Lefty on a 44mm Headtube bike….

Just trying to plan logistics for a potential build. I have a lefty and would like to run it on a 44mm Headtube frame. Is it a case of a different upper headset cup to allow for 1.5inch steerer? Or do I need to find an adapter? I know there are project 321 adapters but I assume they’re mucho expensive. What’s stopping me using a spare generic tapered steerer and then finding a shim for the upper lefty clamp? Just pondering ideas but feel free to shoot me down!

As someone who has run Leftys on a couple of non Cannondale bikes over the years the proper adapters are the way to go. I have 2 of the Lefty 4 All adapters and a Project 321 steerer. With both of these you get a ful suite of clamp adapters.

You need the lower “piece” of the proper adapters  for the lower clamp to clamp to – there is then a mild bulge for the crown race. The only time I’ve run one tapered was on a internal lower bearing arrangement otherwise you often end up with a too larger space between the clamps.

For a 44mm HT 2 1/18” internal (IS41?) cups work best with the correct steerer.

I really like the Lefty but dependant upon which version you have depends how fanickity they are – e.g. bearing resets.

Often not a cheap experiment but a fun one!

This was 2012ish on a tapered HT:

As a side note you need a 90mm (IIRC) to clear the fork leg … let me find a photo …

Found one – this was the same style fork as above on an Inbred 29er with a 1 1/8” HT

Cheers Mark, that’s helpful.