The valve length on the disc is 60 mm.
For the bento it really depends on your race distance an nutrition needs.
Short course FC35 upfront. Next best choice is BTA single bottle.
For 70.3 it depends on how you take your nutrition. FC35 with bento is best.
If you are using the Profile Design FC35 hydration the bento box will not hurt you. Boxes will nest nicely behind the storage portion of the hydration. If you are using a standard BTA then the bento box is not the best solution.
For long course our testing showed a FC35 up front with bento behind and a delta 300 behind the seat worked best (if you need that for concentrate).
Edit: For FC35 use the extensions that come with the hydration (use the mount upside down) and mount as low as possible and as far back as possible (up against the bar) with bento forward just behind the back of the FC 35.
Dan Kennison
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