Sidecars
On this page you can download information regarding sidecars for the 2008 Isle of Man TT.
For more information contact the TT and Motorsport Office by emailing iomtt@gov.im or calling 01624 686834.
You can download the sidecar machine pre-inspection form for the 2008 Isle of Man TT. The form must be completed in full.
Download the sidecar machine pre-inspection form in Adobe PDF format. Requires Adobe Acrobat Reader from Adobe.com
The organisers have also released a clarification for sidecar competitors. The clarification reads:
TT 2008.
Bulletin 1 – Sidecar Clarification.
Please replace the article 1 in Appendix B – Sidecar Specifications with this version .
1 Engine Types
The only permitted engines for this class are:
1. Up to - 350cc, 2 stroke, twin cylinder
501 - 600cc, 4 stroke, 4 cylinder, Production based
Rotary engines are not permitted.
2. Over-boring is not permitted.
3. Induction systems:
Up to - 350cc, 2 stroke: 39mm maximum carburettor choke size
501 - 600cc, 4 stroke Carburettor Engines: Any carburettor is permitted.
4. 501-600cc four-stroke Fuel injection engines: Fuel injection systems are permitted using only the throttle-bodies as homologated for the engine concerned. Where fitted the secondary butterflies or slides cannot be removed.
5. The injectors must be standard units as on the homologated engine.
6. Variable length intake tract devices that function while the engine is operating are not allowed.
7. Butterfly cannot be changed or modified. Where fitted the secondary butterflies or slides may be locked in the fully on position.
8. Any fuel pump may be used.
9. Homologated pressure must remain unmodified.
10. The fuel ignition ECU and Ignition Control Unit may be changed.
11. The airbox intake sizes are as follows
If 1 intake is used a maximum of 103mm I.D. is allowed.
If 2 intakes are used a maximum of 73mm I.D. per intake is allowed.
Or equivalent areas if none circular section/s are used measured within 50mm of the point of entry into the airbox.
For Clarification Purposes please read this additional information in association with the current 2 in Appendix B
Please see
Fig 1 – at the end of this clarification.
Chassis/frame diagram to the F2 specifications section as it is referred to in this version of
2 General Construction.
2 General Construction.
The main frame (See Figure 1A) must consist of a minimum, of a steering head, a frame to accommodate the engine, and a main spar to the chair wheel, which will be made from good quality steel tube. The steel tubing used for the construction of the frame may be of a circular or none-circular section. If circular, the outside diameter shall not exceed 4 inches. If none-circular, the maximum cross section shall not exceed 4 inches measured at right angles to any flat face. These three components must be permanently fixed by welding or brazing.
MONOCOQUE CHASSIS'S ARE FORBIDDEN.
The rear swinging arm outer pivot housings (See Figure 1B) may be detachable from the main frame, the pivot housings must be made from either steel or a suitable solid aluminium alloy billet, the finished article if made of aluminium alloy must be Hard Anodized
THE USE OF CASTINGS FOR THE OUTER PIVOT HOUSINGS ARE FORBIDDEN.
The chair wheel upright or flange plate (See Figure 1C) at the end of the main chair wheel spar may be detachable, the upright or flange plate must be made from either steel or a suitable solid aluminium alloy billet, the finished article if made of aluminium alloy must be Hard Anodized, any supporting tie rods to the upright or flange plate must be made of steel.
THE USE OF CASTINGS FOR THE CHAIR WHEEL UPRIGHT OR FLANGE PLATE ARE FORBIDDEN.
The chair wheel stub axle housing (See Figure 1D) may be detachable from the chair wheel upright/flange plate, the housing must be made from either steel or a suitable solid aluminium alloy billet, the finished article if made of aluminium alloy must be Hard Anodized
THE USE OF CASTINGS FOR THE CHAIR WHEEL STUB AXLE HOUSING ARE FORBIDDEN.
Reinforcement to the steering head is allowed but if the steering head is to be "Fully Boxed In", a maximum measurement of 12 inches (305mm) can be measured from any point between the top and the bottom of the steering head spindle centre line (See Figure 1 X X). Should any lightening or inspection holes be added to the "Fully Boxed In" section, they will be deemed as still "Fully Boxed In" and not open.
The front forks is to be either a leading / trailing fork, or links with the wheel equally supported on each side. The construction of the front forks and yokes must be made of good quality steel and must be either welded or brazed during construction. The lower loop must be made of good quality steel.
The rear-swinging arm must be made of good quality steel, single sided swinging arms are allowed, and must have minimum of 20mm of travel in a single plane. The rear swinging arm pivot spindle must be 90 degrees to the fore and aft centre line of the rear wheel. The swinging arm must either be welded or brazed during construction; the dimensions for the swinging arm are free.
WISHBONE TYPE SWINGING ARMS FITTED TO MONOCOQUE CHASSIS'S ARE FORBIDDEN.
The use of COMPOSITE CONSTRUCTION is forbidden with the exception of the sidecar platform, i.e. aluminium or carbon fibre skinned honeycomb.
The use of TITANIUM in the construction of the frame, front forks, handlebars, swinging arm and wheel spindles is FORBIDDEN.
For wheel spindles, the use of LIGHT ALLOYS is also FORBIDDEN
Under trays must be detachable.
All current frames comply with the above.
Download the clarification for sidecar competitors in Adobe PDF format (requires Adobe Acrobat Reader from Adobe.com) and a larger version of Figure 1.