[MMcG]

This is the current 29er FS frame set that has me most intrigued, and it looks awfully similar in suspension design concept to the Balfa 2 Step.

What do you guys think - is the RIP Nine a refined 2Step with big wheels?

Pictures to help the discussion:

First the RIP 9

Now the 2Step

The Niner again:

The 2Step one more time:

They look awfully similar to me - which in my opinion is a good thing.

Alex - what is your take on these two suspension designs? Will the Niner linkage design work well in the 29" wheel format?

Discuss.......

 

[ÆX]

well, having the ability to tune a reaward axle path when you go later
into the travel keep the tire from the seat tube giving more clearance.

i have yet to see the axle path of the niner though.

for a bike you pedal all the time and is under 4'' i like links.

for a bike you stand on and coast more than pedal I like high pivots.

 

[Smelly]

Sure looks like it to me, though the pivots aren't in exactly the same place.
Does anyone know when the RIP9 is coming out? Or is it out already? I'd love to get to try one of these 5-6" 29ers.
Man, I wish I'd come up with the name for that bike. Who was the lucky SOB that won the naming contest?

 

[N8 v2.0]

I am simply not attracted to how that bike looks.

Not saying that it sucks or anything, just doesn't look nifty at all.

 

[MMcG]

I think it looks killer - when you compare it to the new Fishers (blech). It is defnitely more refined looking than the 2Steps were. I had a 2Step DH demo bike, and that thing was nice (bb was way low though) and I rode a 2Step FR a bit (damned fun bike - but heavy for a trail/light freeride bike).

Smelly - I think July or August for availability and it is down to 4.5" of travel from its original prototype 6" version.

I think of it as an All Mountain 29er so you would sit and pedal on it Alex......so it would give a rearward axle path (similar to say a Canfield FS bike or a BB7 etc?)

Do your inedibles provide a rearward axle path as well?

 

[moff_quigley]

I love how it looks. If there's one bike out there that makes me want to get a big wheeled bike this would be it. If most definitely looks like a 2 Step.

The only thing that might be deal killer for me is the exposed lower linkage when running a 2X and bashguard setup. Maybe a 36T max guard will still protect the link/frame.

I'd take that silver one no doubt about it.

 

[MMcG]

Travis - on the Balfa that link actually worked sorta like a link/guard if you will.

Take care,

Mark

 

[jncarpenter]

...I definitely think it is a nice looking ride & should be somewhat nice to pedal around, similar to the 2-step. Personally, I think I will wait a bit longer for the Turner 9'er. Knowing DT, it will be dialed at 4" & with bushings......like a 29" Flux :love:

 

[MMcG]

when is the ETA on the Turner 29er??

 

[N8 v2.0]

...I definitely think it is a nice looking ride & should be somewhat nice to pedal around, similar to the 2-step. Personally, I think I will wait a bit longer for the Turner 9'er. Knowing DT, it will be dialed at 4" & with bushings......like a 29" Flux :love:

A 29er Turner Flux is in the works....

 

[jncarpenter]

A 29er Turner Flux is in the works....

...is there an echo in here Seriously, that's what I just said

when is the ETA on the Turner 29er??

...we should see something for IB with a release late this year. I'm looking at a Niner (emd9 or sir9) to hold me over

 

[N8 v2.0]

HAHA!

Oh well

oh well

oh well

 

[MMcG]

...is there an echo in here Seriously, that's what I just said

...we should see something for IB with a release late this year. I'm looking at a Niner (emd9 or sir9) to hold me over

If you are riding a Sovereign now - which I think you are or were - I'd opt for the Sir9 ifn you can swing it price-wise.

 

[jncarpenter]

If you are riding a Sovereign now - which I think you are or were - I'd opt for the Sir9 ifn you can swing it price-wise.

...any reason other than the ability to swap between SS & gearie?

 

[jncarpenter]

The drawings are done and in the process of getting in line for tooling etc at SAPA. There will be 4 sizes from 18-24". TT are long and the head angle is 71, with a 73 seat tube angle. The steeper seat angles make them hard to loft the front wheel with the long stays req'd on a 29" wheel, so I went a little slacker than most here. I am not trying to make a 29er with the same #'s as a 26er, not only is that impossible, but I don't think it handles. 13.2 BB with a 18.2 chainstay length. Travel is 3.9" and the triangle is drawn around the 100mm travel Reba.

FYI...from THIS THREAD on the MTBR/ Turner boards

 

[Bicyclist]

Holy long stays batman. 18.2 inches?!?!?!?

 

[narlus]

sounds like a sled.

 

[El Caballo]

sounds like a sled.

I ride a hardtail with 18.5" chainstays. This doesn't slow down the steering at all. What affects the steering is fork trail, and to a lesser extent, weight distribution.

Think about it...if long chainstays strongly affected handling, it would be impossible to turn a tandem.

I don't know how the "long chainstays handle slower" myth got started, but I wish I could kill it. Short chainstays screw up weight distribution for taller riders, ruining cornering and climbing performance by putting too much weight on the rear. The only downside is it's harder to manual.

 

[MMcG]

I don't know how the "long chainstays handle slower" myth got started, but I wish I could kill it. Short chainstays screw up weight distribution for taller riders, ruining cornering and climbing performance by putting too much weight on the rear. The only downside is it's harder to manual.

This is a good point. I've seen a few XL sized bikes, especially 26" wheeled bikes where it looks like the rider has to practially sit on top of the rear wheel - so I can see why longer chainstays due make some sense for taller riders in particular so that the wheelbase is proportionate to their height.

 

[binary visions]

How can you say that long chainstays don't affect steering, but weight distribution does?

Chainstay length has a direct influence on your weight distribution. As you said in your own post.

 

[MMcG]

How can you say that long chainstays don't affect steering, but weight distribution does?

Chainstay length has a direct influence on your weight distribution. As you said in your own post.

Was your reply meant for my post or the other guys?

I must admit that I've never been on a bike that had anything longer than say 17.5" chainstays.

18.5 does seem pretty damned long though, but if I were 6'6" tall maybe it wouldn't feel so bad to me... I dunno.

 

[binary visions]

Was your reply meant for my post or the other guys?

Sorry, it was directed toward El Caballo.

 

[MMcG]

Sorry, it was directed toward El Caballo.

Don't let it happen again okay!

 

[binary visions]

Don't let it happen again okay!

Sir! Yes, Sir!

Never again, Drill Sargent, Sir!

 

[El Caballo]

How can you say that long chainstays don't affect steering, but weight distribution does?

Chainstay length has a direct influence on your weight distribution. As you said in your own post.

I also said "to a lesser extent".

In fact, now that I've thought about it some more, the basic physics model says that if you're not going so slow and turning so hard that you're physically scrubbing the tire on the ground, weight distribution shouldn't matter at all to steering (assuming that your COG is somewhere reasonable, like between the axles).

There are two forces required to turn a bicycle.
1) You need to shift your weight to one side of the line between the two contact patches. The force required to do this will depend on your weight and height, the bike weight, the wheel size and weight, and the speed of the bike.
2) You need to turn the handlebars. Assuming identical handlebars, the force required to do this will depend on trail, wheel size and weight, and the speed of the bike.

I don't see any way that variations of a few inches in the distance between the two contact patches, or the fore-aft position of your COG between them, can meaningfully affect these forces. However, I freely concede that there are plenty of people who are better at physics than I am, so I'm open to corrections here.

I think people are mostly reacting to changes in body positioning, which can greatly affect your ability to steer. Move your seat an inch forward and get a 50mm shorter stem: your weight distribution won't change, but I bet steering feels a lot different.

 

[binary visions]

Hmm.

Well, the physics analysis is interesting, but I'll tell you that I have a bike with an adjustable chainstay between 17" and 15", and the longer chainstay position is tougher to corner with.

I take that back. It's not harder to corner with in all corners. It's harder to handle through switchbacks or super tight, almost-switchback corners, though.

Any idea why that is?

 

[El Caballo]

Hmm.

Well, the physics analysis is interesting, but I'll tell you that I have a bike with an adjustable chainstay between 17" and 15", and the longer chainstay position is tougher to corner with.

I take that back. It's not harder to corner with in all corners. It's harder to handle through switchbacks or super tight, almost-switchback corners, though.

Any idea why that is?

I can think of two guesses right away.

1) The longer your wheelbase, the more your rear wheel slows down in very tight corners, because the rear wheel takes a shorter path than the front wheel -- and the harder it is to stay balanced, because you're moving more slowly. In the extreme case, your front wheel is turned 90 degrees, the rear isn't moving at all.

2) More weight on the front exacerbates the tire scrubbing issue I mentioned above. 29ers also have a longer, thinner contact patch, so scrubbing will be even more noticeable at the low speeds it occurs.

Do either of these sound right to you?

 

[binary visions]

Very possible. But chainstay length directly impacts wheelbase length, , which is why point #1 feels slower, so we're back where we started

Fact is, people have top tube lengths based on their height and the size they want their bike. So, regardless of what brand or model the bike is, people usually pick their top tube at a size that's comfortable to them. If the bike then has long chainstays, it'll have a longer wheelbase. Right?

So on one hand, you may be correct (if your physics are right, and I've got no reason to doubt them - I'm not a physics guy) - chainstay length as an independant variable doesn't hurt your cornering abilities. However, chainstay length generally isn't and independant variable, since top tube length is where you choose your bike fit.

If I like a 23" top tube, I'm going to get a bike with a 23" top tube. If it has long chainstays, it will corner harder due to the longer wheelbase. But I'm not going to choose a short top tube to compensate; if you picked a bike with long chainstays but a short toptube, it might corner essentially the same, but it won't fit right so you don't do that.

 

[El Caballo]

bv: I think this is an important distinction. A longer wheelbase ought not to turn slower in tight turns, but it could definitely be harder to balance. You are correct that this should be the case whether the long wheelbase comes from a long chainstay, a long top tube, or a slack head tube.

My guess is that it probably doesn't matter as much on downhill switchbacks, but I can easily imagine noticing it on uphill switchbacks. Does this sound right to you? (You've got the good test rig.)

Also, you're touching on one of the bizarre inconsistencies in bicycle frame design.

Because of the theory that chainstays should always be as short as possible, top tubes increase in size for larger frames, but the chainstays are always identical in length. This means that weight distribution changes radically as you go up frame sizes: a shorter rider on a smaller frame will have a COG much closer to the middle of the bike, whereas a taller rider on a larger frame will have a COG much farther back towards the rear axle.

You'd think that frame designers would want the rider's COG to be in a certain place based on intended usage (XC, FR, DH, whatever), which would mean that the chainstays would increase in length as the ETT increased. But no one does this.