2.       Increased pedaling efficiency
When a bicycle accelerates forward, inertia pulls the rider’s weight towards the back which results in compression of the rear suspension.  This is known as squat. ART suspension is designed so that when the suspension compresses, the chainstay length increases. This is known as chain growth.  When the rider puts force on the pedals, the chain becomes very tight and the bicycle will accelerate forward.  The chain tension will also force the suspension to extend.  This extension force is known as the anti-squat force because it counteracts the squat caused by the acceleration. With 30% more chain growth than before, ART suspension is designed to resist squat forces and reduce pedal bob, resulting in a highly efficient pedaling platform.

3.      Improved Leverage Ratio Curve
A.R..T suspension uses a lower and more progressive leverage ratio to increase the bottom out resistance and improve the tuneability of the suspension. Lowering the leverage ratio reduces the amount of force on the shock which gives the shock greater control of the suspension movement.  The adjustment dials on the shock will also have a greater effect on suspension performance, allowing the rider to fine tune the suspension to their liking. A more progressive leverage ratio makes the suspension get stiffer as it gets farther into its travel, giving the suspension that ‘bottomless’ feel.

If there is one place in the world to find the top mountain bike mechanics in the world it is at a World Cup Race. Well, Dirt Norco Race Team mechanic Alastair Beckett was nice enough to go through rear derailleur adjustment for us at the Leogang World Cup. So, if you have ever wanted a little bit of help fixing up your Sram drivetrain, watch through this easy, step-by-step video tutorial.

Norco full suspension bikes have featured adjustable travel for quite some time. In fact, VPS stands for Variable Point Suspension, referring to the adjustable travel. The travel is adjusted by moving the shock position between points A and B. For all 2010 Norco bikes with adjustable travel Point A is the long travel position and Point B is the short travel position. In the 2010 lineup there are several bike that offer this adjustability such as the LT series, Fluid series, Faze 2 and 3 and the Phena. Each of these bikes has two travel options as listed below.

LT 6.1, 6.2, 6.3 – 137mm – 158mm

Fluid SE, 1, 2, 3 – 116mm – 143mm

Faze 2, 3 – 100mm-120mm

Phena – 116mm – 143mm

When adjusting travel between settings on many bikes there are adverse affects that can reduce ride quality or decrease performance. Not on a Norco though… when you change the travel on any of these mentioned bikes the head angle, and BB height remain constant. The only difference is the change in travel and a more or less progressive shock stroke. I.E. The long travel mode has a lower leverage ratio and more progressive stroke. The result – short travel is a linear, more XC type ride while long travel is a more active, agressive setup.

Thanks to Steve Bown for asking to learn more on the matter

Dustan

It doesn’t happen often but every once in a while I will admit I get caught on the trail without a tube. Not because I didn’t have one, but because I either gave it away or flatted more than once on a ride. I am slightly ashamed to have admitted this but yes, it does happen. This past weekend I went out riding in Port Moody BC with a friend and it happened to be one of those rides. After Eric flatted once, I followed suit. That was no biggie as we both had a tube, but then Eric tried for round two. Three flats, two tubes, 0 patches.

As Eric got ready to start hiking I made a suggestion, one that I am not sure a lot of people have utilized. Tie a knot in the tube and ride out. That is right, this trick is super simple and low tech but can be the difference between a long hike and finishing a great ride.

To fix this flat, you will need to start by finding the hole. Once you do, tie a knot with the hole at the end which is tucked through the knot loop. Pull the knot nice and tight to be sure that it won’t come undone once inflated.

You will see that the tube is significantly smaller in diameter now that it has been tied. You will need to insert the valve, then stretch the tube around the rim before attempting to seat the tire.

Once you get the tube around the rim you can start to work the tire onto the rim. You should be careful that the last bit you are trying to seat is not at the knot as this area has significantly more bulk around it and could be difficult to work with.

Now that the tire is on, you can re-inflate.I wouldn’t suggest inflating to more than 40psi as the tube is significantly stretched and fatigued. This is not a long term fix but should be enough to get you home. Once you start riding you will likely feel the knot as a bump in your tire. It may be a little rough but it sure beats walking.

If you have your doubts, give it a try.

Dustan

There are a lot of standards when it comes to bikes and the number seems to get significantly larger every year. Just look at Bottom Brackets over the past decade or so. We have Spanish BB, Euro BB and Mid BB, we have widths of 68mm, 73mm and 83mm. Mounting standards like Square taper, isis, octalink, Hollowtech II, Howitzer, GXP, and now BB30… I probably missed a couple as well.

Each and every one of these standards serves a purpose. They were each developed with the purpose of making the bike, lighter, stronger, faster or smoother. Over time this has meant that some have stuck, others have failed and we will likely see more coming soon.

This is not isolated to Bottom brackets either though. We have numerous standards for hubs, headsets, bars, stems, posts and more. I will do my best in this series of articles to clear up the most confusing of these.

Over the next couple of weeks I will be discussing the most common Mountain Bike Standards:

Hub Standards

• 135 x 10mm rear hubs
• 135 x 12mm rear hubs
• 142 x 12mm Syntace Rear Hubs
• 150 x 12mm rear hubs
• 9mm front hubs
• 15mm front hubs
• 20mm front hubs

Headset Standards

• 1 1/8″ Headsets
• 1 1/2″ Headsets
• 1 1/8-1 1/2 Tapered Headsets
• Integrated Headsets
• Semi-Integrated Headsets
• Standard Headset

Bottom Bracket Standards

• 68mm
• 73mm
• 83mm
• Octalink
• Isis
• GXP
• Hollowtech II
• BB30

WOW, that is a REALLY LONG list…..

Check back soon for the first installment.

Dustan

A loose headset is one of the easiest repairs that can be done to a bicycle. The only thing easier, is screwing it up.

The first step to tightening your headset is loosening the stem. This is done usually with either a 4mm or 5mm allen key. Loosen off the stem bolts until the handlebars will move relative to the front wheel.

The second step is the beginning of determining why the headset is loose. The tightening process may be as simple as tightening a bolt, but it could also be a little more complicated. What you will need to do is take a 5mm allen key and remove the top cap of the headset. This is the vertically positioned bolt on top of the stem.

Once this bolt is removed there should be a minimum of 2mm and a maximum of 5mm between the top of the stem and the steertube. The stem should extend higher than the steertube of which it attaches to. If the steertube extends beyond the top of the stem you will need to install an additional spacer above or below the stem.

Correct Headset Spacing

Incorrect Headset Spacing

Once the spacing has been corrected or confirmed, you may start tightening the headset. The next step is to tighten the topcap to the desired tension. Tightening the topcap is preloading the headset bearings and needs to be completed while the stem is loose. As you tighten this top bolt, you will find that the steering will eventually tighten up and bind. There is a happy medium between a knocking in the front end and this binding stage that needs to be achieved. If there is play in the headset moving back and forth, continue to tighten. If the steering is tight and does not move smoothly, loosen.

The last step of tightening a headset is to tighten the stem. Before doing so you must align the cockpit with the front wheels. The easiest way to do this is to straddle the bike and line up the stem with the front wheel. When this is aligned you can move on to tighten the stem bolts. Be sure to notice the torque rating for the stem as over-tightening could cause damage.

Voila, you just fixed it!

Dustan

The bicycle chain is a staple and  a standard for the bicycle. It has been nearly commoditised with its genericy and now, could it become obsolete? Don’t get me wrong there is something to be said about a quality chain but really, it is pretty boring. Isn’t there another choice?

The chain has evolved over the past few decades, it has become, stronger, lighter, narrower and longer lasting but really there has not been a major technological breakthrough since the early 80s.  Comparing something like suspension technology to that of the chain is like comparing a Large Hadron Collider with cavemen using tools… both had their 15 minutes of fame but one is slightly more impressive than the other.

I have recently been given the opportunity to try out a 2010 Norco Judan which is using the Gates Carbon Drive system. The idea of a 29er singlespeed bike using a belt is to say the least – a little bit of a foreign concept. I thru in the towel on hardtails the better part of a decade ago and thought I would never go back. Well, I am, and I am kind of excited about it. The idea of a singlespeed 29er entices me. It will be fast, it will be quiet, and it should be pretty much maintenance free – after all there isn’t really anything to go wrong.

I am a couple of rides into my testing so far and I must say, I am starting to like it. At first I was a little bit detered by the gear ratio. Some of those hills were a little intense for my liking and I was tempted to walk up a couple of steep bits. But, I pushed through and had a blast on the descents. The big wheels can seemingly roll over anything, the frame has the comfort of steel and the belt has been flawless. Only time will tell though if this is the new flavour for 2010. The belt is the first viable option to a traditional chain. There are a few limitations but only time will tell how far it will go.

More Updates Soon… What do you think of the belt? Good Idea? Bad Idea?

Dustan

There comes a time in every cyclist’s journey when they get tired, lazy or indifferent and break a chain. Shifting under torque, whether intentional or not is a recipe for a bent or broken chain. This may seem like the end of a ride but chain repair can be completed quicker and easier than even a flat tire – if you have the right tools.

The only tool that you need to fix a broken chain is a chain break. Seems sort of ironic that you fix it with a break. . . . but we will have to roll with it. There are many different types of chain breaks and the image above depicts a shop quality too. You will find that many multi-tools are more convenient while on the trails.

The second piece of equipment that will make the repair much easier is a masterlink. These are available at your local bike shop for a very low price. Using a masterlink to repair a broken chain will result in a stronger link and much saved frustration.

Now onto the repair:

The first step is to remove the broken link. In the above picture you can see that one link is severely bent. This will need to be removed before the chain will be usable once again.

You will need to use your chain break to push out a pin on either side of the broken link. Try not to push the pin out all the way as this way it will be easier to keep track of the pieces. Push out the pins so that you will end up with two inner links.

The next step is to connect the masterlink. Insert the pin from each side of the masterlink into the chain from opposite sides.

Push the two sides of the mastelink together to make a single link.

Pull the chain along its length to lock the masterlink into place.

Voila! You have just repaired a chain.

Dustan

Recently I posted an overview on air suspension setup which spurred on a flurry of questions about sag. First of all what is sag? and how do I set it up for my riding style?

Sag is the amount of suspension that is used simply by sitting on the bike  in a neutral position. This is the amount of shock compression while your body weight is centered over the front a rear suspension.

So, how to you set it up? Depending on your riding style, the amount of sag which is optimum will differ. Personally, I run about 20% on an XC bike and 30% on a DH/FR bike. For the purpose of this demonstration I have used a 2009 Norco Shore 1. The Shore has 7″ of rear travel so 30% sag is equal to 2.1″.

The First step in sag setup involves measuring the height of the bike from a reference point. I like to use the distance from underside of the saddle to the ground. In this case the height measured 35″. The bike has a total of 7″ of travel so when fully compressed this length will decrease to 28″. With 30% sag, the measurement will be slightly under 33″

If you are using an air shock then you can adjust your sag with your air pressure. Increasing air pressure will decrease sag while decreasing pressure will increase sag. If on the other hand you are using a coil shock, you will need to change your spring weight to alter sag.

I hope this clears things up a bit.

Dustan

A poorly adjusted derailleur can be the difference between a great ride and throwing your bike into the bush with frustration. Having gears that are crisp and reliable will make you ride better, be more efficient and wear out fewer parts. The concept of setting up your rear derailleur can be daunting yet after breaking it down step by step, you will see that it isn’t so bad.

On a derailleur there are four means of adjustment which will each change a different aspect of your shifting. In this article I will break down each of the adjustments into what they control, and how to set them accordingly. The four types of adjustment are:

• B – Tension Adjustment
• High Limit Screw
• Low Limit Screw
• Cable Tension

B Adjustment

The First means of adjustment is probably the least understood part of any bicycle. The B – Adjustment. If this screw is set up correctly, it is likely that you never even knew it existed. If not then your bike has likely never shifted correctly. The B-Tension adjustment controls the height of the upper pulley in relation to the cog.Winding out this screw will decrease the gap between the pulley and cog while winding it in will increase the gap. If the B adjustment is wound too far in, the derailleur will have a large gap and have a tendency to jump gears. If the adjustment is too far out then the jockey wheel will sandwich the chain between the cog and pulley resulting in a grinding/rubbing sound. The optimal position is where the pulley clears the cog and chain by approximately 2-3mm.

B Adjustment Wound Too Far In

B Adjustment Wound Too Far Out

Correct B Adjustment

The second and third aspect of derailleur adjustment are the two limit screws. These adjustments change the extremes of how far the derailleur can move. If your chain has ever gone into your spokes, you can likely blame an incorrectly adjusted limit screw. Both limit screws are labeled with an H for high and a L for low.

Sram Limit Screws

Shimano Limit Screws

Every derailleur has two limit screws, a high and a low. The easiest way to remember which is which is to think in terms of high speed vs. low speed. The H, or high speed limit screw will control how far towards the outside or smallest cog your derailleur will travel. The L, or low speed adjustment will control how far up towards your spokes the derailleur will travel.

Limit Screw Adjustment

Winding inward (clockwise) both the the high and low limits will shift the derailleur towards the center of the cog. For example, if your derailleur is traveling into the spokes, you will need to wind in the low limit. If you are unable to shift from 2nd into first even manually pushing the derailleur, the low limit needs to be wound out. on the other side, if the chain is falling off of the smallest cog, you will need to wind in the high limit, while if you can not shift from 8th into 9th gear, you will need to wind out the high limit.

On a correctly adjusted derailleur, the pulley wheels will line up directly with the highest and lowest cogs.

Properly aligned High Limit

The last aspect of derailleur adjustment is cable tension. The cable that runs from the shifter to the derailleur is an extremely important aspect of your bike. The tension of this cable will determine if your gears will shift or cause you endless frustration.To adjust the cable we can break it down into a few simple steps.

• Shift into the smallest cog which is your hardest gear.
• Wind in your barrel adjustment in all the way and then out one half turn. This is for both the handlebar barrel and the derailleur if you have one.
• Undo the derailleur cable fixing bolt and pull the cable tight without  moving the derailleur.
• Tighten the fixing bolt without letting any slack into the cable.

Cable Fixing Bolt

At this point your derailleur should be close. To make minor adjustments you will now use the barrel adjuster. When shifting, if the derailleur will not shift up, into an easier gear you will need to wind out the barrel adjuster. Start to turn the barrel in a counter-clockwise rotation 1/4 turn at a time until the gear changes smoothly. If by chance the derailleur does not shift down, into a harder gear, you will want to turn the barrel in a clockwise rotation 1/4 turn at a time until the shift is made.

Barrel Adjuster

As you can see, there is a fair bit to correct derailleur adjustment. Really though, it breaks down into four adjustments and a little bit of patience. If you have any input of adjustment, comment, ask questions, provide your two cents.

Until next time,

Dustan