What are you running into with the Calfee that makes 28mm tire clearance undesireable?
Originally Posted by Geocyclist
- Wound Up vs Alpha Q fork?
- Rear brake bridge clearance issue / need for standard reach caliper?
Has Calfee finalized the design and started fabrication?
For what it's worth, IMHO and as a sub 300 lbs team your tire size will be dictated by your road conditions more so than anything else I can think of. We've been running 145 psi 700x23c Vredestein Fortezza tires on our tandems -- including the Calfee -- since day 1 back in '97 when we're on home turf as our roads here in Georgia as well as up in SE Tennessee tend to be very smooth. When we've headed to places where we knew we'd encounter extensive chip seal roads or up north where expansion joints and/or frost heaving makes for busted up roads I've fitted the 25mm version of the Fortezza tires and, if it's really bad, I'll knock the air pressure on the 25mm tires down from 135 psi to 120 psi.
To us, the 25mm tires feel pretty cushy coming off of the rock hard 23mm tires but, then again, on the Calfee tandem everything feels pretty cushy. Moreover, about the only time we'll get a pinch flat is AFTER we've already had a flat where hand pumps have made it hard to get the narrow 23mm tires back up over 100 psi and then encounter a sharp break in the road. I've started to stuff a C02 cart. in our seat back to use for "topping off" as a way of eliminating the rim hit / pinch flat problem now that we're running the more pricey 'boutique" wheels that don't lend themselves to home rim replacement. Nicking a Deep-V rim was never a big deal as I always have a spare rim around and can cross lace a new rim to an existing wheel in about 30 minutes.
Anyway, you're about the only one who can draw on your own experiences with tire size to determine what you'll really want or need for your tandem. 28mm is the 'default' on most non-racing tandems so dropping down to 25mm for a lightweight team really isn't that big of a stretch.
Of course, if Calfee has already fabricated your rear triangle and set the rear brake bridge....