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  1. #1
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    Bonking ... not feelin' well Lurcher BB & crank confusion... Recap, Help,...

    I went through the last 10 pages and really didn't see this posted, but I'm sure it had to have been covered...

    Anyhow, I'm wondering what BB and cranks folks are using on their Lurchers? I guess my "old-skool" external BB's are really old school since in what seems a blink of an eye, there are like 4 more BB types out.
    BB30 / PF30 / BB386evo ? / PF89-92?

    So the Lurcher is BB= PF92, correct? I see that Shimano makes one. Solid!

    Some confusion for some may be that the "wild" sizing from the BB/PF30 to PF92.
    I understand that the BB30 relates to the axle size and the PF89-92 is referring to a newer wider BB standard and not talking about the axle. But... The BB89-92 is using a 24mm axle, correct?

    Seems to me that there are 2 issues to resolve which limits the cranks to be used.
    ~1) BB30/PF30 uses a 30mm axle, from what I've seen are not wide enough for BB92.
    ~2)BB30 meaning a 30mm axle, which won't work with the Lurcher's PF92 bearing that is for a 24mm axle, correct?

    So, my understanding was that SRAM cranks won't work because they use a 30mm axle and all PF92 BB use a 24mm axle.

    None of the cranks that I've seem say that they work with 92mm wide BB, but I see in many build photos that many are using SLX or XT cranks. I'm not seeing any special note as to a wider axle designation or any adapter, so are standard SLX or XT's simply bolting up? I know that DH bikes use 83/85mm cranks, but those specify it.

    My only assumption is that the total length of a crank axle that uses ext. bearings is enough to cover a wider BB shell that also incorporates the BB bearings, correct?

    So I thought that I had this solved (LOL) when I saw on On-One's site the Lurcher XT build and it reaffirmed my understanding, until I noticed that they are selling a SRAM X.9 Lurcher with SRAM cranks! How are they using the 30mm axle then? Even if they replaced the bearings in the PF92 BB, reducing them by 6mm is huge! Wouldn't that kill reliability?

    Any help with cranks and bb choices for the Lurcher would be appreciated!
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  2. #2
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    I just built up a Lurcher, single speed. Used this adapter for my BB:

    Sram Pressfit GXP Bottom Bracket MTB

    They sell these at Jenson, Competitive Cyclist, or even On One. They are relatively cheap.

    With this you can use any Sram GXP crankset. I bought a X.9 crankset and did not need the GXP BB that came with the crankset.

    hope this helps

  3. #3
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    My understanding is that PF89-92 is exactly the same as the usual 68-73mm external bearing bottom bracket setup, just missing the threads.
    If you measure a normal 73mm external bearing bottom bracket setup with the bearings in place, it is 92 mm wide. The PF standard just replaces the threaded external bearings with press fit bearings.
    If you buy a SRAM one, it will have a 30mm hole and if you buy a Shimano one, it will have a 24mm hole.The matching standard cranksets slide right in just like they would with normal external bearings.

  4. #4
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    Quote Originally Posted by Slash5 View Post
    My understanding is that PF89-92 is exactly the same as the usual 68-73mm external bearing bottom bracket setup, just missing the threads.
    If you measure a normal 73mm external bearing bottom bracket setup with the bearings in place, it is 92 mm wide. The PF standard just replaces the threaded external bearings with press fit bearings.
    If you buy a SRAM one, it will have a 30mm hole and if you buy a Shimano one, it will have a 24mm hole.The matching standard cranksets slide right in just like they would with normal external bearings.
    SRAM's GXP cranks have a 24mm spindle that steps down to 22mm on the non-drive side.
    The Lurcher uses the Pressfit GXP BB(92).

    The 30mm spindle cranks are BB30 for frames with BB30 or PFBB30 shells.
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  5. #5
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    Thx Shiggy. I missed that point and appreciate you bringing it up.
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  6. #6
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    I've found these so far and just have to decide on the crank brand I guess:

    -Race Face BB92 Press Fit (Raceface and Shimano fit 24mm axle)
    -Shimano SM-BB91-41A PressFit MTB bottom Bracket (Shimano, and other 24mm axles)
    -SRAM GXP BB92 Bottom Bracket (SRAM/Truvativ GXP cranks only 22mm ND - 24mm DS)
    -Truvativ Pressfit GXP Adaptor Mtb 92-Bottom Bracket (Allows you to screw in your Ext.BB?)
    and..
    -Enduro Seals: PF92 24- 30mm convert bearing kit

    Am I onto something here?
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  7. #7
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    Quote Originally Posted by F5000sl View Post
    I've found these so far and just have to decide on the crank brand I guess:

    -Race Face BB92 Press Fit (Raceface and Shimano fit 24mm axle)
    -Shimano SM-BB91-41A PressFit MTB bottom Bracket (Shimano, and other 24mm axles)
    -SRAM GXP BB92 Bottom Bracket (SRAM/Truvativ GXP cranks only 22mm ND - 24mm DS)
    -Truvativ Pressfit GXP Adaptor Mtb 92-Bottom Bracket (Allows you to screw in your Ext.BB?)
    and..
    -Enduro Seals: PF92 24- 30mm convert bearing kit

    Am I onto something here?
    Mostly.

    The Truvative adaptor is for BB30 frames. Will not work in the Lurcher and other BB92 frames. A BB92 shell is already as wide as threaded external bearing cups mounted in a frame.

    Enduro makes very good BB92 BBs for Shimano and SRAM GXP type cranks.

    I personally would not use the Enduro BB92 to BB30 kit as the bearings have no seat in the shell. I would destroy the bearings and frame in a month.
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  8. #8
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    Quote Originally Posted by Slash5 View Post
    My understanding is that PF89-92 is exactly the same as the usual 68-73mm external bearing bottom bracket setup, just missing the threads.
    So my 180mm FSA V Drive MegaExo crank should slide right in to a PF92 BB?
    Universal Cycles -- FSA V Drive Single Speed MegaExo Crankset
    Last edited by kustomz; 02-26-2013 at 05:48 PM.

  9. #9
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    Lurcher BB & crank confusion... Recap, Help,...

    Quote Originally Posted by kustomz View Post
    So my 180mm FSA V Drive MegaExo crank should slide right in to a PF92 BB?
    Universal Cycles -- FSA V Drive Single Speed MegaExo Crankset
    Don't think that crankset is going to work. The description mentioned an integrated crank/bottom bracket with oversize axle and bearing. That sounds to me like the crank axle is not the standard 24mm and the bearing is also not standard size.
    I think for PF92 bottom bracket you will need either a standard shimano hollow tech II crankset or a SRAM GXP crankset. The only reason why the bottom bracket might be different between the shimano and SRAM is that the shimano crank axle diameter is 24mm on both side while the SRAM crank axle diameter is 24mm on the drive side and 22mm on the non drive side so the BB will either have different bearing or need a shim to take up the extra space on the non drive side for SRAM.
    The non standard crank such as the one listed above probably won't fit unless you can find a PF92 version

  10. #10
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    I can only afford a frame upgrade and transfer all my old parts, so perhaps I will build a Scandal and make a few more upgrades with the lesser costing frame.

  11. #11
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    Lurcher BB & crank confusion... Recap, Help,...

    Quote Originally Posted by kustomz View Post
    So my 180mm FSA V Drive MegaExo crank should slide right in to a PF92 BB?
    Universal Cycles -- FSA V Drive Single Speed MegaExo Crankset
    Should work with a Shimano style BB92 bottom bracket. The 24mm spindle is considered "oversize".
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  12. #12
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    Great.. Now I have to ask too. I have an MRP Camber Crankset I plan on running 1X10 on my new Lurcher (stoked btw) which has a 24mm. spindle. That said, should I grab a Shimano or SRAM BB92? I found a SRAM 24mm. on Price Point that seems like it would work, but I figured that I would ask the Forum before pulling the trigger.

    Many Thanks!

    PF

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  13. #13
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    I've been building a Lurcher single speed and am also confused. Having trouble finding the right crank. What I want, ideally, is a single speed crank with 48 tooth chainring. I ordered an SRAM S300 Courier GXP, thinking any GXP would work. But now I read that there are different spindle lengths for GXP. So I guess it will be too short by 5mm. I was hoping to spend something like 100 euros including chain ring and already have the On One PF92 BB.

    So my first question is whether the S300 will fit. And then, if not, what should I use instead?

    Thanks for any suggestions!

  14. #14
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    I can't say enough positive words about Enduroforkseals BB92. I've mounted the shells in feb 2013 in my old Lurcher frame and moved them to my new Lurcher frame (hit a tree with my old orange/black) I'm a 218lbs rider that ride several times a week in all kind of weather and the bearings are still smooth as butter. I haven't even removed the lip and regreased it - it's simply fit'n'forget. BUT.... Be really gentle with washing even with your garden hose.

  15. #15
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    [QUOTE=Thorjensen;11570505]I can't say enough positive words about Enduroforkseals BB92. I've mounted the shells in feb 2013 in my old Lurcher frame and moved them to my new Lurcher frame (hit a tree with my old orange/black) I'm a 218lbs rider that ride several times a week in all kind of weather and the bearings are still smooth as butter. I haven't even removed the lip and regreased it

    totally agree my enduro bb has been flawless. it is so smooth and quite that I even replaced my bb on a different bike with one once that bb crap the bed with only 100 miles on it.

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