Friday, April 25, 2014

So far I have raced three DH races in China this year. 
Chengdu
The first race was Chengdu Giant DH. Practice was really fun, it started to rain and it seemed like I was the only one who had fun doing practice runs. I enjoy muddy tracks. It was the first time I had raced and ridden in mud with my new banshee mk11. The bike felt amazing and stayed on the ground, allowing me to get more grip than most riders even with regular tires. Unfortunately, by the time we got to race day the track had already dried up and wasn't as fun riding when dry. The race went really well even though I made a few mistakes during my race run. Anyway, I was able to get 1st in the elite category!







The second race was first stage of the BOS dh series, organized by the local Banshee distributor, Jonathan Ley. The race took place in Jinan, Shandong. The track was super high speed and quite pedally which I really don´t like, but I managed to hold on to the 1st place in elite category even though I was riding 90% of the trail chain-less due to a chain failure.


The third race was a downmall race in a big shopping center in Langfang. First time time for me to spend a whole day in a shopping center... The race was organized by Red Bull China. Being inside a shopping center, the track was of course pedaly except for down a few escalators. The track would have been perfect for the Rampant, I was the only rider with a full DH bike. Race day went quite ok even though there were a few hick ups. I only had 2 practise runs since I was unable to go there on practice day. Due to a small communication break down, I thought we were done after the first round where I came 1st. Later I found out that it was the seeding! A couple of hours later the finals started, and I came 2nd.

This was the last race in China before I´m heading to Norway. The season there will start with Norway Cup #1 in Nesbyen on 9th May. Will update you after that. 




BY: ADRIAN AAKRE

Monday, February 24, 2014

Red Lar is a pretty decent actor.. does his own stunts
Mountain Biking Stories from Fakawi Tribe
By Administrator|fakawitribe.com

Monday, February 10, 2014

Fogel is Back on Banshee!!

Home sweet home!

After a two year frame deal with Nuke Proof, I had the opportunity to switch back to my original sponsor, Banshee. The decision was clear and easy. Banshee is a small rider-owned company who has always shown me profound support. I started riding for them in 2009 with a grassroots sponsorship, and undoubtedly never would have made it to where I am today without them. The guys there put me in touch with most of my current sponsors, and opened new opportunities for me that would have otherwise passed me by. The fact that they are a small rider-owned company goes a long way as well. We have built a friendship out of our original relationship, sharing in rides and trips together. This is something that took me a while to appreciate, after having some sponsorship deals that went the entire duration without even seeing my contact's face. I am not a disposable marketing tool to the guys at Banshee; we are a group of riders and friends who are stoked to help each other out. Lastly, their bikes are the best that I have ridden. Banshee's frames suit my style of riding more than any other bike that I have found, and I can't help but feel simply comfortable on them. I was generously welcomed back with open arms, and am looking forward to continuing from where we left off.




For 2014 I am taking myself back to the reasons that I got into riding. I will be putting most of my attention back into making videos, that hopefully share the fun and stoke of riding with others. I am planning on attending the events that I really enjoy, like Sea Otter, Super Sessions, the Santa Cruz Mountain Bike Festival, Goldman Games, AT's Showdown, and Crankworx. Besides this, I am looking to go on more roadtrips, to ride places that I have been too busy to make it to in the past, with intentions to make fun videos along the way.

"At Banshee we have seen Fogel as a member of our biking family for years, and it’s great to know he feels the same way. I personally have spent many fun days riding with him in Whistler and down on his home trails in California, and always have a blast hitting the trails with him. Jack epitomises what I feel mountain biking should be about…fun! It is immediately obvious how much he loves riding a bike, and his passion for the sport is infectious as you hear him laughing down a trail, and grinning as he lands a crazy new trick. Jack also has an amazing ability to film and edit videos that share hilarious and exhilarating riding experiences with the viewer’s, and convey his love of mountain biking with them. Oh and did I mention that he also has crazy skills on wheels (even on a unicycle!). Needless to say I am delighted to have Fogel back on Banshee!"
- Keith Scott - Banshee Bikes Owner / Designer

I will be riding an Amp to assuage my urges of trickery, a Spitfire to attain optimal loam-ripping capabilities, and a Darkside for maximum stoke harvesting capacity. The Amp and Spitfire have blown me away so far, and I'll be getting a leg over the Darkside in about a month! It feels unreal to be back on bikes that make riding a lot more fun for me, and the Darkside looks to be no exception, encapsulating everything that I love in a big bike.



2014 is looking amazing, and I couldn't be more stoked!



-Jack Fogelquist

Saturday, December 14, 2013

Getting back to a routine

I am now back on my bike after breaking my collarbone two months ago. It was a bit of a set back in my training, but with the amount I ride my bike I am bound to have an unlucky spill once and a while.   I just had to make the best use of my down time putting together a training plan and setting some goals for next season. 




I couldn't be happier with my situation this winter.   I've got two jobs currently, working at the Spin Cycles bike shop and at SideStix Ventures.  I am lucky enough to have two boss's that understand my goals and training schedule, so they are helping me out a huge amount by giving me flexible hours so  I can ride, go to the gym and work all in one day.  

Sluggers Family gym is also a local company that is helping me out a ton.  They are sponsoring me with a membership this year and therefore give me access to all the equipment I need for my training.   I'll be spending a lot of my time there this winter.

I am almost done finalizing my sponsors for 2014.   It's incredible the amount of support I've been receiving.  Most of my current sponsors are stepping up and continuing with me for next season.

I am very happy to announce a few new supporters of my racing.   The first is Maxxis Tires!!  I've been riding Maxxis tires by choice for the past several years, and now I have got a real deal with one of the largest mountain bike tire company's.  I will be trying out a lot of tires throughout the winter.  I am also on the testing team, so I will be able to give feedback and test new products.

Second is Genuine Health.   They are a nutrition company that make a variety of supplements from greens powders to pre and post workout drinks.  I've already noticed faster recovery times after my hard workout and rides.  They've even got me up on their brand ambassador page http://www.genuinehealth.com/author/forrestriesco/?view=profile






I've finally upgraded to a full on crf250r moto bike for training this winter.  It's a lot of fun ripping around the local track!  It's good speed training and helps with upper body strength and conditioning. 




I am trying to post as much content as I can on my Facebook athlete page and instagram account.  A follow or a share would be very much appreciated.

Go to the gym, ride, work, eat, sleep and repeat. That pretty much sums up my days for the next few months.   I feel very confident that I've got a good training plan together this off season and I'm excited to get back to racing in 2014!!

Cheers!

Forrest

Friday, November 1, 2013

Wheel size facts Part 3... Contact Patch and Tire Factors.

In this post, I'm continuing with the wheel size theme, but looking at tire related factors such as contact patch, tire pressure and tread. Check out Part 1 and Part 2 of this mini series for some other wheel/tire things to consider. In Part 1, small wheels beat big wheels, but in Part 2 big wheels fought back... so which, if either, is going to come out top for you?

Here, I  discuss contact patch and related factors across the 3 common wheel sizes. Once again I will be taking the wheels and tires from Part 1 for consistency.

Contact patch:

What is the contact patch, and how does it effect grip and rolling resistance?

Fig.1 Contact patch on simplified tire represented in blue
The contact patch (shown in fig.1 in blue) is essentially the footprint of the tire that is making contact with the ground at any instant in time. For any given tire, it will change with tire pressure, as Pressure=Force/Area. So the lower the pressure, the more your tire will deform to the contours you are riding over.

A larger tire contact patch area represents more rubber on the ground, which increases friction and therefore grip (good). However, the larger the contact patch area the greater the rolling resistance (bad). So, as with most things, there is always a compromise, and you just have to pick the right balance between grip and rolling resistance to suit your needs.

Shape and area:

For this section on contact patch shape, let's look at a basic representation of each wheel size (no tread, and no tire stiffness) each with 2.3" width , based on 50kg of weight (assuming 50:50 weight distribution, and bikes + rider = 100kg), and 2Bar (about 29PSI or 200,000 N/m²) of a perfect gas on a flat surface for all wheel sizes. Since the pressure is the same in each tire, the contact patch area will be the same for this scenario as Pressure=Force/Area. This is not very realistic as pressures will change a bit with wheel size (I will go into that later), so this is just to give an idea of patch shape.

Fig. 2 Contact patch shapes for same tire pressure.
In Fig .2 you can see the 3 wheel size contact patches overlapped for the same tire pressure and loads: the bigger the wheel size, the longer and narrower the contact patch. But the variation in shape is probably much smaller than you'd expect, or have been made to believe. So let's look at this slightly differently...

One way of measuring optimal tire pressure is actually as 'tire drop', which is a percentage of original tire height (a little like suspension sag) as seen in Fig.3.
Fig.3 Explanation of tire drop
If for each wheel size we have a 6% tire drop when riding along a flat surface on a slick tire, then this will tell us a lot about required tire pressure, as well as contact patch shape and area for each wheel size.

As you can see in Fig.4, the contact patch area and lengths change as tire pressure changes, but the width remains the same due to same tire carcass width and cross sectional shape. So for the same tire drop of 6% the 29" wheel has a 2.7% bigger contact patch than 650b, which in turn is 1.85% larger than 26". The difference in contact patch area and shape is far less than most marketing would have you believe, but it is present.
Fig.4 Contact patch dimensions for 6% tire drop, and tire pressure for each wheel size
This also shows that the larger the diameter wheel, the less tire pressure is required to achieve the same tire drop. Therefore you can get away with running lower tire pressure on bigger wheels if you wish. That said, the volume of the tire is the more significant factor, so the width of the tire will have a more significant impact on required tire pressure than wheel size.

These factors are the reason that mountain bike tires are wider than road bike tires. For road cycling, traction is less important than minimising rolling resistance (and weight) and so they run narrow low volume tires at high pressure. Mountain bikes run lower pressure, larger volume tires to increase traction as well as shock absorption. It's a case of picking the best tool for the job, by optimising what you want, and compromising on factors that are not as important to you.

Tire tread and compound:
All this marketing chat about contact patch actually ignores the most important factor. Tread patterns are massively relevant, because in reality, none of us ride around on fully slick tires. So when talking about contact patch, we really should be considering actual contact patch of the top of the treads on the surface, and also considering the extra grip provided by the edge of the treads biting into soft ground. Tread pattern and rubber compounds make a bigger difference than contact patch area.

The tread pattern changes the contact area far more than wheel size will!

So when thinking about grip, rather than think too much about wheel size and exact tire pressures, you'd be better off spending that time and effort picking the best tire tread pattern and compound for the riding conditions and experimenting with different tire pressures.

A softer rubber compound (lower durometer) will not only deform more to 'grip' the ground, but will also help damp the ride by compressing more easily under impacts. If you use a new soft compound tire you will be able to brake later, accelerate faster, and corner harder because the tread will bite into the ground with nice sharp edges, and the soft compound will have a higher coefficient of friction, and absorb the shock to stay in contact with the ground better.

For you to consider:

From all the information above, you can see that a bigger wheel will offer a slightly larger contact patch area due to the fact that you can run a slightly lower tire pressure. Therefore, a larger wheel will offer a bit more grip than a smaller wheel with same tire drop, but the increase in theoretical traction of larger wheels is probably less you were expecting.

With the larger tire contact patch comes more rolling friction, and efficiency is reduced. So smaller wheels are more efficient than larger wheels in this area for same tire drop. On a perfectly flat surface with a slick tire, smaller wheels with equal tire drop will lose less energy when rolling along than bigger wheels.

But let's be real... mountain biking isn't about just rolling along flat surfaces and we certainly don't use slick tires! It's about carrying speed through rough sections, cornering hard on the edges of tires, finding traction when climbing steeps and many, many more fun things. For most of these things, tire tread pattern and tire rubber compound are FAR more important than wheel size when it comes to grip. So my advice to you is not to get too lost in these wheel size numbers, instead pick a good tire choice and just enjoy riding your bike!

Sunday, October 13, 2013

Wheel size facts Part 2.... Rollover factors.

Here is some more independant wheel info to help you decide which wheel size is for you. I will be taking the same dimensions as discussed in Part 1 to perform these calculations. These theoretical calculations do NOT take into account tire deformation... which I will talk a bit about later. This week, get ready to deal with everyone's school subject fav - some trigonometry! So belt up, and let's rollover some wheel-based maths (oh dear....!)

'Rollover':

You'll almost definitely have heard 29er riders saying just how much better their bikes roll over obstacles on the trail. "I carried so much more speed through that rough section!", or something similar. This is probably the key reason that riders and manfacturers give for having a bigger wheel size... But what does this mean, and just how much better do they perform this action?

The diagram below (Fig. 1) shows the height of a square-edge obstacle, and the angle of attack vis-à-vis the wheel:

Fig. 1
When a wheel makes contact with a square-edge obstacle (for example, the curb of a pavement - that's British speak for 'sidewalk'), the angle of attack = the angle of the tangent of the wheel at point of contact with the square edge obsticle and the horizontal as shown above.

Fig. 2
Fig. 2 how each wheel size's angle of attack varies with obstacle height across a range of square-edge obstacle heights. Of course these values are all perfect and theoretical (not taking into account tire deformation, tire pressure or bike lean angles etc.)

The angle of attack itself doesn't really tell you much without applying basic trigonometrical functions to to break it down into horizontal and vertical force vectors. In a simplified form without friction or deformation, if a wheel runs into a vertical obstacle higher than the axle height, it will stop you instantly (horizontal force / vertical force = infinity). Conversely, if an obstacle has zero height it will not slow you down at all (horizontal force / vertical force = 0). On Fig. 3, you can see how the force vector varies as obstacle height increases for each wheel size (the higher the Tan (Angle of Attack), the more it will slow you down):

Fig. 3
Fig. 4 shows how the force vectors vary as a % relative to the 650b wheel. A positive number represents a higher horizontal resistance (effectively, this means it slows you down more). So, you can see that 26" wheels will slow down more than 650b wheels which in turn will slow down more than 29".

This graph clearly shows that the relative efficiency is not consistent across all obstacle heights. The larger the obstacle, the larger the effect the wheel size will have. So it is impossible to say that one wheel is x% more efficient over square-edged hits than any other size without saying the size of obstacle, tire size, and tire pressure etc etc.
Fig. 4
It should also be said that not only are big wheels more efficient at rolling over square-edge hits, but they also result in a smoother ride. This is because, for any given speed, the larger the diameter of the wheel the longer it is in contact with the obstacle (i.e. it hits it sooner and leaves it later). Therefore it has longer to react to the obstacle. Plus, the bigger the wheel the less of it is going to drop into holes (think braking bumps), hence 29ers feel like they smooth the trail out.

Once again I want to make it very clear that these numbers are based on wheels that do not deform at all, and that are rolling over perfectly square-edged obstacles, which is obviously not realistic. So let's have a quick look at some real world factors that significantly complicate the situation.

Tire deformation helps to absorb the impact of hitting a square-edge obsticle. This not only reduces the shock that is transferred to the frame and rider, but also makes the wheel roll more efficiently over an obstacle by effectively reducing the angle of attack when it absorbs it. The more the tire absorbs the obstacle the better, so actually lower pressure tires roll over obstacles like this more efficiently (unless you get a snake bite!).

Tire size is an important factor... for example you could realistically have a larger outside diameter running a very high volume tire on 26" wheels than a small volume tire on a 650b wheel. In this situation the 26" wheel would roll over things better than 650b, so tire height should be considered if analysing options.

We have indeed confirmed that big wheels roll over obstacles better than small wheels, and help maintain momentum as a result. But frame geometry and axle path also play a factor if the frame has suspension, as the suspension can help absorption of obstacles and make the bike roll over them better. The slacker the head angle or more rearward the axle path, the better a bike will roll over an obstacle if all other factors are equal.

Plus there is one very very significant factor that none of these numbers take into account...We can bunny hop over things! This is why you should never listen to arguments taken from automotive industry as the car can't be thrown around independently of the driver.


If this second installment of wheel physics hasn't boggled you even more than the first part, the third blog post will tackle contact area and grip. Woop!