29" wheels for DH racing?

[Curtis]

Was sitting around bench racing with a few buds Friday night and we started talking about using 29" wheels for DH racing.
(we had been burning &drinking)
I really think a 29" wheel would be very viable for DH racing. Pretend for a moment a fork/frame with 8" of travel exsist, and tires of YOUR chioce........would you. What are the pros and cons of this ceniario.

Discuss.

[Curtis]

come on none of you have an opinion on this?

[UncleAl]

29s will roll over everything noticably easier, and will maintain momentum better than smaller wheels, but tire sizes are limited (I haven't heard of one wider than 2.2) and the bigger wheels and resulting longer wheelbase make tight switchbacks and such more difficult. I guess it would depend on the course. You'd need a frame and fork to accomodate the bigger wheels - that's a big commitment.
If I raced XC, I'd definitely take a serious look at 29ers.

[WBC]

I think 29ers would kill handling....it would only be good for CA style stuff. Imagine popping the front end up to hop over some big root cluster or whipping over the top of some turn...

anything technical would SUCK.

[UncleAl]

A 29" wheel wouldn't have to be lifted over big stuff as much as a 26" because the hub is further off the ground - you'd just have to ride into stuff and they'll roll right over. And I don't think lifting it will be any more difficult than a 26" - why would it? Also, a 29" tire will have a larger area of contact with the ground - better grip.
I think you're right about it being tougher to whip the bike around though.

[white ri0t]

They would weigh more.
The wheel would be flexier due to longer spokes.
The tires would weigh more.
They would take longer to get up to speed.
Gear ratios would be changed with a 29"
I can't imagine any technical climbing would be fun, either.
Slower to turn
I think that they would be ghey.

[Schaefdog]

Originally posted by Derek Diggler
They would weigh more.
The wheel would be flexier due to longer spokes.
The tires would weigh more.
They would take longer to get up to speed.
Gear ratios would be changed with a 29"
I can't imagine any technical climbing would be fun, either.
Slower to turn
I think that they would be ghey.


:duh:

[Aircorp]

Not to mention that your center of gravity would be higher, less standover clearance so you be a lot more off balance.

[Broken Fusion!]

Annd the wheel would be weaker.

[FlipSide]

- They would require fork manufaturers to make forks that accept these tires. The equipment is expensive enough right now...I don't want the fork manufacturers to do some R&D work on that. They should concentrate on fixing the problems their current forks have.

- They would require chainstays that are too long IMO.

- The Pinkbike Kids will want Nokian to make a 29"x3.0" Gazz and the world certainly don't need that. :lol:

[UncleAl]

Originally posted by Derek Diggler
They would weigh more.
The wheel would be flexier due to longer spokes.
The tires would weigh more.
They would take longer to get up to speed.
Gear ratios would be changed with a 29"

Yes, yes, yes, yes, and yes. But because a 29" wheel will roll over everything quicker and have more momentum, it will have and maintain a faster top speed than a smaller wheel.

I can't imagine any technical climbing would be fun, either.
Slower to turn

Since it's the obstacles that slow you down on a technical climb, and the 29" wheel will roll over these easier, I think the bigger wheel would be better. Fewer stops and stalls. And the rear tire's larger contact patch would mean better grip.

Originally posted by Aircorp
Not to mention that your center of gravity would be higher, less standover clearance so you be a lot more off balance.

No. 29er bikes aren't just 26" wheeled bikes with bigger wheels. They're designed around the bigger wheels. Your centre of gravity would actually feel lower beause your body is closer to being between the hubs. Standover height will depend on the frame design (just like a regular mtb), not the wheels.

[GrimJack]

Bigger wheels turn slower at the same speed as smaller wheels - meaning that bigger equals faster, as a general rule. Less bearing wear at the same speed, too. Bigger wheels roll over things easier as well. And extra 1.5 inches of clearance for your discs and rear derailleur would be nice...

Frames would have to add either 3 inches in ride height (not a great idea) or 3 inches in wheelbase, so your rear tire won't hit the seat on full compression. Or some combination thereof. I wouldn't be happy with the former, but the latter would be nice for a DH race rig, not so nice for the tight corners and slow speed accuracy required for typical north shore style riding.

Forks would just plain have to raise three inches. That's a big deal, IMO. That leaves a seriously choppered bike or a much higher center of gravity.

EDIT - In theory, you could yank three inches in stack height out of the headtube, but in reality, that would make the headtube connection to the rest of the frame too weak. EDIT

Wheels wouldn't necesarily get weaker - that's a function of how many spokes you have, and how long they are. Larger hub flanges and a higher spoke count would fix that... at the cost of added weight. Added weight makes a wheel tougher to get up to speed and more difficult to slow down.

As an idea, I think it could work. In reality, the lack of tire and rim selection will likely prevent this from being useful - just like 24 inch rims. :(

[white ri0t]

Frames and forks would only be 1.5 inches higher;)

[GrimJack]

Originally posted by Derek Diggler
Frames and forks would only be 1.5 inches higher;)

I've got news for you. If you put a wheel that is 3 inches bigger on a fork that's only 1.5 inches higher, you'll have a problem the first time you try to use the suspension aspect of the fork.

Technically, you are correct, the frame and fork only need to be 1.5 inches bigger - but the other 1.5 inches comes from the bottom of the wheels, putting you an extra 3 inches higher on the fork at least. The rear wheel is another story... you can add between 1.5 and 3 inches of ride height, along with 0 - 1.5 inches of chainstay length.

[white ri0t]

draw me a picture, I'll draw you one. I say 1.5 inches.

[BAC5.2]

Derek is correct. Axle to top of the wheel increases by only 1.5"

I have ridden a 29" bike (Gary Fisher Super-Caliber29).

There were a few drawbacks.

The increased weight was noticeable, and to get up to speed took longer than I was used to. The 25 pound bike accelerated like my Stumpjumper did in it's 30Lb months).

Once the bike was going. Goodbye everything in my way. You lean back a bit and just float over things in the trail. Rocks you have to hop over or go around can be rolled right over.

Another benefit was increased traction. Larger contact patch thanks to a larger tire. I ran 28 PSI in my 26" Stumpjumper wheels. I was running the same in the 29" wheel and it felt great. Significantly more traction.

The ride was espically interesting. Instead of moving the bike underneath you like you do on a 26", you are sitting between the wheels rather than on top of them on the 29". When you moved, the bike moved. It was really different. You had to feel the trail with your body, and lean with the bike. Felt faster in a straight line downhill or sweeping turns. In the tight stuff, it just felt like I was riding a bike that was to big for me.

On the climbs, not much difference. Instead of zig-zaging up a hill dodging rocks, you just concentrate on spinning smooth circles and you roll right over everything.

The design has it's good's and it's bads.

Spoke-flex, weight, acceleration, all that jazz definately hurt the idea. It's because of those negatives that I won't be riding them.

The argument is EXACTLY like the 24 Vs 26 argument, only bigger.

It would be good for wide open courses. I didn't like how I couldn't move the bike beneath me in the tech though.

[GrimJack]

Picture attached.

I'm not saying that the axle to crown will increase by more than 1.5 inches.

I am saying that your total ride height will increase by 3.

This picture gives a relatively realistic example of a 29 inch wheel on a front fork. In this case, your bar height (if you run flat bars) would be approximately 45 inches. I'm leaving out the trig calculations to figure out the exact height, as this isn't a straight line, 'cause I'm lazy. And I'm at work. ;)

If you were to build a bike with 26 inch wheels, and the same travel fork, it would be approximately 42 inches for the same measurement, again, ignoring the minimal geometry corrections for non straight lines.

The rear wheel is more complicated, as I've said... especially as the wheel suspension travel isn't linear as it is with forks.

[white ri0t]

you are right about the ride height going up 3 inches, but your picture is wrong.
the wheel adds 1.5 inches to the ride height
you need an extra 1.5 inches on the fork for extra clearence.

[WBC]

I could strip my mx chassis, weld on a BB shell with a fucking long spindle and have similar characteristics in ride?

I've always wanted to do that (turn a mx into a mtb)

[UncleAl]

26" vs 29":

http://www.cyclingnews.com/tech/2001/photos/interbike01/fisher29.jpg

[GrimJack]

How exactly is my picture wrong? Which measurement?

[BAC5.2]

The ride height is not increased by 3". It is increased by 1.5".

[GrimJack]

Okay... explain.

When I add it up, I get an extra three inches. I'd like to know what I'm adding twice, or what you are leaving out.

[BAC5.2]

Look at a 6" brake rotor versus an 8" brake rotor.

lay the 6" on top of the 8" rotor. Measure from the edge of the 6" rotor to the edge of the 8" rotor.

Diameter increases 2", radius increases 1".

Even you're diagram. 14.5" for a 29" wheel. 13" axle to ground height for a 26" wheel. Total difference in ride height is 1.5" (14.5" - 13" = 1.5").

[white ri0t]

Originally posted by BAC5.2
The ride height is not increased by 3". It is increased by 1.5".

no, it is. 1.5 from the tire, right? then you need an extra 1.5 for clearance from the fork. longer stanchions.

[white ri0t]

Originally posted by BAC5.2
Look at a 6" brake rotor versus an 8" brake rotor.

lay the 6" on top of the 8" rotor. Measure from the edge of the 6" rotor to the edge of the 8" rotor.

Diameter increases 2", radius increases 1".

Even you're diagram. 14.5" for a 29" wheel. 13" axle to ground height for a 26" wheel. Total difference in ride height is 1.5" (14.5" - 13" = 1.5").

good point, but the rotor doesn't move or have to worry about clearance. wheels do, like on a fork. if you put a bigger wheel into your same old fork, you won't get past the fork brace. you also have to worry about the tire bottoming against your fork crown when you bottom your fork.

[ronald55555]

it's 3" damnit.

add 1.5 for the bottom half of the wheel, another 1.5 from the axle to the arch of the fork, which would raise the front a total of 3

[ronald55555]

basicly, you will have a bigger wheel and also a longer fork

[BAC5.2]

Look at it this way.

Delete the tire. Just the rim. Total diameter is 29". Axle being the center point, the radius is 14.5".

Ride Height is based on Radius, which is a direct correlation to the diameter.

You gain 3" in diameter, but you only gain 1.5" in ride height increase (1.5" increase in radius per side).

The fork arch need's to be increased by 1.5". The stanchions will also need to increased by 1.5" (angles wont change because the rear would be 29" too).

If the stanchions, and the arch are both increased 1.5" in length, then it will be no different than running a 26" fork in a standard fork.

[barry]

NO. its 1.5. how can you be so silly? think about what your saying here.

diamer goes up 3", so radius goes up 1.5"

its 1.5. im positive. i just swtched from 26"s to 24s and theres a 1" difference.

[BAC5.2]

Originally posted by ronald55555
it's 3" damnit.

add 1.5 for the bottom half of the wheel, another 1.5 from the axle to the arch of the fork, which would raise the front a total of 3

In relation to a 26" wheel, everything is raised 1.5" (chainstays are 1.5" above a 26" norm. Same with fork, and BB).

That's what I thought we were talking about?

[ronald55555]

the rear is 1.5 no doubt.

but lets just talk about the front. What is your definition of how much the ride height increased? are you measuring how much the distance between the axle and ground increased? or are you talking about the distance increased from the head tube to the ground?

if we're talking about how much distance it increased from the head tube to the ground, realisticly, it wont be 1.5 and it wont be 3, probably somewhere in between because of the head angle.

[BAC5.2]

I thought we were talking axle to ground... LOL.

A bike with 29" wheels, running 26" wheels will sit a total of 1.5" lower than it would with 29" wheels.

Just for comparison, take your 6" rotor and your 8" rotor.

standing on edge, the 8" rotor has a stack 2" higher than the 6" rotor. But if each one was mounted on a hub and stood on edge, the axle center of the 6" rotor would be 1" lower than the axle center of the 8" rotor.

See what I am saying?

[white ri0t]

yes, with the rear you would only get 1.5 inches higher. and the chain stays would have to be longer, and the seat stays too, resulting in a heavier frame.

To eliminate the front tire is great, but not very practical. do all the measurements you want without one, but it won't help you out when you go to ride the bike.

[GrimJack]

Started quite the disagreement here, didn't we? :)

No worries.

Going from 26 to 24 on a standard bike you will drop an inch, but this is not the same. You would have an extra inch of clearance in this case. If you dropped your fork to a 24 inch specific fork, you'd lose two inches off your ride height in total.

Going from a 26 to a 29 will add 1.5 inches to the axle height. Furthermore, if you don't lengthen the lowers on your fork by 1.5 inches, you won't be able to fit a tire on your rim. If you lengthen the lowers, you are adding 1.5 inches to the axle to crown height.

The actual addition to the ride height won't be *quite* 3 inches, because your headtube isn't 90 degrees to the ground... but even with the slack headtube angles most DH riders prefer, it is still going to be closer to 3 than 2 inches.

[BAC5.2]

assuming a constant tire height between 26" wheel and 29" wheel.

Without the tire on either rim, makes measurements easier and removes all of the tire arguments.

Put the tires on and say that the overall diameter of the 29" wheel is actually 32" and the actual diameter of a 26" wheel is 29". Either way, the numbers will come out the same.

[white ri0t]

Originally posted by BAC5.2
I thought we were talking axle to ground... LOL.

A bike with 29" wheels, running 26" wheels will sit a total of 1.5" lower than it would with 29" wheels.

Just for comparison, take your 6" rotor and your 8" rotor.

standing on edge, the 8" rotor has a stack 2" higher than the 6" rotor. But if each one was mounted on a hub and stood on edge, the axle center of the 6" rotor would be 1" lower than the axle center of the 8" rotor.

See what I am saying?

I see your point on axle to ground, as well as rotor comparrison :)

[GrimJack]

BAC, I see what you are saying. I think we're talking different measurements.

I'm worried that the 29 inch wheels will put the rider 3 inches higher. In the front, anyhow, the rear could stay even if you were willing to lengthen your chainstays by three extra inches... and not taking into account rear suspension axle paths on different designs, either.

[BAC5.2]

Originally posted by GrimJack
Started quite the disagreement here, didn't we? :)

No worries.

Going from 26 to 24 on a standard bike you will drop an inch, but this is not the same. You would have an extra inch of clearance in this case. If you dropped your fork to a 24 inch specific fork, you'd lose two inches off your ride height in total.

Going from a 26 to a 29 will add 1.5 inches to the axle height. Furthermore, if you don't lengthen the lowers on your fork by 1.5 inches, you won't be able to fit a tire on your rim. If you lengthen the lowers, you are adding 1.5 inches to the axle to crown height.

The actual addition to the ride height won't be *quite* 3 inches, because your headtube isn't 90 degrees to the ground... but even with the slack headtube angles most DH riders prefer, it is still going to be closer to 3 than 2 inches.

Ride height and total height are different things.

You can have a Nissan 350Z 8" off the ground, and a Ford Econoline van 8" off the ground. The 350Z is going to have bigger wheels. But the ride height is going to be the same. The Ford is taller which, by your mentality, would equate to a taller ride height.

Ride Height is measured from the bottom of the fork/frame?BB to the ground, not the bars to the ground.

[white ri0t]

Originally posted by GrimJack
BAC, I see what you are saying. I think we're talking different measurements.

I'm worried that the 29 inch wheels will put the rider 3 inches higher. In the front, anyhow, the rear could stay even if you were willing to lengthen your chainstays by three extra inches... and not taking into account rear suspension axle paths on different designs, either.

the stays would only be 1.5 inches longer ;)

[GrimJack]

Originally posted by Derek Diggler
the stays would only be 1.5 inches longer ;)

Doh! You are correct.

[GrimJack]

Originally posted by BAC5.2
Ride height and total height are different things.

You can have a Nissan 350Z 8" off the ground, and a Ford Econoline van 8" off the ground. The 350Z is going to have bigger wheels. But the ride height is going to be the same. The Ford is taller which, by your mentality, would equate to a taller ride height.

Ride Height is measured from the bottom of the fork/frame?BB to the ground, not the bars to the ground. '

There's the crux of it all. I thought ride height was how high the rider is.

So we agree that the rider - or their hands, anyway, will end up 3 inches further away from the ground.

[ronald55555]

Originally posted by GrimJack
'

There's the crux of it all. I thought ride height was how high the rider is.

So we agree that the rider - or their hands, anyway, will end up 3 inches further away from the ground.

no it wouldnt be 3" higher, it would be between 1.5 and 3" higher, because the head angle isnt 90 degrees.

[UncleAl]

Geezuz.

Click this, and check out the 29" Wheels section:
http://www.fisherbikes.com/fisher101/

:P

[white ri0t]

Originally posted by ronald55555
no it wouldnt be 3" higher, it would be between 1.5 and 3" higher, because the head angle isnt 90 degrees.

hmmm. Good point ;)

now Gary Fisher has XC bikes with 29" wheels. who makes his forks? and tires? and rims? sounds to me like a vain attempt for him to stay current, not having a DH or FR bike.



So what have we decided here?

Heavier wheel, tires
Slower acceleration/braking
you ride higher on the bike
flexier wheel
heavier bike overall
Tire/rim options limited
kinda ghey
gear ratios would be changed

[GrimJack]

Originally posted by ronald55555
no it wouldnt be 3" higher, it would be between 1.5 and 3" higher, because the head angle isnt 90 degrees.

ok, now you've gone and made me all growly. :(

According to my CAD program here, at a 68 degree head tube angle, the difference is 27.91 inches vs 24.98 inches. This makes for a 2.93 inch difference, which in my book is close enough to 3 inches... I mean, we're talking about a sixteenth of an inch here.

[ronald55555]

Originally posted by Derek Diggler
So what have we decided here?

Heavier wheel, tires
Slower acceleration/braking
you ride higher on the bike
flexier wheel
heavier bike overall
Tire/rim options limited
kinda ghey
gear ratios would be changed


you can compensate the slower accel and gear ratio with different cogs or chainrings, compensate higher height with longer wheel base, i would agree on everything else, and it is ghey.
I think it would only have an advantage if the course is fast and slightly rocky, the only advantage is that it can roll over stuff better. On a 26 you can always compensate speed with chainrings or cog.

[Ashek]

BAC is right, it would only be 1.5" (1.39" actually)
I think gary needs to come and get spanked on the shore before making comments and products that he thinks will perform in such an environment.
29" is fine for smooth paths, commuter bikes, stanley park, and general cruising, but for a MTB? Dont think so..
From the picture posted earlier:
http://www.cyclingnews.com/tech/2001/photos/interbike01/fisher29.jpg
It looks like that number of spokes stays the same, hence much weaker wheel. But were talking theory. The geometry of the bike would be severly affected (remember its 3" total wheel increase rather than the drop of 2" going to 24)

The main question is that, is there a fundamental problem with 26" wheels, that going to 29's will solve. If so, what is it, if not, leave it the way it is.

20" works well for BMX, because its suited to that style of riding (strong wheels that dont go over obstacles a lot, high accel/resistance, but thats why you dont see BMX bikes riding over root/rock gardens)

24" is fine for mtb's that do both trail riding and DJ's/urban.

26" is fine for trail / DH

29" wont fit. Its disadvantages of incompatible frames / tires and weakness start making its advantages irrelevant.

and btw, to solve the earlier dillema of fork length change:
Equation: Length = 3" x COS(90-headangle)
3" changes into 2.78" with a head angle of 68, and 2.71" for 65deg.

[UncleAl]

Originally posted by Derek Diggler
hmmm. Good point ;)

now Gary Fisher has XC bikes with 29" wheels.

So does Ritchey and a handful of others. Since the UCI has decided to allow 29ers in races, many more companies are looking at making their own for XC.

who makes his forks?

Marzocchi. And I know that Manitou is thinking about it.

and tires?

IRC, WTB, Bontrager, and Ritchey are the ones I know of.

and rims?

Bontrager and Ritchey label theirs with the 29" tag, but the fact is that 29" rims = 700c rims. Same bead circumference.

sounds to me like a vain attempt for him to stay current, not having a DH or FR bike.



So what have we decided here?

Heavier wheel, tires
Slower acceleration/braking
you ride higher on the bike
flexier wheel
heavier bike overall
Tire/rim options limited
kinda ghey
gear ratios would be changed

Slower braking? Not really. Contact patch of the tire is bigger. That means you can slam the brakes on harder and you're less likely to skid.
No, you do not ride higher on the bike. Your centre of gravity is lower. It's more stable.

Like it or hate it. It's a free country. :P

[ronald55555]

Originally posted by GrimJack
ok, now you've gone and made me all growly. :(

According to my CAD program here, at a 68 degree head tube angle, the difference is 27.91 inches vs 24.98 inches. This makes for a 2.93 inch difference, which in my book is close enough to 3 inches... I mean, we're talking about a sixteenth of an inch here.

2.93 is between 1.5 and 3 like i said, is it not?
dont forget the part between the ground and axle is still 90 degrees, only the stuff above are none 90degrees, and i think most DH bikes have HA steeper than 68 degrees.

dont midn me i've been bored, so i'm just trying to confuse everyone:P

[GrimJack]

Originally posted by Ashek

and btw, to solve the earlier dillema of fork length change:
Equation: Length = 3" x COS(90-headangle)
3" changes into 2.78" with a head angle of 68, and 2.71" for 65deg.

Methinks you forgot that you only apply this to half the wheel. you'll get a full 14.5 inches from the ground the the axle. The angle only counts from the axle up the fork leg to the top of the wheel...

[ronald55555]

Originally posted by Ashek
and btw, to solve the earlier dillema of fork length change:
Equation: Length = 3" x COS(90-headangle)
3" changes into 2.78" with a head angle of 68, and 2.71" for 65deg.

WRONG, the lower part of 1.5 is actually at 90 degrees, only the upper 1.5" is at whatever the HA is.

so, you actually do (1.5" x cos(HA))+1.5

[Ashek]

Methinks you forgot that you only apply this to half the wheel. you'll get a full 14.5 inches from the ground the the axle. The angle only counts from the axle up the fork leg to the top of the wheel...

Hence the very begining of my comment, that its only 1.39" and not 1.5"

[GrimJack]

Ronald: I didn't forget. :) And I took the 68 degree angle off my Bullit... but I could quickly rework it to 66 or 65 if you really want to know.

Like I said - I'm lazy. Especially when my guesstimates tell me that it won't be significant.

Jeez, just imagine if we were going to debate the 29 inch rear wheel subject... espcially if we picked some esoteric frame design, like, say, the VPP. How much would you raise the seat or lengthen the chainstays on that, without bottoming on full compression? Now that's a problem with a few more variables... :)

[white ri0t]

So does Ritchey and a handful of others. Since the UCI has decided to allow 29ers in races, many more companies are looking at making their own for XC.



Marzocchi. And I know that Manitou is thinking about it.



IRC, WTB, Bontrager, and Ritchey are the ones I know of.

meh



Bontrager and Ritchey label theirs with the 29" tag, but the fact is that 29" rims = 700c rims. Same bead circumference.

call me when mavic does



Slower braking?

heavier wheel=more rotating mass=slower braking.

Not really. Contact patch of the tire is bigger. That means you can slam the brakes on harder and you're less likely to skid.
No, you do not ride higher on the bike. Your centre of gravity is lower. It's more stable.

Like it or hate it. It's a free country. :P

i donut like it one bit. 26" for MTB, 700c for road is fine for me.

P.S. sorry for not doing fancy quotes.

[Ashek]

QUOTE:
Originally posted by Ashek
and btw, to solve the earlier dillema of fork length change:
Equation: Length = 3" x COS(90-headangle)
3" changes into 2.78" with a head angle of 68, and 2.71" for 65deg.




WRONG, the lower part of 1.5 is actually at 90 degrees, only the upper 1.5" is at whatever the HA is.

so, you actually do (1.5" x cos(HA))+1.5


What? so your adding the fork length, and then 1.5 for the height between axle and ground? What are you calculating here.. the probability if your fork will swing down and hit the ground when you snap it?
And its not 1.5 x COS(HA). that would give you the height change from axle to headtube with a head angle of 22deg.

[BAC5.2]

Larger circumfrence of the rim = more braking torque. Just like an 8" rotor versus a 6" rotor (shit, those bitches work for every bike part analogy...)

I'd ride the 29er for XC, but that's it. I'm sure with more time, you could overcome the inability to not be able to flick the bike underneath you.

[ronald55555]

Originally posted by Ashek
What? so your adding the fork length, and then 1.5 for the height between axle and ground? What are you calculating here.. the probability if your fork will swing down and hit the ground when you snap it?
And its not 1.5 x COS(HA). that would give you the height change from axle to headtube with a head angle of 22deg.

oops i meant 90-HA.

i have no clue what i said, but anyway, only the upper 1.5" is slanted at the HA, the lower 1.5" from axle to ground is always 1.5" no matter what the HA is.

i wasnt really thinking about the math on that last equation, but i think this one should be correct:
(1.5 x sin(HA))+1.5

the first 1.5 is our hypotenuse, multiply it by Sin of HA to get the vertical component, then add it to the 1.5" from the ground to the axle.

How did this turn from a thread about the advantage and disadvantage of 29" wheels turn into math?

[JOTA]

And, what about a rear end, 1.5 inch more tire will need at least 1.5 more chainstay lenght....so bikes will have over 18.25 of minimum chainstay lenght, but the tire will hit the seat before than a 26" wheel...maybe longer chainstays...

There are some DHbikes that have problems now with the rear tire grabbing the seat at max compresion...with a bigger tire...

I like the 24" rear:eek:, not for DH-racing, but for mountain fun it makes the bike turn clearly eassier, I've never tested a 29" bike but the bike must turn slower and with a longer rear end...

So a 29" DH bike should result like a long train...Maybe for ultra high speed, with open turns... who´s gonna spend that money in a so specifc DH bike?