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Discussion Starter #1
So. I discovered that a 29x2.3 DHR2 on a Boost hub fits in the rear of the 2016+ Balance with plenty of side clearance. I started crunching numbers:

You'd have to prevent the shock from reaching the last 11mm of travel, reducing the total rear wheel travel to 135mm.

You'd have to run a 140mm 29er fork with a zero-stack headset, which would put the head angle at 65.5 degrees.

Bottom bracket height would go from 343mm to 363mm.

For all that work you may as well just buy a Riot, but if any crazy fool wants to try building a mid-travel 29er with 420mm chainstays, there's your recipe.

 

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That's a pretty interesting idea, I've wondered if it would be possible to take advantage of the 1 piece upper link and headtube gussets while also running 29er wheels. It looks like it's doable, though a bit of tweaking is definitely necessary. I would also be surprised if much more than a 2.3 rear tire could fit. Maybe a fun conversion if you already have a Balance.
 

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Why not run more than 140mm fork? The brothers were short shocking balances a while back, there may be threads with the shock sizes they were using.
 

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Discussion Starter #4
A 140mm 29er fork has the same axle-to-crown length as a 160mm 27.5 fork so it would keep the head angle the same.
 

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So. I discovered that a 29x2.3 DHR2 on a Boost hub fits in the rear of the 2016+ Balance with plenty of side clearance. I started crunching numbers:

You'd have to prevent the shock from reaching the last 11mm of travel, reducing the total rear wheel travel to 135mm.
Did you ride it at all with 29 tires? I might give this a shot on my ‘15. Switching to a 210x50 shock should address BB height and bottom out issues. Just need to find a cheap shock to try it.



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A 140mm 29er fork has the same axle-to-crown length as a 160mm 27.5 fork so it would keep the head angle the same.
There is some misconception here... I think most of us that ran the Balance in both 160 and 170 front modes far prefer the 170 (Lyrik was JUST being released after CBros released the '16 Balance so they had initially spec'd the lame 160mm Pike on it at first because that was all that was available). Trying to keep the "same HTA as the original" is cutting yourself short. I would run AT LEAST a 150mm 29'r fork. Considering that myself as my new SB130 RIPS (couldn't wait for the new Riot) and would love to bring my Balance "up-to-speed" so to speak! Keep the rear wheel the same (27.5") so as to not raise the BB height too much - reverse mullet is the new gig. I'll eventually try swapping my fork over from the SB130 to see how she goes!

Have FUN!

G MAN
 

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Discussion Starter #10
I never did try it, but the release of the Norco Optic has me thinking about it again. Since the Optic is a 140-front 125-rear 29er bike with a 65-degree head angle, the Balance could be converted to the same fairly easily I think. A shock with the right measurements would prevent bottom-out and also keep the bottom bracket from getting too high, as visus mentioned above.

The one major difference, though, is the Optic has a much longer wheelbase. It's quite a large bike. The Balance is quite short in comparison.

I'm still quite tempted to give it a try.
 

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Discussion Starter #11 (Edited)
Well I tried a shorter shock and it sadly doesn't look like this will work. There just isn't enough room to keep the tire from bottoming if you want a tire bigger than a cyclocross tire. The shorter shock also throws the head and seat tube out of whack.

I'll just have to save for a Revel Rascal if I really want 29s on a CBF platform.
 

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Discussion Starter #13
I’m still not quite sure I can give this idea up without trying a 210x50 shock. With that shock the bottom bracket would actually be 3-4mm lower than the Rocky Mountain Instinct BC Edition.

I should’ve mentioned earlier: The shock I tried was a 200x55. It sure looked like even a 210x50 wouldn’t clear, but the tinker itch in me won’t rest until I actually give it a whirl.
 

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Discussion Starter #14
CONFIRMED: 210x50 shock won't work either. A 29x2.5 rear tire will still have 5mm of travel to go when it hits the seat tube.

Darn. Maybe the rear triangle and links from the new One.2 would bolt on to a Balance frame.

Or maybe we just wait for Canfield to release a 150mm CBF 29er. I'd sell what's left of my soul for that.
 

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Discussion Starter #16
I know the Tilt was just released but budget constraints have me considering this AGAIN. A 210x50 shock with a 5mm DIY spacer stuck at the bottom of the damper shaft would drop the rear travel to 120mm. Paired with a 130mm fork up front, the bottom bracket height would stay perfectly reasonable and the head and seat tubes would only slacken about 1.5 degrees.
 

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Why not go mullet? 150 or 160 29er fork, keep the 27.5 in the rear. I run a 160 on my Riot, and it's amazing.
 

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Discussion Starter #18
Why not go mullet? 150 or 160 29er fork, keep the 27.5 in the rear. I run a 160 on my Riot, and it's amazing.
I unexpectedly found myself really loving the "sports car" feel of short travel last time I demo'd a bike. Now I want a bike in the 120-130mm range but I also want to keep my heavy-hitter 160mm option. Two bikes is the best answer obviously but budget says otherwise. Swapping shocks and wheels on the same frame every once in a while wouldn't bother me since I could do it significantly cheaper.
 

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Why not go mullet? 150 or 160 29er fork, keep the 27.5 in the rear. I run a 160 on my Riot, and it's amazing.
Yes. Still want to put my 29 Diamond at 160 on my old Balance.

Lemke how does the bottom bracket height feel? 29 front and rear? Angel set headset?Put my Balance rear on my Riot and really enjoyed it. Quicker steering and just a little slacker.
 

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Discussion Starter #20
Continuing my number crunching on suspension kinematics. If there's any platform to attempt a wheel size and travel conversion on, CBF is it, thanks to the aim of consistency throughout travel. Though we still have to take into consideration of the changing of the sag point regardless—it will still have some effect.

I run my Balance at 21mm of sag on the DVO Topaz shock, right at 33% of travel. With air pressure matching rider weight and a single positive volume reducer, I find this the best balance between supple small-bump compliance and bottom-out support for when I hit the occasional jump. (No, I don't get anywhere near as sendy as I should on a Balance, hence why I'm even considering this.)

If I were to take a 210x50 shock and put a 4mm plastic spacer on the damper shaft to prevent a 29er wheel hitting the frame, the result would be 46mm of shock stroke and ~120mm of rear wheel travel. Assuming I run 30% sag, that would equate to ~14mm of shock stroke. With the 6mm reduction in eye-to-eye, 6+14mm means that 30% sag on a 210x46 shock puts the wheel in the same physical position as running 33% sag on the stock size 216x63 shock.

TL;DR - The sag point ends up in the same physical spot. That means the kinematics and frame angles under compression at the sag point should be unchanged with a 140mm 29er fork as with the stock bike.

How that particular range of the kinematics will work with the shorter travel and larger wheels remains to be seen.
 
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