[GrantB]

I have a26 inch hardtail that I love, but I am convinced that a29er is the way to go when I get back into endurance racing. What I want to do is find a29er that handles much like my present bike with the benefits of the rollover/smoothness of the 29er.

So the present bike...19" seat tube, 23.5 actual top tube, 100mm fork with head angle in the neighborhood of 68/69 degrees. 120mm stem. I can't remember the chainstay lengths. So what 29er numbers translate roughly into what I have here?

Thanks ahead of time if this is a question that has been done to death.

 

[gvs_nz]

I'm newish to the 29er scene but there are now a new generation of 29ers that use longer offset in the forks that use very similar geometry to an equivalent 26er. Scott Spark and Gary Fisher bikes are some. Kona are pretty close. Some are based on old geometry using 29er forks that used to have similar short offset as 26" bikes. They will have at least 1 to 2 degrees steeper in the head angle. They were designed to imitate a 26" hard tail and are quicker handling and not quite as relaxed to ride and don't carve or as accomplished as later gen bikes on the downhills.They are well suited to single speeding and boutique brands still seem to use the steeper angles.I think eventually, as they are doing with 26ers the geo will slacken back a bit.

 

[shiggy]

I have a26 inch hardtail that I love, but I am convinced that a29er is the way to go when I get back into endurance racing. What I want to do is find a29er that handles much like my present bike with the benefits of the rollover/smoothness of the 29er.

So the present bike...19" seat tube, 23.5 actual top tube, 100mm fork with head angle in the neighborhood of 68/69 degrees. 120mm stem. I can't remember the chainstay lengths. So what 29er numbers translate roughly into what I have here?

Thanks ahead of time if this is a question that has been done to death.

This comes up 2-3 times a week (or it seems like it).
Bike fit is bike fit, regards of the wheel size.
Compare the seat tube angles and ETT (and the reach and stack if it is listed) to find your size.

As far as HTAs, it is going to vary with the fork used on the 29er as there is a wide range of fork offsets used. You really want to compare the trail numbers, which is affected by the HTA, fork offset and tire diameter. Change any one and the trail changes.

Chain stay length is going to be longer on the 29er. IME it has less affect on overall handling than having proper fit and position relative to the front axle, and trail.

 

[gvs_nz]

And unfortunately very little specs out there on trail for various models. Some now have reach and stack.The various fork offsets available makes 29er world Geo a shambles.26ers are much easier to compare because their is only two stds, GF and the rest.From what I can gather most of the established brands doing 29ers come on board with the longer offset and GF is always going to be out there with G2. The boutigue brands still seem to want to keep their steeper angles which is close to their hardcore xc philosophy, the heart of the 29er movement.

 

[LyNx]

OK, as Shiggy said, comes up all the time about fit, but since you gave specific angles, I'll chime in with.....Look at the new crop of HT's coming out like the Banshee Paradox or Canfield YS. They are based on newer offset forks, have nice shorts stays and are super fun, yet super stable - all that I think you want.
I too like most rode the old school, super steep HA, 29ers to help bring in the long WB and make handling "snappier" for years, but after getting the Paradox I will NEVER ride anything with a HA steeper than 69* again - absolutely LOVE my Paradox with Minute 120m fork. It is so much fun, so responsive to your input, stable and confidence inspiring on the descents and climbs like a damn mtn. goat on crack.

Oh and as Shiggy said, fit is fit, doesn't matter what wheel size your riding. If you like a 23.5" ETT on your 26" wheeled bike, chances are you'll also like it on a 29er.

I have a26 inch hardtail that I love, but I am convinced that a29er is the way to go when I get back into endurance racing. What I want to do is find a29er that handles much like my present bike with the benefits of the rollover/smoothness of the 29er.

So the present bike...19" seat tube, 23.5 actual top tube, 100mm fork with head angle in the neighborhood of 68/69 degrees. 120mm stem. I can't remember the chainstay lengths. So what 29er numbers translate roughly into what I have here?

Thanks ahead of time if this is a question that has been done to death.

 

[shiggy]

OK, as Shiggy said, comes up all the time about fit, but since you gave specific angles, I'll chime in with.....Look at the new crop of HT's coming out like the Banshee Paradox or Canfield YS. They are based on newer offset forks, have nice shorts stays and are super fun, yet super stable - all that I think you want.
I too like most rode the old school, super steep HA, 29ers to help bring in the long WB and make handling "snappier" for years, but after getting the Paradox I will NEVER ride anything with a HA steeper than 69* again - absolutely LOVE my Paradox with Minute 120m fork. It is so much fun, so responsive to your input, stable and confidence inspiring on the descents and climbs like a damn mtn. goat on crack.

Oh and as Shiggy said, fit is fit, doesn't matter what wheel size your riding. If you like a 23.5" ETT on your 26" wheeled bike, chances are you'll also like it on a 29er.

I would not consider the Paradox or YS for endurance racing, though. They are more of long travel "hard core" hardtails than all day trail/race bikes.

Pretty much any non-Trek 29er will now come with a fork with ~46mm of offset. A frame designed for 100mm of travel and a HTA around 71 degrees will be similar to a 26er with a 69HTA and 100mm fork.

 

[laffeaux]

Yep, as other said top-tube length and stem length are the same regardless of wheel size.

Otherwise, the numbers that effect the way a bike handles the most are "trail" and bottom bracket height. If you know these numbers for your 26er, find a 29er that has the same or similar BB height and trail and you'll have a bike that handles similarly.

Because of the larger diameter wheel, to have a similar trail compared to a 26er, in the past due to limited fork option a 29er often had a steeper head tube angle to make the trail numbers similar. However, with forks now coming with different offsets, this isn't always true now. Trail is a calculated measurement that is determined by head tube angle, fork offset, and wheel size.

BB height is often measured as "BB drop." In the cases where BB drop is published, the number will be bigger for a 29er (compared to a 26er) because of the larger size wheel. However, if "BB height" is published a 29er and 26er can be compared easily. The BB height that you prefer should not vary based on wheel size.

 

[LyNx]

I will give that the Paradox is definitely not a "soft" ride being alu and because of it's box stays (also what makes it so great and responsive), but as to the Geo not being for Endurance Racing, I'd have to disagree on that. I thought the 71-72* HA was great, UNTIL, I got the Paradox and besides the intial FS to HT learning curve I experienced I won't eve r go back to a HA over 69*. I could easily see myself riding the Paradox as an endurance bike (course permitting) over the more race oriented 71*+ HA frames. The ultimiate Enduro race HT for me would have the Paradox's geo and be made from Ti Not that I've done a crap load of endurance events, but after doing Laramie and Leadville I can tell you, having abike that you don't have to be constantly watching and worrying about terrain features because of the steep HA or steep descents and instead can sit and pedal and enjoy the ride makes a world of difference, just build it up suitably light and you're golden.

I would not consider the Paradox or YS for endurance racing, though. They are more of long travel "hard core" hardtails than all day trail/race bikes.

Pretty much any non-Trek 29er will now come with a fork with ~46mm of offset. A frame designed for 100mm of travel and a HTA around 71 degrees will be similar to a 26er with a 69HTA and 100mm fork.

 

[gvs_nz]

Agree. I've done plenty of 100km races on my Trance X and wouldn't have wanted anything more skittish. I like the Paradox geo, and if he wants a slightly more refined ride with similar angles but longer chain stays you can get the Scott Scale elite 29er as a frame set. If he's feeling rich and wants a much more refined ride then the Carbon framed Scott Scale 29ers have long waiting lists of prospective buyers.

http://www.bikeradar.com/news/article/scott-scale-949-29er-first-ride-review-26798

Here's a comparison between Scott Scale 26" and 29" for ultra endurance events.

http://forums.mtbr.com/showthread.php?t=688855

 

[shiggy]

I will give that the Paradox is definitely not a "soft" ride being alu and because of it's box stays (also what makes it so great and responsive), but as to the Geo not being for Endurance Racing, I'd have to disagree on that. I thought the 71-72* HA was great, UNTIL, I got the Paradox and besides the intial FS to HT learning curve I experienced I won't eve r go back to a HA over 69*. I could easily see myself riding the Paradox as an endurance bike (course permitting) over the more race oriented 71*+ HA frames. The ultimiate Enduro race HT for me would have the Paradox's geo and be made from Ti Not that I've done a crap load of endurance events, but after doing Laramie and Leadville I can tell you, having abike that you don't have to be constantly watching and worrying about terrain features because of the steep HA or steep descents and instead can sit and pedal and enjoy the ride makes a world of difference, just build it up suitably light and you're golden.

I ride 71degree/47mm 29ers in rough techy terrain and it is far from twitchy and needing looking after. I also have steeper 29ers and they are more 'lively."
I stand by that a 70.5-71 HTA 29er with a 46-48mm offset fork will behave similarly to a 26er with a 69HTA and 38mm offset.

I could see going slacker for a longer travel fork, but not 100mm or less travel.

Too short chainstays can also make a bike a handful to control when it gets fast and rough.

 

[BeerCan]

I think geometry is user preference just like with 26" bikes. Like shiggy I ride a bike with ~71 degree HTA and don't find it twitchy at all (100mm fork). I rode a few bikes that were slacker and did not like them so much. I think a lot of it has to do with the fact that there are not a lot of long downhill runs where I live. Bikes should definitely match terrain and riding style. FWIW when I went from 26" to 29" the only thing I tried to closely match was ETT length. I new I was comfortable on my 26" at a certain top tube length and figured it would transfer to the 29er. It worked for me.

 

[LyNx]

:thumbsup: :thumbsup: :thumbsup:

I think geometry is user preference just like with 26" bikes. Like shiggy I ride a bike with ~71 degree HTA and don't find it twitchy at all (100mm fork). I rode a few bikes that were slacker and did not like them so much. I think a lot of it has to do with the fact that there are not a lot of long downhill runs where I live. Bikes should definitely match terrain and riding style. FWIW when I went from 26" to 29" the only thing I tried to closely match was ETT length. I new I was comfortable on my 26" at a certain top tube length and figured it would transfer to the 29er. It worked for me.

 

[gvs_nz]

From memory the Paradox is 70 degrees for 100 mm fork. That's mainstream for many mfg now. The short stiff chain stays are the standout. I'd rather look at wheelbase than chain stays regarding handling because I'm flexible with seat posn and bars, hence COG, to get best handling in pref to KOP fit rules.

 

[shiggy]

From memory the Paradox is 70 degrees for 100 mm fork. That's mainstream for many mfg now. The short stiff chain stays are the standout. I'd rather look at wheelbase than chain stays regarding handling because I'm flexible with seat posn and bars, hence COG, to get best handling in pref to KOP fit rules.

The KOPS setup is where the stack and reach specs can come into play. Gives you a better idea if the length will work than ETT because it is based off of the BB and not the seat tube. Also tells you more about where the bars will be in relation to the front wheel, though HTA does affect that.

Another way to think about fit is how you are positioned when standing. STA make no difference. Everything is based off of the BB and where your hands are. Stack and reach tells you where your hands will be.

 

[Blaster1200]

I'm with you LyNx. For an all-day, all-terrain 29er, I prefer short chainstays (16-5/8"ish), slack head angles (67.5-69 degrees) with a 100 mm fork. After riding that setup, those old school 71 degree head angled 29ers with 17-1/2"+ stays are horrible and no fun to ride.

Like geo has changed with 26" bikes over the years, the average 29ers will likely soon progress to match the advances of 26ers with the benefit of the larger wheels.

 

[gvs_nz]

One word describes short chain stays ride quality. HARSH. Fun bike yeh, for popping the lip and carving while standing. Not my preference for long days in the saddle on a hard tail. Longer chain stays and slack seat angles gives more cush from both the rear triangle and the seat tube/post. Has similar affect to handling when seated as short chain stays anyway[ same COG posn. Slack seat angle will keep wheelbase short which is prime for handling and longer stays give better high speed stability when standing going downhill. Only draw back is short people can't fit the bike if they want to use the KOPS rule. Something with moderate chain stay length is a good balance for endurance racing. Scott scale 29er.

 

[shiggy]

One word describes short chain stays ride quality. HARSH. Fun bike yeh, for popping the lip and carving while standing. Not my preference for long days in the saddle on a hard tail. Longer chain stays and slack seat angles gives more cush from both the rear triangle and the seat tube/post. Has similar affect to handling when seated as short chain stays anyway[ same COG posn. Slack seat angle will keep wheelbase short which is prime for handling and longer stays give better high speed stability when standing going downhill. Only draw back is short people can't fit the bike if they want to use the KOPS rule. Something with moderate chain stay length is a good balance for endurance racing. Scott scale 29er.

STA has no affect on the "cush" of a frame. It is still a rigid structure. The angle of the seatpost can add flex to it.

Longer CSs simply move the bump further from the rider, which lessens the vertical movement at the pedals and saddle.

 

[mtroy]

I have a26 inch hardtail that I love, but I am convinced that a29er is the way to go when I get back into endurance racing. What I want to do is find a29er that handles much like my present bike with the benefits of the rollover/smoothness of the 29er.

So the present bike...19" seat tube, 23.5 actual top tube, 100mm fork with head angle in the neighborhood of 68/69 degrees. 120mm stem. I can't remember the chainstay lengths. So what 29er numbers translate roughly into what I have here?

Thanks ahead of time if this is a question that has been done to death.

Here is a thought...wanting a 29er that feels just like your 26er is a red herring in some ways and I think has come from thinking that some of the things about 29ers need to be 'fixed'. It just may be that as we get closer to that '26" feeling' we begin to lose much of what we loved about 29ers to begin with.

Still pondering this, but the rush to shorter CS and slacker HT angles, etc....that has some compromises that are not that great for all things.

In any case, I think Shiggy has it pretty well stated. As usual.:thumbsup:

 

[starre]

anybody compiling a list of stack and reach for mountain bikes? thanx!

The KOPS setup is where the stack and reach specs can come into play. Gives you a better idea if the length will work than ETT because it is based off of the BB and not the seat tube. Also tells you more about where the bars will be in relation to the front wheel, though HTA does affect that.

Another way to think about fit is how you are positioned when standing. STA make no difference. Everything is based off of the BB and where your hands are. Stack and reach tells you where your hands will be.

 

[shiggy]

anybody compiling a list of stack and reach for mountain bikes? thanx!

More companies are including it on their geometry charts.
Salsa, Specialized, Turner, On-One...