Saturday, February 21, 2015

I'm fat and that's probably not changing anytime soon

We just got back from Frostbike, which is QBP's winter mixer dealer event. If you don't know, QBP is the parent company of Surly Bikes and some other fine bike brands. QBP also serves as a distributor for lots of other brands of components and accessories.

We always go to the Surly bike booth first. Our insider info proved correct: Surly didn't unveil any new products or variants of old products at Frostbike this year. But they did tell us that they have some overstock on last year's Pugsley (XS, S, and XL only) and "trail" bikes like the Karate Monkey, Krampus, Krampus Ops, and Instigator, and they've reduced prices accordingly, in some cases to unbelievably low levels. Right now you can buy an Instigator frame AND they are throwing in some free 26" Rabbit Hole rims and 26x2.75" Dirt Wizard tires for $599. They also knocked about $750 off the price of a complete Instigator to $1899, which is quite a deal for the fork and components alone. I'm not sure this is the bike for just anybody, but if you're the kind of person who rides hard and breaks stuff, then maybe this is the deal for you. I forgot to ask if these deals can be combined with the $150 Superfan coupon, but I'm guessing we could work that out for you.

You can find "spy photos" and other info about new products at Frostbike on the internet, so I'm not going to add to that noise. Instead I'd like to mention a mixed "vibe" I picked up. On the one hand, there were the accessory and component companies. Some of them were late to the party with fat-bike parts and accessories, and now they're enthusiastically on the bandwagon, making some stuff that definitely appeals to a fat bike guy like me. I saw several new(ish) tires, rims, hubs, and cranks for fat bikes. There's a fat bike compatible child seat from Thule (planning to get one for my youngest kid), and lots of fat bike compatible car racks now. On the other hand, there were some folks from more established fat bike entities who seemed genuinely surprised when I told them that we are seeing good sales on fat bikes this year. Honestly, we have shifted the focus of HC to fat and plus-sized tire bikes (though we are more than comfortable with selling and repairing other bike styles too, of course). In some larger shops, fat bikes may seem like an oddity among dozens of more conventional bicycles, and if the sales staff isn't enthusiastic about fat bikes, not many will buy them. Personally, in my little bubble here at HC, I see a lot of growth potential for fat bike sales. The bikes are simply too much fun, and too practical. I'm not referring to the racer/athlete end of the market, but the casual offroad and winter rider who will be much more confident on a fat bike than on a more conventional bike. At HC, we ride and love our fat bikes, and we'll probably try to talk you into buying one (or at least something "plus-sized"*).

*Speaking of plus-sized wheels and tires, I have something to say about that, too. Look for that in a near-future post.

Wednesday, February 18, 2015

Don't worry about bike weight

I don't weigh my bikes. Every part or accessory on my bike was put there for a good reason, and usually that reason is much more of a priority than the "weight penalty" of using that part or accessory. My bike gets me to work, allows me to have some offroad fun along the way, and haul a load of groceries on the way home. I've accepted that this level of versatility involves a compromise. To torture a car analogy, I'm opting for the versatility of the SUV, rather than the fun impracticality of the 2-seater sport coupe. Even though I don't really care what my bike weighs, when I'm looking at bikes and components, I often take note of what they weigh for reasons that aren't directly about weight. This is especially true of tires and, to a lesser extent, rims. Lightweight tires tend to be more supple and have a better ride quality, which is a priority for me. A lot of the negative associations people have about heavy bikes are the result of lousy-rolling tires. And the weight of a rim can indicate whether it was designed for big hit dirt jumping or for superlight road racing - I'd rather not mix up the two (usually I'm looking at intermediate weight rims). Weights of handlebars and seatposts and derailleurs and such aren't on my radar.

Not giving a damn about weight is a matter of basic physics. The weight difference between a 'heavy' bike and a 'light' bike is typically only a few percent of my robust body weight. Therefore, a few hundred grams here or there is a laughable and negligible change in the total weight of bike plus rider (at least 250 pounds or 113,500 grams, in my case).

Even if I could spend enough thousands of dollars to make a non-negligible change to the weight of my bike, would it matter? For me, the answer is NO. Most of my riding is simple transportation and social bike rides. I'm usually riding in my easy comfort zone, and not trying to red-line my heart rate. In other words, if I want to go faster, I can just pedal faster. I'm not racing against a competitor or a clock, and I'm limited mostly by my desire (or lack of desire) to ride faster, and my fitness level.

But even if I was more of an intense competitor, I could turn the cranks to the limit of my ability on every ride, and weight still wouldn't matter except on prolonged climbs, twisty corners, or when accelerating/decelerating frequently. Riding a straight line on flat ground at constant speed requires no acceleration, and therefore no force (F=MA) except to overcome aerodynamic drag, rolling resistance of the tires, and mechanical inefficiency of the moving parts on the bike. To overcome those losses, a heavy bike with its extra momentum actually has an advantage over a lighter bike.

Here in Minneapolis and Saint Paul, I spend relatively little time riding my bike up big hills. But some people do ride up big hills, where weight has the biggest effect. This velo-news article has a fun infographic that shows the calculated difference of hill climb times with different bike weights and different hill grade (steepness). In a nutshell, the difference between the light bike (15 lb) and the "heavy" bike (18 lb) is just under 12 seconds for a 150 lb rider doing a one-mile climb on a 7% grade at a constant 200W output. Since I'm more in the fat bike world, where weight differences can be more profound, I could easily double or triple the percentage weight savings, but even a 30-60 second difference on the biggest hill I'm likely to ride all year seems like a paltry reward for the investment I'd have to make to take that much weight off my bike.

There's nothing wrong with having a light bike, if it makes you happy, but if you expect that a lighter seatpost (or whatever) is going to give you some measurable performance advantage, you're wrong. Also, I can empathize with apartment dwellers who have to carry a bike up several flights of stairs everyday. There are plenty of reasons to try to save weight on a bike, but, for most of us, performance shouldn't be one of them.

Thursday, February 12, 2015

Wheelbuilding class, February 28

Do you want to learn to build wheels? I am offering a class on February 28, 8am until noon. The class costs $60, and spots are limited. Call me or stop by HC to reserve your spot.

You'll need rims, hubs, and spokes, which I can supply at competitive prices. When you leave the class, you'll most likely have completed one wheel. Some people build two wheels.

Saturday, February 7, 2015

Surly Straggler kids' bike

Ever since Surly announced that the Straggler would be available for 650B wheels down to 38 cm frames, I've been scheming to build a bike or two for my kids. Well, my scheme finally came to fruition yesterday.
With disc brakes, there's no mechanical reason not to use other wheel sizes, so I chose to use 26" wheels instead of 650B. This improves stand-over clearance by about one inch. Standover at mid-top-tube is approximately 68 cm or 27 inches.

One concern with using smaller-than-spec wheels is pedal strike. If the bike is lowered too much by using smaller wheels, the pedals can strike the ground in corners, which can cause a crash. Since my 9-year-old daughter is only about 4'2" (125 cm) tall, I decided that typical "short" adult cranks (typically 165 mm) would be far too long for the biomechanics of her kid-sized legs. After consultation with my friend Mark at Bikesmith Design, I decided to follow his rule-of-thumb that crank length should be approximately 10% of the rider's height (or 23% of inseam). Ten percent of 125 cm is 125 mm. Bikesmith has a thriving business shortening cranks, and within 24 hours, he delivered a set of shortened SRAM S600 cranks with 125 mm arms.
By the way, lots of people can benefit from crank lengths that are shorter than the industry standard 165 mm length. If you have short legs, or suffer from knee or hip pain or other range of motion issues, or ride in an unconventional position (aero position), I strongly urge you to discuss the benefits of short cranks with Bikesmith Design.

Even with the tiny 38 cm frame size, smaller wheels, and short cranks, the bike is still marginally too large for my daughter, who is shorter than average for her age. Standover clearance is tolerable, but the reach to the bars seems pretty long. I found a short stem (60 mm) and a riser bar with a bit of sweep.
I think kids (and adults) who are new to multi-speed bikes benefit from a simple drivetrain and some kind of display that indicates the gear number. Cheap SRAM twist shifters and a 1x7/8/9/10 drivetrain accomplish this. And, by the way this bike has Shimano M396 hydraulic brakes. These are great brakes for a relatively small amount of money. I selected these because they are actually substantially less expensive than decent mechanical disc brakes and levers. The added benefit is that hydraulic brakes can be actuated with a light grip, perfect for a small kid with small hands.

She took it for a ride around the block and didn't even slip on the ice. The bike fits great (better than I expected), and she looked pretty fast and confident on it. Happy kid!

Total MSRP for a bike similar to this is in the neighborhood of $1400 plus tax (less for me, because I have insider hook-ups and lots of spare parts). Seems like a lot of money for a kid's bike, but I believe she will get my money's worth. With minor adjustments, she will likely ride this for many years (possibly through high school or longer), and if/when she outgrows it, one of my younger kids can ride it. Or I can sell it, because it's a brand that has good name recognition and resale value. But the best justification is that she will have a high-quality cycling experience that will (I hope) forge a lifelong love of bikes and cycling.

Thursday, February 5, 2015

Fat bikes aren't slow

Fat bikes are changing the way we think about what bikes are capable of doing. By now everybody knows that the comically fat tires are able to maintain traction through and over surfaces that would seem difficult or impossible on skinnier tires. The downside, according to popular intuition and Internet experts, is that the large tire size means added rolling resistance. The belief in the added work of pushing the big rubber is the most insurmountable barrier to mainstream fat acceptance.

Last evening after the shop closed at 6pm, I rode my Ice Cream Truck, which is no lightweight, to weekly family dinner at my in-laws' palatial estate in New Brighton. I've done this ride many times (on at least 4 or 5 different bikes) by now, following one of the Google Maps bike routes through South Minneapolis, the U of M, Nordeast, and into New Brighton, for a grand total of 13 miles. Typically, with stoplights and other interruptions, this takes me around 75 minutes, even on a "summer bike". Along the way, I rode some bike lanes adjacent to high traffic streets. The bike lanes on these streets tend to accumulate a chaotic mixture of snow, rutted road slop, and ice chunks, in addition to the ever-present cracks and potholes. It was dark and cold (single digits Fahrenheit), and there was a persistently stiff headwind. These unpleasantries combined with traffic whizzing by a few feet from my left elbow had me ready to throw in the towel and head for home. But I tend to embrace a challenge, so I kept pedaling. My Dillinger 5 studded tires earned their high price tag time and time again, allowing me to pay attention to the traffic situation while they got a firm bite into the unpredictable road surface. After I got through the craziest part of the trip, in the area around the U of M, I checked the time. Because of the wind and the fact that I was riding my heavy wheels with studded tires, I was expecting to be later than usual, but I was making surprisingly good time. I pressed on. When I rolled into my in-laws' driveway, I checked the time. Total travel time: 67 minutes, which I believe to be a personal best. I wasn't trying to break my record. I just wanted to be on time for dinner.

What does it mean that I achieved one of my best times on a familiar route, while wearing heavy winter clothes, rolling studded tires, and fighting a freezing headwind, without actually trying to be fast? I think it means that the high rolling resistance of fat tires is a myth. Fat tires are definitely heavier and slower up hills, but on flat ground, there is nothing to lose. I'd actually make the case that the fatties are faster simply because I could ride through the shit without being careful to pick a line through the winter road hazards.