Thursday, May 8, 2008

why 650B road bikes?

The recent resurgence of the 650b wheel size road bicycles has generated a lot of interest but there are still a lot of people seemingly on the fence about it. I just want to summarize some of the benefits of 650b wheeled road / touring bicycles.

I will not be looking into the history of the 650b size; others had covered this.

To begin with, 650b means an effective rim diameter of 584mm as compared to 622mm of 700c, and 559mm of the popular 26” wheel used in a lot of mountain bikes. Current tire width selections for 650b size ranges from about 32mm to 42mm for road tread while there is one mountain tread at 58mm (more to come very soon). This condition has ruled out certain application for this rim size, e.g. modern day racing. While tire choice is certainly on the short side as compared with 700c or 26”, those available are not bad at all for its intended purposes - mainly paved road use but also good for hard pack dirt or gravel roads. With this description, it meant most randonneuring and touring condition would be covered.

Looking from another point of view, it is beneficial for some riders to simply choose to use wider tires, no matter if they are using 650b or 700c wheels. Wider tires simply make more sense for most riding conditions, it provides more traction, more comfort to the rider and a lower chance of tube failure for heavier riders. So, if you have decided to use wider tires already, should it be with 650b wheels or 700c? Read on.

With a 32mm to 42mm width tire mounted, the resultant wheel diameter of a 650b wheel is quite close to a 700x23c wheel, this means that if you are used to modern sport bikes with such a wheel size, you will easily adapt to the 650b size since the gearing on the bike will feel very similar. However, you can also easily gear down for loaded applications or off road riding conditions. For those concerned about speed, I must say that riding a 650b wheeled bikes is not any slower than a 700x23c wheeled bike on most recreational sport riding provided that the bike fit well. The up side though is a much more comfortable ride which may give the rider a stronger ride for a longer duration.

Another thing about gearing is that with a wide tire 700c wheeled bike, it will be harder to accelerate or require down shifting more. If in a stop and go situation, it can be tiring with all the shifting duties. I think that on a 650b wheeled bike, a compact crank (50/34) combined with any road or off road cassette can cover most riding conditions easily.

A lot of riders chose to have fenders on their bikes dedicated for randonneuring, touring or commuting applications and this is an important issue. If you are planning for a bike for this use with 700c wheels, the resultant diameter of a 700 x 32c wheel plus fender clearance would mean a very high chance of toe overlap unless you are quite tall or require a bike that has a relatively long top tube. For most riders between 5’4” and 6’ considering this kind of a bike, a 650b wheel choice would make most sense. The resulting bike with 650b wheels will also look more balanced than a 700c wheeled one.

Some may ask why not use 26” (559 erd) wheels.  And I do agree if you plan to ride across regions that will not give you access to 650b tires, it may be prudent to use 26” wheels and tires.  Otherwise, a 26” wheeled bike is too limited to extreme loaded applications and makes gearing a bigger problem when a more sporty riding is called for. Some may also argue that wheel strength is an issue, but I think modern hubs, spokes and rims are so well developed that it is no longer an issue, just look at all the 29er wheel doing well even in rugged off road use.

In order to achieve good handling on such a bike, a low trail front end is best suited. It provides stable handling at low speed and when a front load (eg handlebar bag) is used. This low trail design can be achieved by a shallow head tube angle or a fork with high rake. A 650b wheeled bike with this design feels very natural, especially when compared with a bike with similar width tire on 700c wheels. The 700c wheeled bike feels a little clumsy on low speed or maneuvering around tight areas; the same feeling or complain some people have for 29er off road bikes. This is easy to understand, as your wheel diameter gets bigger the mass is also concentrated further from the bike and when turning your handlebar, there is more force required to turn the wheel. This feeling only happens at low speed, as the wheel is not needed to turn at higher speed when cornering.

In the end, I think application, rider body geometry, and fit specifics would be the key factors when choosing among these 3 wheel / rim sizes. A well designed frame with the appropriate wheel size will not just look good, but function to its fullest and handle optimally.

If you are interested to try out this wheel size, I suggest to skip the adapt-to-a-700c-frame route and go for one of the dedicated production frames although there are not too many to choose from. The geometry will be more appropriate plus if you use rim brakes and just put on one of those super long reach side pull calipers on a 700c frame I am not sure if it will stop the bike quick enough. Of course, a made to measure bicycle would be the best way to go with all the features that is desired, be it lights, rack, fenders, and fit and handling specifics.

Well, I will not go back to finishing the 650b I did not complete before the accident. 



Thursday, May 1, 2008

It's been long

Wow, it has been long. It is approaching 8 weeks since my accident, which I initially thought would be over in a short time, well, it turned out to be way worse than I thought. I am still recovering and had just started hand therapy this week.

It was 1:20pm or so and I was going lazily to my fitting appointment at Lee’s south store. This was a kind of a special appointment, my client, Judy, was going to meet me outside the bike shop as her husband had asked her. This was supposed to be a gift from her husband, Dan, as he was planning a couple of bike trips with her for this summer and also a way of staying fit. 

Wait as she did but no one came to meet her and invite her to the fitting studio.

It was such a nice day, temperature was about mid 50s, sun was shining, it was a day when there could be no excuse to not ride. I decided it should be a casual easy ride to the store so I just wore casual clothes but put one my riding shoes since the pedals on the bike was clipless. I decided to wear my helmet, which I sometimes did not wear especially when my wife was not in town – a desperate hope to blend in with the young and hip college bike riders.

Not a minute from my home along the bike path, I laid face down on the ground, my body half turned. I did not feel much pain if any but noticed the lost of my front teeth. I was gasping from the sudden change and yelled out two “Help”. I could not quite move but wanted to turn my body so I can lie on my back and take a break to catch my breath. I heard a lady voice from a distance; probably from the sidewalk about 100 feet away, asking if I was okay. I saw my right arm and tried to move it but it did not obey. I tried harder and this time it moved but it flopped to the side and hit the ground. I could not feel any pain from my arm hitting the ground. Now with my torso pretty much lying on my back, I tried to turn my hip and legs as well so I can really lie down, but again, my legs were just kind of flopped. I was finally lying down. I thought, ok, just rest, give it 15 minutes and I will get up.

About this time, a gentleman stopped by to check in on me and let me know an ambulance was called. I asked this gentleman to call in to Lees and inform of my mishap but I forgot to ask someone to fetch Judy from outside the store.

A runner stopped by who happened to be an EMT asked me a few questions and helped the other EMTs who arrived on an ambulance. I was strapped onto a board with my head secured and loaded into the ambulance. They were very concerned if I had broken my neck, but I kind of knew my neck did not break because I moved it quite some and there was no pain at all and I can feel it too. However, I never thought of what was really injured.

In the ER, I received quite some attention and went through x-ray, cat scan, and finally MRI. My upper lip was cut through and required 6 stitches. It was 4 weeks later that my dentist found a fragment of my broken front tooth embedded on my upper lip on the inside that was never checked in the ER. It took another small procedure to take it out since the 4 weeks of healing had took that in as part of the new me.

About 7 hours after the accident, a technician finally came and let us know what the doctor found was injured after seeing the MRI results. They injected a steroid through my IV to help fix the injury. After some research since I got home, it was revealed that if the steroid had been injected earlier, maybe the healing would have been faster and more complete. At this point they finally informed me and my wife, who just arrived from Utah (she was on a business trip there), that I have to stay in the hospital for a couple of nights. No one in the ER thought I would have to stay, but also, none of them thought my extremely numb and tingly arms and hands would last so long either. So, we spent another 2 days in the hospital and were sent home after that.

Our neurosurgeon visited the next day and told us that I had a form of spinal cord injury - spinal cord contusion. It was swelling and bruising of the spinal cord, and it happened on my neck region (cervical), which controlled pretty much all the functions from the neck down. I regained all leg movements and normal sensory in the ER, but not my arms and hands. Doctor said we should just let it heal but it would take some time. He asked us to visit him again in 4 weeks. I was a little shocked that it would take so long but somehow their positive attitude seem to indicate I would be completely back to normal in about 3 weeks.

During the first 3 weeks, anything that graces or touches my hands would cause me much discomfort and so I did not do anything at all, just sitting around or sleeping. But sleeping usually only last 2 – 3 hours each session as any body movement causes discomfort and woke me up. I gradually improved along this time and we visited the neurosurgeon who further explained my condition and the fact that I have a genetically narrow spinal canal, which makes this kind of injury a higher occurrence. I also got a taste of what it is like without hands and how life changes under the circumstances. In fact I was quite close to becoming a quadriplegic and I guess I had a glimpse of what it was like during the first couple of minutes after the crash.

In the last few weeks I have been able to do more by myself with various ways of coping and avoiding the sensitive areas. I am not sure if my hands will be completely back to the way they were, but I am hopeful that my hand therapy will complete the loop.

Totaling all the losses, I had missed my first trip home (Hong Kong) after 6 years, 2 very nice pieces of cycling garment were cut up in the ER, the shoulder trap of my messenger bag, my cracked helmet, the front wheel of the bike was toasted, as was the front fork and the fender, but most importantly, 8 weeks + of my productive life, and of course all the medical bills that are arriving. I have medical coverage through my wife’s employer, but there are all sorts of deductibles, overages and uncovered expenses.

I have to thank all the fine folk who helped at the scene, especially the EMTs, the nurses at the ER, friends from Lee’s who stopped by and called during my recovery, friends and neighbors who helped to take care of Lucky and offered words of encouragement along the way and of course my wife. She had gone through much hardship to dealing with a husband without hands for this period while holding down a full time job.

I should be gradually getting back to building frames and fitting riders soon.