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Discussion Starter · #1 ·
I currently have a 26" bike that was converted to 650b (Nickel with a 140 mm Fox). If I wanted to buy a dedicated 650b frame and transfer all my components over, would I run into problems with the 26" fork?

Is it the same length as the dedicated 650b forks? Or is it a different length that would mess with the geometry of the bike?

Anyone have any opinions on this?
 

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There are some forks that can take a 650b wheel. 32 mm Stanton fox forks aren't one of them. The xfusion vengeance can and I know people with 36floats running 650b. They are still a compromise as the trail is different. Doable for sure but not optimal
 

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Discussion Starter · #3 ·
I think you misunderstood the question. I already have a 650b wheel on the fork (and its a 32mm Fox, its been great), but what I'm asking is there any problems with using this 26" fork with the 650b wheel on a 650b frame?

Is it gonna mess up the geometry? Head angle or bottom bracket, etc.?

Or is it essentially the same length as an actual 650b fork, and won't change anything?
 

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There are some forks that can take a 650b wheel. 32 mm Stanton fox forks aren't one of them.
This is not correct. I have 2 32mm stanchion Fox forks in my garage with 2.35x650b wheels/tires in them.... Sounds like the OP has one himself.

You're on the mark about the trail issue though...

richulr, If you like the way the BNickel handles with that fork on it, it will be good to go on a 27.5 frame as well, assuming the steerer tube is compatible in length,taper, etc. But if the new frame has a much slacker head angle than the Nickel, then the short offset (39mm, right? IIRC) of the fork may not be ideal....starts to feel floppy and slow steering, but it will add wheel stability at speed and when pushing through soft loose surfaces. A new Fox 650b fork (well, pretty much any dedicated 650b fork) will have more offset to mitigate the steering trail-increasing effects of bigger wheel and slacker head angles.

Even if the new bike is slacker, you might like a lot of trail.... nothin' to lose
 

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Discussion Starter · #5 ·
I'm thinking about the future. Am wondering if I can just buy a frame when I want to upgrade and transfer everything over from my Nickel conversion (that includes the 26" fork with the 650b wheel). Or if that's a bad idea, get a full 650b. For example, could I buy a 5010 or Process frame and just transfer everything over? Or should I just get a full bike.

Gets more complicated if I need to match head tube lengths and all. Not sure if I'm smart enough for that.
 

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Or is it essentially the same length as an actual 650b fork, and won't change anything?
The difference is about 1cm in axle crown height, so 0.5-ish degree on your head angle all other things being equal.

The offset issue isn't such a big deal, the 650b new Pike has the same offset as the original Pike from 2005 (42mm). Some 650 forks have a bit more/less and some 26 forks have a bit more/less than that.

With 650/26 I think people have gotten overly hung up on rake/trail numbers, it's not nearly as big a difference as with a 56mm offset 29er fork. Your new frame will ride fine with the 26fork, even if it might be (very slightly) more fine with a'proper' 650b equivalent.
 

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The White Jeff W
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The 140mm 26er fork is roughly equivalent to a 120mm 650b fork, so assuming your new frame is designed around a 120mm fork you should be OK. The 5010 uses a 130mm fork so 10mm probably wouldnt be that big of a deal. The Process 134 is 140mm up front. I wouldnt. The Process 153 is 160mm. Definitely not.
 

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Discussion Starter · #10 ·
The 140mm 26er fork is roughly equivalent to a 120mm 650b fork, so assuming your new frame is designed around a 120mm fork you should be OK. The 5010 uses a 130mm fork so 10mm probably wouldnt be that big of a deal. The Process 134 is 140mm up front. I wouldnt. The Process 153 is 160mm. Definitely not.
Wait, this confuses me even more. My 140mm fork would be a 120mm fork on a 650b frame? How does that happen?
 

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with a shorter fork length, your tire might hit your down tube...so might want to check to make sure that doesn't happen...
 

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The White Jeff W
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Wait, this confuses me even more. My 140mm fork would be a 120mm fork on a 650b frame? How does that happen?
Im talking about axle to crown length. A 120mm 650b fork is about the same length as a 140mm 26er fork. Your 140mm fork would work OK on a 650b frame designed to use a 120mm 650B fork +/- 10mm or so. Your fork is still 140mm, its just shorter overall than a 140mm 650b fork by about 20mm.

Here's a picture I took of a 140mm 29er fork (left) and a 160mm 650b fork (right) Notice that although the 650b fork has 20mm more travel, the axle to crown length is the same

uploadfromtaptalk1394821818810.jpg

Here's the axle to crown length of 3 different Manitou forks


26" Minute - 140mm travel - 515mm
27.5" Mattock - 120mm travel - 515mm
29er Tower - 100mm travel - 510mm
 

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Discussion Starter · #13 ·
jeffw-13, thank you for the detailed response and the pictures. It makes sense now. That really helps a lot.
 
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