RS500GP Engine Mounting Cradle Kit
| Above is the cradle kitset, comprising: |
| LH and RH cradles |
8 x M8 nuts for the mount bolts, comprising:
4 x short M8 bolts for the top cradle mounts
4 x long M8 bolts for the bottom rear cradle mounts |
| 2 x M10 nuts for the front and rear main bolts |
| 4 x fat M10 washers for next to the rubber bush tubes on the engine. |
| 3 x M10 washers, 1 for under the nut on the front mount bolt, the other 2 for under the head and nut on the rear bolt |
| L & R rear engine mounts |
| 17T 18.6mm offset sprocket |
| Front engine mounting main spacers - LH and RH |
| Engine tie rod system, comprising central adjuster bar; LH & RH thread rod ends & locknuts; rear brackets with round-head cap screws, nuts and washers; under-engine bolts and spacers and washers |
| Long front engine bolt with non rotation plate |
| Rear engine mount bolt - 120mm long |
| New stainless steel shift rod, with CNC machined shift rod lever; forged rod end, CSK screw and nyloc nut (plug and play with existing Aprilia RS250 rearsets) |
| |
4 x short M8 bolts installed - top cradle attachments.
Note: front engine mounting bolt has a non-rotation plate that is installed as shown in the picture.
This bolt can be put through from the other side if desired.
PLEASE NOTE: The CNC ends of the cradles are bored with holes that are a 'dead fit' to the mounting bolts; this is important because we are using the cradles to arrive at the correct position for the engine. Thus there is virtually no bolt 'play' in the cradle mounting holes.
This can make mounting of the cradle tubes a little tricky; as there can be tiny alignment variances brought about on the opposite side of the tube as bolts are rotated into position. Typically the way around this is to start off with one bolt in either end of the cradle tubes, wriggling and threading the bolts in together ... even better if you have a friend to help!
It may look at times like mounting holes are out of alignment, but it's just a function of the bolts being a 'dead fit' in the cradle holes, and the interplay between the threads and tiny little variances brought about when you rotate the bolts. It just takes a little fiddling around to get the alignment right and of course, a tiny variance at one end can blow out to half a hole's alignment error at the other.
You will notice that the OEM Aprilia cradle has mounting holes that are far larger than the bolts, this is done for ease of assembly. But because TSS is using the cradles to align the engine in a precise location, we don't have the luxury of being able to assign loose tolerances in this case.
If you ancounter any issues, please feel free to get in touch with Steve or Wayne at TSS - contact details can be found by CLICKING HERE. |
Sabre saw and 5" flat flap wheel used to cut and tidy up rear engine mount removal.
5" flat flap wheels - coarse work with the sanding wheel at right, finer work with the Scotch-Brite type disc at left..
This picture shows the relative positions of the new rear engine mounts to the old ones; with front engine
mounts in place and lightly tightened, and the engine allowed to swing downwards to illustrate positioning.
IMPORTANT NOTE: Make life easy for yourself by fitting the rear engine mounts and bolt/nut first, before putting the engine into the
frame; as it is difficult to feed the rear engine mount bolt in once the engine is in situ. |
Looking at the rear mounts sat in place, the front spacers set the position, thing to note is the thick washers between the mount faces and the thin tube exiting the engine bushes. Depending upon the weld thickness to the left, a little material may be needed to be removed at an angle on the left mount in this pic ( frame is upside down).
Positional check is done by sighting down on the outer faces of the engine BOTTOM CASE - they should be equidistant from the inside faces of the bottom cradle mount tabs, on the frame.
IMPORTANT NOTE: To make the job of removing the engine smooth and easy, ALWAYS remove the front engine mount bolt and both cradle tubes FIRST - leaving the rear engine mounting until last. Then remove the rear engine mount nut and inner thick washer, and push the bolt far enough out to enable the engine to be rotated clockwise (looking from above with the frame upside-down, as in the pic below) and this will allow the exit of the shouldered bolt head through the bolt access hole on the right hand side of the frame. |
View showing engine rotated clockwise - which allows entry/exit of the rear engine mount bolt
through the right-hand side bolt access hole (as the engine and frame are both inverted.)
View of cradle and front engine mount setup (with engine and frame inverted), showing
position of
spacers and two thick washers.
The two thick
washers are there to protect the
spacers
from the thin tube
bush
wearing into the engine mount faces.
(Below: Zoomed-out view of pic above .... )
Looking at the cradle with spacers mounted on the front engine mount - the two thick
washers are there to protect the spacers from the thin tube bush wearing into the engine mount faces.
Engine tie-bar arrangement:
Centre adjuster bars threaded LH thread one side, RH thread on the
other side
to house LH and RH thread
rod ends.
Adjusters are tensioned equally against each other to provide positive location for the engine, i.e. to
prevent 120 crank horsepower from causing the engine to yaw or pitch in the chassis.
RS500 Modified Rear Shock Linkage and Dogbones
 |
 |
| Stock Aprilia RS250 rear shock linkage & dogbones |
Modified RS500 rear shock linkage and dogbones:
Centre bearing tunnel of shock linkage is trimmed (specs below) and replacement stainless steel dogbones installed in order to make room for the peak 123mm Outside Diameter of the RS500 expansion chamber exhausts, while allowing for racing lean angles/ground clearance. |
The Two-Stroke Shop
Wayne Wright and Steve Rothwell
9 Compass Close, Edge Hill
Cairns 4870
Tropical North Queensland, Australia
Tel. (In Australia): 0427 774 285
Tel. (Outside Australia): +61 427 774 285
Web: http://www.twostrokeshop.com
Email: offbeat@iinet.net.au
