Steps to Install rear brake calliper on Bonneville series Triumph

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Please read the Disclaimer and terms before proceeding. These operations need to be performed by certified technicians.

The image above shows a Tiger caliper of the freespirits relocation bracket.

In reference to the problem that exists in the position of the rear calliper position of stock bonneville bikes. We did install the Freespirits Scrambler, Bonneville  & Thruxton rear Caliper relocation bracket on our bonneville and we realized that even though the company does provide the mounting instructions on there website that is just one part of it for Bonneville owners. This is majorly because of the design of the stock callipers having the bleed valve located on the top and the difficulty in bleeding them once they are relocated to the new position .

We are going to be a briefly repetitive (please read the manual for photographic steps) on the first few steps but the part specific to Bonneville will highlighted in blue for comfort. Here are some things that you will need.

  1. Allen wrench 5-8 mm.
  2. Open end box wrench 8,12,14,19,24 mm
  3. Torque wrench
  4. Medium thread locker
  5. Scissor lifter
  6. Rear lifter
  7. Dot4 Brake fluid
  8. Small stool or box about one ft height
  9. Ring Spanner 8mm for bleeding
  10. A pipe for disposing the brake fluid and a container
  11. A few pieces of cloths to soak spillage as DOT 4 is corrosive
  12. Bleed Kit ( we will expand on this soon)

We shall split this into two parts, 

  • Installation of the caliper relocation bracket. 
  • Mounting the caliper on the bracket with or without brake line fluid bleeding.

 

IMG-20150129-WA0006

Installation

  • Place a scissor lifter under the frame to support the bike.
  • Remove the OEM banjo bolt
  • Remove the rear tyre and then the OEM brake caliper.
  • Carefully release the torque in the banjo bolt, but do not loosen to let brake fluid leak.
  • Remove calliper mounting bolts and remove OEM rear caliper bracket.
  • Insert new bracket included on kit.
  • Put back the wheel axle, restore the correct tension and fasten.
  • Take care of the chain tensioner bolts.
  • Please do not connect the caliper to the new bracket just yet.
  • Read on and choose how you would like to go about the next steps of installing the OEM caliper on the new bracket ( whether with or without bleeding)

Mounting the caliper on the bracket without brake line fluid bleeding.

Disadvantages:

  1. Brake line will be twisted and under constant stress. 
  2. Brake line guide on the swing arm will pull the brake line down. 
  3. The brake line routing under the master cylinder adds to more stress in stock routing direction . 
  4. Crush washers loose their property and you might have to torque the banjo by 1 or 2 Nm more than the specification.

Advantages: 

  • Easy install. This is the method that allows you to do this entire relocation, without bleeding the brake lines.

Method:

  • With surgical precision, twist the brake line and install it in the new bracket. 
  • Take care that brake fluid does not leak,do not loosen the banjo too much and lastly take care the brake line is not getting trapped in between the rear shock absorber springs.

Mounting the caliper on the bracket with bleeding

Disadvantages:

  • Takes too much time and skill.

Advantages:

  • Reduced twist and tension in the lines.
  • Longer untwisted life of the wire
  • Most importantly, peace of mind.

( Blue part is for understanding why we can’t bleed the lines once installed on the new bracket)

  • The bleed valve of the calliper is designed to work only in the stock position. That is when the ca
  • When you move the callipers to the new location i.e upside down the bleed valve now is facing the bottom. The bleed mechanism doesn’t work well enough for you to get the breaks working. If you install the calliper in the new location and try to bleed it you will encounter the difficulty of bleeding the fluids with the air bleed valve at wrong position, which may lead to spongy feel or poor braking .
  • The solution :  The only way the bleed mechanism will work is to bleed the brake lines by holding the caliper in the stock orientation i.e the brake bleed valve facing up. 

Method:

  • Remove the break line from the banjo bolt to reroute the lines. You will need cloth to clean the fluid spillage. 
  • Reroute the brake line: You should take into account re-routing the lines from the master cylinder and guiding it behind the battery compartment. Also take into account removing the brake line guide and then routing the line under the rear shock absorber. The brake lines should be away from the springs. In principle the brake line should not be twisted or under any tension.
  • Once your brake lines are routed to your satisfaction, mount the brake line to the caliper and use the stock banjo and tighten to correct torque value ( When reinstalling a banjo nut, you must use new crush washers, do not reuse the old ones ) Now to start the bleeding process:-
  • So now that you have connected the brake lines.  We need to  keep the the caliper in the stock position(not location)  to bleed the brake line correct ? Here is what we do.
  • There are two parts to it beginning with the bleed.
    • The gap between the brake pads. When you bleed the system the brake pads will come together and to make sure you can put them back easily without damage once the bleeding is done put something between them. Something that is even and doesn’t damage the pads something like wood, a deck or cards etc.
    • The location of the caliper when you bleed it needs to be higher or at least equal in height to the brake fluid master cylinder. ( Why do you do this? Air bubbles tend to get trapped in pockets when you orient the air bleed valve to the bottom position. It is like holding a half filled bottle upside down, you get the air bubbles at the top. In order to have a very effective hydraulic system, there should not be two fluids, so use judgement to get air bubbles out by orienting the caliper in such a way that the air bleed valve is at the highest position. ) Here is what we did. We took a  stool and kept the caliper on it.

Images:

Below show sample of wood being kept between padsIMG-20150208-WA0020Stool being used to keep the caliper 
IMG_20150209_124132Below: Deck of cards between the pads ( instead of wood this time)

IMG_20150209_124607Below: Another angle IMG_20150209_124620 (1)

We bleed the lines in this position… After brake bleeding has been done in this position. We increase the gap between the pads and fix them again.IMG_20150209_125100

Final Steps

  • Secure the OEM caliper on to the new bracket with the new bushes provided.

IMG_20150208_140137

Check the system and give it a trial. Your done.

OEM Caliper for Triumph BonnevilleThe image shows the Tiger Explorer caliper. The top centre is the bleed valve. If you do decide to get this the bleed valve will be facing up for the bleed system to work. ( It fits like a charm on Bonneville and has dust protector and air bleed valve at the top once installed on the new bracket.)

 Notes

  • Any shock up with the gas container being installed with the springs being upwards and the shock case being downwards will obstruct the calliper you may have to invert them if the shocks allow that.
  • Once you relocate the calliper you will realise that there is a hole under the calliper which after relocation is above. You might want to close this to protect it from the elements.
  • Tiger Adventurer has awesome calipers. They can be mounted on the bonneville. They have dust protection built in and and mostly the bleed valve is located on the top.
  • Make sure the brake fluid line is safely secured as now it may be exposed near the shock up/suspension coils
  • Read our article on how to bleed the brake line.
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