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Talk Me Out of a Capra 29?

Flo33

Turbo Monkey
Mar 3, 2015
2,057
1,298
Styria
He had quite the conversation with Brian Tantrum Berthold, if I'm not fooled by my memory though.

Steve's channel is indeed a beacon of light on YouTube.
 

Jm_

sled dog's bollocks
Jan 14, 2002
18,850
9,556
AK
In all seriousness I'm curious to compare its anti-squat curve to the Nomad 3's.
The linkage blog curves show 90-95% mid-travel, that's where I look first, because a lot of the time you are going to be pedaling close to that as you go through rocks, compress the rear on little steps and trail irregularities, etc. It's a typical horst-link "curve" that starts real high and falls fairly linear to the end though, so towards the sag point it may feel a little harsher and if you get to pedaling beyond mid-travel, maybe to 2/3rds it will get much soggier, but around 90% should be decent. The Nomad has a flatter curve that stays around 100% out to around 2/3rds travel, and then falls off, so should be a little more supple off the top and pedal a bit more consistently through the travel, however, the Capra seems pretty decent for a horst-link bike, better than the Spec Enduro which is at about 80% mid-travel. Conventional specialized-thought is to only consider the AS at the sag point, but I find this is extremely short sighted and the bike kind of gets into a feedback-loop when the AS falls off very steeply, because as you weight the rear in a climb, maybe with a heavier pack, you go over some bumps, all of a sudden the travel is now in the area where it takes even more power to power-out-of the bog due to much less AS, the light front end weights the rear even more, etc. This one just showed up today and is a classic example of the euro horst-link worship, with an absolutely ridiculous AS curve that will pedal like a wet mattress compared to both the Spec Enduro and the Capra.
 
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Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
I went to 29er DH land...and I came back. Got tired (literally) of riding up berms, having to pedal harder in between turns and jumps, not going as far on the jumps/gaps, and so on. They make wheel-catchers almost an impossibility, but the other negatives are too much IME. One can go fast and shred on one, but I find that you can go a little faster much easier on slightly smaller wheels. Id try a mixer bike, but I don't think a 29er rear wheel does anything useful on a DH bike.
At first, I was going to agree completely, but then /i thought, naa, this is RM...

For the last year or so, I have been convinced that the mixed wheel combo is best. As an ex moto guy, I was already biased, but the same logic applies here as there.

The gains of the big wheel up front :
more front stability(for example, less prone to headshake)
Better rollover
more contact patch/grip

outweigh the negatives by a noticeable amount.
more weight
clumsier handling
flexier wheel
higher stack

The gains of a smaller wheel in the rear:
shorter CS
lower BB
less weight
stiffer wheel
better handling
lower CG

outweigh the negatives by a noticeable amount
worse rollover
lass contact patch/grip

Lately though, I've been riding a 160 29er fr and rr. it might be changing my mind. Why? I might be thinking my latest geo tweaks have minimized the negatives of the 29er rear. They are still there....but then so are the positives and the thing is a freakin monster truck in gnar.

After a couple months, I'm about to switch back to a 27.5 rr for my Sea Otter race bike. It will be interesting....
 

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
He had quite the conversation with Brian Tantrum Berthold, if I'm not fooled by my memory though.

Steve's channel is indeed a beacon of light on YouTube.
We did? About too much low speed compression being bad? I don't remember, but it must have been in agreement.
 

4130biker

PM me about Tantrum Cycles!
May 24, 2007
3,882
447
All else being equal, there is more B.B. drop on a 29 which makes getting the front off the ground more difficult. I think it affects how a bike rides in a significant, but often overlooked way.
 

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,535
5,470
UK
All else being equal, there is more B.B. drop on a 29 which makes getting the front off the ground more difficult.
This really isn't much of a problem at all if you choose the wheelbase you rode 3 years ago rather than going for an XXL to get a fashionable 1300mm battleship wheelbase when you're 5ft fucking 8" tall.
At 25mm It's not a huge BB drop for the 29er. If you find getting the front wheel up on a 29er Capra the problem is YOU or a combination of YOU and your choice in fashion. Which still makes it YOUR problem rather than the bike's.
 
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Lelandjt

Turbo Monkey
Apr 4, 2008
2,508
821
Breckenridge, CO/Lahaina,HI
And that's why I chose a large instead of XL. I'm 6' 1.5" tall so most people would say I should be on a XL but I think the 465mm reach of the large is perfect. It's the same as the Hightower XL.
I do notice the difference in BB drop when popping a wheelie on a 29er (my girlfriend had a Specialized E29 and I have a Spark RC) but it's similar to a slight difference in chainstay length, you can quickly adjust.
 

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
@Tantrum Cycles how do you link wheel size and bb height? Or why did you write that a 29" rear wheel requires a higher bb? Was that considering a wheel swap for a given frame?
because basically, apples to apples, you can't stuff a bigger wheel with the same amount of travel in the same space as a smaller wheel.

At full travel, the limit is the tire hitting the seat tube (or even seat). To put a bigger wheel in there, you are either going to have to move the wheel backward (longer CS) or move it down (higher BB) or both. In the case of my bikes, my first cut was to do both for the 160 mm 29er.

I'm gonna make another set of dropouts that lower the BB and lengthen the CS and see which compromise I like better. Since my dropouts bolt on, it lets me play a lot of geo games, especially when combined with angle headsets.

but there is no geometry game that will cover up the fact that you have a larger wheel, requiring more space and more force to change direction
 

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
All else being equal, there is more B.B. drop on a 29 which makes getting the front off the ground more difficult. I think it affects how a bike rides in a significant, but often overlooked way.
The 160 mm 29er as I currently have it configured has a pretty high bb/low drop. I noticed this characteristic right away. not as much in "getting the front off the ground" specifically, but the front feels light and poppy. I know, it sounds like the same thing, maybe it is.

Some claim that the large BB drop is needed for handling/cornering, to feel "in" the bike. To me, that's a little more down to suspension and other geo factors.
 

Happymtb.fr

Turbo Monkey
Feb 9, 2016
1,907
1,252
SWE
because basically, apples to apples, you can't stuff a bigger wheel with the same amount of travel in the same space as a smaller wheel.
Ok, I now see what you mean. Mtg here wrote that he limited the travel of his Smash to 140mm in order to not compromise the geometry. If I remember well his bike has rather short chainstays, steep seat tube angle and middle of the pack bb-height.

Have you also considered a slightly rearward axel-path to solve this equation?
 

4130biker

PM me about Tantrum Cycles!
May 24, 2007
3,882
447
This really isn't much of a problem at all if you choose the wheelbase you rode 3 years ago rather than going for an XXL to get a fashionable 1300mm battleship wheelbase when you're 5ft fucking 8" tall.
At 25mm It's not a huge BB drop for the 29er. If you find getting the front wheel up on a 29er Capra the problem is YOU or a combination of YOU and your choice in fashion. Which still makes it YOUR problem rather than the bike's.
I ride a 29 with a short read end in an unfashionably small size, so I’m well aware of the effects on BB drop vs a 26” with similar geo. You’re preaching to the choir about the ridiculous sizing trends going on these days.
:cheers:
 

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
Ok, I now see what you mean. Mtg here wrote that he limited the travel of his Smash to 140mm in order to not compromise the geometry. If I remember well his bike has rather short chainstays, steep seat tube angle and middle of the pack bb-height.

Have you also considered a slightly rearward axel-path to solve this equation?
So the Smash is choosing the "compromise" of less travel to avoid the need for compromises in geo. The 160 mm 29er is a monster truck, for sure. now, it actually needs more in the front, to match how capable the rear is, just absolutely impervious to stuff.

So my goal now is to find the right combination of geo numbers that let me take advantage of the monster truck rear, while minimizing the disadvantages. I'm not sure I'm there yet, but it's one damn fun bike.

My rrr axle path has a fair rearward component, and to go further would cause other problems.

But you see, there's no "solving" the equation. You can't get something for nothing, EVERYTHING is a compromise. The art is to find the right combination to maximize the strengths and minimize the negatives. Even then, there will always be horses for courses.
 

Lelandjt

Turbo Monkey
Apr 4, 2008
2,508
821
Breckenridge, CO/Lahaina,HI
Brian, this Capra 29 is just a place holder until I can get a 160mm 29" Tantrum. In the sorting of compromises remember no one has ever complained that a seat tube angle is too steep and 9point8 make an offset head for their dropper so you could push the seat tube WAY forward. Weld up a test frame with a radically steep ST and "normal" BB drop and CS.
 

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
Brian, this Capra 29 is just a place holder until I can get a 160mm 29" Tantrum. In the sorting of compromises remember no one has ever complained that a seat tube angle is too steep and 9point8 make an offset head for their dropper so you could push the seat tube WAY forward. Weld up a test frame with a radically steep ST and "normal" BB drop and CS.
I actually have a small problem with radically steep seat tube. It makes the saddle so high off the ground that 1) CG is very high and forward when seated (good for climbing, not necessarily good for other stuff) and B) I can't swing my short legs over without dropping the saddle and if I have to get off with the saddle at full extension, it can be awkward.

Of course, I also claim i can get away with slacker static seat and HTA, due to the steepening effect of the Missing Link

As for "normal, 160 mm 29er cs??

bwahahahahahahhahahahahahahahhahaahahhahahahahahahahahahahahhahahhahahahahahahhahahhahahahhahahahahahahhahahahahahahahhahahahaha
 

Udi

RM Chief Ornithologist
Mar 14, 2005
4,915
1,200
I actually have a small problem with radically steep seat tube. It makes the saddle so high off the ground that 1) CG is very high and forward when seated (good for climbing, not necessarily good for other stuff) and B) I can't swing my short legs over without dropping the saddle and if I have to get off with the saddle at full extension, it can be awkward.
It's called a dropper?
Most people want steeper seat angles because climbing already sucks, and with a dropper (a modern longer one if needed) it's not that hard to get the seat out of the way / into an acceptable position for descents (at least for most people). Most things on a heavy-use enduro bike should be optimised for descending where possible, but the seat position is the one thing that has comparatively small impact on descending performance, and very large impact on climbing performance. Like you said, everything's a compromise, but this is one of the best value exploits you can make.

Don't get me wrong, I'll certainly sacrifice a slightly inferior seat angle for a way better leverage curve (for example) when choosing from existing bikes, but in a perfect world I'm with @Lelandjt - give me the steep SA (actual, not effective).

Agree with you on the mixed wheel stuff by the way. Cool that you've been trying the combos.
 

Tantrum Cycles

Turbo Monkey
Jun 29, 2016
1,143
503
It's called a dropper?
Most people want steeper seat angles because climbing already sucks, and with a dropper (a modern longer one if needed) it's not that hard to get the seat out of the way / into an acceptable position for descents (at least for most people). Most things on a heavy-use enduro bike should be optimised for descending where possible, but the seat position is the one thing that has comparatively small impact on descending performance, and very large impact on climbing performance. Like you said, everything's a compromise, but this is one of the best value exploits you can make.

Don't get me wrong, I'll certainly sacrifice a slightly inferior seat angle for a way better leverage curve (for example) when choosing from existing bikes, but in a perfect world I'm with @Lelandjt - give me the steep SA (actual, not effective).

Agree with you on the mixed wheel stuff by the way. Cool that you've been trying the combos.
The issue with the steep seat tube is more for riding that a dropper is not quite useful. My home trail has a lot of short steep up and down gullies, for example. Using a dropper isn't really practical, it happens fast and the default saddle position is up, because there's always a short climb. A less extremely steep ST angle just feels more versatile in more varied conditions.

I'm not knocking 75, I'm not calling that extreme, but I'm not sure how much more is practical. At one point on the magic Link bikes I was up to 75.8. It just felt too tall and too steep.

And as for climbing performance, I can get away with less extreme just due to the fact that it is much steeper than any other bike while climbing. Believe me, you don't have to sell me on the climbing advantages of steeper geo. that's why I made the Magic Link and this bike in the first place.

A little confused about your "actual v effective" comment. If I can use a horizontal seat tube (actual angle zero), which places the saddle at a 75 degree angle from the BB (75 degree effective), how does that not work exactly like an actual straight tube from the BB at a 75 degree angle? obviously at a given height, typically full extension.

I kinda feel like a slacker actual ST angle isn't bad, because as you drop is, it goes forward more, further getting it out of the way for hanging off the back
 

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,535
5,470
UK
The issue with the steep seat tube is more for riding that a dropper is not quite useful. My home trail has a lot of short steep up and down gullies, for example. Using a dropper isn't really practical, it happens fast and the default saddle position is up, because there's always a short climb. A less extremely steep ST angle just feels more versatile in more varied conditions.
Sounds like you don't really know how to use a dropper well TBH. Stop thinking of the default position as up. think of it as down/ This way you ride everything stood up using your core but at the touch of a button you have a nice perch to rest on for a few seconds when required.
I used to do full 2 hour XC rides on my bike with the saddle completely slammed. Dropper posts actually made me weak and lazy.
I kinda feel like a slacker actual ST angle isn't bad, because as you drop is, it goes forward more, further getting it out of the way for hanging off the back
Depends hugely on the rider and bike size. I've always preferred riding as short seat tube bikes as I can and do actually slam the saddle on them. I have 33" inseam and 4 of my bikes have sub 14" seat tubes. two have a 250mm dropper. the other two have QRs and (450mm) seatposts. If I use the QR bikes for a longer ride the seat is at full pedalling extension height and correct position for pedalling. I'f I'm messing around it's lowered as far as it will in that seat tube. for arguements sake let's say that's 9" lower. if that angle were whack there's a good chance I'd hate the saddle position when dropped if the saddle was in the correct position fully extended and vice versa if the saddle was in the right place when slammed. Same goes for the dropper post equipped bikes. Ok my case is the extreme but it highlights the issue nicely.
FWIW I've never owned a bike with too steep a S/A but I've had plenty that were too slack.
 
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toodles

ridiculously corgi proportioned
Aug 24, 2004
5,479
4,719
Australia
I agree with @Gary (I know - shock horror). Steep AF for the win. Climbing anything remotely steeper than a wheelchair ramp with a slack SA makes you end up getting a prostrate exam from the saddle tip.

Running a dropper with a proper underbar remote lever lets you get that mofo out of the way as quick as a gear change once you're used to it. IMO, Transition has got it dialled with their new super steep SAs. I'd love to be on one of the newer bikes once they sort out the carbon Scout/Patrol and their Aussie retail pricing....
 

Jm_

sled dog's bollocks
Jan 14, 2002
18,850
9,556
AK
I used to do full 2 hour XC rides on my bike with the saddle completely slammed.
Pretty sure you are the only person that does this.

Also, I think we are gravely understimating the amount of riding that is not a fire-road climb and not a double-black descent. There's a hell of a lot of "kinda level" stuff out there, even in the big mountains.
 

Gary

"S" is for "neo-luddite"
Aug 27, 2002
7,535
5,470
UK
Pretty sure you are the only person that does this.
Kids do it. Riding bikes for me is all about feeling like I did as a kid. You know. care free. invinsible. sometimes invisible too.

Deep, eh?

Also, I think we are gravely understimating the amount of riding that is not a fire-road climb and not a double-black descent. There's a hell of a lot of "kinda level" stuff out there, even in the big mountains.
There's only one fireroad climb within a 10 mile radius of my house. I ride a lot from my house. There aren't any double black (not that I ever use colour grading system speak) trails for 40 miles. I travel the 40miles to ride more challenging elevation and terrain. But I don't mind if I don't for weeks and weeks. I'll still ride. Even on the dullest most miserable flat xc rides I'll still geek the fuck out finding a line that works through a shady flat bog littered with tree debris to try and ride it without dabbing, wheelie an entire road climb or maybe just ride a kerbstone to see how long I can manage it without falling onto the road. Sometimes I might switch to clips and ride a fixed height XC saddle height on my dirt jump bike with street tyres in the mud. just because. You know? Maybe not. either way it doesn't matter.
 

Jm_

sled dog's bollocks
Jan 14, 2002
18,850
9,556
AK
Kids do it. Riding bikes for me is all about feeling like I did as a kid. You know. care free. invinsible. sometimes invisible too.

Deep, eh?

There's only one fireroad climb within a 10 mile radius of my house. I ride a lot from my house. There aren't any double black (not that I ever use colour grading system speak) trails for 40 miles. I travel the 40miles to ride more challenging elevation and terrain. But I don't mind if I don't for weeks and weeks. I'll still ride. Even on the dullest most miserable flat xc rides I'll still geek the fuck out finding a line that works through a shady flat bog littered with tree debris to try and ride it without dabbing, wheelie an entire road climb or maybe just ride a kerbstone to see how long I can manage it without falling onto the road. Sometimes I might switch to clips and ride a fixed height XC saddle height on my dirt jump bike with street tyres in the mud. just because. You know? Maybe not. either way it doesn't matter.
Well, it always seems like someone claims that all of their climbs are on fireroads and then the ride down is always some extreme DH trail.
 

rockofullr

confused
Jun 11, 2009
7,342
924
East Bay, Cali
Since we're talking about Capras any Capra owners, @Gary , figure out what to do with the goofy front derailur mount? I pulled it off and there's a raw aluminum bracket under it. Dafuq am I supposed to do with this thing lol

I'm planning on nail polishing it black and finding something to plug the exposed bolt holes
 

slimshady

¡Mira, una ardilla!