November 19th, 2008

Belt Drive

This is the new Trek Soho commuter with an Alfine 8-speed belt drive transmission. Traditionally, belt drives on bicycles have had problems with slippage and jamming, but I’ve heard good things about the latest generation from Gates. Is anyone out there riding a current generation belt drive? If so, I’d love to hear your thoughts.

Gates Carbon Drive

November 12th, 2008

Alfine Shifter with Drop Bars

One of my readers worked out this creative way to mount an Alfine shifter for use with his drop bars.

The Old Raleigh with the Shimano Nexus 8 hub now has a new shifter and It works well for me. I can shift while going uphill without taking my hands off the hoods. This is nearly like an STI set-up for me, since I have been using a twist grip shifter for a long time, I have experimented with the placement of that twist grip for a long time. This new trigger shifter works very precise and quiet. I am posting this to show the odd way I have mounted this shifter. A Minoura Space Grip adapts mountain bike size accessories to a road style handlebar. I have tried so many ways to find a satisfactory set-up with the internal gear hub. I liked the convenience of flat bars, but they make my wrists hurt. After posting my old Raleigh on “Ecovelo” gallery a few months ago and mentioned that I wished for a good shifter for internal gear hubs to be used on road style handlebars, I got a few suggestions after that post. I thought I should try this new Alfine shifter.
This trigger shifter is it for me. The only thing that could be better, are the brifter style brake/shifter levers. (Ergo or STI).

I hope this can help other riders looking for a unique and convenient way of setting up their internal gear hub. — Jim

Thanks for sharing Jim!

November 10th, 2008

See and Be Seen

By their sheer power alone, lights that emit 400-700 lumens (or more) serve as both “see with” lights and a “be seen” lights. Unfortunately, powerful lights are expensive, and not every bike commuter is in the position to spend $400+ on a bike light. An alternative is to combine a pair of relatively inexpensive lights: one with a tightly focused beam pattern to see with, and one with a wide angle beam pattern to be seen by.

See With
A relatively low output light with the right beam pattern can put plenty of light on the road for typical commute speeds. The trick is to take that small amount of light and concentrate it where it’s needed — on the road right in front of the bike. A good “see with” light should emit at least 100-200 lumens and have a narrow, focused beam. Here are a few possibilities:

Be Seen
“Be seen” lights should have relatively wide angle beams and large diameter reflectors to create a large visual footprint and good side lighting. Here are a couple of possibilities:

Batteries
High output lights often use proprietary Li-ion batteries that are very expensive to replace. After being taken to the cleaners more than once when replacing a proprietary battery, I’ve opted to use lights that accept off-the-shelf rechargeables in AA and AAA size. With today’s highly efficient LED emitters, it’s possible to get 100-200 lumens and reasonable run times with AA batteries.

One Set-up
My current set-up includes a Fenix L2D and a Busch & Müller Ixon. The sharply focused L2D is pointed down toward the road and provides a well lit patch in front of the bike. The Ixon is pointed straight forward and level; its large reflector and diffuse beam signals my presence to motorists both in front and to the side.

This set-up is just one among many possibilities. The important thing is to use a combination of at least one tightly focused beam, and one wide angle beam. And if your budget allows, forget all this two light stuff and look into a good hub dynamo system or one of the many high output LED systems on the market; they’re expensive, but worth every penny.

October 23rd, 2008

Three Birds, One Stone

The stock Surly Long Haul Trucker (LHT) is a capable touring bike, and with a few modifications, it also makes an excellent city bike. The thing I like most about it is its versatility; it reminds me of the do-everything steel-framed bikes of the 1980’s and ’90’s such as the Trek 720 and Bridgestone XO-1.

I’m riding a modified LHT as a commuter/city bike/grocery hauler. It’s been a great bike so far, but there were a few nagging issues I’ve been wanting to deal with:

  1. The stock 175mm cranks were too long for me and I’ve been wanting to swap them for 170’s.
  2. The stock triple comes with 26/36/48 chainrings which are fairly standard for loaded touring, but because I’m using the LHT for city riding, I found myself frequently shifting between the 36T and 48T chainrings, and rarely ever shifting to the 26T granny. What I really needed was a 40T ring for everyday city riding, and something around a 32T small ring for carrying loads.
  3. The lack of a chainguard was becoming a real nuisance.

In searching around the web for a replacement 170mm crank, I ran across an unusual set-up on the Rivendell site. Their Quickbeam (QB) singlespeed comes outfitted with a reversible rear hub with a cog on each side, and a Sugino XD2 triple crank with a chainguard, 40T middle ring, and 32T inner ring.

Here’s the concept:

The Quickbeam is our orange only single-speed that’s actually a two-speed and is a quick change away from being a four-speed. That’s because it comes with two count ‘em  chainrings (40t and 32t) and a flip-flop hub with an 18t freewheel on one side and room for another cog on the other. But there’s more to it than that.

The idea of a four-speed with no derailleurs is vintage esoteric Rivendell, but what caught my eye is the QB crankset. With its 40/32 chainrings, chainguard in place of the outer ring, and square-taper compatibility, it was exactly what I was looking for. My original plan was to order a standard Sugino XD2 triple, change out the two smaller rings and ditch the 48T for a chainguard - a relatively expensive and wasteful idea. Fortunately, Rivendell sells the XD2 triple in the custom QB configuration on their website, so I ordered one and it arrived today.

The QB Sugino is essentially the same crank as the Sugino that came stock on the LHT, so it was a simple bolt-on affair. I slapped it on, took it our for a ride, and it feels great. The 40T places my cassette in the center of my comfort range for city riding, the 170mm arms feel more natural and easier on the knees, and the chainguard does what it’s supposed to do. I really lucked out; it’s not often you stumble upon a solution like this that kills three birds with one stone.

October 21st, 2008

Bacchetta on Seat Height

Photo © Bacchetta

There’s an interesting article on the Bacchetta website that discusses published versus actual recumbent seat heights. [Note: We're talking recumbent seats as opposed to traditional saddles as on upright bikes. —ed.] For the uninitiated, an important factor in determining whether a recumbent fits a person is seat height measured from the ground. This is not to be confused with saddle height which is the distance from the saddle to the pedals on an upright bike, or seat position which is the distance from the seat to the pedals on a recumbent, both of which determine leg extension while pedaling.

Seat height on a recumbent is critical because it determines whether a person can reach the ground with their feet while seated. Unlike riders on upright bikes, who dismount the saddle while stopped, recumbent riders remain seated while stopped, and must be able to touch the ground to keep from tipping over. If a rider is unable to firmly plant a foot while stopped, they’ll often feel less than fully confident on the bike, particularly in heavy, stop-and-go traffic.

The gist of the Bacchetta article is that there is no one industry standard method of measuring seat height and published seat height numbers are ballpark figures, at best, so it’s important to test ride a recumbent before making a purchase. I couldn’t agree more. Seat height is a critical factor that a person coming from uprights to recumbents might not consider until after the purchase. I can personally attest to the fact that not paying close attention to whether you can comfortably touch the ground, particularly if the bike is to be used for utilitarian riding of any sort, may eventually lead to dissatisfaction with the bike; I have a pile of receipts to prove it. :-)

A lot of this is old news to seasoned recumbent riders, but for ‘bent newbies this is a critical point to remember, particularly if the bike is to be used for utilitarian transportation, a style of riding which invariably involves lots of stops and starts, load carrying, and tight maneuvering.

Bacchetta Article

October 16th, 2008

More on Saddle Height

If you’re a regular reader of this blog you’re probably aware of the fact that I’ve been recovering from an “overuse” knee injury for the past couple of months. The injury might be better described as an overuse/maladjustment knee injury; I’m convinced incorrect saddle adjustment, as well as overuse, played a role. As part of of the process of resolving the injury, I went back and took a very close look at the saddle height on all of my bikes and now feel confident that they’re consistently adjusted and very close to where they need to be. I’ve always known correct saddle height is important for long-term knee health, but it’s never been as clear to me as it is now, after going through this process.

In an earlier post I outlined some of the common methods for determining saddle height:

  • LeMond Method - Adjust the saddle to a distance equal to your PBH* x .883, measured from the top of saddle to the center of the bottom-bracket
  • Petersen Method - Adjust the saddle to a distance equal to your PBH x .873, measured from the top of saddle to the center of the bottom-bracket
  • Hamley Method - Adjust the saddle to a distance equal to your PBH x 1.09, measured from the top of saddle to the pedaling surface (with the crank at bottom-dead-center inline with the seat tube)
  • Holmes Method - Adjust the saddle so your knee is bent 25-35 degrees with the ball of your foot on the pedal (with the crank at bottom-dead-center inline with the seat tube)

My pubic bone height (PBH) is 88.5cm (34.84″). Using the LeMond and Petersen formulas, I come up with 30.77″ and 30.42″ respectively; these measurements are used to set the distance from the top of saddle to the center of the bottom-bracket. After doing a fair amount of experimentation, I’ve settled on just over 30.5″. The Holmes method, which uses the knee angle as a way of setting saddle height, closely corresponds to the LeMond and Petersen methods.

Once you’ve used one of these formulas to get your saddle within a safe range, listen to your body to determine if you need to make small adjustments.

Crank length isn’t mentioned in regards to the LeMond and Petersen methods, but it needs to be considered since both methods use the bottom bracket to set saddle height without factoring in crank length. If you use either of these formulas, you’ll need to adjust the saddle up or down slightly to compensate for longer or shorter cranks. Most people are running 170-175mm cranks, so adjust the saddle up or down approximately .10-.20″ depending upon which crank you’re running.

Among the above methods, Hamley is the only one that gives a significantly different result. According to Hamley, my seat should be set nearly .75″ higher than what is indicated by the other formulas. Even though the Hamley method gives me what appears to be an incorrect result, I like the fact that it factors in crank length by setting the saddle height based upon the distance to the pedal surface.

By taking a few measurements and doing a little math, I determined that by modifying the Hamley formula from PBH x 1.09 to PBH x 1.07, you end up with a seat height nearly identical to what is indicated by the other methods. Modifying the Hamley method in this way puts it in line with the other methods while also taking into account crank length. This is probably the most accurate way to set saddle height short of employing a professional fitting service.

Once you’ve used one of these formulas to get your saddle within a safe range, listen to your body to determine if you need to make small adjustments. Conventional wisdom says pain in the front of the knee indicates a saddle that’s too low, and pain in the back of the knee indicates a saddle that’s too high. This has been consistent with my experience. Many people may find their saddles were too low prior to using these methods (Rivendell’s Grant Petersen says 80% of the riders they see have their saddles adjusted too low). If you’re one of these people, give yourself time to adjust to the new position; it will feel strange at first, but in the long run you’ll be doing your knees a favor.

*PBH - Pubic Bone Height. Read this for instructions on how to measure your PBH.

October 4th, 2008

Smoothies

Bell Metropolis

There is growing evidence that the new crop of hyper-ventilated helmets that are so popular these days are potentially less safe than traditional smooth-shelled designs. These “racing” helmets may pass the current Consumer Product Safety Commission drop tests, but accident reports suggest their squared-off edges and aerodynamic “tail” can grab the road, increasing the possibility of rotational brain damage, neck injuries, and helmet dislodgment. Both Consumer Reports and the Bicycle Helmet Safety Institute are recommending more traditional “commuter” style helmets with smooth, rounded shells and fewer vents. The Bell Citi for example, received Consumer Report’s highest safety rating and a “Best Buy” designation. Follow the links below for more information.

September 28th, 2008

North Road Bars

Quite a few people have asked me about the handlebars on my Surly Long Haul Trucker (LHT). Following are the answers to a few of the most frequently asked questions:

  1. They’re not stock.
  2. They’re made by Nitto and they’re named “North Road”.
  3. They can be ordered through any dealer that orders parts from Quality Bicycle Parts.
  4. There are two versions, one aluminum alloy, the other CroMo steel. The alloy version usually has a red “heat-treated” sticker at the center knurling, the steel does not.
  5. The steel version accepts Shimano bar-end shifters, the alloy does not.
  6. They fit the stock LHT stem, but depending upon how upright you want to sit, you may need to change the stem.
  7. You’ll need to replace the stock road levers with mountain bike-style levers.
  8. They accept mountain bike grips. If you want to use cork grips with bar-end shifters, be ready for some surgery (e-mail me for instructions).
  9. They’re supremely comfortable and turn the LHT into a capable city bike.
  10. I luv ‘em!

Waaay back in ‘05, my pal Perry over at The Velvet Foghorn wrote a wonderful piece about the Rivendell Albatross bar, also made by Nitto. The Albatross is a close cousin to the North Road, but it has a little less rise and slightly softer bends. If you like the North Road, you’ll probably like the Albatross as well. Check out Perry’s article here.

September 19th, 2008

‘Tis the Season

It’s that time of year. The days are getting shorter, the nights are getting longer, and it’s time to dust off the bike lights and charge the batteries.

I’ve used many different lighting set-ups over the years, and I think what I’ve finally learned is that there is no one perfect lighting set-up; as long as basic safety requirements are met, it doesn’t really matter what lights you use. The important thing is to see, and be seen.

With that in mind, listed below are a few of my old (and not so old) articles on bike lights. Take them for what they’re worth, and keep in mind that I don’t currently agree with everything I’ve written in the past. Please take note of the dates; some of the older reviews are no longer valid, but I thought they should be included because they may provide a few kernels of pertinent information.

I’m currently running a pair of Fenix L2D headlights and a pair of Planet Bike Superflash tail lights, all powered by rechargeable NiMH batteries. Inquiring minds want to know; what are you using for lights this season? (leave a comment below)

August 25th, 2008

Bar-Ends with Alfine Hub

Hiawatha Cyclery has managed to make an 8-speed indexed bar-end shifter work with a Shimano Alfine hub by installing a Travel Agent at the downtube shifter boss. Pretty cool.

More here

[via The Lazy Randonneur]

August 12th, 2008

Uncle!

Since going car-lite, I’ve ridden my bike nearly every day for 4 months, with only a day off here-and-there for illness or smoke-filled skies. It’s amazing how fast the miles add up when you ride every…single…day, even if your trips are relatively short. All of this bike-time finally caught up with me this weekend and I ended up with a case of tendonitis in my knee. Since then, I’ve been off the bike, whining like a baby and hobbling around between ice packs. Fortunately, my work keeps me sitting in one place, so at least I’ve been able to keep busy and bill some hours while I pout and heal up.

This injury got me thinking about bike set-up in general and saddle height in particular. Based upon the various analytical methods for setting saddle height, it does appear I’ve been running my saddles too low, but it’s so hard to say for sure until an injury crops up, and by then, it’s too late. I tend to pedal flat-footed (always have), and even more so on platform pedals, so I thought I was in the “safe zone” with the saddles on my new bikes set a little on the low side (flat-footed pedaling causes the leg to extend further, toe-down pedaling causes the leg to extend less). It may not be that an incorrectly adjusted saddle was the primary cause of my injury, but I have no doubt it was a contributing factor. Ah well, live and learn.

There are a number of popular methods for setting saddle height. None of them are foolproof. All of them will get you in the ballpark. Beyond that, it’s up to you to pay close attention to your body for signs that something is not quite right and make adjustments accordingly (as a grossly over-simplified general rule, pain in the front of the knee indicates a saddle that’s too low, pain in the back of the knee indicates a saddle that’s too high). Most importantly, don’t be a numbskull like me and wait until your knees are screaming “uncle” before you take a pause and figure it out.

Common Methods

  • LeMond Method - Adjust the saddle to a distance equal to your PBH* x .883, measured from the top of saddle to the center of the bottom-bracket
  • Hamley Method - Adjust the saddle to a distance equal to your PBH x 1.09, measured from the top of saddle to the pedaling surface (with the crank at bottom-dead-center inline with the seat tube)
  • Holmes Method - Adjust the saddle so your knee is bent 25-35 degrees with the ball of your foot on the pedal (with the crank at bottom-dead-center inline with the seat tube)
  • Heel-on-the-Pedal Method - Adjust the saddle so your heel just barely touches the pedal with a straight leg (with the crank at bottom-dead-center inline with the seat tube)
  • Hips Rockin’ Method - Keep raising the saddle in small steps (1cm or less) until your hips start rocking while pedaling and then back off just a little

More
Sheldon Brown on setting saddle height
Grant Petersen on setting saddle height
Peter White on setting saddle height

*PBH - Pubic Bone Height. Read this for instructions on how to measure your PBH.

July 23rd, 2008

Seats & Saddles

Recumbent bikes have seats. Upright bikes have saddles. They’re not the same thing. Seats support the rider’s entire body weight, saddles support only a portion of the rider’s weight, with the rest supported by the pedals and the handlebars.

It’s difficult to deny the fact that seats are more comfortable than saddles. By their nature, seats distribute the rider’s weight over a larger area than any saddle possibly can, reducing pressure points and encouraging greater blood flow. Unfortunately, seats are only practical on recumbents because their width would interfere with pedaling on an upright bike. The most we can hope for on an upright is to choose a saddle that somewhat mimics the comfort of a recumbent seat while still allowing unfettered pedaling and mobility on the bike.

Seats
Recumbent seats come in a wide variety of shapes and sizes. Nearly every manufacturer has their own proprietary design, and even within individual manufacturers’ product lines it’s not uncommon to see 2-3 seat designs. Designs include (but are not limited to): hard-shell “Euro” seats (usually made from carbon fiber or fiberglass) seen mostly on reclined racing bikes; “Euromesh” type seats that mimic hard-shell seats but provide more adjustability and better ventilation at the expense of more weight; full mesh seats as seen on the Lightning P-38 and Rotator; and combo foam base/mesh back seats such as those from RANS and Easy Racers.

The most we can hope for on an upright is to choose a saddle that somewhat mimics the comfort of a recumbent seat while still allowing unfettered pedaling and mobility on the bike.

Euro-type seats are narrow with a short seat pan to reduce weight and optimize aerodynamics; they make up for their diminutive size by distributing the rider’s weight evenly up-and-down the spine.

Full mesh seats provide the best ventilation and are usually used on bikes that require a moderate amount of recline.

Combo foam base/mesh back seats are usually used on bikes that require a more upright position. Their foam base acts somewhat like a saddle, though they’re much softer and wider than any saddle. Even still, some people complain about derriere pain (sometimes called “recumbent butt”) with these “lounge chair” seats.

Unlike saddles on upright bikes, recumbent seats are integrated parts of the bikes they’re mounted on and when a person buys a recumbent they’re most likely going to use the seat that came on the bike. Fortunately, most recumbent seats are very comfortable and what works for one person will probably work nearly as well for the next.

Saddles
Saddles look very similar to one another, but their similarities belie the fact that they’re all subtly different in design, material, shape, and size. This is a natural consequence of the fact that saddle fit is hyper-critical to rider comfort on upright bikes. Since such a large portion of the rider’s weight is supported by such a small area, it’s extremely important that the interface between the rider and saddle is perfect. This is why saddle manufacturers offer a such wide variety of models; they’re attempting to provide a good fit for a wide range of different physiques.

A person’s anatomy, combined with bike fit and riding style, all play a role in determining saddle choice. Racers are typically willing to sacrifice comfort for less weight, and they usually prefer narrow saddles for unfettered movement on the bike. Tourists and commuters, on the other hand, usually insist upon comfort at the expense of extra weight, and they generally prefer wider saddles that provide greater support for riding in a more upright posture.

Relatively wide saddles that fully support the sit-bones are best for commuters, tourists, and casual riders. Combined with handlebars that are at a minimum the same height as the saddle, a sufficiently wide saddle places the pressure points on the rider’s sit bones and takes all of the pressure off of the soft tissues of the perineum (the area that most often causes saddle-related problems). A bike set-up this way can be ridden in street clothes without the use of padded shorts, and if the width of the saddle’s support area precisely matches the distance between the rider’s sit-bones, the comfort can approach that of a recumbent with an upright seat.

The Brooks B-67 is the best fit I’ve found for my particular physique. It’s a relatively wide saddle that works well with high handlebars. The width of its main support area perfectly matches my pelvic width. I rode the narrower (and more popular) B-17 for many years and it was a decent fit with drop handlebars. But with a more upright posture, the B-67 fits me even better than the B-17. Of course, my recommendation is meaningless unless the B-67 also happens to fit you. It’s much more important to find the saddle that best interfaces with your body.

I can’t overemphasize the importance of saddle fit. Many people have either resolved themselves to riding in pain, quit riding altogether, or switched to recumbents, simply because they didn’t make the effort to find the saddle that fits their physique. Unfortunately it’s not always possible to try a saddle in a bike shop, so you may have to purchase a number of expensive saddles before you find a good fit; if you’re riding an upright everyday it’ll be money well-spent.

May 26th, 2008

Brompton S-Type Cockpit Mods

Stock bars and grips : cramped and uncomfortable

The Problem
The Brompton S-Type folding bike comes outfitted with a low, narrow, mountain-type flat bar for better aerodynamics and lighter weight than their other models. It’s a popular configuration, but people frequently complain about the minimalist, 105mm-wide, factory-supplied handgrips. After riding my Brompton for a couple of months, I too have found the stock grips to be uncomfortably narrow and lacking in support. Normally I’d just replace the stock grips with a pair of my favorite 130mm-wide Ergon GP-1 grips, but on the S-Type there’s not enough room on the narrow bar for a full-width handgrip, shift lever, and brake lever.

The Solution
One possible solution was to keep the stock bar and cut down a pair of standard 130mm grips to the Brompton 105mm width. I tried this with a pair of size-L Ergon GP-1s, but found it to be an unsatisfactory solution. The Ergons did provide more lateral support, but my hands were still cramped and confined along the width of the bar.

Stock bars, modified Ergon grips : more comfortable, but still cramped

Ultimately, resolving the issue required replacing the stock handlebar with a Race Face Air Alloy mountain bike flat bar (any standard 25.4mm mountain bike flat bar would work equally well). Installation was simply a matter of replacing the bar and trimming with a tubing cutter to the minimum width required to accommodate the full-width Ergon grips, brake levers, and shifter; this ended up being approximately 515mm (35mm wider than the stock Brompton bar).

Wider bars, full-width Ergon grips : roomy and comfortable

The new bar/grip combo is a dramatic improvement over the minimalist stock set-up. The full-width Ergon grips provide substantially more shock absorption and support, and the brake lever and shifter are in a more ergonomically correct position in relation to the grips. The overall width is only slightly wider than stock and doesn’t affect the fold at all. Brompton would be doing their customers a big favor by supplying a wider bar and better grips as standard equipment in the future.


 
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