Posts

Email from reader about stem length and bar width. (from New Zealand!)

I love getting happy emails from students but happy emails from halfway around the world from riders I have never meet?! That is cool! Feels great to be helping riders all over the planet.  Here is the email:

Hey there
Low, wide bars.

I am 5 ft 8, broad shouldered and ride a medium Ibis Mojo.

Until last week I had an 80mm stem, 670mm bars set at (XC) saddle height.

I had thought this a great setup.

However after pondering your suggestions for a while I finally made the change:

60mm stem, bars 1.125″ below saddle, and 725mm width.
Wow.
Amazing.

No downsides, no oversteering, just way way better stability, agility smoothness and control.

My local trails have heaps of close trees and rocky banks, however the increased stability combined with greater agility means the extra width is not an issue.

And with more practice things will only get better.

My bike loved cornering before (low BB etc) however it settles into a turn much more quickly and is just plain way more fun.

Downhill braking is much nicer, and climbing is uneffected.

And the front end is way better planted over the rough stuff.

cheers!

Rob

The Ideal Confidence Inspiring Mountain Bike!

I just received a great question from a newsletter subscriber: “Hi Gene, I’ve been following your blog posts and emails. After recently moving and having to sell my old hardtail, I am now in the market for a new mountain bike. I would like to get one that would be ideal for improving my skills. I don’t care much about performance at this point. I know from you that wider tires, shorter stem, wider bars and an adjustable seat post, all improve confidence and control, and I’ll make sure I get all of these. But since I am not dealing with an existing bike that I’m riding — since I’m in the situation where I can pick any kind of mountain bike — which characteristics would you recommend? E.g. large vs short wheelbase; what kind of suspension and how much travel; type of breaks; size of frame (go smaller, go bigger), etc. Thanks! Alon

A lot of this really depends on the goal/s of the rider and Alon gave me his goal/s: “…ideal for improving my skills. I don’t care much about performance at this point.”.  So we will go from there.

Unless you are a cross country racer and/or really care about being as absolutely fast as you can on climbs I feel most riders would greatly benefit from a 5 or 6″ travel “all-mountain bike”.  They tend weigh a little more than a 3-4″ travel bike but have a lot of features that make them more fun and confidence inspiring.  The number thing they have is a slacker head angle (which means the front wheel is further in front of you).  There is a tired out standard of 70 and 69.5 degree head angles on “cross country” bikes. These angles make descending terrifying compared to the slacker (68.5 to 67 degree) head angles on “all-mountain” bikes. The steeper head angles do help on really steep climbs though so you must weigh how often you do really steep climbs and if you want to have a bike that climbs those climbs a little better but descends scarier (steep head angle bike) or a bike that causes you to worry about body position a little more on a steep climb but is confidence inspiring on the descents.  Yeti is one of the few companies that make 4-5″ travel bikes with 68.5 or slacker head angles.

As far frame size my head coach Andy (who is 5’6″ a great technical climber and pro downhill racer) likes to ride bikes on the big side.  He likes the longer wheel base of medium because it makes the bike a little more stable and predictable.  He also likes the longer top tube allowing him to run a 40mm stem for greatly control. He feels this worth giving up the ideal amount of stand over height for. His weapon of choice, a medium Yeti 575.  I too like longer top tube bikes and being 6’3″ that means I ride a large or XL depending on the company (some XL’s are just a little too long for me, more fitting for 6’4″ and up).  The bike I ride most is my Specialized Enduro SL set in the low bottom bracket/slack head angle position. The low bottom bracket keeps my center of mass lower (making the bike corner better) and I love the 67 degree head angle (with an adjustable fork I can slacker the head angle and drop the bars two inches for steep climbs).

As for suspension design, most companies make great full suspension bikes now and there is definitely not one way to go.  As long as you do your research in general the more you spend (within each company) the more you will get (the shocks themselves will be better). Spend enough to get at least rebound adjustment on both front and rear suspension.  As for brakes you definitely want hydraulic disc brakes.

I hate to but a price on this because nearly all bike store bought bike are pretty darn good these days but if look at $2,000 msrp bikes and up you will get a lot of nice features such as good components and quality shocks and forks

Well that sums up what I am looking for in a 26″ mountain bike.  The two main things are a slack head angle (67-68.5 degrees) and a longer top tube (over 24 inches for a large).

Another option is definitely a 29er. I love 29ers and feel that they are a great bike for many riders.  Since this is about confidence inspiring bikes first I will mention where 29ers really shine, going over obstacles! Their taller tires just plain roll over things easier. The only real down fall (confidence inspiring wise) is many 29ers have steep head angles to keep their wheel base short (this is slowly changing at some companies) which has made many of my students say that they were intimidated on steep descents.

The pro’s of 29ers: They get over obstacles easier, they hold their momentum well, they have better traction do to a larger contact patch, they plain ride smoother and with less effort

The con’s of 29ers: Their big gyroscopes (wheels) make going from tight left to right turn slower and more difficult, their longer wheel base makes tight switchbacks more difficult, they are a bit more cumbersome, especially in the air, they don’t fit shorter riders well (they make them to fit short riders but the handle bars end up way to high for good body position), they are bit slower to accelerate.

In short for riders who really enjoy cornering and jumping 29ers are not the best choice (yet). For most other riders, especially riders that really enjoy long rides and want to make getting over “step up” type obstacles easier, 29ers are great.

Another Thing You can Buy and Instantly Have More Bike Control!

Last month we talked about the control you get from a short stem and wide bar combination and hopefully you have experimented with that set up.  Now for another great bike handling increase, tires! Get ye some wide tires (2.2-2.5) and run lower pressure (20-32 pounds of pressure depending on body weight and tire type.  For instance on my xc bike I run 30 pounds of pressure and weigh 188 pounds.  On my downhill bike with downhill tires (which are much thicker, stronger and heavier) I run as little as 22 pounds depending on the track.

What is the right pressure for you?  Experiment!  Find the lowest pressure you can run without pinch flatting (if you run tubes) rolling the tire or dinging your rims (if you run tubeless).  For lighter riders this will be somewhere between 18-24 pounds and for bigger riders some where between 25-38 pounds.

Why a bigger tire and less pressure?  More traction and shock absorption.  Instead of deflecting off small rocks and roots your tire will simply compress and roll over the rock or root.

There is a big misconception in mountain biking that the more tire pressure you run and the narrower your tire the faster you will roll.  Well, that simply isn’t true and here is a link to a study that proves this:

http://www.bernhansen.com/Tester/Dekktrykk,%20bredde%20og%20knastens%20innvirkning%20-%20schwalbe.pdf

Reading this study shows that wider tires (given the same tread pattern) roll faster/easier than narrow tires and less pressure also rolls faster/easier offroad! So much less rolling resistance it makes up for the added weight of wider tires.

Now for tread design.  What tread is best for me? First figure out your goal.  Is traction and control my number one goal? or is it rolling resistance because I have a technically easy but long ride (like the Leadville 100).  If control is my goal I want to use a more aggressive tread pattern (larger knobs) if low rolling resistance is my goal I want to use a semi-slick or short, tightly space knobs.

Then think about the typical conditions you ride in, in Colorado we tend to have hard packed trails that when dry get a layer of dust on them.  On the East coast and Pacific NW they have softer soil and mud is more common. On hard conditions big blockly knobs of medium height that don’t flex a lot work best.  In loamy to muddy conditions slightly taller knobs with more space between each knob dig into the earth and shed mud better.  Most tire manufacturers will explain on there website what each tread pattern is designed to do so do a little research.

Tires also come with different rubber hardness.  In general the softer the tire the better traction at a cost off wearing out faster and rolling slower. The harder the rubber the faster it will roll, the longer it will last but the less control you will have.  Each tire manufacturer has different names for their tire compounds so do a little research to find the ones best for you.

Your tires are your contact with the ground so spend some time choosing the best tire for you. Lastly be weary of internet reviews as often the reviewer is not qualified to review the tire.  Example: “I hate this tire, it slides out in the corners too much”, well, does the reviewer know how to corner correctly? Does he have the right tire pressure?

Create your best ride yet,

Gene