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Discussion Starter · #1 ·
Been thinking of setting up the bruja in more of a terremoto mode, with a 160-170mm fork, and trying to monkey around to get about 160mm in the back. I talked to Sherwood about this, and he thinks the only way to do it is to have a shock customized to 8.25" length and 2.25" stroke, yielding 160mm travel (The T-moto rockers aren't compatible).

Any ideas about this, particularly the resultant geometry changes and any unforeseen problems?
 

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Ultra Ventanaphile
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You're kinda the opposite of the Tmoto with long fork. I think going longer is generally easier than going shorter. The first thing I can think of is you'll lower your bottom bracket. The seattube will be quite steep at around 75 degrees you'll probably want a setback seatpost. What wouldyou do for the shock? Avalanche?
 

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Discussion Starter · #3 ·
Either Avalanche or Push, basically a tune with custom length/stroke. Any idea what the bb height might look like with the 8.25" shock and a Lyrik (160 or 170)? I'm kinda hoping the angles/bb would be the same or, if anything, slacker/lower than the stock bruja with a 180mm fork.
 

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Proud lame eBiker
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albeant-sounds like you've already talked with 'the man' about this, so I'd say if the answers weren't clear enough, or you have changed your mind with your intended use, give him a call back and pose these specific questions.

Usually the designer of the bike can more fully answer your questions about altering shock length/fork length and their impacts on the 'ride'...much more than the rest of us e-engineers at least.


But alas, if all that falls on deaf ears.....why do you want to shorter up the Bruja's legs? If you're trying to make it pedal better, jacking the seat tube angle so will NOT make it pedal any better.
 

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albeant said:
Either Avalanche or Push, basically a tune with custom length/stroke. Any idea what the bb height might look like with the 8.25" shock and a Lyrik (160 or 170)? I'm kinda hoping the angles/bb would be the same or, if anything, slacker/lower than the stock bruja with a 180mm fork.
Just noticed the 8.25" eye to eye part and I don't have time today to do a full mock of the V2 Bruja on ACAD to get you exact numbers bit that would lower the BB at least .25" if not more, (In theory the shorter eye to eye would translate to the rear wheel moving .725" (18.4mm).

So you can ignore my 75 degree Seattube issue as you would effectively lower the bike both front and rear, if you went with a 170 Lyric, you would slacken the angles, a smidge, maybe a quarter of degree. 160 Lyric, you'd end up the same geo just lower BB.
I'd guesstimate (Based on the work I did with my V1 Bruja) about 3/8" lower.

Myke has a good point, it won't pedal any different as the kinematics will be the same, the pivot is in the same location and the rocker is the same.

What is the intention for the changes?
 

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Discussion Starter · #6 ·
Ciclistagonzo said:
...if you went with a 170 Lyric, you would slacken the angles, a smidge, maybe a quarter of degree. 160 Lyric, you'd end up the same geo just lower BB.
I'd guesstimate (Based on the work I did with my V1 Bruja) about 3/8" lower...
Cool, thanks, exactly the info I'm looking for. Based on your guesstimate, it sounds like the geometry would be pretty dialed for a 160mm bike, maybe even better (for me) than the stock t'moto.

Regarding my purposes, I have another beastly dh bike built up with a granny ring, so I'm thinking of enhancing some of the Bruja's AM talents. I'm not interested in changing pedaling dynamics, so all's good there. There's a big weight difference, however, between 160mm and 180mm forks, and with such a fork change, maybe an air shock, tires, etc., I might be able to get rid of significant weight, while getting the bb a little closer to the ground. Basically, terremoto-ize it.
 

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I'm thinking of enhancing some of the Bruja's AM talents. I might be able to get rid of significant weight said:
pretty much what i was trying to do until the Terremomto went on that tremendous Winter sale @ Ventana. mission accompli:D
 
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