Tacx Drop Bar Light.

The good folks at Tacx have come up with another great idea. The "Lumos" drop bar light. It fits into the bar end of any drop bar and has a nice powerful red LED light that alerts drivers following of your presence. Now this is not a new idea, there are many makes and models that do the same thing however, where this Tacx unit differs is that it also has a forward facing white LED light as well. It obviously has to drop down below the bar a little to be able to shine forward but it is completely unobtrusive and stays out of the way of any hand position and fits well to the bar.  

We have fitted a few already and the initial feedback has been very positive.

New, Old School Wheel

We have a pretty lugged frame Cinelli road bike in the store at present for repair and service. One of its issues was a trashed rear wheel so we needed to find a suitable rim for replacement. A big problem when replacing rims on classic road bikes is matching the "look" of the original. Well good news, the folk at Soma, whom we are big fans, have just produced this beauty. The "Eldon" rim comes in 700 and a 32 or 36 hole count. It looks fantastic and, more importantly, is built well. Double eyelets like the old original Mavic rims and double wall obviously. Highly polished with non machined sidewalls. It built up very well and took 100kilos without any trouble.

2013. The Year of the GPS.

This is the time of year when we start to see new product brochures hitting the mail box. This year has seen its fair share of literature describing new shiny products that should hit the shelves in 2013. one such flyer that caught my eye was from the good folks a t Cateye. Well known for their fine cycling computers and light systems they are now eying the gps market, long the domain of Garmin. While I have nothing against the Garmin systems, they have produced great performing units for some years now, however good as they may be they are pretty expensive. Any other company looking to break the Garmin hold on gps is going to have to do something special and this is where Cateye could make a dent, they are planning to offer some pretty low priced models. One even has a tentative price tag of below $120. It remains to be seen if they can pull this off but that kind of price point certainly will have some takers. I will keep you informed and hopefully we will start to see them soon.

Re-Inventing the Wheel.

The bike business is a business like many others, ideas come and ideas go, some good some bad and many are just there to let people know that the company ain’t dead. Every once in a while an idea comes along and just kind of hangs in the periphery, just waiting for their time to come. One such idea is 650b wheels, not that the 650b wheel is a new idea, hell it’s not even an old idea it has been around for decades, but to mountain bike designers and riders it is relatively new. There are some people, and I myself am one, that contend that if we had designed mountain bikes from the ground up in the beginning instead of modifying road bikes and cruisers to go biking in the woods, we would probably have opted for 650b wheels right from the start, however modifying frames led us to the smaller 26 inch wheels that then became the mountain bike standard for so many years.

        A few years ago we made the quantum leap to the 700c wheel, more commonly referred to as the 29er, which has made a huge impact with off roaders. This has made it difficult for the 650b though. Going so long with one choice, the 26, then adding the 29er quite recently has meant some reluctance from mass manufactures to add yet another wheel size and different bike geometry to already swollen product lines. Luckily the fear of being left behind by the competition has won out and we are seeing many choices from frame companies along with tire and rim manufacturers for 650b. This is very good news. And here's why; Choices.

As mentioned before the industry standard 26inch wheel MTB has been around since the start of mountain biking, the 29er or 700c MTB wheel is a relative newcomer and the 650 b is the new kid in town. The important thing to keep in mind here though is to not disregard any of the old wheel sizes just because there is a new one. They all have their place when looking for a new bike.

During this bike season we have seen a lot of new customers, which is very nice, a lot of new MTB’ers have come through the door as well and a good deal of them have opted for the 29er. Now don't get me wrong a 29er is a fantastic machine but it is not for everybody.

Designing frames and frame geometry for big wheels is tough, sure anyone can build a bike to accept big wheels but getting the handling and feel dialed in is a very different matter and it is especially difficult getting it right on mid to small frame sizes. We have seen many, many riders lately that look like they have been swallowed whole by their bike and, while this arrangement is fine for a gentle trail ride, on a more MTB specific trail or good single-track it must be akin to riding a bull elephant with colic.

Before I carry on let me clarify what we actually mean when we talk about these different sizes. Below are the measurements, in millimeters across the wheel, bead to bead. The bead of a rim is about 3mm down from the top of the rim.

26        559mm

650b    584mm

29er     622mm

As you can see the 650 falls about midway between the other two you will also note that the bead seat diameter of the 29er is the same as a standard road 700c so why do we call it a 29er when it is really only a modern 27inch road wheel. Well it is because some bright spark decided to measure the diameter outside to outside with a fully inflated mtb tire on, which gives you a measurement of roughly 29inches. Confused yet?

Anyway, back to the business at hand.  If you are a tallish or leggy person the big wheel option is definitely a choice for you. The frame size will be plenty to accommodate the extra clearance while still maintaining the ride characteristics of a good mtb. All the rules of bottom bracket height and head and seat tube angles still need to be obeyed and they can be with a mid to large frame size. However, if you are, shall we say a little vertically challenged, this is where problems arise. The rules of designing a bike to perform well for the rider tend to get thrown out the window and it all becomes about designing a small enough frame to at least reach the pedals on while the design is sacrificed to fit a big set of wheels. This really does not work. The cut off for a bike designed for the rider instead of the wheels generally falls somewhere around the 5’6” mark. There are exceptions for those with exceedingly long legs in relation to body height but generally speaking this is where sticking with the 26” wheels tends to be the better option.  Now though we have another option 650b.  This is where the slightly smaller size gives us, as frame designers, much more scope to still design the bike for the ultimate ride and handling but still giving the option of bigger wheels.

A Soma "B-Side" Built and ready to roll.

For those wanting to know more about the options available in the 650 or 29er range stop in or fire me an email. There are lots of choices. At the moment some of the best 650b frames tend to be from companies like Soma who offer the B-side. I expect some of the major names to start producing complete 650 bikes in the next year’s product line.

Laser Lights Are Here!

Well we are nearing the time of year when light begins to fade and safety becomes a concern. The last few years have seen quite an influx of new lights and high density LEDs that function for many hours on little power etc. Something a little different this year though is the inclusion of laser beams. Yep lasers, hell I'm of the opinion that anything with a laser has got to be good. We should be receiving our first batch any day now so I will have a test report soon but for now take a look at the pictures to see what they are all about. Basically in addition to the high density LED light we have two lasers pointing down to highlight a path for motorists to stay clear as they pass.

What's What With Watts...

A few days ago I published a post on choosing a power meter and, though it seems to have been well received, I have been asked some follow up questions.

Firstly it seems that there is some interest in knowing what kind of power output is attainable and how does your output compare to others. To try and answer this I have broken down some previously published data and averaged out the results into four rider groups. Lastly, so that it is possible to compare riders of differing weights, I have broken down the power output into watts per kilo of body weight

(a kilo =2.2lbs)

Rider	1 Minute Burst( watts per kilo)	Maintained (watts per kilo)
Pro Tour Rider	11.2	6.1
Cat 2 Rider	8.85	4.6
Cat 4 Rider	7.6	3.75
Regular Recreational Rider	5.85	2.4

The higher wattage figure in each category is what the average rider, in that group, can reasonably expect to sustain for 1 minute. The second, lower figure, is the average output for a usual distance ride in each group.

These figures are by no means written in stone and I have done my best to average everything out with the intent of giving you some kind of baseline in each group. There are plenty of riders, in every category, that produce figures well outside of the norm and if you want to compare your wattage to your favorite tour rider then a five minute search online will glean you a set of figures to use. Top sprinters are capable of producing around 1200 watts output over the last run to the line and top climbers are getting close to 525 watts on extended climbing stages. Tour guys love to show off their power figures I have found…

 

The Second questioned, that has been asked more than once. Is there a way to calculate watts without a power meter?

Well, kind of. The first thing to remember is all the variables that act against your forward motion, as mentioned in my original post, the terrain, weather, equipment etc; all act against you gaining an accurate set of data from anything other than a power-meter but, by choosing a flat course and a mild day with no adverse wind conditions, a fair judge of power output can be recorded.

Using the table below, again I have taken an average of many power output readings to try and lessen inaccuracies; you can see what kind of power is required to propel you along at a given speed. The data used in the calculations all came from drop bar road bikes using tires from 18 to 25 wide. There may possibly have been the odd 28 in there too but not enough to make much of a difference.

The following is the chart that was produced.

Speed,(kmh)                                     Watts

20                                                           78

25                                                           123

30                                                           186

35                                                           273

40                                                           378

It is interesting to see how the wattage required to increase your speed grows substantially the faster you go. At low speeds the wind resistance plays very little part in holding you back along with other resistance factors. However the faster you go the more wind plays a part. This is because the resistance increases in line with the square of the forward velocity. All pretty technical but this is the basic factor that we have battled with since we decided to start going places on something else other than our feet. The bottom line is that the better you get the harder it is to get even faster.

Choosing a Powermeter

First things first, what does a power-meter actually do and why do you need one? Traditionally cycling performance has been measured by using a basic sensor fitted to the bike which tracks and monitors speed, distance and, more recently, cadence. Within those features we also have average speeds, max speeds attained, etc. Whilst this information is good and for most people who just want to keep a general record of miles ridden and average speeds probably all that is necessary, however the data and feedback does not take into account ride conditions such as headwind, tailwind, altitude or gradients. More importantly there is no measure of effort from you, the rider.

                 Lots of riders nowadays use some form of cardiac feedback, usually in the form of a band with a sensor worn about the chest and, though this data is useful, it still has large gaps and omissions plus it is wildly inaccurate at times. Again, outside factors of terrain and climate, altitude, whether you had a late night or two shots of espresso before you started all have effects on your base line. There is also a significant lag between pedaling output and your hearts increased beat rate.

                 So this is where a power meter takes over. It really is the only accurate way to gauge and compare performance. Power-meters measure power output in wattage and, more importantly, remove all the variables from the data. As an example; you completed a ride last week in fair weather and kept up a steady output of 285 watts for two, twenty minute training intervals. Today you did the same ride, this time in driving rain and a headwind but still completed two, twenty minute intervals, your distance covered was much shorter but your power output was 288 watts. You did better, but your ordinary computer would show that as a bad day. With the power meter this is accurate usable data, no need to discount the day or make notes to allow for bad weather. Watts are an accurate measurement of your performance regardless of all the changing forces acting against you. The end result is a phenomenal training tool and record of improvement.

                 During racing and endurance events it is a great source of feedback for maintaining calorie intake to match output and also keeping a comfortable pace for a long endurance event.

               

So, now that we have covered what a power meter can do for you we shall take a quick look at your main choices.  The benchmark device is probably the SRM range of crank mounted power meters. Very reliable, accurate and the company has been producing meters for many years. Sadly though, what limits their popularity is the price. While any of these devices are not cheap, setting up a bike with an SRM unit is going to run around 3 grand. Ouch. 

Next in the line-up is Ergomo, these guys produce a solid, bottom bracket device which you can install with a crank-set of your choice. Accurate and the company produce the usual range of data analysis software. Ergomo is cheaper than the SRM meters but still a little more expensive for a full system setup than the third choice.

 Power-Tap from CycleOps is about the cheapest option for a reliable power meter system and, for that reason, it is this system I shall concentrate on here. Still not cheap but they do have an option below a $1000 which is considerably less than the SRM. Even the top of the line G3 ceramic is less than the next player in the market and for that reason alone Power tap has become a very popular choice.

I shall start at the top with the G3 ceramic. This hub is the world’s lightest power meter and the complete hubs weigh in at a mere 315g. Next we have the standard G3, basically the same hub but without the ceramic bearings. The weight is still excellent at 325g and you can always upgrade to a ceramic bearing at a later date if you feel the need. The G3 series hubs are a complete makeover from the original power tap hubs. They have a significantly reworked body and allow for much easier servicing. One of the main differences and to my mind the most important one is the increased gap between the flanges. This dimension is very important and affects greatly the final strength of the wheel. The G3 series hubs increase the gap by 5.6mm over the original models and this makes it possible to build a very stiff and strong wheel, the dimensions are much the same as any road race hub in fact.

The original design is still available; it is called the Power-Tap Pro. With a sticker price of less than 900 a hub it is by far the cheapest meter option out there. Each year it gets a basic makeover to keep the internals up to date but shape and external dimensions have changed little. The pro is a fine piece of equipment and has accuracy the same as the G series, all the hubs have great accuracy, to within +/- 1.5%, and the company produces a great range of analytical software, it is quite a bit heavier than the G3s but it is also a lot cheaper. Over the years we have built a lot of them up and I always recommend getting one with a higher spoke count. With the closeness of the flanges on this hub we need to get as much strength as we can from the spoke number. You are not going to be making massive weight savings opting for the 24 spoke, not when the hub itself is 450g, so do yourself a favor and opt for the 32. With a 2x pattern and maybe an offset rim or a deep V at least, it can be built up quite strong and stiff.

When used for training purposes and accurate performance recording the standard Power-Tap Pro is a fine choice however, if like many you are looking for a wheel to race with I would suggest opting for the G3 series. These hubs are much the same as any of the many race hubs that we use and with the extra flange width I can build a super race wheel that gives you feedback as well.

A final thought on some other options. Recently there have been some forays into the power meter market by a few well known players. Over the past few months I have read some interesting press releases with regard to pedal devices. On the face of it a pedal option sounds a good idea, easy to transfer from bike to bike for one. But some of the price points that I have seen are ludicrous and I would like to see them in action first with some good field testing and data collection behind them. Some of the accuracy reports I have seen are a little disappointing, but it is early days. For the moment I suggest the Power-Tap , for best accuracy and bang for the buck.

Wheel of the Week

A customer with very good taste and a lot of patience finally received his reward today. The new Chris King R45 road hub with the Campy freehub body hit the store, after a long wait, last week and was coupled with a Velocity' Fusion' rim, DT Competition spokes in black and DT brass nipples. The fire red hub added the required splash of color. The newborn hit the scales at a very respectable 918grams and is this particular customer’s third one of my hand- built wheels.