Tech & Wearables

Technical FAQ: Campy crank removal, flat-bar disc brake conversions, and more

Campagnolo drivetrain maintenance, Shimano wide-range gearing, and mounting racks on carbon road bikes.

Have a question for Lennard? Please email him at veloqna@comcast.net to be included in Technical FAQ.

Dear Lennard,
I have a first-gen Campy Super Record 11-speed group on one of my bikes, and when I went to remove the crank, the fixing bolt was stuck or seized (it probably has been 3 years since I last did it, but I haven’t ridden in rain or on a trainer with this bike). I believe the bolt is right-hand threaded for Super Record, and I’ve tried a long breaker-bar and all my muscle, but the bolt would not budge. What’s even worse is now the bolt removal tool is stuck and lodged in the bolt and I can’t remove that either with hand tools. Any suggestions to get myself out of this pickle? The shops in my area don’t deal in Campy, and I’ve removed and installed Ultra-Torque before, but this is a new problem for me.
— Paul

The bolt on the end of the Campy Ultra-Torque bottom braket spindle is “left-hand” threaded. Photo: Paul Lee

Dear Paul,
I think you may have been turning that 10mm hex key in the wrong direction. As I say twice in the crank chapter in Zinn and the Art of Road Bike Maintenance, “On Campagnolo Super Record cranks with a titanium Ultra-Torque spindle, the crank bolt is left-hand threaded.”

I would try an impact wrench on that tool. That’s what they are made for. And turn it in the correct direction! Once you get it out, you’ll have to replace that crank bolt as well as the 10mm hex key.
― Lennard

Dear Lennard,
I am transitioning my current modern steel road bike to a commuter and would like to salvage as many parts along the way. I’d like to convert this frame into a flat bar build, and my current brakes are Shimano Ultegra flat-mount calipers with Ultegra levers. Can I still use the Ultegra flat-mount calipers but instead install Shimano mountain levers for the flat bar build? As I understand, many Shimano road components are not cross-compatible with their mountain components (shifters, derailleurs, etc.), but does this also hold true for brake calipers? Ideally, the Ultegra flat-mount calipers could stay, and I would not have to get MTB brakes with flat-mount adapters.
— Kevin

Dear Kevin,
Yes, you can. While cable-actuated Shimano road rim-brake calipers are not compatible with Shimano MTB rim-brake cable levers (because mountain bike cable levers have lower leverage and pull more cable than road levers do), this incompatibility does not exist with hydraulic disc brakes.

Since you’re using the existing Ultegra flat-mount caliper, you have no issue at the caliper of a banjo bolt being required as some MTB calipers require; the hose comes straight into the Ultegra flat-mount caliper with no banjo fitting. The Shimano fluid is the same with both brakes, and the master cylinder works with either caliper. The lever feel with the Shimano MTB hydraulic levers is the same whether it is hooked up to a road caliper or an MTB caliper.
― Lennard

Dear Lennard,
I have a carbon fiber bike with a carbon seat post and want to install a rear rack for credit card touring. Because the bike lacks dropouts, I identified a seat post clamp with a bolt adapter and a rack that clamps onto the seat stays near the rear hub. If the load is kept to under 15 pounds and care is taken to not over tighten the clamps, does this setup sound advisable, or am I missing something that makes this a potential problem and not advisable?
— Howard

Dear Howard,
While this depends on the particular carbon bike, and while installing a rack may void your frame warranty, it’s hard for me to imagine that 7.5 pounds loaded on each seatstay via a band clamp down near its dropout would cause any problem on most carbon bikes.
― Lennard

Dear Lennard,
I see multiple people seeking lower gears for gravel with Di2. Why not pair a medium cage rear derailleur with 46/36 front chainrings and an 11-40 cassette? The capacity of the derailleur should not be exceeded as you are reducing the difference in the front chainring teeth by six while increasing the rear by six. If you have difficulty getting the b screw adjusted sufficiently to clear the 40-tooth cog, a Wolf Tooth road link will solve the problem. Now you have a 36 x 40 low gear. At the other end, a 46 x 11 is completely sufficient for all but highest speed gravel racing and is even tolerable with road tires in the hills along as you are not trying to keep up with a fast group down a gentle descent. I also find the jump from big to small chainring to be less jarring with the 46/36 and not to require as many additional simultaneous shifts in the rear.

You could also probably use a 50/34 with full Synchro Shift to prevent the 50×40 combination but would have to be careful to never shift the front derailleur to the big ring while in the 40. You could reprogram the front left shifter to shift the rear or both shifters to mimic SRAM eTap, but would lose the ability to adjust the low limit on newer front derailleurs. The best solution would be to find a way to lock out the big/big combo like Shimano does with the small front ring and smallest two rear cogs.
— Turner

The Shimano GRX group includes a wide array of gearing options for 1x and 2x drivetrains, but some may want to go even wider.

Dear Turner,
That should work and should provide plenty of gear range for most gravel riders. Matt required Synchro Shift to prevent him from hitting a lot of gear combinations since he was going for a really extreme range, namely from 53 X 9 on the high end to 34 X 46 on the low end.
― Lennard

Dear Lennard,
I climb a lot of mountains and ride off-road, so I need a bailout gear. I recently set up this configuration shifts well (unlike my old bike!)
I would have tried a small subcompact crank but worried about front derailleur clearance

Cervelo C3
Shimano Ultegra ST-RS685 Disc Brake Dual Control Lever 2×11
Praxis Zayante Carbon 165mm 48/32
Ultegra 11sp Direct Mount FD-R8000-F
Shimano XT M8000 Shadow RD+ Long Cage 11sp RD-M8000-SGS
Wolf Tooth Tanpan Shimano 11 INLINE
Shimano XT M8000 11-speed 11-42

The Wolf Tooth Tanpan should adapt GRX shifters to XT Rear.

After further research, to get better shifting performance/less weight penalty, the key is getting smaller gears up front, not bigger ones in the back.
I suggest getting a smaller 11/36 in the back and using either of these cranksets:

Shimano FC-RX600-11 46-30
Q151, Chainline 46.9

Or for SUPER Low:

Sugino OX2-901D Compact Plus+ with CY5-SHC 46-27
Q145, Chainline 43.5

Front derailleur performance is improved with their adjustable FD Mount for OX

I love your Pedro’s Vise Whip II! Stay on the bike!
— Norman

Dear Norman,
Throughout this recent discussion on wider GRX gear range, I forgot all about the Tanpan! Thanks for reminding me!
― Lennard

More on skin sensitivity:
Dear Lennard,
For decades, I used the world-famous non-irritating chamois cream. A couple of years ago, I developed problems in the crotch area with itching and irritation. After trying many of the suggestions delineated in your column, I changed chamois creams. Almost immediate relief. Perhaps something changed in my body, or perhaps the formula for the crème was altered.
— Phil


Lennard Zinn, our longtime technical writer, joined VeloNews in 1987. He is also a custom frame builder (www.zinncycles.com) and purveyor of non-custom huge bikes (bikeclydesdale.com), a former U.S. national team rider, co-author of The Haywire Heart,” and author of many bicycle books including Zinn and the Art of Road Bike Maintenance,”DVD, as well as Zinn and the Art of Triathlon Bikesand Zinn’s Cycling Primer: Maintenance Tips and Skill Building for Cyclists.” He holds a bachelor’s in physics from Colorado College.

Follow @lennardzinn on Twitter.