[MMcG]

How's about this for a discussion thread? What makes for a good regional 29er geometry configuration for a 29er trail bike (not an uber light XC race machine here).

East Coast - Short Chainstays, High or Low bottom bracket height?, shorter ETTs? steeper HT angles? Or Slacker? 100mm or say 120mm?

How would you configure your take on the ultimate East Coast Trail Bike 29er Hardtail?

Midwest - Longer chainstays, lowest bottom bracket you can reasonably get away with??, longer ETT, Steep HT angle?

West Coast - Long stays for extendo climbs and stability on long descents? Low bottom bracket height, Slacker HT angle than the Midwest geo?

PNW - beefier tubing, slack angles, ability to run big meaty tires for PNW Northshore type riding, highly sloping top tube. etc. etc.

So I live in New England and I'm wondering how a 29er Trail bike would ride with a 120mm fork, a 69 degree HT angle (with sag figured in), say something like a 72.5 degree ST angle, a 12.75" bb height and say 17" chainstays. Too tippy? It certainly wouldn't get hung up in rock gardens I wouldn't think. I'd like to see how something like that might feel and ride. Steel of course.


If you were to design or have someone custom build your go to trail bike 29er how would you have them do it?

Discuss Monkeys!

 

[nitrousjunky]

I've played around with different geometry bikes here in western NC some. I've come to find that around here, I do not like steep HT angles or long chainstays.

We have some tight switchbacks and the shorter stays really help to negotiate that. I also found that I had issues with the rear tire trying to spin when climbing steep stuff with a long stay bike.

For HT angles, the problem I noticed with steeper angles is the front tire always gets more hung up on roots and rocks. I could hit the same root on a climb on a slacker bike and the front tire would roll right up over the root. Next ride on a steeper angle bike, it's like it would momentarily stop the bike, then kinda pop up over it. Similar feel in steep, techy downhill spots.

I'm getting ready to have my first custom 29er SS HT built and the numbers will more than likely be as below. Either going with a 100mm Fox fork or a 95/120 Fox Talas. Also will have the 44mm HT and run a tapered ST, 15mm axle fork.
69 degree HT angle with 100mm
73 degree St angle with 100mm
12.5" Bottom Bracket Height
short chainstays 16.3-16.8" range with sliders.

 

[Buck Fever]

I'll play this game...

IMO it's more rider dependent than area dependent. Before I started building my own my favorite bike when I lived out east was an Ellsworth Specialist, which they billed as a trials/4x bike (though no good trials bike would have an HTA that slack). With a 5" travel fork, it had something around a 67°HTA and a 14.5" BB height and 16" chainstays. I felt like I could plow through or bunny hop anything. Core to my love of that frame was my trials riding and competition experience which molded my riding style to more of a herky-jerky trials nerd type of riding when the trail got super chunky.

When I moved to Portland OR, it didn't take long for me to realize that combined with my style of riding, the Ellsworth was crap for most of the riding I've been able to find within a 3hr drive of my house. Too slack for efficient climbing, with too high a BB for effortless turns on long down hills. I changed my bike AND my riding style to work better for me in the areas I ride.

So...if your an SSer, a masher or generally a rider who stands a lot because that's how your style developed and it works for you in your area, you'll probably really like a bike with short stays, maybe a BB a little on the high side and an HTA dictated by plowing or picking your lines. If you sit and spin, longer stays are going to be more comfortable and a steeper HTA will let you steer the bike rather than lean it through turns.

 

[Leppah]

we have everything out here in Utah. I wouldn't know what to have geo set for out here. I usually just get my bike and adapt to it to make it work. We've got everything from smooth singletrack, to bumpy as eff and rocky as eff, to steep and lumpy and rooty, to Moab, to Gooseberry. You basically learn how to make your bike work for everything no matter what the geo is.