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Technical bulletin: Bicycle

Gabes, Tunisia

Some of you asked about my equipment, and so I thought I would start with the bike and occasionally add some other technical tidbits as I go along. The bike was designed by the good people at Pedal Power in Acton, Massachusetts (with a lot of "what if's" from me). The frame was measured to my body and fabricated in Somerville, Massachusetts by the Independant shop from Reynolds 853 steel tubing. Specs follow:

Reynolds 853 - heat treated
UTS: 81 - 91 Tsi, 180 - 210 Ksi,
1250 - 1450 MPa

"This seamless air-hardening steel tube sets new standards for professional cycle frames and proves that steel still has a future at the highest levels. It is suitable for TIG welding and brazing, using lugged or lugless construction. The production process ensures tight tolerance, gauge tubes. The strength to weight ratio of 853 is close to that of quality titanium frames. A normal chrome molybdenum steel will lose strength in the joints after the heat has been applied.

This material (853) INCREASES in strength as the frame cools to strengths well in excess of the delivered values shown above. This unique air hardening property of Reynolds 853 provides additional stiffness through reduced microyielding at the joints, allowing stiffer frames with excellent fatigue strength (when compared to standard chrome molybdenum) and a superior ride quality from the finished frame. On road and touring frames we recommend the use of 631 or 725 fork blades with 853 frames".

I got that off their website.

This material eliminates the need for butted or double butted tubes and brazing because it is strengthened by the heat of the welding operation, and should a weld ever fail, any old shop in Africa stands a chance of repairing it. This is why aluminum or carbon or any number of other possible (and possibly lighter) frame materials were not selected. The frame has holes and braze-ons for every conceivable configuration of component parts in case anything I have now should break and I can't find the same replacement parts. The forks are extra wide to accept both mountain bike and regular street width tires.

The rear axle is solid steel, not the hollow axle that usually houses the quick release mechanism. I was concerned about the asymmetric stresses of the trailer, as well as the stress of my 195 pounds and the weight of the bike bags, and so we took this extra measure.

I am using bar-end shifters because they are easy to adjust and repair and replace. There is a cassette of 9 gears on my back wheel, with three gear wheels in front for a total of 27 gears. We calculated all the gear ratios but I've forgotten whether there were some doubles in there or not and I'm not about to start counting teeth now. Originally we had a lower "granny gear", but the wheel is so small that there is a risk of breakage and I opted to go one larger. I'm pretty happy with the range of gears available to me, though I could occasionally use more power on the downhills.

The bike has disc brakes in both the front and rear. The stopping power is immense, even fully loaded, and there is no risk of damaging my wheel rims as sand might begin to grind between them and a set of normal brakes. If the disc brakes do ever fail and I can't fix them, the frame will accept normal brakes. The disk brakes have a small tolerance and I have had to adjust them a bit as the cable stretched among other things. Though its finicky, adjustment is fairly easy with some dials on the brakes.

I am using 26" rims that accept both narrow street tires and wide dirt tires. The originally planned trip had 1500 km of dirt track and 3500 km of paved road, but the new route shifts the proportion more towards asphalt. Spokes are heavy-duty, and my concerns about breaking them has proved unfounded so far. On my trip from Amsterdam to Morrocco in 1979 I had a lot of trouble popping spokes, and they are a real pain to replace. So far, so good.

The seat was measured to my butt (not kidding!), and I have suffered less for it: they are configured to maximize circulation in the seated position, and they really work.

Pedals clip into my shoes, which I always thought would limit my shoe options too much on a long trip, where I don't want to bring 2 pairs of shoes. Fortunately, I found the perfect set of bike shoe/boots that do it all: let me ride in comfort and hike around without any problem at all in something other than a sneaker type shoe. They are made by Lake out of...I think Illinois.

Handles are wrapped with gel tape, and I wear bike gloves because I lose circulation in my hands and fingers. It has helped a lot, but I still suffer from circulation problems.

The bike racks are the toughest racks I could find, Old Man Mountain out of Santa Barbara, California.

The bike bags are by Arkel, out of Canada, and they are truly fantastic. I opted for 4 equally sized bags in order to distribute the weight on the frame fairly evenly. Each bag is a bit heavy, but incredibly durable and with a waterproof inner bag that has proven to be very effective. The laptop I am typing on now has weathered some drenching inside those inner bags.

The trailer is by Radical Design in the Netherlands (thanks to mom for picking it up on her last trip to Holland, since they don't sell to the US). I chose it for it's weight capacity, which exceeded the one wheel trailers on the market by 10-15Kg. I will be carrying 40 liters of water on some legs of this trip (40 liters=40Kg=88lbs), and so the capacity is no small issue. The trailer has performed extremely well, and the removable wheels make it convenient to put on airplanes. It has a nylon rain jacket which has performed well, though on Day 2 I failed to notice it rubbing against one of the wheels, and the wheel rubbed right through the fabric. I almost never feel the trailer at all. My only concern about the 2-wheel design is how the rig will perform on narrow dirt tracks. I'll find out soon enough.

permalink written by  roel krabbendam on January 4, 2007 from Gabes, Tunisia
from the travel blog: Harmattan
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i recognize the focus on minutia of tech detail.. the mine does wander a bit when faced with long endless rides.. been there, done that.. iusually just zoneout , and actually can not even remember most of the rides..unless some your pretty thing rides by, and I have to come up with a little testosterone to keep up.. that I remember..
carry on!

permalink written by  franklin on January 4, 2007

Lieve Roel,
Happy New Year !
Wat een verhaal zeg. Ik heb net je blog helemaal gelezen en zal het nu dagelijks gaan bijhouden, wat een uitdaging waar je mee bezig bent.
Heel veel succes (and good luck to Polly and Mia to hang on without you!).
Wij denken aan je, liefs (ook van Luc en mijn ouders) Judith

permalink written by  Judith den Bruinen on January 5, 2007

Hi Roel,
Happy New Year to you, Mia and Polly!
Eventually, you will probably need to switch to the wider tires. When you do this you may need to remove the fenders. If you can leave the fenders on, all the better. They protect the moving parts from grit as well as from water. If and when the fenders come off you may find that the rack stays interfere with the action of the rear brake. You'll see what I mean when the time comes. If the rack stay does interfere with the working of the brake you can use one of the presta valve knurled nuts as a washer to space out the rack stay. Tighten the rack bolts TIGHT and check them often, as they see a lot of vibration.
I'm enjoying your blog very much and check it every day.
ps Braising is a way of cooking lamb. Brazing is a way of joining metal.

permalink written by  Lawrence Libby on January 6, 2007

Brazen of you Larry, to comment on my braizing. It must be all that lamb I've been eating. Anyway, thanks very much for the tips. With this new route I shouldn't need the fatties for another month, but that time will certainly come.

Good to know you're out there for support! I need it!

permalink written by  roel krabbendam on January 6, 2007

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7 Trips
687 Photos

Here's a synopsis of my trips to date (click on the trip names to the right to get all the postings in order):

Harmattan: Planned as a bicycle trip through the Sahara Desert, from Tunis, Tunisia to Cotonou, Benin, things didn't work out quite as expected.

Himalayas: No trip at all, just...

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