Comments on: A Note on Geometry http://twentynineinches.com/2008/02/19/a-note-on-geometry/ 29er Bike Reviews, Rumors and News Fri, 29 Aug 2008 08:45:25 +0000 http://wordpress.org/?v=2.5.1 By: Evan http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-36716 Evan Tue, 18 Mar 2008 22:42:42 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-36716 I've been researching A LOT of frames for my first 29er. I've got all the parts already, including a White Bros rigid fork; all I need is something to hang them on. With all these choices, I am coming back to the geometry question. A lot of people seem to think that a steeper head angle (around 72 deg) with increased fork rake to counter the trail problems brought on by the larger wheel is the way to go. But then I look at the Fisher 29ers and they all have pretty slack head angles, less than 70 degrees! I'm also intrigued by the relatively low BBs on the Misfit Dissent. You don't have to be a genius to understand the merits of BB placement, but on a 29er a difference of 20mm is quite a bit. I really appreciate all this discussion... I’ve been researching A LOT of frames for my first 29er. I’ve got all the parts already, including a White Bros rigid fork; all I need is something to hang them on. With all these choices, I am coming back to the geometry question.

A lot of people seem to think that a steeper head angle (around 72 deg) with increased fork rake to counter the trail problems brought on by the larger wheel is the way to go. But then I look at the Fisher 29ers and they all have pretty slack head angles, less than 70 degrees!

I’m also intrigued by the relatively low BBs on the Misfit Dissent. You don’t have to be a genius to understand the merits of BB placement, but on a 29er a difference of 20mm is quite a bit.

I really appreciate all this discussion…

]]> By: Brendan http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35751 Brendan Tue, 26 Feb 2008 16:45:45 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35751 It may be a thinly veiled sales pitch, or it may just be a plea for people not to get too wrapped up in one set of numbers. From my Niner experience they build a pretty neutral bike (even with less trail/rake then seems to the new holy grail) that gives some of that "in the bike" feel 29ers have long touted. I'm not sure why they felt the need to put it out there, other than to beef up their position v. the trends of the day. On that note I'd love to give one of the new Fishers a whirl to see how they handle. Who knows, it may work out great for me. You never really know until you actually use the things. Personally I think it's nice to be at the point where I know enough to know that I don't need to know too much. I'm not sure it's worth getting too wrapped up in all the numbers on a stock frame, unless you're looking at the bike as a whole. A real test ride will always tell you what works for you. If you're going full custom then by all means obsess over every angle. Does that make sense? It may be a thinly veiled sales pitch, or it may just be a plea for people not to get too wrapped up in one set of numbers. From my Niner experience they build a pretty neutral bike (even with less trail/rake then seems to the new holy grail) that gives some of that “in the bike” feel 29ers have long touted. I’m not sure why they felt the need to put it out there, other than to beef up their position v. the trends of the day. On that note I’d love to give one of the new Fishers a whirl to see how they handle. Who knows, it may work out great for me. You never really know until you actually use the things.

Personally I think it’s nice to be at the point where I know enough to know that I don’t need to know too much. I’m not sure it’s worth getting too wrapped up in all the numbers on a stock frame, unless you’re looking at the bike as a whole. A real test ride will always tell you what works for you. If you’re going full custom then by all means obsess over every angle. Does that make sense?

]]> By: EuroWheels http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35698 EuroWheels Tue, 26 Feb 2008 00:35:46 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35698 Two quotes from the opinion voiced by Niner... 1) "it’s important to understand that the way a bike rides and feels is the SUM of all of the angles and lengths that make a complete frame, and no one aspect of it can be taken into account without knowing the whole picture. " 2) "...there is a movement to longer offset rakes in forks and slacker head tube angles. We aren’t sold here. I would say, with sarcasm, that statement #2 seems to conflict with the sensibility of statement #1. But wait, hmm, Niner doesn't make bikes like described in statement #2. Is this all an education or a sales pitch here? Two quotes from the opinion voiced by Niner…

1) “it’s important to understand that the way a bike rides and feels is the SUM of all of the angles and lengths that make a complete frame, and no one aspect of it can be taken into account without knowing the whole picture. ”

2) “…there is a movement to longer offset rakes in forks and slacker head tube angles. We aren’t sold here.

I would say, with sarcasm, that statement #2 seems to conflict with the sensibility of statement #1. But wait, hmm, Niner doesn’t make bikes like described in statement #2. Is this all an education or a sales pitch here?

]]> By: Steve http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35541 Steve Fri, 22 Feb 2008 19:18:35 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35541 Chris and Steve cite a 1/2 " difference in effective CS length between 11 and 12" BB heights. I measure something closer to 5/32" (.156 or about 4mm) on a 16.75 stay. It's a factor, but not as dramatic as they state. And effective CS can be deceptive. Lower BBs will result in a shorter effective measurement, but this is not going to make your bike much easier to wheelie. Chris and Steve cite a 1/2 ” difference in effective CS length between 11 and 12″ BB heights. I measure something closer to 5/32″ (.156 or about 4mm) on a 16.75 stay. It’s a factor, but not as dramatic as they state.

And effective CS can be deceptive. Lower BBs will result in a shorter effective measurement, but this is not going to make your bike much easier to wheelie.

]]> By: jeremy Uk http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35533 jeremy Uk Fri, 22 Feb 2008 17:42:18 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35533 You can't really draw a conclusion from the Specialized since their offset is the other end of the spectrum from 08 ally Fisher You can’t really draw a conclusion from the Specialized since their offset is the other end of the spectrum from 08 ally Fisher

]]> By: Big t http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35527 Big t Fri, 22 Feb 2008 15:18:15 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35527 I agree with niner, steeper head angles are better for 29 inch wheels. I just did a demo on a Specialized 29 enduro that has a 69 degree head angle. I was left inimpressed with how slow the turning was and the weight of the bike at 29.7 lbs, pigish at best. My point: Ive allways liked the steeper head angle especially on a 29er. Niner has listened and thats why they will continue thrashing the big boys in the market. I agree with niner, steeper head angles are better for 29 inch wheels. I just did a demo on a Specialized 29 enduro that has a 69 degree head angle. I was left inimpressed with how slow the turning was and the weight of the bike at 29.7 lbs, pigish at best.

My point: Ive allways liked the steeper head angle especially on a 29er. Niner has listened and thats why they will continue thrashing the big boys in the market.

]]> By: Fort James http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35507 Fort James Fri, 22 Feb 2008 01:19:39 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35507 I absolutely love my Niner and I am East Coast with tight twisty singletrack all around me. Niner's rule! I absolutely love my Niner and I am East Coast with tight twisty singletrack all around me. Niner’s rule!

]]> By: Steve http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35491 Steve Thu, 21 Feb 2008 14:31:54 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35491 What drives me nuts is when people dismiss different geometry ideas (chainstays especially), even for different riders on different trails in different parts of the country. Especially when they bash geometry that they have never even tried. 29er has such a grip over some riders that they cannot fathom that their bike, with it's geometry, is the perfect set-up for everything, everywhere. It's as though any criticism would diminish them in some way. Sorta like the Ford/Chevy thing. I love my 29er and I know that it's not designed for riding out West. What drives me nuts is when people dismiss different geometry ideas (chainstays especially), even for different riders on different trails in different parts of the country. Especially when they bash geometry that they have never even tried.

29er has such a grip over some riders that they cannot fathom that their bike, with it’s geometry, is the perfect set-up for everything, everywhere. It’s as though any criticism would diminish them in some way. Sorta like the Ford/Chevy thing.

I love my 29er and I know that it’s not designed for riding out West.

]]> By: Guitar Ted http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35471 Guitar Ted Thu, 21 Feb 2008 00:12:36 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35471 Mike, Greg: I was talking about 29"ers. ;) Not Salsa's previous 26"er history. I think you guys are astute enough to see the difference there. Mike, Greg: I was talking about 29″ers. ;) Not Salsa’s previous 26″er history. I think you guys are astute enough to see the difference there.

]]> By: Cloxxki http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35464 Cloxxki Wed, 20 Feb 2008 20:31:02 +0000 http://twentynineinches.com/2008/02/19/a-note-on-geometry/#comment-35464 Long stays if you want to sit out a climb and not tumble back over. Short stays when you get out of the saddle to sprint them up and not spin the rear tire out. Oddly, between long and short may be half an inch or less, while the difference in seat tube angle can make up for that with a single degree. A steep seat tube angled bike, you'll use more seat setback for. Look where your azz ends up relative to the rear axle. Show me a long-stay 29" you can spin out, and I'll show you a short-stay 26" that I can spin out. Long stays if you want to sit out a climb and not tumble back over.
Short stays when you get out of the saddle to sprint them up and not spin the rear tire out.

Oddly, between long and short may be half an inch or less, while the difference in seat tube angle can make up for that with a single degree. A steep seat tube angled bike, you’ll use more seat setback for. Look where your azz ends up relative to the rear axle.

Show me a long-stay 29″ you can spin out, and I’ll show you a short-stay 26″ that I can spin out.

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