Arcane headset standard micro-variations...

goosey

I bought a Ritchey semi integrated headset (1 1/8 - 1 1/2 tapered) to replace the shockingly rubbish bearings in a Trek. Having knocked out the old cups I offered up the lower cup to the frame...and found it was too small. On measuring, the Trek original had an external diameter of 56mm and the Ritchey was 55mm. Fortunately the cartridge bearing fitted ok into the old cup so all was not lost.
But - what did I overlook here? Help me prevent similar mistakes in the future!

nicklouse

what frame?

yes there is a 56mm standard and no there is not a 55mm standard but Trek are known for doing things differently.

goosey

It was a Fuel IIRC. So are you saying that Rickey are making a headset cup that doesn't match any existing standard? It was their cup that measured 55mm, not the Trek's.

nicklouse

any ID on the Ritchey headset or box?

goosey

The headset is this one:
http://www.bike-discount.de/shop/k690/a32860/headset-zero-pro-press-fit-taper-1-1-8-~-1-5-10mm.html

nicklouse

that is odd.

they state it is a ZS55 but there is no ZS55 standard. it is ZS56 or EC56

i was thinking it might have just been a poor cup but it seems not.

goosey

Trust me to come up with a unique problem!