Kids DH Bike Part 5: Choosing the right brakes

When it comes to choosing the right brakes for a little downhill rider, I recommend that you evaluate both Trail and Downhill (DH) brake caliper options.  A rider that is lighter and often times slower just doesn't require the same braking capacity that full sized professional riders do.  There is weight and money to be saved here, and both of those are important considerations when building a bike for a Little DH'er. Let's start this topic by discussing downhill bikes and what bicycle manufacturers choose for a brake spec. This is what you will deal with if you're buying a complete bike spec'd by the manufacturer.  A typical off-the-shelf DH bike will come with the most powerful braking system available and the most sophisticated heat management features. These systems have brake calipers with four ceramic pistons and large brake pads to ensure high power, a strong initial bite and good heat management.  On some models, there will be a smaller diameter pair of pistons located towards the rear of the caliper to improve modulation, but the system is still designed manage the conditions full sized riders demand. These systems are heavy, expensive, and designed to handle the toughest conditions - think UCI Mountain Bike Pro Downhill. Considering this - brakes are one of the aspects of a custom bike build were I recommend you look to trail-spec components for your little DH'er. A Trail brake will typically have only two pistons and in comparison the brake pad surface area is substantially smaller than downhill pads.  This smaller size is based on the fact the trail rider is not expected to need as much braking power, nor generate as much heat as their downhill counterpart.  That said, even though the dimensions are smaller, the caliper will still have ceramic pistons and metallic pads (not resin) with integrated radiator fins for heat management. These features will ensure the brake performs in the conditions downhill riders face.  The whole point here is to take the features you need for downhill conditions, but not the ones that only heavy, very fast riders need.

 

In our 2013 Specialized Demo 8 XS Build, the original choice I made was to use downhill brakes - the Shimano Zee.  These brakes were great, they always did their job, and we didn't think to be critical of that choice.  It seemed natural, downhill bike = downhill brakes. But there was a point during year two that I decided to conduct a bit of an experiment and change to Shimano M785 (trail) brakes.  The purpose was two-fold:  1) to save a bit of weight and 2) save money during pad changes.  Here are the figures:

  1. Weight savings:  60 grams
  2. Cost difference for a set of (2) brake pads MSRP: $42.99 vs 55.99
  3. Cost difference for the entire brake system (MSRP): $140.00 vs $220.00
  4. Overall savings year 1:  $145.  That's based on saving $120 when you buy the brake system + $25 less for a complete set of pad front and rear.  $145 Savings.

Here is the rider feedback: I changed these brakes in the second half of Ben's 3 year period riding this bike without discussion. He didn't even really notice. He never complained about any diminished braking performance and there were never any indications of overheating even on long fast runs down the Western Territory at Snowshoe.  Then fast forward to current day and his first experience riding on his 2016 bike. I asked him how he liked the Shimano Saint brakes on his Transition TR500 compared to the XTs on his Demo 8.  Funny thing was he said he liked his XTs better.  To add a bit of color to that feedback - that was from riding at Bailey Mountain Bike Park during a race weekend on a very steep trail system.

Bottom Line:  while it is tough to prove the statement trail-spec brakes are actually better for an 80-140 pound rider - it is our opinion here at DoubleBlack Bikes that is the case.  We also like the price point and weight advantages - and those are easy to quantify.