the worldchampionship winning 748. The main new feature is the all new rear geometry which improves rear traction while still keep an excellent rotation and steering in the corners. This is combined with improved accessability and ease of maintanance of crucial parts as the diffs for example.
Other key features of the 748 like big-bore shocks and Xli gearbox will remain unchanged.
Serpent 750; details
Symmetrical chassisplate optimised flex and torsion, in 7075 T6 aluminium, anodised and laser engraved. Chamfered edges for more ground clearance when cornering and countersunk holes. Central slots to mount weight, which can slide into the right position and then secured.
The 2mm carbon fibre radioplate has multiple functions. It holds the fueltank in place which is mounted on 3 alu posts in rubber. On the left hand side the receiver and right side the battery mounts to a nicely shaped carbon fibre plate that connects to the radiotray, sqeezed in right between belt and tank. The radioplate sits again lower on the car , for lower center of gravity. New features include the possibility to mount a second belt tensioner and improved accessability and flex control through a new way of fixing the servosaver.
Central Flex system
The rear section of the radioplate incorporates a nice flex-control system. It consists of 2 machined aluminium parts. The lower one connects to the radioplate supports an the upper one with screws to the upper alu plate and radioplate. You can either run the 748 rigid or with flex . The optional ball-bearings and screws are sold seperate. Testing has shown that flex in the center rear of the car has the most effect and reacts most predictable as well.
750 servo holder
The composite servo holder is unchanged from the 748. It is designed to have both servo closer to the center line of the car and as low as possible. The 2 lay-down low profile servos are seated very close together and mount in a very efficent and easy way. The holder mounts to the radio-tray.
The throttle / brake linkage is same style as used on the 977 1/8 car. A pivot-lever system with an ingenius ball-cup system to the guide the wire and have almost friction free action.
750 receiver box
The composite receiver box is small but holds and protects the most common modern receivers easily. The antenna mounts to the top. The box is securely fastened to the radioplate with a nylon bracket . The box has been moved as much to the inside as possible. On the radioplate a small holder is fitted to accept the plugs of the battery, to act as on/off switch.
Carbon fibre battery-holder positioned between the tank and pipe, for the best weight balance. The battery is easy to strap down with tape to the bracket. Spacers can be used to mount the battery higher or lower depending on the battery you plan to use.
Proven 75ccm nylon fueltank with transparent material to easy see fuel-content. Large springloaded quick-fill cap with seal with large tank opening for fast and easy refills. The bronze sintered filter will keep fuel clean and make sure tank will empty till last drop if needed. Fueltank sits very low in the car for low center of gravity. Fueltank is mounted with clips on 3 alu posts with rubber buffers.
Low bigbore shocks
Coated threaded shockbodies in high quality aluminium. Supersmooth x-ring / machined bushing package, to guide and seal the spring-steel piston rods. Precision machined pistons included in 3 types. Threaded pre-load shocknuts in alu with o-ring inside. Light but strong nylon spring-cups. Selected, matched and paired shockabsorber springs with color coding.
Front bumper and bodymount
The new front bumper has an improved aerodynamic effect and excellent protection. Medium or small foam bumper pad can still be fitted as optional. The upper carbon fibre bodyplate mounts to the front bumper with alu post and secures the front bodyposts
Superlow 3.0mm carbon fibre shocktower with 3 positions for upper shockmounting. In the centre you can mount the 3rd bodypost as needed.
A compact and superlight structure of topquality aluminium parts consist of top-brackets, L and R equal bearing brackets, lower suspension bracket front. The open style design allows for very fast parts exchange as needed, like belt, diff or anti-roll bar. Also te upper bulkhead are now split-design aluminium brackets. A separate nylon downstop bracket secures consistent and easy-to-adjust settings.
New front liwer arms are no a closed-bottom design. Plastic or optional carbon covers provide adjustable stiffness. The strong long double A-arm suspension work with aluminium pivotballs, which pivot in light nylon cups. The arms pivot on the inside on springsteel pins. The upper pivot-inserts are used to change rollcenter. Easy to access and change ride height, front width, toe-in, caster and camber.
Very strong composite steeringblocks with 2 Ackermann positions, L and R use the same . The steeringblocks feature inserts, which allow to change the kingpin inclination to a leading or trailing position. The steeringblocks also allow use of the optional carbon fibre aero disks to be mounted for less flex and a more direct steering feel.
Wheelaxles / cvd
The spring-steel wheelaxles are seated in high speed bearings. The light and durable spring-steel cvd’s bring all the power to the front and rear wheels. Wheels are mounted to orange anodised high grade aluminium hex-adaptors using flanged wheelnuts.
Anti-roll bar front
The ballraced wire type anti-rollbar in the front is really easy to access and change for other type or thickness as needed. The anti-roll bar is linked to the lower a-arms with a unique pivotball/cup system, which provides direct and smooth operation and is easy to set and adjust.
Servo-saver / steering
The servosaver is now fixed differently on the top. It can remian fixed in the car when tje radioplate is removed. This also improves tweak of the car. Two different inserts allow 2 ackermann settings. Due to the open design the linkages with L/R threading can be reached easily. The whole system allows for very precise steering and minimum bumpsteer.
Middle shaft holder
Machined 2 piece aluminium middle shaft holder, which securely holds the spring steel middle shaft, and doubles up as holder of the pipe-mount.
Very rigid but open rear end design with a composition of machined alu brackets, allowing for easy maintenance. The differential brackets, L and R equal, are toothed and seat the excentric bearing holder, which allow for setting the belttension. The new designed rear bulkheads made it possible to use super narrow rear lower pivots for improved traction and rotation. Also the acces to the diff is now possible without removal of the belt. The machined aluminium lower suspension brackets have roll-center inserts with 2 positions to choose from.
The 2-speed gearbox shaft holders are all new. They are lighter than the previous versions. The right hand side is also carrying the complete new brake system which is similar to the one if the 988 and super easy to maintain. All topquality machined parts with anodising and laser-engraving.
The new brake system is fixed with only 2 screws and allows for easy access and maintenance. The superlight disk allows for smooth and even braking, and the open system avoids overheating. The ball-raced excenter and lever gives a very smooth and direct brake-feeling.
Rear carbon shocktower and camber bracket
The low 3.0mm carbon shocktower has 3 upper mounting position for the shocks and it mounts the body-posts. The camber bracket offers 8 positions to choose from, 4 inner and 4 out holes. The shocktower is prepared to mount the extra body-protectors, which are optional.
The lower rear composite arms are a new design and as the front arms the bottom is closed. With a plastic or carbon top cover the stiffness is adjustable. They are quite a bit longer than the arms on the 748 and create a wider set-up sweet-spot with more grip and more steering. The upper camber rods connect to the carbon camber bracket with 8 mounting positions for roll-center and the camber rod is easy to access and has L/R threading for fast changes. The aluminium pivotball system allows for fast changes in width and toe-in. On the lower inside the wishbone pivots on springsteel pins, which seat with roll-center inserts in the anodised alu suspension brackets.
Uprights / wheel-axles
Durable medium type composite uprights, which seat the wheel-axles bearings. The upright offers the mounting position for the steel camber-rod with L/R threading. Rolll center chnages can be made on top of the upright with shims. The upright can be mounted with the optional carbon fibre aero disks for more rear grip and straight line stability.
Wheelaxles and driveshaft
The durable spring steel wheelaxles combined with spring steel driveshafts bring the power from the gear-diff to the wheels. Wheels are fitted on high grade anodised alu wheelhex adaptors and secured with flanged wheelnuts.
Anti-roll bar rear
The ballraced wire type anti-rollbar in the rear is really easy to access from the top and change for other type or thickness as needed. The anti-roll bar is linked to the lower a-arms with a spring-steel rod.
The compact, durable and lighter gear differentials are the proven design of the 748. Precision moulded steel gears, 2 small 14T and 2 large 28T ones. The very durable and light spring steel lightened diff-adaptors connect to the driveshafts. Front and rear geardifferential share the same internal parts.
Spring steel, light and very durable CVDs used in the front and rear. Precision mounted hard steel pins
Precision moulded super-true pullies, which feature holed sidewalls to let debris move out easier. Light and durable.
Low friction Kevlar reinforced belts with fine pitch. Longlasting and smooth.
Ball raced belt-tensioner, machined from aluminium and can mount on top or below the radioplate. With the new design radioplate its possible to mount a second tensioner for improved belt tension.
Gear-box SL6 - Xli
The well proven SL6 gearbox has been redesigned and lighter. Smaller bell, adaptor and shoes reduce overall weigth and rotating mass, so lower intertia. Durable and longlasting gears. High quality bearings. Very grippy smaller springloaded 2-speed shoes, easy to set.
True Motion Centax clutch
Serpent invented the Centax clutch in the mid 90-ties, and all brands followed it. Small improvements are found to make the original system even better. The True Motion Centax has a flat flywheel, and the taper part on the pressure plate. This allows the flyweights to work even better. The hard anodised aluminium flywheel has 4 holes to have easy access to keep the flywheel in position when setting the pre-tension. The flyweights are made of topquality teflon and feature an additional hole to use grubscrews to make them heavier. The red friction clutch shoe is very grippy, and works excellent with the steel clutch housing. The hard anodised gears screw onto the threaded steel bell.
The light machined and anodised engine mounts perfectly seats the engine, well alligned with the gearbox. Small adjustment can be made to move the engine closer to the gearbox.
Manual / set-up sheet
The 750 comes with a full color assembly manual, with easy to follow assembly steps. The manual also includes exploded views section showing all part numbers, and a full parts-list, showing also all optionals. The kit includes a default and blank set-up sheet. Editable sheets are in the Serpent website.
The 750 includes one sheet with Serpent generic logos and one with 750 logos. Decals are very thin material and come pre-cut.
The 750 comes in a strong, small carton box with nice graphics. The packing of the bags follows the steps in the manual.
Designed by World and European Champion Michael Salven and tested by world champion Dominic Greiner.