Drafting from the Front. Chain Prep and Monitoring.

On-Bike Chain Waxing; Measuring Lateral Chain Wear

Dear Lennard,

We all know about drafting. Get behind someone (preferably a big someone) and save energy by drafting.

But it seems to me that there would be a benefit to the person being drafted as well. My understanding that a component of "air resistance" or drag is the disturbance of the air flow behind the moving object. Add a fairing to the rear of the object and smooth the air flow so the lead object (rider) has less drag. Some trailers on tractor-trailers have such fairings. So does the rear rider in a group serve as a fairing so the lead rider has less drag?

Regarding nearby motorcycles, such as camera motos, is there a bow wave effect if the motorcycle is just ahead of the rider? Dolphins and porpoises seem to do this a lot with large ships by swimming in the bow wave. (Hydrodynamics, not aerodynamics, but similar.) It would seem that the UCI rules should rule out such juxtaposition between the two.
Richard

Dear Richard,

Absolutely, there is a benefit to the rider in front having a rider behind pushing air forward. This has been well known for decades demonstrated in wind tunnel testing for team pursuit and team time trial.

I assume you are asking about a bow effect on a bike rider from a motorcycle just behind the bike (you asked it the opposite way, “if the motorcycle is just ahead of the rider”, which I assume you don’t care about, because it would be a negligible boost to the motorcycle). If that is your question, the answer is yes, the “bow wave” of the motorcycle following the rider would push the rider forward.

We saw numerous incidents in the Tour this year where the moto ahead of a rider was close enough to be giving him a significant draft. There probably were cases of the opposite as well. Yes, it seems as though regulation and enforcement of both circumstances would be in order.

― Lennard

A little back-and-forth with Jeff about chain waxing:

Dear Lennard,

Here is my chain waxing method:

1. Clean and hot wax new chain and install

2. After 250 to 350 miles of dry road riding, wipe off chain with rag

3. Melt chain wax in small old chain lube drip container, in 180 F hot water, shake well

4. Warm up bottom run of chain, about 10 inches at a time, with hot air gun (careful not to melt tires, frame, etc.)

5. Drip wax on to chain. Repeat for entire chain.

6. Pedal slowly about 10 revs while heating chain, and wax will be sucked into the chain

7. Clean chain on bike every 1000 miles or so with Park Chain cleaner and solvent, heat chain to dry, reapply chain wax.

8. My Ultegra chain was only 0.3% longer after 8000 miles!

FYI, I started racing in the 1970s while a Mechanical Engineering student, still riding hard at age 70.

Jeff

Dear Jeff,