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I think I can remember reading that older Lefties lock out solid, once it's locked out, it is completely rigid, while newer ones have got a gate/blow off/threshold so they will move if they take a big hit, like a Fox or Rock Shox fork.
Have I got that right ?
If so, what's this one got ?
http://www.ebay.co.uk/itm/220953131146?_trksid=p5197.c0.m619#ht_500wt_1287
Also, there doesn't seem to be much information on Lefties on the web, none of these are all that much help really.
http://www.cannondale.com/gbr/innovation/lefty_headshok/
http://www.cannondale-parts.de/epages/61764971.sf/en_US/?ObjectPath=/Shops/61764971/Categories/Gabeln/Lefty
http://qwertycycles.co.uk/collections/cannondale-forks
Is there a beginners guide to all the various models somewhere ?
Mine has a simple lever on the top that you flick through 90* and yup, it locks out solid..
But this is a 2003 vintage..
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Try speaking to Ellis on here who works at Alf Jones as he seems pretty clued up on them...
And the servicing from there is 2nd to none.
Post the question on the Cannondale forum on MTBR, there are a couple of Lefty experts on there.
I've got the FOX RLC internals on mine and it's ace.
It's a PBR version, which if I recall correctly uses a rockshox damper with a gate/blowoff type lockout.
It's the old DLR dampers that lockout completely.
Thanks everyone.
A bit of searching and I found this.
http://www.rad-laden.de/shop/BICYCLE-COMPONENTS/FORKS/FORKS/CANNONDALE-LEFTY-ULTRA-2011-CARBON-W-PBR-120--6603.html?XTCsid=i7eel30e2u5e1ja8p65un605f4p6sj63
LOCKOUT MIT übERDRUCk VENTIL
Der Lockout hat ein einstellbares Überdruckventil,
das ab einer gewissen Stossintensität die Gabel vorrübergehend öffnet.
Which google tells me means
LOCKOUT VALVE WITH overpressure
The lockout has an adjustable pressure valve,
the shock intensity above a certain fork opens temporarily.
So,l it looks like you're right, glenh.
Edit;
There's this one as well, which mentions threshold.
http://www.radkom.de/lefty-ultra-carbon-pbr-and-solo-air-opi-120mm-1159.html