Ride Mechanic

The test method matters.

Do you *really* understand the methodology behind comparative lab test results? #chainl**e #tribology #friction

'Straya Day. . . Bike Cream made in Queensland from coconut wax and Gold Coast rainwater. . . Surprisingly long lasting. Surprisingly clean running. Surprisingly easy to degrease. Surprisingly not made overseas. #australianmade #chainl**e #ridemechanic #bikecream

ISO is a lovely concept.


It does not work in the world of bikes.

Ten years ago...


An article appeared outlining the work of Friction Facts that started the chain wax era. No-one remembers the first paragraph, just the summary chart showing power savings from the lab test rig.


A more recent review of lab test rigs was published by Hambini Engineering which outlines concerns with test methods and the analysis.


We are almost 3 years into a University research project on lab test rigs of drivetrains and it has many limitations. Any result is only as good as the method used to create it. Anyone reading a summary of results must thoroughly understand the test method first.


This 10 year old paragraph written and published by a well respected cycling tech journalist is the way it is. Different l***s for different bikes, riders and rides. Just have to accept the diversity.

Tyre tech...


Tyre casing is crosslinked under the external rubber coating and composed of various fibre layers. It is built into the tyre sandwich construction process before the final heat and pressure rubber vulcanisation. These fibres can be made from various materials (e.g. nylon, cotton, silk) and have different strengths, thickness and densities. This is the TPI (thread per inch) tech talk that tyre manufacturers promote. There are less fibres in the more flexible sidewall and more under the tread.


The fibres are where sealant binds in order to repair a puncture. If the fibres are not present, for example in an inner tube, then it is better to use a "log jam" glycol fibre type sealant.


If these fibres become coated with an aged and impotent carrier liquid they become less reactive to active fresh sealant and a plug will probably be required, even for small punctures.

A well constructed road tyre with multiple layers of fibre capable of handling the high pressure is remarkably difficult to puncture through the tread and is why tyre plugs can be very hard to insert causing further damage to the casing (or rim).
Something to consider for tubeless riders

What are you good at?


My thing is chemical product development. This means navigating the infamous *valley of death* wherein, after an initial sign of good potential in R&D, cash flow flips to negative and motivation wanes. It is a fatal pit for around 90% of new ventures that are unable to attract sufficient support.


The exact same seems to apply in cycling. Very talented riders simply cannot find the funds to privateer the events, get the podium results and remain motivated. Since the brand navigated the valley in 2010 I have been able to offer a tiny bit of financial help to some very talented athletes. This year with Ride Mechanic NZ and have been assisting Sammie Maxwell MTB She has gone in with total commitment, high motivation and these combined with her talent achieved some very good World Cup results. Now she wears a rainbow jersey in U23 XCO and has become a "success" hopefully see her cash flow flip to positive and become an Olympian.


Very proud that she has reached this point and has experienced the emotion on top of podium and on top of the world. Also very grateful to all other supporters who helped on the journey through the valley. Congratulations. Sammie!

Some November race data.


Last NRS race of 2022 in Tasmania. One thorough preload and then race. Total energy through drivetrain for the 8h racing over 5 days was 2kWh hitting max of 1800W.


Cattlemen 100 MTB in Victoria preload with and then race. Total energy through drivetrain for 7h racing 2kWh.


Race proven by real riders.

.

Regular on this SRAM AXS 12sp flat top chain the rider reached an astonishing 50,000km and still under 0.75% wear on the chain checker. Quite an incredible effort!

Despite acceptable chain checker reading the rider was suffering slippage when riding. Wear was evident on the cassette and it was replaced along with chain. Limited elongation in chain but wear on cassette is quite unusual.

Chain and cassette handed over for autopsy and many pins had almost no wear. This meant that overall the chain was not showing excess elongation. However some pins, in particular those on the POWERLINK connector, were quite worn. This most likely due to l**e not penetrating onto all pins evenly or perhaps individual pins having different hardness out of factory. A chain is only as good as its weakest link!


ADVICE FOR AXS USERS
Remove and replace the relatively cheap PLCK-D1 POWERLOCK at service intervals and carefully inspect it for wear. If it is wearing then indicates some other pins are also wearing. Suggest change chain. Chain checker result should be considered knowing that localised link wear is likely.