Technical Q&A with Lennard Zinn: Torque wrenches and temps; shifting and shimmy
By Lennard Zinn
Torque wrenches and temperature ranges
I own both deflecting beam and click-type (Giustaforza) torque wrenches. They are stored in my garage where the temperature can get below freezing in the winter and over 100 degrees Fahrenheit in the summer. Do torque wrenches need to be stored and used within a certain temperature range to maintain accuracy?
Answer from Effetto Mariposa:
Lubricant is the only element of mechanical click-type wrenches (like the Giustaforza) influenced by storage temperature. While the elastic properties of the spring are largely unchanged at temperatures between -20 and +100°C, grease can freeze at a certain temperature or become very fluid and migrate at high temperatures.
The Giustaforza wrench is aluminum (a good thermal conductor) and its small body can be quickly heated by just keeping it in the hand, returning the grease to within its range of operation. To make sure the grease is working properly and to take it back to the joints (in case of migration), we recommend making the wrench click a few times at the lowest setting before using it, pushing the head on the side with the thumb. We use a grease with a very wide range (from -20°C to +90°C), but clicking the wrench head once or twice after long storage at extreme temperatures won’t hurt.
Alberto De Gioannini
President and founder
Answer from J.H. Williams Tool Group:
The really short answer to the question is “Yes.” However, there’s more to it than that. Since Mr. Pettit asked the same question about two completely different tools, I will have two answers addressing each separately.
CDI click-style (“clicker”) torque wrenches: Avoid storing CDI clickers below 32 degrees Fahrenheit and above 120 degrees Fahrenheit. When a wrench is stored below freezing, you run the risk of developing condensation that can cause the internals to rust, affecting the accuracy and performance of the tool. Temperatures exceeding 120 degrees, meanwhile, will cause the grease inside of the wrench to melt and seep out, affecting performance and accuracy.
The ideal storage temperature for our CDI clickers is “room temperature” (roughly between 65 and 78 degrees Fahrenheit). The consistent temperature reduces the risk of the freeze/thaw cycle, helping to eliminate the possibility of condensation and rust over time. The ideal working temperature is between 40 and 110 degrees Fahrenheit.
Before the torque wrench is used, either in hot or cold temperatures, it should be exercised to get the internal parts and grease moving around. The best way to do this is to set the wrench to a low setting and flex or click the head 10 times in the same direction (in the clockwise position). Once the wrench has been exercised, it is ready to be used.
Deflecting beam torque wrenches: CDI Torque Products does not make this wrench. It, too, can be stored in a wide range of temperatures. Cold will affect performance more than heat, because in the cold, the molecules in the steel slow down and the beam becomes more stiff or rigid, thus affecting the reading on the scale. Like clickers, even beam or deflecting style wrenches should be exercised before use.
Marketing product manager
J.H. Williams Tool Group, a subsidiary of Snap-on
53/36 combo? Not likely
With the new season coming upon us (current snow and cold notwithstanding), I’d love to hear something about expanding the range on crank gearing. I seem to recall reading that the riders on last year’s Giro were riding 53/36 combinations. Living in Colorado I’d love to see something like that on my bike. What’s the word?
I’ve seen Giro riders using 52/36 combinations on compact cranks (110mm bolt circle diameter), but I’ve not seen a pro using a 53/36. I have ridden FSA 52/36 rings on a compact crank for the entire 2007 summer, including lots of riding and Gran Fondos in the Dolomites and the Alps and super-long mountain day rides in Colorado. I used them with Campagnolo Record and SRAM Force and Red front derailleurs and found them to shift quite well. However, that stays within the 16-tooth difference that front derailleur manufacturers have generally decided is within spec; the 53/36’s 17-tooth difference is not. Furthermore, the 52/36 rings are meant to be mated with each other, whereas if you were to slap a 53 on there (if you could even find one with a 110mm BCD holes) it would not have shift ramps in the right places for a 36T chainring.
Response from FSA:
I have not heard of that (53/36 in the Giro). That is quite a large spread for a front derailleur — it would be finicky to set up and shifting performance may vary by manufacturer. Our company line is that a 53-tooth ring on a 110 BCD flexes too much to be a viable option. As you know a 36-tooth will not fit on a 130 BCD. Some companies do make a 53-tooth 110 ring. The most likely crank to be encountered with this setup, especially in the Giro, would have been an SRM. I have one here in the office with a 130 BCD outer and a 110 BCD inner combo. I know the FSA-arm SRM comes stock that way — I’m not sure about their other models. I do know a guy in California who lives at the SlowTwitch complex and runs a 52/34 combo on his compact cranks on a Cervelo P3. He is using a bar-end shifter up front, but says it works great.
Full Speed Ahead
E-Dura-Ace is smart, but not that smart
I read somewhere that the electric Dura-Ace has some intelligence built in so if the rear gears are rattling it’ll correct itself. Does this mean you could use it with Campagnolo 10- or 11-speed cassettes and it’ll sort itself out each change?
No, you re-center it by holding down the adjuster button on the pod to put it in adjustment mode and then center it by sound by pushing the shift buttons.
Shimmy has a host of possible causes
I was doing a bit of pre-holiday drooling at the Calfee website when I came across the information pasted below. Seems that I recall a recent string of Q&A relating to speed shimmy and thought I’d share this. Seems to make a lot of sense, but I still have a question: Would switching out a fork cure shimmy?
“Calfee Design has identified a cause of speed wobble (a.k.a. shimmy) and instability that can be prevented. Speed wobble is a dangerous condition that can cause the rider to lose control of the bicycle and crash. While a skilled rider can prevent and stop speed wobble, it is better if it doesn’t start. Some experts state that speed wobble is caused by the rider, which is technically true because the rider responds to the steering dynamic, initiating a resonance that causes the frame to act as a spring. While loose headsets and out-of-true wheels and frames can contribute to starting a speed wobble, we have found that fork asymmetry can also get it going.
“Fork symmetry is defined as the symmetrical position of the fork dropouts in relation to the steering axis. Specifically, the equality of the distances from the dropout faces to the steering axis must be within a certain tolerance for the bike to ride in a stable and confident manner.
“Traditionally, steel forks were cold set after welding or brazing to realign them after possible distortion caused by the heating and cooling of the metal. A diligent steel-frame builder can align the fork blades to within a millimeter of symmetry. Certain well-known builders align them to within 1/2 mm.
“Carbon fiber forks cannot be cold set. They must be molded straight to begin with. We have found that a small percentage of carbon forks by various makers were molded with asymmetrical fork blades. Some are off by a little over a millimeter and others are off by two or more. Forks that are off by over 1.8 millimeters in symmetry have a good possibility of being prone to speed wobble. A symptom of a fork that is off by 1.8 mm or more is a noticeable difficulty when riding no hands at a slow speed (less than 10 mph). One has to lean to the side slightly to keep going straight. A bike with asymmetrical forks seems to corner better in one direction but not so well in the other. At speeds of 30 mph or more, the bike can develop speed wobble.
“If your bike has the above-mentioned symptoms, the fork should be measured for symmetry. This is difficult to measure without proper tools. Calfee Design measures all forks for symmetry and is equipped to measure any fork. If any Calfee customer wishes to have their fork checked, please send it to us with a letter requesting a fork inspection. Non-Calfee customers may send their forks for inspection for a nominal fee. Replacements may be available for asymmetrical forks, depending on the individual fork maker’s policy.”
I ran that recommendation from Calfee here a couple of years ago. I have many times seen an improvement in fork alignment improve a high-speed shimmy problem. But I have also seen bikes with perfect fork alignment that had high-speed shimmy. It’s not a cure-all. I’ve also seen bikes with shimmy problems fixed by interchanging one perfectly aligned fork with another one with more rake (offset).
Technical writer Lennard Zinn is a frame builder (www.zinncycles.com), a former U.S. national team rider and author of numerous books on bikes and bike maintenance including the pair of successful maintenance guides “Zinn and the Art of Mountain Bike Maintenance” – now available also on DVD, and “Zinn and the Art of Road Bike Maintenance,” as well as “Zinn and the Art of Triathlon Bikes” and “Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists.” Zinn’s regular column is devoted to addressing readers’ technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn. Zinn’s column appears here each Tuesday.
Zinn’s regular column is devoted to addressing readers’ technical questions about bikes, their care and feeding and how we as riders can use them as comfortably and efficiently as possible. Readers can send brief technical questions directly to Zinn. Zinn’s column appears here each Tuesday.