Mountain Biking for Dummies, Part 3

For reference, here are parts 1 and 2.

Wheels, hubs, and axles OH MY!

Here we are in our third installment of The Mountain Bike Series!  We are now deeply educated individuals when it comes to the basics of mountain bikes in general and the basics of their suspension systems.  Along those lines, we’re going to take today to look into the basics of wheel systems.

The first step is to look at the various wheel sizes offered with off-road bikes, which come in varieties of 29 inch wheels, 27.5 inch (or called 650b), and 26 inch wheels.  For quite a long time, 26” was the only option.  You will still find 26” sized wheels on entry level bikes, youth bikes, and even some (adult sized) “downhill” bikes.  With the exception of the downhill bikes, you will really only find 26” on what could be classified as “entry level” bicycles.  It has been generally agreed upon that “bigger is better” when it comes to mountain bike wheel sizing.  

So most of the choices we - as new mountain bike purchasers - will make are going to fall into either the 650b or 29” category.  Let’s examine some pros and cons of each, shall we?

When 29” wheels first came out (which was before my time) they were - like many new things in the cycling world - met with skepticism.  These huge new wheels weighed more, looked silly, and couldn’t possibly be better, could they?  Well usually: yes, they are better than 26” wheels in almost all applications.  Some of the things you might not think about at first glance are the bigger contact patch with the ground and the shallower angle of attack these wheels will have as compared to their smaller brethren.  The bigger contact patch is simply due to the larger circumference of the wheels, which results in more of the tire coming into contact with the ground.  The benefits of this are obvious, as there is more grip for cornering and braking.  The shallower angle of attack is a little more difficult to explain, but it essentially means that every object encountered on the trail is smaller as it relates to the wheel itself.  As a consequence, a 5 inch tall rock which, with a 26” wheel, would’ve been met a bit more “head on” is now lower on the 29 inch wheel.  This picture makes it more obvious, although the size disparity is a little dramatic:

So the bigger wheel gives the rider a little more room for error.  It makes obstacles “ride” smaller, it makes drop-offs easier to deal with, and in general it feels as though you cover more ground more quickly as compared to smaller wheels.  The wheels do, in fact, generally run a bit heavier.  Is this a big deal? In my opinion definitely not, but some may argue that the bigger wheels are more difficult to “spin up” or get up to speed, but to be honest I have not compared a 29” bike to a 26” bike so can offer no personal perspective.  It IS noticeable, however, when doing tight and twisted singletrack at slow speeds that a 29” bike can have more trouble than a smaller wheeled bike.  The bike has a longer wheelbase and bigger wheels and, as a consequence, can be more difficult to maneuver around tighter, smaller radius turns.

The 27.5” or 650b standard is newer and was created in no small part to resolve some of the concerns mentioned in the previous paragraph (or maybe it was created just to create more bikes to buy??).  Without taking into context the size or style of a bike, the 650b standard is most often viewed as a “best of all worlds.” It has many of the benefits of the larger wheels, such as better angle of attack and bigger contact patch, but with a lessening of the drawbacks such as weight and maneuverability.  It is still a bit newer but has mostly caught up in terms of availability of tire selection and wheel brand choices.

In my personal opinion, if I am looking for a cross country or trail bike I am probably going to say go with whatever size wheel “feels” appropriate.  For example, on a medium or large (or extra large) bike, 29” wheels are likely NOT going to feel “big” to you.  On the other hand, if you ride a small or extra small frame then 29” wheels likely ARE going to feel big, and as a consequence I’d say focus more on 650b bikes lineups.  If, on the other hand, you are looking for a big hitter bike (all mountain, DH, etc) then it’s much more normal to see 650b wheels on those big travel bikes.  

Let’s also take a few moments to talk about hubs.  Not just the hub itself, but how the wheels are bolted/attached to your frame.  We are ALL used to quick release skewers, as these have been used on bikes for quite some time.  The idea is pretty simple as it’s basically an axle that slots into your dropouts and is tightened using a cam pressure system.  For a long time, this was the most common thing seen on mountain bikes as well.  Nowadays, however, the system is completely different.

Most off road bikes (this is now beginning to include cyclocross, gravel, and even some road bikes) now use what is called a “thru-axle.” The desire for this system began with a desire to increase the overall rigidity of a bike. Dropouts (the openings into which a wheel’s hub fits) are wider on a mountain bike to help achieve this.  The thru axle is another mechanism that aids this rigidity goal, as the axle itself literally bolts the dropouts together THROUGH the wheel’s hub.

Quick releases are usually 9mm, whereas thru-axles are generally much bigger.  At first, mountain bikes began utilizing thru-axles only in the front while still keeping a quick release in the rear.  Now, however, that has changed to be thru-axles on both the front and rear.  Whereas a road bike has dropout spacing (basically the width between the dropouts) of 100mm in the front and 130mm in the rear - with 9mm quick relases - modern mountain bikes are most commonly 100mm in the front (with a 15mm thru-axle) and 142mm in the rear (with a 12mm thru axle).  

Interestingly, the rear hubs themselves are still 135mm, but the frame has 3.5mm cutouts in the rear to allow the hub to be more easily guided into place before the axle is inserted through the frame and hub and bolted tight.

All of this is to say that thru axles represent a stiffer, more robust form of wheel to frame attachment that, in general, results in a more responsive and predictable ride through the trails.  The “size” of your thru axles depends entirely on the type of bike you buy, with 15mm being a common front axle for everything except the biggest hitting (mainly downhill) bikes, which use 20mm.  In the rear, you will most often find 12mm thru axles. The only real downside to a system such as this is that it can take a bit longer to change a flat.  Especially with the axle type that’s in the middle in one of the above pictures, as it requires carrying allen keys. A little extra preparation never hurt anybody, however, and the increased stiffness and precision is DEFINITELY worth it.

Now that I’ve said that, I feel bad for my next and final section.  Like with anything in the bicycle world, nothing remains “standard” for very long.  Enter what is called “boost” spacing.  Most simply, this “standard” (ha. ha.) replaces 100/142mm with 110/148mm.  Big whoop, you say? I agree, mostly. But let’s dive into a little deeper to see what this difference REALLY means.

One of the changes between 26” and 29” wheels is the size of the wheel (umm, duh.). This larger diameter wheel has many benefits, which we’ve already highlighted.  One of the things it has that is potentially a negative, however, is longer spokes.  These spokes, despite being attached to the same width hub (100/135) are significantly longer, and are attached “further out” in the triangle.  The boost standard is designed to allow the triangle to have a wider base - as each spoke is attached to the hub a few mm further outboard - which results in a stronger, stiffer overall wheel.

What may seem like a subtle, small change actually has a huge effect on other parts of the bike.  You must now have wider frame dropouts and a crankset that moves your chainring a bit further out to accommodate the different rear hub spacing (this is done to maintain what’s called the chainline, which is chain deflection - or how straight or not straight a chain is - in the middle of a cassette).  The frame itself has a bit more clearance, which allows for wider tires and better mud clearing.  But the endgame here is that this new “standard’ (I still chuckle every time I hear that in the bicycle industry) really requires entirely new bicycles designed around the standard.  New wheels, new bike frames...it’s almost like the bike industry wants you to buy new stuff!!? Who would’ve guessed it...

Performing exceptionally or exceptionally under-performing

It's been interesting watching Christine race and being engaged in her races and who she has racing. It's a departure for me, as I usually really only care about myself. Historically, anyway, I am very selfish when it comes to racing. But over the past year I've watched her and her competition and a few things have stood out to me.

1) Women are significantly tougher than men

Now, those women out there who read this will not likely be surprised by the statement. But all the dudes out there who read that in shake their head in disbelief, I feel sorry for you. On the whole, women kick your ass up and down the [triathlon] block.

Sometimes I feel like the last 5k of a 70.3 run is pretty tough. It hurts, I'm whining, I just wanna be done. Then I imagine pushing a human out of what is essentially my butthole and I'm back to reality. I don't have it that hard.

2) By that same token, women are much more likely to f*** themselves up from training than men

Maybe in part BECAUSE women are so tough, they seem much more inclined to treat training a little differently than men do. For example, if I don't feel that great or I don't hit my watts, I just kinda whine a little bit and either change my workout or just stop; explaining to my coach that "I didn't feel that good." The thought of Christine doing this kinda makes me chuckle, because she - like most women - will dig super deep to nail workouts. Sometimes it's detrimental. Maybe it's not "worth it" to use those little bits of toughness that you have stored in your lady genes in certain instances?

I think most coaches would agree that you tend to treat women differently from men. Men you have to encourage and mollify all while appealing to their ego and/or insecurities. Women you just have to hold back and help them not do too much damage.

There are a few women that have been on Christine's radar at most races over the past year. They are very fast and historically near the top of the female age group field. But for almost this entire year, a couple of them have had serious injuries. Injuries serious enough such that they don't race or they blame a bad race on these injuries. Even more interestingly, at least two of them are coached by the same high profile coach. When they are "on" they are VERY "on" but the downside appears to be injured and poor performances.

So the moral of this story is: it's better to be smart, consistent, and slightly back from the "over-reaching" line while maintaining an extremely tough mental focus but not at the drawback of added emotional stress all while pursuing racing at a high level!

Ironman 70.3 World Championships

Well, I suppose that after all this lead up I suppose I just HAVE to recap the event. Wouldn't want to leave any one of the tens of readers out there hanging by the thin thread of blogspot anticipation.

I came into this weekend unprepared and undertrained. But that was ok! It was, in effect, on purpose. No injuries to speak of and no weird ailments to derail training were in my way; my self was in my way. But it was a low stress weekend, at least for me. My goals were simply to watch Christine dominate as much as possible and then have a solid event myself on Sunday. Getting up early Saturday to spectate and help Christine in the morning was tough knowing I'd have to do the same thing myself in 24 hours, but it was worth all the time on my feet and in the sun throughout the day to see her race so well. Not my normal pre-raceday routine, but well worth any fatigue or soreness it added to the weekend.

My own race morning dawned bright and early and everything was very smooth leading to my race start time of 8:22.

Swim - 31:07

The rolling wave start was kind of cool and unique, so I was excited to try out a new format. I figured the swim would be relatively tough, but after seeing the pro males swim 23ish I knew that we were potentially not facing as much current as the ladies did on Saturday. Given that I only had a swim skin I was pleased with that.

Further, given that over the past 13 weeks I have averaged about 1hr in the pool per week...I was thinking it might be a slow, rough swim. Be that as it may, I dove in optimistically after seeding myself in the 28-30 minute section. I ended up passing quite a lot of athletes throughout the race, so the suspicions of over-seeding by guys was very confirmed. The swim was pretty uneventful and wasn't difficult, relatively speaking. I was working a steady pace and dealing with the chop and very mild current without too much trouble, although I had no time reference until I got close to the end of the pier (about 200m to go perhaps?) and glanced at my watch, which read 29:xx so I knew my time wasn't going to be blazing fast.

T1 - 3:52

This was a pretty long run up to the transition area and a long run through transition area so my time wasn't particularly speedy, but I didn't waste any of it.

Bike - 2:42:06

The bike was where I figured I'd lose the MOST time at this race. Everyone is an uber biker at a world championship (or certainly thinks they are) so I knew with my paltry fitness that I'd have to play it safe or I'd suffer the consequences on the run. I figured 190-200w was a pretty good goal that would probably result in a 2:35-2:40.

I took the climb pretty easy and was passed quite a lot and it was a while before I got the change to enjoy some overtaking myself; on the downhill section I re-passed a few who had passed me and settled into somewhat of a rhythm. I continued on uneventfully for most of the race, taking in calories throughout and trying to make up for a dropped bottle early on in the bike meant that I was grabbing and chugging at aid stations.

There was relatively little drafting, but I was very solidly in the middle of the pack as far as the overall M30-34 race goes so I can't comment on other parts of the race. There were a few offenders who were mostly from countries in south america (I know this because they had their country on their tri kit). That was pretty annoying.

At mile 35 or 40ish I had to pee so bad that I could barely get into my aerobars. I had to pull over at a porto into which someone had just entered so my pee break ended up being a little longer than ideal (2mins) but the relief was priceless. I needed the aerobars for the last 10 miles or so and got off the bike feeling ok with my effort although I was a little sad that my bike time was bested by Christine's from the day before :(

T2 - 2:18

Nothing to see here, except talking to a guy who had been drafting the last 10 miles on myself and a couple other guys. Someone else actually called him out in transition as well. Down with the cheaters!

Run - 1:29:03

I have been the most consistent with running over the summer, so I figured I had a decent chance at a solid run. I underestimated the difficulty of this run course, however, as I was unaware of the 2 serious climbs on the other side of the river...

I started off way too fast, for sure, as my first mile was 6:20ish and basically entirely uphill. I knew Christine and fam would be at the underpass so I made sure to "raise the roof" and yell real loudly when I passed. Unfortunately this ruined pictures of me as I look like a moron but, all in all, I'd say it was a fair trade.

I carried on for a while and the first real nut-puncher is just before mile 4ish and it was a real short but steep hustle. That was kind of the first "oh shit this could be rough" moment of the run, so I slowed down and took it conservatively before getting back on the gas and over the bridge. Shortly thereafter we had another monster climb followed by a nice descent then another monster climb then another sharp descent and then we got back to the pedestrian bridge to head back south across the river and loop #2. I was in a pretty solid rhythm and clicking off relatively consistent miles without feeling too bad. I was not enjoying my gu but I WAS enjoying red bull for the first time in a race, ever.

Normally I'm not a red bull fan, but that ice cold piss looking drink was oddly satisfying. Perhaps it was the caffeine? Lap 2 was more of the same, but slower, as I really started struggling on the uphills. I knew that my time was going to be close to what Christine told me her time was (I didn't remember specifically) so that last mile involved some hustle to try and make sure I

a) beat her

and

b) snuck under 1:30

I was glad to be done and honestly pretty pleased with my effort!

Overall - 4:48:26 (142/318)

So yea, not the fastest time, but it was the best slow race I've ever had! So that's fun and exciting. It was also really nice to kinda take a step back and race without the normal "nobody else matters as much as me" attitude that I have historically normally raced with. Taking the time to pee, while a bit frustrating, was amazingly revelatory as it obviously did not affect my race at all. 2 minutes is a long time but realistically, unless you are fighting for the absolute age group win (i.e. top 3) it's not such a bad thing to take a chill pill. I loved that feeling!