Ask B Rose 3 – More Torque Wrench Wisdom, Old Elastomers, Tight Rim and Tire Combos
Industry tech legend B Rose is back with another dose of tech answers. In this column we cover torque wrench choices, ancient elastomer suspension replacements, tight tire and rim combinations and some gripping feedback from another wrench. You ask, B Rose answers.
Submit your own questions in the form at the end of the column.
Q: In an effort to completely befuddle your doubt’s that I won’t use a torque wrench (Ask B Rose 1), I would like to know what torque wrench to purchase. Mi amigo Julio has one from Ritchey, but is there one from Park or maybe Craftsman….Snap-On Tool? Which one is the most simple to use? Is there a general rule of thumb or some resource you can think of regarding the torque I should apply to my bike?
B Rose:There are many torque wrenches on the market. And there are none that cover every range, torque requirements run from units of mouse fart force to metric elephant shit foot tons. But I will do my best to save you some coin, here is my theory… Most people over torque bolts rather than under torque bolts. So things like 4 mm stem bolts (average 4-6 nm) get way over tightened till they break and 8 mm crank arm fixing bolts (39-49 nm) get under torqued. I think the more important end of this spectrum is the smaller bolts, the ones that get over torqued. Face plat bolts, seatpost mast fixing bolts, ect. So if you can buy only one torque wrench get a small one. The small Park TW-1 is cheap and easy to maintain. Most of my torque needs are met with a Syntace TT 1-20 (there are a million branded versions of this including the Ritchey.). It is not cheap and you must remember to dial it down after every use but the easily impressed will go gaga at the sight of it.
As I get old I use the Barnett Manual or this page to remind me of the numbers everyone thinks I already know.
Q: My elsastomers are rock hard, my proflrex sat for many years, sorry old bike. How can I revive them? CPR, Heart defib paddles, it puts the lotion on and puts it in the basket… what kind of preventive maintenance could help?
B Rose: Well there really isn’t much you could do to prevent this from happening. It happens to all of them Proflex bikes. Elastomers filled a need in their day, they were a lightweight spring that provided its own damping. What that means is the shock on your Proflex has no damper and if you put a coil spring on it, it could become a self energizing ejection system that may someday kill you (although its rarely that severe). Now I am going to ruin many Proflex owners days — your shock should have two 40 mm elastomers, that is 80 mm of stack. If your elastomer’s are less than that, your bike is not handling the way it should (probably very poorly).
You should retire the bike… No one ever wants to hear that, I totally understand. But you should retire the bike. It has earned its eternal slumber. If you are unwillingly to to that (and please do not explain to me why, it’s none of my business) Suspension Fork Parts can help. These are not great elastomers but they will last and keep the bike rideable.
Q: I would like to add to the grip discussion. As a 20+ year mechanic I have found it beneficial to wrap the handlebar surface directly under the grips with electrical tape Before installing them it acts as a shim and makes it much mor likely to not slip.
B Rose: Sure, that could work, and hose clamps and a wood screw will do it too. I have seen people do this, but I have had great luck with with keeping it simple. Hairspray, clean bar, air compressor and safety wire in the worst cases. There are a million ways to skin a cat, I try and only recommend things that I can say have worked for me. Working on Pro bikes you could find yourself at the short end of some long looks if a grip mishap occurred on your watch.
Q:My Campy Eurus wheels have a rim diameter that makes clincher tire mounting/dismounting extremely (I mean extreeeemly) difficult. I punctured on the road last week and could barely get the tire back on after 30 min of struggle. Other than canned puncture seal, or attempting to “prestretch” the tire beads, do you have any recommendations for making this easier? I am wary of riding these on training rides.
B Rose: A tight clincher rim can suck the life out of you and make you second guess your wheel choice. In my youth as a bike messenger in Pittsburgh many of us ran Ambrosio Elite rims that we got from the local legendary shop Kraynicks. They were cheap, pretty, eyeleted and affordable; but they were terrible to put tires on.
One thing to remember when you install a tire or take one off, its easier if you keep the beads of the tire centered in the rim (because the cross section is concave like my old Staab, the diameter of the rim is at its smallest in the center). Keeping that in mind can help; and extrapolating from that, a thin rimstrip (like ROX smart tape) could buy you an extra millimeter or two (that is enough to be a big help).
So keep the beads in the center of the rim when you are pulling that first inch of tire over wall of the rim or pushing the last inch on. If it is still unbearable dish soap and water won’t hurt the rubber but it will lubricate the tire a little for ya.
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