Low rear tire pressure - help finding cause??
Seasoned HDF Member
Joined: Jan 2011
Posts: 157,518
Likes: 57,069
From: Michigan 15 Minutes East Of Hell
Make sure you use valve stem caps. The centrifugal force of the tire rotating can push the valve partly open causing an ever so slight leak at speed.
I bought a "https://www.amazon.com/dp/B00YCAVGMK/ref=cm_sw_r_cp_apa_H7hgzb75ZXZGW]FOBO bike[/url]" TPMS. I haven't got to use it since the bike is apart for engine upgrades. You can see, on your phone, what you tire pressure is. You can set high and low pressure alarms. Just my attempt at being more diligent about my tire pressure. I hate laying in the driveway checking it before heading out.
I bought a "https://www.amazon.com/dp/B00YCAVGMK/ref=cm_sw_r_cp_apa_H7hgzb75ZXZGW]FOBO bike[/url]" TPMS. I haven't got to use it since the bike is apart for engine upgrades. You can see, on your phone, what you tire pressure is. You can set high and low pressure alarms. Just my attempt at being more diligent about my tire pressure. I hate laying in the driveway checking it before heading out.
Grand HDF Member
Joined: May 2010
Posts: 3,599
Likes: 5,175
From: SWMO
My my, this is certainly a vexing conundrum! I recommend the private investigators pictured below.
And, my money is on old Mr. Wiggins, the retired nightwatchman from the old abandoned amusement park. Most of the time he would have gotten away with it if it weren't for those meddling kids.
And, my money is on old Mr. Wiggins, the retired nightwatchman from the old abandoned amusement park. Most of the time he would have gotten away with it if it weren't for those meddling kids.
Thread Starter
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Road Master
Joined: Sep 2013
Posts: 1,091
Likes: 84
From: Southern Maine / Seacoast NH
I bought a "https://www.amazon.com/dp/B00YCAVGMK/ref=cm_sw_r_cp_apa_H7hgzb75ZXZGW]FOBO bike[/url]" TPMS. I haven't got to use it since the bike is apart for engine upgrades. You can see, on your phone, what you tire pressure is. You can set high and low pressure alarms. Just my attempt at being more diligent about my tire pressure. I hate laying in the driveway checking it before heading out.
My my, this is certainly a vexing conundrum! I recommend the private investigators pictured below.
And, my money is on old Mr. Wiggins, the retired nightwatchman from the old abandoned amusement park. Most of the time he would have gotten away with it if it weren't for those meddling kids.
And, my money is on old Mr. Wiggins, the retired nightwatchman from the old abandoned amusement park. Most of the time he would have gotten away with it if it weren't for those meddling kids.
Road Master
Joined: Oct 2006
Posts: 832
Likes: 6
From: Vermont
Well, I've thought about it and agree that centrifugal force would tend to open the poppet. However, the mass of the valve stem internals is so small that it wouldn't be much of a concern at speeds of less than 200 mph or so.
Seasoned HDF Member
Joined: Jan 2011
Posts: 157,518
Likes: 57,069
From: Michigan 15 Minutes East Of Hell
This would also depend on which way the scooter was headed while factoring the rotation of the earth. right?
Stellar HDF Member
Joined: Jun 2007
Posts: 2,178
Likes: 600
From: SoCal.....I'm only here for the weather
I use a braided SS extender about 12" long designed for dually pickups. I thread it thru the slots in the brake discs and then onto the valve stem. This allows me to gage and fill from the end of the extension. I still remove the right saddle bag but it is much easier than trying to get a gage or fill adapter directly on the stem.
Road Master
Joined: Jun 2011
Posts: 974
Likes: 13
From: Chesapeake Virginia
You can't use the rotation of the earth. It does not turn at at a consistent speed. The Feds make up for it when everyone is asleep.
Road Warrior
Joined: Dec 2012
Posts: 1,686
Likes: 242
From: Glen Mills, PA
I've heard guys complain about balancing the wheels when using the 90 degree stems. You may want to research that before installing.
I use a braided SS extender about 12" long designed for dually pickups. I thread it thru the slots in the brake discs and then onto the valve stem. This allows me to gage and fill from the end of the extension. I still remove the right saddle bag but it is much easier than trying to get a gage or fill adapter directly on the stem.
I use a braided SS extender about 12" long designed for dually pickups. I thread it thru the slots in the brake discs and then onto the valve stem. This allows me to gage and fill from the end of the extension. I still remove the right saddle bag but it is much easier than trying to get a gage or fill adapter directly on the stem.
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Grand HDF Member
Joined: Aug 2014
Posts: 3,612
Likes: 1,606
From: Eastern Ohio
I'm not going to get into a physics debate, but you need to think about it Larry.
HDF Community Team
Joined: Nov 2012
Posts: 6,190
Likes: 2,419
From: USA
As for checking the tire carcass and sidewalls, it's not precise, and much harder from the outside.
inflate the tire and get the bike up so you can rotate the wheel.
Look closely along the sidewalls for signs of excessive flexing and heat buildup. Funny looking rubber, flaking, checking, shiny band, etc. anything that looks like an odd band around the tire.
Run your hand along the sides. Does it feel consistent, or does it feel bulged or wavy in places? When you rotate the wheel does the tire look consistent, or do you see bulges or runout.
if it passes all those tests, you're probably ok. The stock Harley tire has a very beefy sidewall. Others, not nearly so.
how wimpy can a tire be? Wife pulled out of our driveway and could tell a tire was flat. Turned around and came home. Total drive distance of about 100 yards. Tire was destroyed. Now that was a very thin sidewall mind you.
inflate the tire and get the bike up so you can rotate the wheel.
Look closely along the sidewalls for signs of excessive flexing and heat buildup. Funny looking rubber, flaking, checking, shiny band, etc. anything that looks like an odd band around the tire.
Run your hand along the sides. Does it feel consistent, or does it feel bulged or wavy in places? When you rotate the wheel does the tire look consistent, or do you see bulges or runout.
if it passes all those tests, you're probably ok. The stock Harley tire has a very beefy sidewall. Others, not nearly so.
how wimpy can a tire be? Wife pulled out of our driveway and could tell a tire was flat. Turned around and came home. Total drive distance of about 100 yards. Tire was destroyed. Now that was a very thin sidewall mind you.
