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Posted
http://www.lenzsport.com

They have a 6" 29er bike called the l\Lunchbox I have a 5" 29er with 135mm white bros fork

Not close to DH's 200mm or FR's 180mm. But it's getting there. Will be interesting to see how this all pans out.

 

I'd love to get my hands, feet and ass on a 650 to demo.
Posted
kiwi... It is not the weights of the wheel... it is the gyro effect it creates...

 

 

Doesn't more weight mean more gyroscopic effect / less weight, less gyroscopic effect? Lighter 29er wheels, less gyroscopic effect?<?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

The faster the wheel spins and the more it weighs the more gyroscopic effect. So if you make the wheel bigger so it spins slower compared to a smaller wheel which has to rotate faster for the same speed, then make that slower spinning bigger wheel lighter and you will have even less gyroscopic effect?

 

I think that was part of the science Moser used when he went for one of his Hour Record attemps (in Moscow?) with this massive back wheel:

 

http://www.marca.com/perico/perico/consejos/bicicleta/Moser85.jpghttp://www.marca.com/perico/perico/consejos/bicicleta/bici-Moser85.jpg

Kiwi2008-11-11 03:37:09
Posted

 

I think that a 29er DH bike would be a bit of a barge. The bike will have less agility because of the larger gyro effect the wheel will give the bike. So the fast switch backs will be more PT for the rider to turn the wheel. And at the speed that these guys and girls haul' date=' will the amount of travel the bikes have. I am not sure how much of an advantage a 29? wheels will have over a 26?. I mean. Look at the XC  scene, and even marathons. The 29? wheels is still just a handful of singled out riders. It?s a theory of commuting and week end riders. But I think it will have a long way to go to prove a really remarkable difference in DH and XC. Marathon riders however would benefit from this size as long as there is not too much technical stints

[/quote']

 

 

....and you my friend, have not ridden a 29er

 

 

 

 

Posted
kiwi... It is not the weights of the wheel... it is the gyro effect it creates...

 

 

Doesn't more weight mean more gyroscopic effect / less weight' date=' less gyroscopic effect? Lighter 29er wheels, less gyroscopic effect?<?: prefix = o ns = "urn:schemas-microsoft-com:office:office" />

 

The faster the wheel spins and the more it weighs the more gyroscopic effect. So if you make the wheel bigger so it spins slower compared to a smaller wheel at the same speed, then make that slower spinning bigger wheel lighter and you will have even less gyroscopic effect?

 

I think that was part of the science Moser used when he brope one of the Hour Records (in Moscow?) with this massive back wheel:

 

http://www.marca.com/perico/perico/consejos/bicicleta/Moser85.jpg

[/quote']

 

what gear was he pushing on that?
Posted

the wheels spins at an unnoticeable different in speed between the 29&26" when you ride it. Of course you can measure it if you want.  But, if you spin a 20" wheel at 20km/h and swivel it at the axel. It is easy enough. If you take a 26" wheel, spin it at 20km/h. You struggle a bit. Do the same with a 29"... even more on an effect. All at the same speed.

 

 

Posted

I think that a 29er DH bike would be a bit of a barge. The bike will have less agility because of the larger gyro effect the wheel will give the bike. So the fast switch backs will be more PT for the rider to turn the wheel. And at the speed that these guys and girls haul' date=' will the amount of travel the bikes have. I am not sure how much of an advantage a 29? wheels will have over a 26?. I mean. Look at the XC  scene, and even marathons. The 29? wheels is still just a handful of singled out riders. It?s a theory of commuting and week end riders. But I think it will have a long way to go to prove a really remarkable difference in DH and XC. Marathon riders however would benefit from this size as long as there is not too much technical stints

[/quote']


....and you my friend, have not ridden a 29er



 

... And you my friend , have not done DH

 

I have riden a 29er and it is too bulky for me. Takes some fun out of the ride compaired to the 26". Having said that is was more comfortable... So... Yes... I can voice from experiance...

 

 
Posted

 

I think that a 29er DH bike would be a bit of a barge. The bike will have less agility because of the larger gyro effect the wheel will give the bike. So the fast switch backs will be more PT for the rider to turn the wheel. And at the speed that these guys and girls haul' date=' will the amount of travel the bikes have. I am not sure how much of an advantage a 29? wheels will have over a 26?. I mean. Look at the XC  scene, and even marathons. The 29? wheels is still just a handful of singled out riders. It?s a theory of commuting and week end riders. But I think it will have a long way to go to prove a really remarkable difference in DH and XC. Marathon riders however would benefit from this size as long as there is not too much technical stints

[/quote']

 

 

....and you my friend, have not ridden a 29er

 

 

 

 

... And you my friend , have not done DH

 

I have riden a 29er and it is too bulky for me. Takes some fun out of the ride compaired to the 26". Having said that is was more comfortable... So... Yes... I can voice from experiance...

 

 

 

 

Out of curiosity, what 29ers have you ridden? A lot of companies do not have the geometry completely dialled yet and as such, some bikes tend to feel very 'bulky'.

 

I was refering to your last comment...."as long as there is not too much technical stints"....because I find a 29er to be faster in technical areas. Actually, in just about all areas except acceleration.

 

It is always going to feel slightly(and I mean very slightly) more bulky, but I find it so slight that it becomes a total non-issue after just a few rides as you learn to compensate for it without thinking about it.

 

As for DH, I have not done a DH race since the mid-90's when we were using bikes with less travel than todays XC bikes and similar geometry.

 

I don't think the gyro-effect would be that noticable. The times when you really have to turn the bar a lot are in technical areas where you're not travelling fast enough for it to have much effect....IMO of course. At higher speeds you'd be relying on leaning the bike to steer more than actually turning the bars.

 

In tight, technical sections the problem with 29ers has been caused by the drag of having to turn a wheel that makes better contact with the ground and also because of the different geometry.

 

From what I've read, the general opinion seems to be that Niner is leading the pack with regards to geometry. I have ridden two and they are as close in flickability(is that a word?) to 26ers as to not be any different. They are currently working on a 160mm travel bike that should be available next year. Will be interested to see how that turns out.

 

How the geometry affects a DH bike will remain to be seen once more companies start experimenting. 29ers generaly have steeper head angles to speed up the steering and DH bikes obviously lean towards the other side of the spectrum in order to improve stability at speed and on steep terrain. Will be interesting to see how it develops.

 

 

Posted

I ride 29er, these bikes excel in technical sections esp protruding rocks that want to stop yr momentum, I am tall and was concerned about riding tight slow switchbacks, but I tried it last week in Tokai and notice no negitives in this dept compared to 26" The only downside to 29 is acelleration and BMX style jumps are allot harder- use 26" fixie jump bike for that. I feel the advantages of 29 out weigh 26, even more so if you are tall. Drop-offs and wheelies are no problem either

Posted
I ride 29er' date=' these bikes excel in technical sections esp protruding rocks that want to stop yr momentum, I am tall and was concerned about riding tight slow switchbacks, but I tried it last week in Tokai and notice no negitives in this dept compared to 26" The only downside to 29 is acelleration and BMX style jumps are allot harder- use 26" fixie jump bike for that. I feel the advantages of 29 out weigh 26, even more so if you are tall. Drop-offs and wheelies are no problem either [/quote']

 

surely a singlespeed, not a fixie singlespeed?

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