Project 321 Adaptor Question (xpost, sorta, from 29er forum)
Posted this recently in the 29er forum:
One idea was that maybe the clamps are offset along the axis of the Lefty's shaft?
I saw the followiing statement in the description of the P321 Lefty Adaptor:
"Two versions. One for stack heights of 5.675" - 6.125", and one for stack heights of 5.3" - 5.75". Also available in black or silver. Specify color and size at checkout time."
What is the difference?
I am totally confused. The stack height (or distance between the clamps) is a totally adjustable by sliding the top clamp up and down on the steerer so why are there two versions now? Are the steerer tubes butted or something like that?
Last edited by marty_hd; 07-17-2007 at 07:18 AM.
on the aluminium lefty, you can adjust the claps up and down as you say, BUT on the carbon version of lefty, you canīt, becouse on that the clamp ar fixed/bounded to the leftyleg. thats why they mention stackhight
Yeah, but it was in the add for the Project 321 Lefty Adaptor (with clamps for the AL shaft) and not in the add for the Project 321 Carbon Lefty Adaptor.
hmm, strage, could it differ between the 110 mm lefty and the 140 mm lefty?
A hopped on pop.
ok, i will try to eplain this, but i think you;d get a better answer from jake (aka pumpkinbiter) himself.
for the alloy type lefty max forks, you can slide the clamps up and down the fork shaft. the top clamp has to stay in the area that is butted (if you have a lefty max in you hands, you will see that the very top of the fork is butted for the upper clamp).
you can slide the bottom clamp up and down but you will also alter the crown to axle of the fork....you will end up changing the way your bike rides. a few mm won't make a huge difference. the clamp is meant to be placed where the end of key way slot for the stock c-dale clamps.
basically, for the two diffrent models of clamps (for the two different stack height ranges), the difference is in the upper (top clamp)...one has a drop in it, the other either does not, or the drop is not as much. i wish i had a pic.
for the bonded model leftys (the carbons and the alloy bonded fork)....you are pretty much stuck at a total headtube length (with headset) of about 5 3/8" or less. you can always play with headsets if you don't have alot of room to spare. campy records have low stacks and there is a steel heasdet that eai imports that stack to like 18mm (really low).
hope this helps.
"forget kings...forget hadleys......they all have crap engagement. just run your bike fixed gear." - FoShizzle
Yep, Kam's got it pretty much. Taller stacks require a dropped top clamp, or they run out of room on the Lefty. Carbons, your stack height is locked in, too tall? It just won't fit......
Ah, the top clamp is different!
Which clamp was delivered with the original P321 Lefty Adaptor (short stack or long stack version)?
Any chance of just buying the top clamp alone?
I have two P321 Adaptors purchased before the two different clamp versions were available. I have noticed this issue on my Kona Unit 2-9 which has a longer headtube than my GF 293 which has a way shorter headtube. At the time (for the shorter headtube) I was wondering if the top clamp could be flipped but somehow I managed to get everything to fit.
Hey guys, sorry for not butting in sooner.
Kam said it pretty well. The top clamp drops 3/8" to allow the
stack height to be taller. There is a pretty small butted area you can clamp on
at the top of the lefty leg. As your stack height gets taller you have to
move the clamps apart, but as you do that the top clamp tops out and
then you have to move the lower clamp down on the leg. The hazzard of
that is that you loose tire clearance and potentially will hit the tire into the
crown when the lefty is fully compressed. (That is why we insist that you
leave the factory recomended tire clearance when installing our clamps.)
To fix this we just dropped the clamping area of the top clamp 3/8" to allow for
more headset and headtube to fit between the clamps without moving the bottom
clamp down. That is pretty much what Kam and Mendon said with a few extra boring details.
I have included a picture of both of options. The grey set is the original and the black
and silver sets are the dropped version of the top clamp. Both have a specific range
of stack heights they can accomodate so you need to know what your stack height
is before you order.
Marty Hd - we do sell the top clamp seperate. Give me an e-mail (jake at project321.com)
and I will get you all the details.
"42 lbs and climbing!"
Third size option?
Any news on the extra long reaching top crown you were considering making for us extra tall head tube guys?