29ers...here to stay or fade away?

[Eldron]

Iron' date=' that's easy, oops I hope Eldron is not reading this [/quote']

 

Ohhhhh like a knife between the shoulder blades

 

It should, however, be much easier now that you've been RIPped he he he. How is the pimped out American Classic toting bulldozer doing?

[Mats]

Iron' date=' that's easy, oops I hope Eldron is not reading this [/quote']

 

Ohhhhh like a knife between the shoulder blades

 

It should, however, be much easier now that you've been RIPped he he he. How is the pimped out American Classic toting bulldozer doing?

That bulldozer is not taking any prisoners it only DESTROY people.

[Ox_Wagon]

Ok, as they say there is no rest for the wicked.  <?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

I had a look at the moment of inertia of the WTB Laser trail wheels.  I assume some one has already spotted that I made a mistake comparing the Lazerdisk XC with the Lazerdisk Trail, will fix that.

 

The results are a bit disturbing so please don?t allow sensitive viewers to see it.  I really hoping I got it wrong.  Using the simple I = mass x r² formula. I get that the 29? wheels has around 43% higher inertia! This will explain why it feels like it keeps it speed better but will also not speed up as quickly as a 26?.

 

This is good thing on a Marathon/24hr/Single speed bike and not so good on a XC race bike. 

[GoLefty!!]

keep going... you're getting it.

 

Now in a 24hr race, do you maintain constant speed..?

 

in fact, where except on a oval banked race track does any vehicle maintain constant speed?

 

 

 

[Ox_Wagon]

The moment of inertia indicates the wheel?s resistance to change speed.   <?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

A wheel with higher moment of inertia will take longer to accelerate on the other side will also take longer to slow down.  It has the same effect as a flywheel.  

 

You want a light flywheel on a sport car to post low 0-100km times. (XC)

 

In your bakkie, while towing your caravan (I am a ?bit? overweight), you want a heavier flywheel so that you don?t loss to much speed going over a rise in the road. (<?: prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Marathon)   

[Wyatt Earp]

Iron' date=' that's easy, oops I hope Eldron is not reading this [/quote']

 

?

 

Ohhhhh like a knife between the shoulder blades

 

?

 

It should, however, be much easier now that you've been RIPped he he he. How is the pimped out American Classic toting bulldozer doing?

 

 

 

 

 

That bulldozer is not taking any prisoners it only DESTROY people.

 

Hahahahahaha Dobby, I blame the wheelsize.

 

Eldron, sorry it was a typo, it was meant to read "Elvis on a 26 inch wheeled bike " is easy to beat, the Eldron I know who rides 29'ers is a monster.

[Kiwi]

 

 

Even though you need more energy to get a 29er wheel up to speed - it's not much more when you are out on the trail, because of it's size a 29er wheel is going to over rather than into everything from roots to large stones.

 

The 26er wheel is going to lose energy every time it has to go up and over an obstacal that a 29er wheel is going to go over. So the loss of speed is less on a 29er wheel on a bumpy bit of track than on with a 26er wheel.

 

When you look at 29er race wheels compared to 26er race wheels you can now get a reasonbly priced 29er race wheel at 1650 grams a set and a no holds bared set down to 1380. Same sort of weights as for 26ers.

 

Tyres for 29ers 650 grams down to 500 odd grams. Next year there will be 29er race tyres in the mid 400's for 29ers.

Kiwi2009-12-04 09:22:29

[Johan Bornman]

The moment of inertia indicates the wheel?s resistance to change speed.   <?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

A wheel with higher moment of inertia will take longer to accelerate on the other side will also take longer to slow down.  It has the same effect as a flywheel.  

 

You want a light flywheel on a sport car to post low 0-100km times. (XC)

 

In your bakkie' date=' while towing your caravan (I am a ?bit? overweight), you want a heavier flywheel so that you don?t loss to much speed going over a rise in the road. (<?: prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Marathon)   

[/quote']

 

Ox, you need to calculate the inertia of the entire package. Rider, frame and wheels.

 

Your figure of 40-something percent is meaningless unless you do the entire package. It'll then be a low single digit percentage.

 

I often see this argument wrt wheel weight. Rotating weight bla bla bla.  Now suddenly it is just the reverse, and inertia is good.

 

Futher, if you give your rider a certain amoutn of power - say 700 watts and calcualte the accelleration to 30kph, you'll also get a more realistic figure that one can relate to the real world.

 

 

[Goodbadugly]

 

 

"I often see this argument wrt wheel weight. Rotating weight bla bla bla.  Now suddenly it is just the reverse, and inertia is good."

 

Johan Bornman 

 

A friend of mine asked me about a Superfly 29. My answer? YOU. You even ride the Epic with normal folding tires because UST's weigh more. And you would probably sell a kidney for a wheelset with Tune hubs, 1.8/1.5 Revo's and 7000 rims!

Makes me think of the story of the three couples queuing to enter the Pearly gates after being involved in a bad motor vehicle accident.

St Paul looks down at his clipboard when the first couple reaches him. He says: "You sir! You loved your drink so much, you even married a girl named Sherry. Please go next door."

The second couple. St Paul looks up and says:"You sir! You loved money so much you even married a girl named Penny. Please go next door."

The third guy looks up at his wife and says:" Listen Fanny, maybe we should queue next door and save time."     

Goodbadugly2009-12-04 12:58:29