Mods & Fixes

Bonneville to Thruxton Rear-set Conversion

    This is a modification upon which opinion seems to be a little divided - many hold that it can be done, others insist it cannot. As is often the case in such instances, the truth lies somewhere between.

    It can be done, and very easily too. However, there is one proviso - the Thruxton gear change and rear brake master cylinder assemblies can not be accommodated without first replacing the stock exhaust silencers. In addition, whilst the original Bonneville/T100 header pipes can remain, their replacement with Thruxton headers will make things a lot easier (particularly where the Bonneville left header may limit the travel of the gear change lever). All in all though, even taking this into account, it is a quick and easy job.

    In addition to suitable silencers, here are the Thruxton parts you're going to need:

a - Foot pegs (with pins & springs)
b - Outriggers
c - Brake lever (with pivot bolt & return spring)
d - Gear lever (with pivot bolt, linkage rod & arm)
e - Heel plate
f - Rear brake reservoir, master cylinder, light switch & hoses

    Many of the fixings for these parts can be salvaged from those securing their stock Bonnie/T00 counterparts.

    A more complete step-by-step account of how I did this conversion will be available soon. Meanwhile, here are a few diagrammes relating to the relevant parts.

Bonneville outrigger parts

 2.  Outrigger (RH)
 3.  Outrigger (LH)
 4.  Cap screw (HD, M10 X 1.25 X 23)
10. Cap screw (S/head, M10 X 1.25 X 35)
27. Guide wire (dia 2.5)
32. Plug (M10)

Thruxton outrigger parts

 2.  Outrigger (LH)
 3.  Outrigger (RH)
 4.  Cap screw (HD, M10 X 1.25 X 23)
10. Cap screw (S/head, M10 X 1.25 X 35)
27. Guide wire (dia 2.5)
32. But screw (HD, SKT, M8 X 1.25 X 25)
33. Heel plate (RH)

Bonneville & T00 rear brake lever & master cylinder assembly

 2.  Connector set (O-ring, circlip & union)
 3.  Piston set (spring & piston)
 4.  Circlip
 5.  Push rod assembly (dust boot & rod)
 6.  Reservoir tank
 7.  Hose clamp
 8.  Reservoir hose
 9.  Rear brake switch
10. Washer (15.2 X 10 X 1.0, plated)
11. Banjo bolt (M10 X 31.0 X 1.25)
12. Brake hose
13. Clevis pin (8 X 13.7)
14. Ext circlip (split pin) (8 X 0.89)
15: Cap screw (M8 X 40)
16. Brake pedal
17. Bush (MB 2015 DU)
18. Shouldered bolt (M10 X 1.25)
19. Brake pedal spring
20. Reservoir bracket
21. Bolt (RHHF, M6 X 1.0 X 16)
22. P-clip (8mm ID)
23. Domed bolt (M6 X 16, S/S)
24. But screw (HD, SKT, M5 X 0.8 X 8)

Thruxton rear brake lever & master cylinder assembly

 1.  Master cylinder assembly
 2.  Connector set
 3.  Piston set
 4.  Circlip
 5.  Push rod assembly (dust boot & rod)
 6.  Reservoir tank
 7.  Hose clamp
 8.  Reservoir hose
 9.  Rear brake switch
10. Washer (15.2 X 10 X 1.0, plated)
11. Banjo bolt (M10 X 31 X 1.25)
12. Brake hose
13. Hard brake line assembly
14. Inline brake switch adaptor
15. Bolt (RHHF, M6 X 1.0 X 16)
16. But screw (HD, SKT, M5 X 0.8 X 8)
17. Reservoir bracket
18. Domed bolt (RHF, M6 X 16, S/S)
19. P-clip (8mm ID)
20. Brake pedal assembly
21. Brake pedal bush
22. Shouldered bolt (M8 X 1.25, ENC)
23. Clevis pin (8 X 13.7)
24. Clevis pin clip (8mm)
25. Brake pedal return spring
26. Cap screw (HD, M8 X 1.25 X 25)

Exploded diagramme of Bonneville & T00 frame

 1.  Frame assembly
 2.  Outrigger (RH)
 3.  Outrigger (LH)
 4.  Cap screw (HD, M10 X 1.25 X 23, SLV)
 5.  Cylinder head bracket (RH)
 6.  Bolt (HHF, M12 X 1.25 X 130, 10.9, blk)
 7.  Bolt (HHF, M12 X 1.25 X 172, 10.9, blk)
 8.  Bolt (HHF, M12 X 1.25 X 55, 10.9, blk)
 9.  Bracket (M10)
10. Capscrew (S/head, M10 X 1.25 X 35)
11. Lock nut (Flgd, M12 X 1.25, blk)
12. Cradle assembly (RH, ed & painted)
13. Cradle assembly (LH, ed & painted)
14. Cradle stiffener (link) plate
15. Bolt (HHF, M8 X 1.25 X 16, S/S)
17. Lower rear engine plate
18. Oil cooler bracket
19. Screw (M10 X 1.25 X 30)
20. Washer (M10, form B, S/S)
21. Cap
22. Exhaust mounting pin
23. Cylinder head bracket (LH)
24. Captive nut (U-type, M5 X 0.8)
25. Bung (black, dia 12)
26. Lock nut (M8)
27. Guide wire (dia 2.5)
28. Bolt (HHF, M8 X 1.25 X 35, SLV)
29. Cable clip (14.3 X 10.7)
30. Grommet (dia 13.0 X 1.8, panel)
31. Flanged sleeve (M6, black)
32. Plug (M10)