New England & Northeast Ski Forums - AlpineZone Forums - View Single Post - Whats the advantage of the 29" mtb wheels?

marcski · Jun 3, 2008, 9:53 PM

First I think 29" wheels won't fit on a 26" wheeled bike frame. 2nd, a buddy of mine has a 29er which he built up as a single speed. According to my LBS, this is being done more frequently. (29er as a single spd).

As Dr. Evil stated, they supposedly roll over obstacles better. Also, I believe most 29ers are hardtails as opposed to fully's.

Here's a good recent article:
http://www.timesargus.com/apps/pbcs....015/FEATURES06

Also found the following on Wikipedia, for what it is worth:

"Advantages

* Larger wheels roll over obstacles more easily due to decrease in approach angle
* Larger wheels have a lower rolling resistance for the same width tire
* 29”er wheels are less prone to sinking in soft material such as sand and mud
* Larger wheels are less prone to pinch flatting
* The longer contact patch increases cornering and straight line traction
* 29"er bikes tend to offer taller riders a more "natural" frame geometry.

It is worth noting that most of these claims have yet to be objectively verified one way or the other. Small scale, unpublished studies (including one done by Pepperdine University, reportedly at the request of Gary Fisher) exist but both proponents and detractors of 29" wheels are generally unimpressed with their lack of scientific rigor. Long debates over how to conduct a "fair" test of the efficiency of 29" vs 26" mountain bikes have raged online, but no serious efforts have been made to conduct a large-scale, scientific study.

[edit] Drawbacks

* Increased wheel weight and rotating mass - the spokes, rim, and tire are all larger.
* Many types of tires, rims and forks do not come in 29"-compatible versions, though the expanding popularity of the size is reducing this problem.
* Longer spokes and rim result in a more laterally flexible wheel.
* Longer spokes and increased angle between hub flange and rim result in a weaker wheel.
* Smaller riders (i.e. less than 5'5" tall) may not be able to find a 29" bike with a geometry suitable for them. Numerous examples exist of custom bikes built for very small riders with 29" wheels, but in many cases smaller riders face significant geometry tradeoffs in order to ride a 29er, especially with regard to toe overlap, handlebar height, and standover.

[edit] 96er or 69er Variations

One variation is to have a 29 inch front wheel and a 26 inch rear wheel. Using the smaller rear wheel allows shorter and quicker handling frames, more options for rear suspension designs and lighter bicycle weight. Another variation is to have a 26 inch front wheel with a 29 inch rear wheel. Both are commonly called 69ers or 96ers, depending on the manufacturer. For example, Trek Bicycle Corporation introduced a 69er in 2007 with a 29 inch front wheel and a 26 inch rear wheel.[5] Carver Bicycles also has, what they call, a 96'er with a 29 inch front wheel and a 26 inch rear wheel."

Jun 3, 2008, 9:53 PM	#11 (permalink)
marcski Devil's Castle Join Date: Jan 2005 Location: Westchester County, NY and a Mountain near you! Posts: 1,006	First I think 29" wheels won't fit on a 26" wheeled bike frame. 2nd, a buddy of mine has a 29er which he built up as a single speed. According to my LBS, this is being done more frequently. (29er as a single spd). As Dr. Evil stated, they supposedly roll over obstacles better. Also, I believe most 29ers are hardtails as opposed to fully's. Here's a good recent article: http://www.timesargus.com/apps/pbcs....015/FEATURES06 Also found the following on Wikipedia, for what it is worth: "Advantages * Larger wheels roll over obstacles more easily due to decrease in approach angle * Larger wheels have a lower rolling resistance for the same width tire * 29”er wheels are less prone to sinking in soft material such as sand and mud * Larger wheels are less prone to pinch flatting * The longer contact patch increases cornering and straight line traction * 29"er bikes tend to offer taller riders a more "natural" frame geometry. It is worth noting that most of these claims have yet to be objectively verified one way or the other. Small scale, unpublished studies (including one done by Pepperdine University, reportedly at the request of Gary Fisher) exist but both proponents and detractors of 29" wheels are generally unimpressed with their lack of scientific rigor. Long debates over how to conduct a "fair" test of the efficiency of 29" vs 26" mountain bikes have raged online, but no serious efforts have been made to conduct a large-scale, scientific study. [edit] Drawbacks * Increased wheel weight and rotating mass - the spokes, rim, and tire are all larger. * Many types of tires, rims and forks do not come in 29"-compatible versions, though the expanding popularity of the size is reducing this problem. * Longer spokes and rim result in a more laterally flexible wheel. * Longer spokes and increased angle between hub flange and rim result in a weaker wheel. * Smaller riders (i.e. less than 5'5" tall) may not be able to find a 29" bike with a geometry suitable for them. Numerous examples exist of custom bikes built for very small riders with 29" wheels, but in many cases smaller riders face significant geometry tradeoffs in order to ride a 29er, especially with regard to toe overlap, handlebar height, and standover. [edit] 96er or 69er Variations One variation is to have a 29 inch front wheel and a 26 inch rear wheel. Using the smaller rear wheel allows shorter and quicker handling frames, more options for rear suspension designs and lighter bicycle weight. Another variation is to have a 26 inch front wheel with a 29 inch rear wheel. Both are commonly called 69ers or 96ers, depending on the manufacturer. For example, Trek Bicycle Corporation introduced a 69er in 2007 with a 29 inch front wheel and a 26 inch rear wheel.[5] Carver Bicycles also has, what they call, a 96'er with a 29 inch front wheel and a 26 inch rear wheel."