A number of people who own the GT186 have had their reeds break. There has been a number of theories as to why, but one cure is to double up on the reeds. Another solution is buy a set from Darrell Taylor of Taylor Tuning. He is supplying reeds for the GT kits.
The standard thickness for the GT reeds is 0.28mm. The Taylor Tuning ones are 0.40mm in carbon fibre for the GT reed Blocks.
Darrell also supplies reeds in different thicknesses and for various reed blocks
You can contact Darrell on the Taylor Tuning FB page