Keeping your pressure under control

Why?

So why care about your tire pressure? There are a few reason: Punctures can be dangerous and affect riding performance, riding off-road is usually better with lower pressure and the basic fun science thing of what is going on while riding and how can it be measured. I also noted that good riders (Simon!) usually care quite a bit about their pressure while riding with them.

These days there are monitors that keep track of the pressure in a wireless way. While looking for one I did a bit of Googling and found the SYKIK Rider SRTP300 to be a popular choice. So I ordered one and it showed up a couple of weeks later.








Installation

The system is meant to be super simple to install and I expected no problems after setting up my warning levels of temperature and pressure. Off I went to the garage and installed it but things were not working as easily as every one said.






Fixing the problem

SYKIKs email support works all good and they identified that the rear sensor hadn't turned on correctly and a reinstallation i.e. remove the cap and reinstalling it should fix the problem. Such an easy fix sounded unlikely but after trying it out it all started working perfectly.








Testing it out

To test it out I took the bike for a spin over to Stanley. It is about 30 minute ride from Mid-levels so would work well for testing the system out. The display is pretty easy to read while riding and fairly interesting to see how temperature a pressure changes while riding. The key learning is that the rear tire is the one that changes the most while being ridden.







Science

For the little scientist inside you might remember the Gay Lussacgas law. If not here is a refresher



We have four observations to test this out on:

Front wheel 1.9 bar @ 32 C and 2.0 bar @ 33 C

Rear wheel 2.0 bar @ 33 C 2.2 bar @ 40 C

The law says P / T = k which means (1.9 + 1) / (273.15 + 32) = 0.0095 for the front tire at start.

0.0095 x (273.15 + 33) - 1 = 1.91 so not quite 2.0 so possibly we could just jumped from 1.94 to 1.96

Lets try the rear wheel

(2.0 + 1) / (273.15 + 33) = 0.0098 which will give our prediction

0.0098 x (273.15 + 40) - 1 = 2.07 so not quite the 0.2 jump as expected but roughly in the right range 




Comments

Post a Comment

Popular posts from this blog

Nav Tower

Image
  Getting lost in exotic countries can sometimes be fun but can also be dangerous in case you don't get to where you need to in time. For the upcoming trip next year the navigation system, or nav tower for short, is built on top of the Rally Raid front tower. First off some prototyping was needed: Then a first rough acrylic glass prototype was made: Initially I thought about laser cutting a aluminum metal plate. However, the makerspace with the laser cutters in Hong Kong only cut carbon and stainless steel so instead decided to go with a bit thicker acrylic glass (4mm) compared to the prototype (3mm). The idea behind the setup is to have redundant instrumentation for all critical systems much like in an airplane cockpit . The key instrumentations are: Navigation Primary: Carpe Iter Backup: Mobile phone Speed Primary: Bike standard instrument Backup: Carpe Iter Distance Primary: Bike instrument Backup: Carpe Iter Fuel Primary: Bike instrumentation Backup: Open tank and look Electri
Read more

Getting stuck in New Territories

Image
Last Sunday the weather was great and I hadnt been out riding for a while so thought I would head out for a ride. Not having ridden for a few weeks I noted the battery had gone flat. I took it out and put it on charge for an hour while having breakfast. Normally I charge it longer but I was keen on getting out on the road and while riding the bike the battery is getting charged so didn't worry to much of having a flat battery. I was just coming over the mountain range on Route Twisk, where plenty of sport bikes go racing, when I noticed I was low on fuel. I pulled into a gas station and filled the bike up. Once I was ready to go I turned the ignition back on but nothing happened when I pushed the start button. Since the light came on and the headlight looked fine it wasn't obvious what was wrong. The most obvious sign was that the service light was showing after a few seconds when turning the ignition on. I thought maybe the ECU, the bikes computer, had gone wrong so
Read more

Trying out the bluetooth OBD connector

Image
I want to connect my laptop to my bike in order to both get diagnostic info out as well as hook up new toys to it. The most promising way to do this sounds like the OBD2 diagnostics interface. Unfortunately it doesn't seem to be easy to do on bikes from 2014 or later having the "Fly by Wire" throttle. In the past I've happily connected my KTM 990 Adventure to TuneECU but the 2014 690 Enduro R is not playing a long as easily. So far I've tried out the Lonelec cable and USB cable to laptop Konnwei KW902 Bluetooth dongle Vgate Scan OBD Bluetooth dongle Only the Vgate dongle is responding but is not talking to TuneECU. However connecting with a serial comm terminal like Tera Term then it responds to the basic ELM commands. I also wrote a small diagnostic Python program based on python-OBD to try to see what was supported: import obd obd.logger.setLevel(obd.logging.DEBUG) # enables all debug information ports = obd.scan_serial() print (ports) connec
Read more