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The dreaded lefty- jet 9 question again

1892 Views 5 Replies 3 Participants Last post by  yeoman11
I just ordered a Large 2010 Jet 9 and I already have a carbon lefty I'm going to put on it. I know on here it's been stated that they do work on the frame with the supplied headset. Well apparently they don't send the headset with the frameset anymore, or it appears that way on the niner site. What headset is everyone using the get the clearance they need for the lefty? Anything else I should know about before trying to put the lefty on? I read someone stating they had to modify the dust cap... I'll be using a project 321 adapter.

Any help would be much appreciated!
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My closeout (2010) frame came with the headset. I believe that they are excluding them going forward (2011).
If you get the "original" FSA headset, it will just fit with the Lefty and the Project 321 adapter. You do NOT need to modify the dust cap.
You can get the FSA via Niner but there are other headsets that Niner also recommends. Check with them. In another topic the other headsets are also mentioned but cannot find that topic right now.

Edit:
Here it is: http://forums.mtbr.com/showthread.php?p=7769889#post7769889
Cool, thanks for the info....

For the folks that are running a lefty and the Project 321 adapter, I assume you guys are running the tapered adapter? I spoke with Jake at Project 321 today and he mentioned that using the tapered adapter adds another 1.5mm of stack height which may make it too large, he mentioned that there was a way to run a 1.125 adapter on the bike which made me curious as to which you guys are using. Any and all help is much appreciated!

Thanks!
frontier2k1 said:
Cool, thanks for the info....

For the folks that are running a lefty and the Project 321 adapter, I assume you guys are running the tapered adapter? I spoke with Jake at Project 321 today and he mentioned that using the tapered adapter adds another 1.5mm of stack height which may make it too large, he mentioned that there was a way to run a 1.125 adapter on the bike which made me curious as to which you guys are using. Any and all help is much appreciated!

Thanks!
Anyone able to help me out with a little more insight into this? Jake at Project 321 said that in order to use the 1-1/8 adapter the lower crown race would have to be split so that the adapter could be slid through the lefty without trying to press it on slamming against the bearings/headset while on the bike. After adding the headset using the 1-1/2 lower crown race I can't get the lefty crowns over the head tube and dust cap. Adding the 1.5mm that is necessary to use the tapered adapter isn't really any option for me at this point without machining down the dust cap as it is already too tall without the added stack height from the adapter. I'd really appreciate it if anyone could give me a little more insight on what they did or maybe even a couple close up pictures so that I can see the clearance and figure out what I need to do to make this work.

Thanks!
OK. Few things:
- It is not needed to split the crown race. Having a split crown race does make it easier to install (!) but it is not possible to split all crown races...
I agree with the guys from 321 that you should not try to bang the crown race on the adapter with a hammer because it won't work and it will damage things. After all parts (headset, crown race, etc) are in the right order on the adapter, I use a simple cramp to press the crown race on the adapter. That works just fine without the need to split the crown race.

- The total height of the headset and the headtube together is a little (I think about 1 to 2 mm) more than the space you have between the lefty crowns. That is not a problem because the upper spacer of the adapter that will be clammed in the upper Lefty crown does not need to align exactly with the Lefty Crown. It can be seated a little (1-2 mm) higher. Therefore you do not need to modify the dust cap.

- Now: How to install this (first time better do this with 2 persons):
1. Place the bearings (use a good amount of grease so the lower bearing will stick).
2. Place the upper parts of the headset on top of the upper bearing.
3. Place the Lefty crowns over the headtube and headset
4. Place the crown race between lower bearing and lower Lefty crown (this requires a bit of "fiddling".
5. Now push the adapter through untill it is properly aligned with the lower lefty crown
6. Tighten the lower Lefty Crown
7. Put spacers (or a stem) on the adapter till the adapter "falls below the spacers"
8. Place a cramp on the spacers and the bottom of the adapter and press the crown race over the adapter till it is properly seated. Adjust the headset with the cramp and tighten the upper Left Crown

In principle you can use the star nut to press the crown race on but I have noticed that with a cramp it is a lot easier and quicker.

Anyway, this is how I do it and hope this was clear enough. If not, I will take a few pictures.

Good luck!
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