Originally Posted by
elcruxio
The Spyre/Spyke concept is nice but it's severely lacking when compared to the BB7. The main flaw they have is the lack of a floating piston, which the BB7 has. The floating piston essentially means one pad will always be in perfect contact with the rotor. If properly adjusted and setup the non moving pad will also be in almost perfect contact since the CPS washers align the caliper body.
The Spyre/spyke system does not allow for CPS washers, nor do they have the aforementioned floating piston which A) makes setup quite tricky and B) there's a high likelihood the pads will initially not contact the rotor perfectly meaning there's then bending and twisting of the pads when one brakes. This is what I suspect is the reason why spyres are extremely spongy when compared to BB7, which has a nice firm lever feel.
Also, like I've mentioned earlier, I got more power from BB7 160mm rotor than I got from Spyre 203mm rotor. Same pad compound. The BB7 road is so powerful in fact that I'm hesitant of putting a 203mm rotor on even with a full touring load. It's above and beyond more powerful than the mountain version BB7.
Also the lack of some sort of retaining system in the spyre pad adjusters just means they'll back down to their original positions. There is some weak thread locker which of course is useless after the first proper application of the brakes since threadlocker isn't heat resistant.
Spyres are also quite badly sealed (read, they're not sealed) against the elements so to keep them from seizing they do require maintenance. Problem is that TRP doesn't want you opening these bad boys so you need some exotic stuff to maintain them (T40)
Are we talking the same BB7 here?
The one with a fixed caliper and adjustments for both pads because one piston is not floating? The one were the moving pad distorts the disc over on to the fixed pad, ie there's NO floating piston in the BB7, not even a floating caliper, which is what a single piston disc brake should have.
And the CPS washers that the Spyke doesn't need, because it's not a single piston fixed caliper, so it doesn't wear the disc unevenly and thus doesn't need CPS washers (best you send a strongly worded email to Shimano and ask them why the don't supply CPS washers with their twin piston calipers?) The set up instructions for the Spyke are: Loosely fit caliper, adjust each adjusting screw evenly with a 3mm allen key, to get the pads close to the disc, tighten the cable adjuster to lock on the caliper, tighten mounting bolts, loosen cable. That's it, by design, like all twin piston calipers, the body is already in alignment with the disc. A hell of a lot less than trying to align a BB7, especially with worn pads and discs, where you need to decide which pad you are going align parallel with the worn disc surface, which will always have a slight taper because the caliper and psitons are fixed and the disc flexes.
And the fact that neither the BB7 or the Spyke have seals on the inside of the piston(s) next to the rotor so both can get water inside easily and both need basic servicing, with the adjuster of the fixed piston of the BB7 regularly seizing up so you need a torx driver to adjust it? The BB7 only has a seal on the outside of the actuating shaft. I'll give you that TRP should put a little more grease on the anti friction ball race from new (which the BB7 doesn't have, thus contributing towards that spongy bending the disc feeling they have) but neither caliper has a way of stopping water from coming in from the disc side and getting into the cam area.
From the point of view of being able upgrade the discs, the BB7 is a dead end in anything other than disc size because it flexes the disc sideways, so no aluminium center rotors. It needs thin flexible discs.
I have both TRPs and BB7 on my touring bike. TRP on the front and BB7 on the back,and the front was previously a BB7 so I could compare the two, on the same bike under roughly the same conditions (the BB7 had a 160mm disc however). The feel of the TRP is heaps better.