Solving the solvent question
Dear Lennard,
Thanks for the recent notes regarding carbon fiber and solvents/lubrication.I wonder if you could recommend a safe way to remove old tubular cementfrom carbon rims. If you have already addressed the issue, can you pointme in the right direction?
ScottDear Scott,
This is one of those questions that warrants an answer straight fromthe horse's mouth. I sent off your question to a few carbon rim manufacturersand got these responses back.
LennardAnswer from Hed

Acetone, a stiff plastic bristle brush, and a lot of time arewhat you use to get the cement off a carbon rim. You need to softenup the glue and scrub it off. Acetone won't hurt the carbon, butyou will need a bowl of it so that you can continually dip your brush init - it will gum up quickly. Gloves are a good idea. Plan onspending a while.
Andy Tetmeyer
Hed Wheels

Answer from from Zipp

You can use Acetone and sometimes the latex paint remover "Goof-off."Both seem to work, but you may find that one is better than the other withcertain glue types. You can buy one or both at the paint or homestore near you.

You can soak or wet the rim either by pouring the Acetone or "Goof-off"onto the area or better yet, soaking a paper or lint-free cloth and bathingthe area. (A rough-texture cloth and Acetone or "Goof-off" can be usedon the sidewalls to remove spilled glue.) After wetting the area,you can use a popsicle stick (dry or wet) to scrape the area. Sometimesyou can shape the popsicle stick to better fit an area either with a knifeor sandpaper.
Bill Vance
ZIPP Speed Weaponry

Do I really need these?
Dear Lennard,
I recently heard that there is no performance benefit to using carbon-specificbrake pads with carbon race wheels. The only real benefit that I was toldto using special brake pads is they last longer compared to using regularbrake pads with carbon wheels, which doesn't seem like that big of deal(since I only use my race wheels maybe six times a year), and all I wouldhave to do is replace my brake pads more often.Is this true? Are there any other benefits to using special brakepads with carbon wheels?
AronDear Aron,
I can say from personal experience that standard brake pads on carbonrims are grabbier, giving louder, less predictable, potentially dangerousbraking, and they wear faster, even melting down rapidly at a criticalmoment on a long, fast, tortuous descent, leaving you with no brakes atall. Furthermore, conventional pads on carbon rims are downright scaryin the rain, making for unpredictable braking until the rim is wiped clearof water enough for them to grab.
LennardWhat about the other way around?
Dear Lennard,
My question to you is about carbon rims and the pads for braking.Now I realize that there are different compounds for different conditionsand that Zipp and Kool Stop made an all-purpose pad. But do thesepads accommodate the traditional rims and/or will heavy breaking tear downthe alloys very quickly and destroy the rim? I have read some reviewson the new Kool Stops and it said that they where too soft for the carbonto have a long life, what could I use if my race wheels are carbon rimsand the training and free lap spare wheels are alloy if I don't want toconstantly change my pads and/or shoes?Thanks for your time and concern,
PatrickAnswer from Zipp

All manufacturers of carbon rims have a brake pad they recommendor have made for them. The problem is that most of the rims are somewhatlight and build up heat quickly and are somewhat soft and get softer withheat. The pads designed for them are often then very soft and whilethey work pretty well on carbon tubular rims, on alloy they wear down veryquickly.

Koolstop makes a pretty good carbon pad...one of the best with allcarbon rims, but it does wear very quickly with all alloy rims. ZIPP,who has it's pads made by Koolstop, is somewhat different.....it is madewith bags of mystery carbon fiber and other materials. We actuallysend them the material in plastic bags for them to make the pads out of....theydon't know, despite several years of trying, the breakdown of the materials.(One of the materials is Carbon Mesophase pitch material from the carbonbrake pads of F-1 cars that is incorporated into the pads to reduce heatbuild-up and wear on both carbon and alloy rims.)

First, our tubular rims are coated with a Silica Ceramic braking surface.This Silica Ceramic surface brakes very well, better than alloy, but getssomewhat hot, melting most standard pads. Our pad is designed to melt ata temperature of 75-100 degrees hotter temp than any of the standard orcarbon pads. In addition, when it melts, it turns into a powder atthe melting temp and does not fowl the rim. Because of the CarbonMesphase pitch material, it wears pretty well on alloy rims and, as mentioned,melts away as a powder rather than building up on the rims. In fact,the hotter it gets, the better it performs until it is all used up.The pad works better that any other pad for carbon with both the carbontubular rims and with the alloy regular rims.

The only caution is when putting them on for the first time, you shouldclean the carbon tubular or alloy rim with a Scotch Brite® pad designedfor woodworking. Get the finest available pad, the green level, andgo to work with that dipped in Acetone. On the part of the rim wherethe brake pad touches, work it over with the pad dipped in Acetone, letit dry and go ride! (Acetone is great stuff...use it to clean offthe old brake pad material and loosen and soften the old tubular glue.)
Bill Vance
ZIPP Speed Weaponry

Is it just hyperbole?
Dear Lennard,
I was recently looking at an aftermarket brake pad, brake pad holder,and cable manufacturer's website (Jagwire).For Campagnolo caliper brakes, they offer aluminum and carbon pad holders.In their product description for the aluminum pad holders, one of thefeatures listed is "Heatshield(R) technology (that) resists heat buildup." I've never given thought to brake pad holders being heat sinks. Ifa brake pad holder does work as an effective heat sink, then it seems carbonbrake pad holders are a really bad idea for carbon rim tubular wheels.If a brake pad holder is not an effective heat sink, then it makesno difference if you use carbon or aluminum pad holders on carbon rim tubularwheels. Would you provide your comments on this?
RobertDear Robert,
Carbon is an insulator, whereas aluminum (or steel) is a conductor.Thus, an aluminum rim is working to get rid of heat, thus taking heat awayfrom the brake pads. On the other hand, a carbon rim is trying to holdheat, thus retaining heat in the brake pads. Furthermore, carbon rims,being generally lighter than metal rims, have less thermal mass to transferheat to than a heavier rim would. So, I would say that a pad holder designedas a heat sink is a very good idea, and a carbon pad holder would be theopposite of that, being lightweight and insulating.So, you won’t find me riding with carbon rims and carbon brake-padholders!
LennardSilent running
Dear Lennard,
I recently rebuilt my right 10 speed (year 2002) Ergo Power lever.I replaced both g-springs and the index gear. After reassembling the lever,I noticed that it worked fine, but there was no "click" as I shifted itup and down and the indents were not "solid". Thinking that I must havegotten grease on the index teeth and springs, I disassembled the lever,cleaned all the grease (except for a very thin film) off the index teethand the area of the g-springs that contacts the index gear and reassembledit. The lever was still dead silent. The lever works fine and holds whatevergear I shift in into, but I like to hear and feel the positive indent whenit shifts. Your bookcalls for greasing the gear and g-springs. Did I use too much greasestill? What exactly do I grease when reassembling the lever?
DavidDear David,
That's strange. I usually use Buzzy's Slick Honey, which is actuallylightweight grease for rear shocks and the like, and I get a loud click.And I am not particularly sparing with it, either. I put a good glob oneach G-spring and smear a layer around the teeth of the index spring. Theclick noise is also a function of the ratchet ring up at the top and, forthe thumb lever, of the smaller teeth around the lower skirt of the indexgear, so check all of those teeth for wear as well. I just rebuilt a Choruslever last night, and it was certainly loud when I got done. If your G-springsare new, and the teeth on your index gear look good, I would think thatthe lack of noise is maybe due to particularly fibrous grease filling thevalleys between gear teeth. I suppose as the grease moves out of the teeththat it may get louder with use, though.
Lennard

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Technical writer Lennard Zinn is a frame builder (www.zinncycles.com), a former U.S. national team rider and author of several books on bikes and bike maintenance including the pair of successful maintenance guides " Zinn & the Art of Mountain Bike Maintenance" and "Zinn & the Art of Road Bike Maintenance."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.