A Cycling & bikes forum. CycleBanter.com

Go Back   Home » CycleBanter.com forum » Regional Cycling » UK
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Increasing the Pressure Range Of Vehicle TPMS



 
 
Thread Tools Display Modes
  #1  
Old January 6th 21, 02:46 PM posted to uk.rec.cycling
Bret Cahill
external usenet poster
 
Posts: 875
Default Increasing the Pressure Range Of Vehicle TPMS

It's a great advantage to get early warning when a tire is losing air. If I get appointed to my suggested new cabinet position as cycling czar I'd require every new bicycle sold in the U.S. come with TPMS. Even little kids bikes.

For about $200 US including shipping from Australia you can get TPMS that does road bike pressures.

Vehicle TPMS is an order of magnitude cheaper and you get 4 sensors. It's accurate but unless there is some hard to find in the menu high pressure range button, cheap vehicle TPMS only goes up to 3.3 bar.

So reduce the pressure going to the sensor so that when the monitor reads 2 bar its really 4 or 6 bar.

A home brew pressure reduction insert to trick the sensor might not be linear but it's better than paying $200.

The way it works is a spring loaded piston receives half or more of the pressure from the tire reducing the pressure in the sensor.

You need a metal schrader valve cap with gasket, a ball inflation needle, same threading as schrader valve, a furniture tack/ nail for a piston, a piece of inner tube rubber that fits inside the ball inflation needle for a seal, the spring from a ball point pen, cold weld and a drill.

By using the needle end of the ball inflator as a cylinder and a small pop rivet as a piston I was able to get a rough idea of the pressurized volume of the sensor. The volume of the threaded end of the ball inflator is an order of magnitude larger.

The head of the nail is turned in the drill or rotary tool like a lathe until it fits inside the ball inflator. The end of the nail should slide loosely inside the needle. Both are measured two or 3 times and cut to the right length to open the valve. I'm using a presta schrader adapter but the assembly isn't too long

The cross sectional area of the large end of the ball inflator requires a spring force of about 4 loops of the ball point pen spring. Slightly squeezed 4 loops just happens to fit inside of the ball inflator, between the sensor and the piston.

Drill a hole in the cap for the needle and glue it together. Finally you need a calibration sheet.

Left over from double tubing and tubeless w/ Mylar tube experiments I have a spare front wheel with 2 valves.

After several attempts I pumped up to 5 bar and the monitor read about 2.5. Like everything else with this project, that was luck. My calculations and measurements were not that accurate.

Then the luck ran out. The epoxy broke. The assembly may be too long.


Bret Cahill


Ads
  #2  
Old January 6th 21, 04:58 PM posted to uk.rec.cycling
TMS320
external usenet poster
 
Posts: 3,875
Default Increasing the Pressure Range Of Vehicle TPMS

On 06/01/2021 13:46, Bret Cahill wrote:
It's a great advantage to get early warning when a tire is losing
air. If I get appointed to my suggested new cabinet position as
cycling czar I'd require every new bicycle sold in the U.S. come with
TPMS. Even little kids bikes.


When you're 10 miles from home and the warning goes off how are you
better off than the standard realisation of "this feels a bit odd"?
  #3  
Old January 6th 21, 06:39 PM posted to uk.rec.cycling
Bret Cahill
external usenet poster
 
Posts: 875
Default Increasing the Pressure Range Of Vehicle TPMS


It's a great advantage to get early warning when a tire is losing
air. If I get appointed to my suggested new cabinet position as
cycling czar I'd require every new bicycle sold in the U.S. come with
TPMS. Even little kids bikes.

When you're 10 miles from home and the warning goes off how are you
better off than the standard realisation of "this feels a bit odd"?


Assuming he made it back there should be a cyclist in the UK who has known the answer for over 2 years. I found him in the park patching a tube. Tall vegan from the channel islands. Forget his name, Alex or something short.. He told me he wasn't an axe murderer so I let him sleep on Rusto's couch..

For the pandemic I keep a lot of quinoa, canned beans and frozen fruit and veggies and would be a much better host. He continued to Mexico on an empty stomach.

Several years earlier another vegetarian stopped by but he got his flat after he left for Phoenix.

I know goat head patches where I could log 2 - 3 million punctures in a matter of hours if I wanted. Maybe Guinness could list that achievement.


Bret Cahill




 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Tubular tire advantage = able to run at high pressure or able to runat low pressure? Sir Ridesalot Techniques 16 May 10th 15 10:43 PM
Increasing Q Factor? (PeteCresswell) Techniques 9 May 16th 09 08:43 AM
Top of the range 'budget' bike or bottom of the range 'quality' bike? Roja Doja UK 73 April 23rd 04 12:13 AM
Increasing distance? Doki UK 47 April 1st 04 09:09 AM
Increasing gear range on old road bike cheg Techniques 14 November 17th 03 04:55 AM


All times are GMT +1. The time now is 11:29 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 CycleBanter.com.
The comments are property of their posters.