Part 6: Building a Kids 20inch Full Suspension MTB
Brakes. It was always my intention to get the kids disc brakes as although the standard V-Brakes on kids bikes are generally fine, my kids wanted to do downhill events and hence we needed superior stopping power.
Cable Operated Disc Brakes setup
I thought I would try out Cable Operated Disc Brakes first as they are generally cheap and I didn’t yet know how to correctly setup/bleed hydraulic brakes.
I went for the cheapest but decent quality ones I could find and so opted for Clarks CMD-21.
Fitting is really easy as I could thread the new brake cable in the same places as the original V-Brakes. The bike frame also had holes ready cut for the fitment of disc brakes. I could also use coloured brake cable (which is most important for kids!):
However issues started occuring when being used. There seem to be no end of adjustments, either brakes too tight (wheels not spinning freely) or too loose (too much brake lever pressure needed). So I decided to ditch them and install a set of hydraulic brakes instead.
Hydraulic Brake Disc setup
When looking for a set of hydraulic brakes, the main issue was most setups where for adult bikes, so the brake levers where massive. However I had some short levers on my Trek Fuel EX7 which where the same size as the junior cable levers. So I found a set of Shimano M395 and BR-M395 on Ebay to use (fairly cheap at only £30 for the pair including cables and pre-setup) which had the same short levers:
Although the cables where designed for an adult bike I actually didn’t need to cut them which was a relief (although I had bought a cable cutter and new olives just encase).
The other main problem was how do I attach the hydraulic cables to the existing wire cable guides as the hydraulic cables where a lot thicker. This was dealt with by using JagWire 3m Stick on Cable Guide, which actually worked out really well:
So I did a quick bleed of the brakes to make sure they where topped up correctly, and adjusted the reach of the brake lever so a bit closer for little fingers:
Fully setup the difference is like night and day. So much more stopping power and they need far less strength in their fingers to brake efficiently.
