marciero

The Whisky #9 fork has a stated max rotor of 160. I know a number of teams have used this fork on tandems without issue. Has anyone used this fork with a spacer and 200 rotor? This of course puts greater torque forces on the fork.

twocicle

The current batch of Whisky No.9 (thru-axle) road and CX forks are standardized to a 160mm max rotor spec. FK99(00) series. These new forks are not the same spec as older No.9 forks such as the one we use.

Our Whisky No.9 (367mm A-C, 15mm thru-axle, post mount, 1.5" tapered) road fork is from 2015/2016 timeframe, series FK52(00). I do not have the disc max spec handy, but believe this one was 180mm max (though it can fit a 203mm). We are using powerful hydraulic calipers and so I would not want to try testing the fork limits with a >=200mm rotor.

I do not have a newer Whisky No.9 on hand and so my impression is only from the product photos, but the new forks appear to have somewhat slimmer blades than ours. What does that mean (if anything)? I am not sure if the newer forks are built as beefy as the older ones.

Bottom line, our experience with the older Whisky No.9 is probably not relevant to the newer Whisky No.9 forks. I would suggest phoning Calfee and inquiring with them because they frequently do spec various carbon forks with their builds, and may have current knowledge of the latest feasible tandem options.

akexpress 

We have this fork on our Calfee and use a 180mm rotor on it. There is adequate room for a 200 or 203 but you would have to stack adaptors if that is even possible. It takes a 203 adapter to use a 180mm rotor on this fork. Like Brian ^^^ we are also using hydraulic brakes and see little need for a 203 and have many long descents with this combo including some loaded touring without issues with 180mm. We also have a #7 fork and use the same combo.

marciero

Okay this sheds a little light, thanks. The one I am considering is used so not sure what version it is. Also, it's possible that hydraulic brakes give you as much or more stopping power with 180 rotor as my mechanical do with 200. If that is the case I would be fine with 200 rotor and mechanical brakes, since it's the stopping force, not the force at the brake pad/rotor, that determines the torque on the fork.
But yes, will check with Calfee.

joe@vwvortex

Looks like the pads aren't using the whole rotor - in fact - only about 2/3 of the rotors looks like it's being contacted. Why is that?

akexpress 

That is the majority of the pad width. The Hope V2 rotor is pretty wide so yes there is lots of rotor not in play as braking surface.

twocicle

Actually, the proper adapter on our #9 fork with 140mm post mounts and a 180mm rotor, is a SRAM 40mm adapter (meant for a 200mm rotor), not the Shimano 203mm adapter. Think about it... fork post mount = 140mm + 40mm = 180mm. 183mm caliper placement puts the caliper too far outboard. All this came about because Shimano decided to stick with 203mm big rotors, but SRAM and others went to 200mm which uses a slightly smaller adapter lift. So yeah, a 203mm adapter != 200mm adapter. Probably just ends up being a little 1.5mm tweak to get optimal pad placement

akexpress 

Brian Good info, although inspection of the pads does not show a band of pad not being used so I don't
think it makes much difference at least with this and the R785 (Xt) brakes. I will try a Sram adapter and see if it makes any difference ,its a cheap thing to try.

twocicle

curious if you find less brake howl from the Saint calipers... especially the rear?