Motard Update – Aug 2015

Some good news, a delivery arrived with the fasteners needed for the sprocket and brake bracket. Nice black finish high-tensile metric capscrews and countersunk socket screws.

Some bad news, I dis-assembled the RS caliper and found that I may not be able to simply drill and tap the second boss for the banjo fitting to allow proper brake bleeding whilst the caliper is installed on the bike as it doesn’t have dual cross-flow galleries. I will be popping the pistons out to see what the internal passages look like to see if it is possible to machine the required galleries.

The pistons are also sized so that the trailing pistons is larger in an effort to even out pad wear. This isn’t critical as some manufactures size the leading pistons larger to reduce pad wear. Either way the only downside is a possibility of uneven pad wear.

So the options at the moment are:

  • Build as planned using the RS-125 Caliper and machine the M10x1 hole for the banjo / bleed fitting (if the internal passages allow).
  • Build as planned using the RS-125 Caliper. Bleed the brakes off the bike before mounting. Not a great option but allows use of the Rs-125 4 piston caliper.
  • Find another front left hand caliper and make a new bracket. Would mean scrapping the current brake bracket and making a new bracket.
  • Make a bracket that uses the CRM-250 caliper. This is common with motard conversions as it doesn’t require bleeding the caliper or swapping many parts but it does require a dog-leg type bracket. This is my least favourite option as the dog leg bracket isn’t the strongest design however it would be fine for testing of the bike with the new wheels to see if the suspension and steering geometry works well together.

This happened because I made an assumption that the caliper could easily be reversed and tapped. This may be the case but won’t be known until the pistons & seals are removed. This should have been done at the planning stage.
Lesson learnt.

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