Getting really confused with all this headset standard stuff, can anyone help me out please? I just bought a Scott Voltage FR10 frame which I believe has a 1.5″ headset. I think this is the headset that’s in it now. It’s for tapered forks which I don’t have at the minute – I’ll be putting my Sektor on for the time being which is a straight 1.1/8″. What do I need bottom-cup wise to make it work?

Looking at the hope stuff on CRC it looks like I may just be able to get away with getting the HS136 1.1/8″ to 1.5″ lower steerer crown converter? Will that fit in the FSA headset though or am I gonna need to buy a new Hope bottom cup?

Or do I need a Hope D type ZS49/30 bottom cup?

So long as the FSA headset that is currently in the bike has a 1.5 lower crown race the hope adapter should work.

In essence the adapter is just a lump of alu that makes the bottom of the steerer of the fork 1.5 and provides a point to mount a standard 1.5 crown race on.

A quick bit of googling suggests FSA bearings have. 36 degree angle and Hope have 45 degree, so are not directly compatible. I know Hope and Cane Creek bearings are interchangeable.
Edit: however what RustyMac said about reducer is true.

Ah balls, he didn’t include the crown race but I’ll ask to see if he’s just forgot about it, maybe he’ll let me have it! If he doesn’t, will that Hope D Type lower cup work?

edit – actually would this do the job?? http://www.ukbikestore.co.uk/product/402/160_5540/fsa-15-crown-race-for-no-57e-cup-for-1-18-steerer.html

If you are lacking a crown race then there are a few options

1 – i think FSA do a pancake type lower crown race that goes on the 1 1/8 steerer and stretches all the way out to the 1.5 bearings, whether the one you have linked to is compatible with the headset you have I do not know. I’d email FSA to ask about compatibility.

2 Buy the standard 1.5 crown race for that headset and then the hope adapter.

3 Buy the hope adapter and the hope headset for a 1.5 steerer fork.

[edit] the spec on that tredz page has me confused, a 55mm OD head tube wouldn’t initially allow a zero stack lower cup for a 1.5 steerer (a 55mm ID on the head tube OD on the cup would and that would be the same as a Hope G cup0[/edit]

If you can get the lower bearing out and see what markings are on it, if it has 36 degrees etched on the the UKbikestore one will work.