Lennard Zinn

What can I do about a broken SRAM road shifter lever?

Can Dura-Ace shifters be rebuilt?

Can I use a Shimano 7900 chain with a 7800 rear derailleur?

Can I use a Dura-Ace 7900 crank with a 9-speed drivetrain?

Can I mix SRAM XX parts with SRAM road parts?

How can I stop my rear wheel from slipping in the dropout?

Does greasing threads negate the effects of threadlock?

Can I convert or rebuild Campy 8- or 9-speed shifters?

Are Shimano road and MTB external bottom brackets interchangeable?

Are Ultegra 6700 parts compatible with Ultegra 6600?

Can I rebuild SRAM Red shifters?

Should I remove my fork's wheel retention tabs?

How can I fix my creaking cranks?

My SRAM Force shift lever broke, what can I do?

Are Shimano external bottom brackets interchangeable?

Should I rebuild my Campy 8-speed shifter, or switch to 10-speed?

How do the big races produce custom leaders' jerseys so fast?

Why does my bike 'autoshift'?

Why is my bottom bracket noisy?

Can I retrofit QR15 legs on my SID fork?

Can I combine SRAM mountain and road components to produce hillclimb gearing?

What road wheels do you recommend for a 250-pound rider?

Can I get a Trek Madone seatcap with more setback?

Can I put a 105 compact crank on my Dura-Ace bike?

Why should I always put a spacer above my stem?

Any tips for traveling with bikes with tubeless tires?

Should I re-glue my tubulars annually?

Do vintage Campy rear derailleurs have non-standard mounting bolt threads?

What is the environmental impact of a ProTour race?

Why does my tubular tire thump near the valve stem? - Feedback

What are the rules for a 'Cannibal' time trial?

Why does my tubular tire thump near the valve stem? I have ridden them several times and I have noticed a significant pulsation whenever I coast at 20-28 mph. I don't notice it when I am pedaling although it is probably there.

Can I use a Campy 11-speed shifter with a 10-speed cassette?

Why do my vintage Campy shifters not shift well?

Why does my vintage Campagnolo drivetrain shift on its own?

Why does my Campagnolo hub have only eight ball bearings?

Dear Readers,
I’m in the Denver airport about to fly to Italy for the Giro d’Italia. I have enjoyed a lot of the feedback from a few recent columns, and I thought you might as well. Next time you hear from me will be from the Giro, so look for some cool bikes for the team time trial soon.
Lennard

Dear Lennard,
In your Earth Day column there was a question about a cracked carbon frame. Since it is a save the earth day of posting I thought I would ask about the possibility of repairing a cracked carbon frame (small crack obviously). Since you can buy epoxy and carbon, would it be possible to repair a carbon frame? It would be ugly but would it be rideable?
Scott Dear Scott,

Dear Lennard, I am considering storing my new full suspension bike using a vertical type rack that stores a single bike hanging vertically from the wheel. I was wondering if that could cause any damage to either suspension, front or rear. Does it make sense to hang the bike from the rear wheel? Nir Dear Nir, Hanging it from the front or rear wheel will not hurt it unless either of your shocks leak oil through the upper seals. In that case, hanging it could still be a good thing, because it will alert you to the problem and motivate you to fix it. Lennard

Do you have some bike suggestions for tall riders?

Why are my bottom bracket bearings wearing out so quickly?

Can you recommend a tall stem for a tall rider?

Why does my new bike tick?

How will Q-factor affect IB Band Syndrome?

Do you have any advice for correcting leg-length discrepancies?

Torque wrenches and temperature ranges Dear Lennard, 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? Gary Answer from Effetto Mariposa:

Do I need wedges under my cleats?

Should I wax my carbon seatpost?

Why do my Speedplay cleats wear out?

Polishing scratched aluminum cranks, tubeless road tires and Scotch-brite pads

Dear Lennard,
Why would changing a tire on a Zipp 530 be so difficult? I beat my fingers and snap tire levers trying to get a tire off.
Steve Dear Steve,
It’s a good question, but one I thought might be best answered by the folks at Zipp.
Lennard

Dear Readers,
I have received so much mail about the " tubulars vs. clinchers rolling resistance debate that I could not resist running some of the better ones. The debate may never end, but your letter sure have raised a lot of issues that I’d never considered.
Lennard

Tubes, tubulars or NoTubes?
Dear Lennard,
I'm currently running Campy 10-speed and am interested in running Hutchinson Tubeless Tires. It appears that the only officially approved system is the Shimano Dura-Ace wheelset, which is obviously not an option for me. My question is will a wheelset with rims that do not have pierced spoke holes on the interior (like the Mavic Ksyrium SL, Campy Shamal Ultra or Fulcrum Racing Zero) suffice and is there anything special that has to be done to make them work?
Phil

Questions about inspecting carbon forks for safety, trying Wippermann chains with Campy 10-speed systems and using Shimano MTB derailleurs with 10-speed road systems. What to do? I'm low on funds and that's the main reason I haven't replaced them as yet. I will add there are no stress fractures or noticeable wear.

Questions about fork failure from squirrel collisions, talcum powder and rolling resistance and bottom bracket life spans.

Mix-and-match
Dear Lennard,
At one time I read in your column that you can change Campy 9-speed ergo shifters to 10-speed. Is this true and what are the details?
Guido Dear Guido,

What can I do about a noisy Mavic freehub?

Dear Lennard,
I've just read your article article about the SRAM ceramic bottom bracket and its maintenance. We at CeramicSpeed have been working with ceramic bearings for the past 11 years, introducing systems for bicycle applications eight years ago.

Are longer cranks 'harder to push'?

Are ceramics that delicate?
Dear Lennard,
In your article on ceramic bearings in the recent VeloNews Buyers Guide I got the impression that these things were not only smooth but durable as well. As a result, I ordered a ceramic SRAM bottom bracket with the Red crankset on my new bike. To say the least, I was surprised when I read the SRAM maintenance instructions that came with it and saw the recommendation that one should disassemble and lube the bearings after every 100 hours of use and immediately after riding in the rain or wet.

Dear Lennard, Question for you re: forks for long head tubes. I'm 6'4" and have a Seven Axiom with a roughly 30cm head tube and a Seven rebadged Reynolds carbon fork on it. It is a bit flexy when braking while cornering and I'd like to improve that. What options are out there and how do they rate vs. each other? I know Alpha Q makes one with a steerer long enough (as seen on your bike) as does Storck, but want to understand if they are better than the Reynolds vis a vis flex/rigidity. Ted Dear Ted,

What can I do about foot pain while cycling?

Dear Lennard,
In a recent article you make mention of the fact that you do not use adhesive tapes, like that produced by Tufo, on tubular wheels, preferring instead to use the old system of building up with glue.

Will orthotics help my foot pain?

A recurring pain
Dear Lennard,
I'm writing because I just read the shoe review in the VeloNews Buyer's Guide, and you mention in there that you use a custom orthotic. I was happy to see that the Shimano SH R300's I just purchased got high marks, but I am still having issues with my right foot even with the new shoes. I got the new shoes because I was having the problem with my four-year-old Northwave Evolutions.

One more gear?
Dear Lennard,
We have a 27-mile climb just outside of town that I ride up occasionally. My problem is that I tend to spin out on my way back down and find it difficult to keep up with some of my riding partners. A friend of mine told me that I could swap my 10-speed Shimano cassette (12-25) for a SRAM (11-26), which would give me both a better climbing and descending gear. Although I understand 45MPH is plenty fast, is the swap compatible?
Brian Dear Brian,

Dear Lennard,
I'm interested in buying the Deda Zero 100 stem you recently reviewed. However I noticed that the clamp size is listed as 31.7mm. The bar I wanted to use is the FSA K-Wing Carbon which has a clamp size listed as 31.8mm. Will the 0.1mm difference in size make this combination incompatible?
Steve Dear Steve,

Questions about torque wrenches, torque and threadloc

Dear readers,
Most of today's column is devoted to a selection of the many, many interesting letters I got in response to my June 26 column, addressing the many factors that add to - or reduce – rolling resistance.
Lennard

Roundness
Lennard,

Dear readers,I’ve been wanting to write about rolling resistance for years, and I’ve had ongoing e-mail conversations with a number of you on the subject. Indeed, I’ve built up enough of it to compile a collection of some of the most interesting.Lennard WaterDear Lennard,As I was riding though an unexpected rainstorm, I noticed that, even with the rain, it seemed to take less effort to ride on the wet road than when it is dry (all other things – especially wind and temperature – being constant). I know that there is less friction when it comes time to stop or to turn. Could it be possible

Side steppin'Dear Lennard,Regarding your April 10, 2007 article "Whatis it?", I was wondering if you had any thoughts or opinions on modern-daypedal systems which are attempting to bring the ball of the foot directlyto where the pedal spindle typically is. The two that cometo mind are SideMount pedal (SMP) of Pasadena, CA and VistaMagic X of France.DavidDear David,I have not used the Vista Magic X, but I’ve used Steve Lubanski’s SideMount Pedal and Tom Slocum’s HighSierra dropped pedal built into a Speedplay. Both of them feel absolutelyfantastic to pedal with; most riders would be amazed

How can I duplicate my position on a new bike (more tips)?

Can I use the same brake pads on my aluminum and carbon rims?

Why does my bike shimmy at high speed?

Can I rebuild my Mavic freehub? (More feedback)

How can I record my bike position so I can duplicate it?

Making the transitionDear Lennard,I have spent a couple of years "tinkering" with my position on thebike. I feel like my position is now as close to perfect as possible.I am now worried that if I change shoes or damage my bike, etc. that Iam going to lose my "perfect position". What measurements shouldI record in order to duplicate my current setup on a new bike in the future?Also, I currently wear Sidi cycling shoes. How difficult is it toduplicate my cleat placement on a different manufacturer's shoes if I chooseto switch brands in the future?RyanDear Ryan,This is a perfect question for

Old-school rims at Paris-RoubaixDear Lennard,I noticed that all the teams for Paris-Roubaix used old-school tubular rims for the race. How come they don't use the fancy composite tall rims as they do during the rest of the season? Did it have to do with their stopping power in the dry, dusty conditions or the punishment of the cobbles?Peter Dear Peter,Both. Carbon rims, especially deep-section ones, are so much stiffer that they are likely to crack rather than flex and bend like an aluminum rim would. In a crash, jagged carbon edges are worse than bent aluminum. And of course,

The sourceDear readers,I received a boatload of great responses on creaking noises from the March7 column, and it is something so commonly plaguing all of us as cyclists that I’m running a whole list of the fixes for them that I did not mention.LennardIt's the headsetI also have a Basso Diamante that I occasionally have creaking issueswith. Like many creaking issues, it's hard to track down where the noiseis coming from. I suggest it isn't coming from the seat area with the riderwho sent you the question. I would check the front of the bike. First,make sure the quick release

TorqueDear Lennard,I recently purchased my first full carbon bike, absolutely love it. Yet, I'm scared of over-torquing the seatpost clamp. Is there a torque wrench you could recommend that works on Allen wrenches? What's the worst that happens, the seatpost clamp needs replacing or I have this fear of the actual seat tube deforming, I'm not doing the Samsonite luggage monkey torque on it, but "hand tighten" is just too open to quantify.ThomasDear Thomas,First of all, carbon frames generally have a separate band clamp to tighten the seatpost, and, yes, the worst that can happen,