Click, Click, Click

We’ve all experienced annoying little clicks and creaks on our bikes. You know, like the kind that happen each time the crank comes over the top at 2 o’clock. I often hear people talk about tightening crank arms and checking bottom brackets when this happens, but odds are it’s a pedal. See, many of the pedals we commuters use, particularly those such as the low-end models from Shimano or the touring pedals from MKS, contain the cheapest bearings on our bikes. They’re the most likely to run rough, and they’re also the most likely to click and creak. If you find one of your pedals making noise, it’s usually a simple matter of disassembling the pedal, cleaning, and re-packing with Phil (be careful to make note of how it came apart and don’t lose any ball bearings). The MKS pedals are particularly simple to overhaul, one among many reasons I prefer them over Shimano pedals, some of which require special tools to adjust.

V/O and Riv on Traditional Sizing

Chris over at Velo Orange recommends sizing* a bike based upon pubic bone height. His recommendations are not unlike Grant Petersen’s recommendations outlined on the Rivendell site. Their guidelines are both what I’d characterize as “traditional”; using either of their methods will put you on a frame slightly to dramatically larger than if you were sized at a racing-oriented shop.

Here’s Chris at V/O:

I generally recommend getting a traditionally-sized frame, one that’s larger than many race bike oriented shops would recommend. The traditionally sized frame will allow you to get the handlebars to proper height without a super-tall stem. And it will allow a reasonable stem extension that does not put too much of your weight over the front wheel. The frame will handle better, be more comfortable, and you’ll look better riding it.

And here’s Rivendell’s Grant Petersen on the same subject:

Most riders are most comfortable when the handlebar is a few centimeters higher than the saddle. Some like it four or five inches higher. Some like the look of the bar lower than the saddle, but few riders over 35 like a low bar once they’ve ridden a higher one.

To achieve that bar height, it helps to start with a bike that’s the largest practical size you can ride. We suggest you get the size that allows you to put the handlebar at least 2cm higher than the saddle. That works great for most people. You can always lower the bar if you find it’s too high, but it’s rare when that happens.

One of our past polls showed that a whopping 72% of the respondents prefer their handlebars either at or slightly above the height of the saddle. One way of making sure this is possible is by riding a sufficiently large frame as recommended above. Shops using “modern” sizing methods will disagree with these traditional methods and the resulting size recommendations, but some variation of this approach has worked well for many people, for many decades.

*”Sizing” should not be confused with “fitting”. Sizing methods are used to determine the frame size that will work best for an individual. This is only a starting point after which the more precise process of fitting takes place. Fitting is the process of adjusting the rider’s position through component selection and adjustment.

Velo Orange on sizing
Rivendell on sizing
More Rivendell on sizing

45-Day Belt Drive Maintenance

Belt Drive

It’s been 45 days since I installed the Gates CenterTrack drivetrain on my commuter, so I figured it was time for some maintenance. Here’s the process:

  1. Roll the bike outside
  2. Hose off the belt
  3. Wipe off the water with a towel
  4. Roll the bike inside

Grand total time invested: approximately 5 minutes. A properly set-up belt drive is truly a low- to no-maintenance commuter drivetrain. Good stuff.

A Few Thoughts on Geometry and Weight Distribution

Bryant Fork

[As a follow-up to yesterday's post on rack stiffness, here are a few thoughts on geometry and weight distribution. —ed.]

Like so many production bikes on the market, my commuter has high trail geometry optimized for carrying a rear load (more on trail here). The assumption seems to be that a person will throw a rack and a pair of panniers on the back and call it good, which is probably true in most cases. Up to a point, my Civia handles well when loaded in this way, with the steering livening up as some weight is placed on the rear. But beyond a certain amount of weight, the front end starts feeling a little light and squirrelly, an issue that may be exacerbated by the fact that the internal gear hub also shifts the weight bias rearward.

To provide greater carrying capacity, while also mitigating for the unbalanced feeling of overloading the rear of the bike, I run a Pass & Stow porteur rack and Freight Baggage bag on the front fork. This is the rack/bag combo I’ve been running on various bikes for the past couple of years. With this set-up I’m able to balance large loads between the front and rear of the bike. Though carrying weight on the front slows down the steering and increases wheel flop, the bike feels more steady and planted on the road when cargo is split fore-and-aft in this way.

Very few production bikes have low trail geometry optimized for carrying a front load. But, in my experience, for commuting and utility riding where trips are not often more than 15-20 miles tops, front loading a high trail bike is not as much of an issue as it is for randonneuring or touring where trips can be hundreds of miles at a stretch, sometimes when the rider is tired and sleep-deprived. In other words, for short hops and city riding, I’ve had little issue with porteur racks on high trail bikes, particularly when the racks are stiff and the loads are carefully balanced between the front and rear of the bike.

The Importance of Rack Rigidity

Civia Bryant

Rack rigidity and load securing are closely linked to bike stability and predictable handling. Far more than where a load is carried, a stiff rack with zero flex and a completely secure load are the biggest contributors to stable and controlled handling when carrying cargo.

A number of people have complained to me about loaded bikes handling poorly. In almost every case, the culprit was a weak, flexible rack, or a loosely secured load, both of which allow the load to sway, taking control away from the rider. This problem is particularly acute when loads are carried on the front fork. I know quite a few people who don’t like to carry a load on the front of the bike. I’m guessing that in a majority of cases, the underlying issue is a sub-par rack or mounting method, and that a sufficiently stiff front rack with a high quality bag would change their minds.

On my Civia Bryant (shown above), I run a Tubus Cargo in the rear, and a Pass & Stow up front. Both are made from tubular steel and act as rigid extensions of the frame. I can comfortably carry 75-100 lbs. on that bike with no issues whatsoever. I attribute this excellent performance more to the racks than to the bike itself.

From the Archives: Taking a Look at Crank Length

[This article on crank length from last year dovetails nicely with our saddle height post from earlier this week. —ed.]

Crank length is an often overlooked aspect of bike fit. A majority of production road-oriented bikes come outfitted with either 170mm or 175mm cranks. You do occasionally see 165mm cranks spec’d on the very smallest frame sizes, and some manufacturers offer 172.5mm cranks on their mid-sized frames, but it’s a rare occasion to encounter a crank under 165mm or over 175mm on a bike primarily intended for road riding.

There are a number of methods for determining proper crank length. Peter White recommends 18.5% of the distance from the top of the femur to the floor in bare feet. Leonard Zinn recommends 21% of inseam measured in bare feet. Bill Boston recommends measuring femur length from the center of the hip joint to the end of the bone in inches, then using this measurement as crank length in centimeters (for example, if your femur measures 17 inches, you would use a 17cm [170mm] crank).

If you accept that muscles and joints work most effectively when operating in a certain range of motion, then it only makes sense that muscles, bones and tendons work that way for everyone.
-Lennard Zinn

Let’s use Peter White’s method as an example. For simplicity, let’s assume a rider with a top of the femur to the floor measurement of 919mm (36 1/16″). Multiply by Peter’s 18.5% (919mm x .185 = 170mm) and you end up with a recommendation for 170mm cranks. That’s convenient for someone with a 36″ floor to femur measurement, but it gets more complicated for individuals outside the “normal” range. Shorten the floor to femur measurement by three inches (33″) and the recommendation quickly drops down to 155mm (838.2mm x .185 = 155mm). Lengthen the floor to femur measurement by three inches (39″) and the recommendation jumps up to 183mm (990.6mm x .185 = 183.25mm). Both fall outside the normal range of sizes typically offered in road cranks.

I believe there’s quite a bit of room for personal preference in these formulas. I also think the human body is amazingly adaptable and we can probably get used to just about any crank length currently being manufactured, regardless of our leg length. That said, it’s only reasonable to assume that crank length should vary based upon an individual’s physiology. As Lennard Zinn said, “If you accept that muscles and joints work most effectively when operating in a certain range of motion, then it only makes sense that muscles, bones and tendons work that way for everyone. Short riders should not be required to force their muscles through a greater range of motion than the person with an 80cm inseam riding a 172.5mm crank. And on the other end, 7-foot basketball players do not bend their legs any less when they jump than shorter players. So why should they use minimal knee bend and operate their muscles only through a tiny part of their range when they ride a bike?”

Assuming Mr. Zinn is correct, taking a closer look at crank length should be particularly advantageous for those who are significantly taller or shorter than average. On the outer edges of the bell curve, it’s very unlikely people are riding cranks that are close to their ideal length.

While it’s not easy to find unusually short or long cranks, they’re out there. The Specialites TA Carmina is a beautiful, if expensive, production crank that has interchangeable arms available from 155mm up to 185mm. Lennard Zinn offers oversized cranks, and da Vinci Designs offers custom cranks in almost any size within reason.

Those who aren’t involved in the recumbent community probably don’t realize that recumbent riders have been experimenting with ultra-short cranks for some time now (see the links below). Some of their findings are quite interesting and may possibly be applicable to upright bikes. Short crank advocates claim reduced knee strain and higher crank RPMs among their advantages.

Ultra-long cranks may introduce more knee strain, and they will definitely reduce cornering clearance, so both of these facts should be taken into account if you’re considering retrofitting a longer crank on your existing bike.

And finally, whether you’re going up or down in length, keep in mind that a major change in crank length will very likely require a change in saddle height, which, of course, will affect overall bike fit.

Related Reading

Selle An-Atomica Squeak Fix

Selle An-Atomica

As you may know, I’m a big fan of Selle An-Atomica saddles. I ride one on my primary commuting bike and have done so for a couple of years now (for the record, I was riding these saddles long before S-A became a sponsor of this site). I find them the most comfortable among all of the saddles I’ve ridden. They’re unique in that they flex and move more than other leather saddles, conforming to your physique like a hammock (some people describe them as “hammock-like”). Like any saddle, Selles aren’t for everyone, but they work exceptionally well for me.

Because they’re designed to move and flex more than other saddles, S-As can sometimes squeak. If you have a squeaky Selle, you can contact the manufacturer via their website and they’ll send you a nylon gasket at no charge that should solve the problem.

Selle An-Atomica Contact Page
How to Install the Gasket


 
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