Tyre Pressures

[Gordon Ryley]

Hi Graham My Dad use to just kick the pre WW2 tyres before we went to the
sea side after WW2 there were no tyres to buy,on the Vin if the tyres are to hard
my fillings fall out hitting the pot holes .

 

[vibrac]

So at risk of filling the thread what pressure should we use?
Comet solo two up
Twin solo two up

 

[Peter Holmes]

Twin I am invariably two up, sometimes with panniers full and sometimes fully loaded bag across the top also (although not so often these days)
Twin Front 21inch 30psi Rear 19inch 32-34psi
D Comet (pillion + tank bag) 19inch Front 30psi Rear 32psi
I always prefer to ride hard as opposed to soft!

 

[Alyson]

During my service, I used a foot long stick type. I have a few vintage stick types that I use and all, knock on wood, seem to do the job. Not to steer the topic in another direction, but is anyone using Nitrogen ?

 

[oexing]

Nitrogen is typical in aviation.But I don´t even care about it for aircraft. Breathing air is 80 percent nitrogen anyway, so why have the hassle about last 20 percent of oxygen in it ?

Vic

 

[danno]

I used to use an old home made air compressor but when that packed up, used
cheap foot pumps. They never lasted so after reading this article, I opted for the Michelin double barrel one.

Best car foot pumps 2023 | Auto Express

Which unit takes the pressure off inflating your tyres?

www.autoexpress.co.uk

Only problem is the button batteries need replacing regularly so I bought this Draper flexible pressure gauge.
https://www.drapertools.com/product/69924/tyre-pressure-gauge-with-flexible-hose/
On my BMW RS, there’s very little space between the front discs and wheel rim
and the flexible hose gauge makes it much easier.
Accurate too unlike the cheap foot pump gauges.

 

[dapleb]

Hello Graham,

The industry standard for tyre pressure gauges test/calibration is +/- 2PSI.

The quality of internals on all of those units you have pictured can vary greatly by manufacturer.

The first contestant, I can't see a brand but Euro Dainu and WIKA make good versions of this design.

The second contestant, inflator and gauge. The same design is rebranded by many different companies. These are very fragile and often up to 5PSI out from new. Again it will vary greatly depending on manufacturer. They are standard issue on most tyre machines and are often useless other than for seating a tyre.

The stick types are OK but will vary in quality and accuracy by manufacturer. I have 4 and none of them give the same reading. Alyson mentions a foot long version of the stick (master stick) these are normally quite accurate.

The tyre pressure gauge I have been really impressed with is this item https://www.halfords.com/tools/gara...44BRER97*MTY0NTUxNDc0MS4xLjEuMTY0NTUxNDc0Ni4w

The readings are very consistent and I have yet to see one out by more than 0.5PSI. They also have a very accurate tread depth gauge built in. The design should make it small enough to fit on a Vincent spoked wheel, though I have never tried.

All digital gauges are definitely not equal. I was sent several Yamaha promotional tyre pressure gauges and they were 3 to 4PSI out. Which is obviously not very useful for bikes where pressures are critical.

In terms of inflators with gauges there are many good but expensive options.

PCL MK3 (not so keen on the later MK4 version). There are many rebranded versions of this from Sealey, Draper etc.

Euro Dainu / Schrader / Michelin dial inflator

PCL Airforce (and digital derivative).


So to answer your question Graham, the safe answer is none of them. Without some form of calibration it is possible they are all out. None of those you have pictured are easy to adjust if calibration is out (there is some scope for adjustment on the PCL MK3 inflator/gauge type).

Since you have such beautiful bikes balanced on these tyre pressures it may be worth investing in the Halfords one linked and using that as a baseline to check the others you have pictured...it would be cheaper than getting even one of the existing units calibrated!

 

[vibrac]

I have one of those Halfords gauges but the problem I have is expounded in post #22!
It doesn't matter how accurate your gun is if you can't see the target!
Only Peter H has ventured some data, what do you use?

 

[dapleb]

Hi vibrac,

I don't need to worry about Vincent tyre pressures as I don't own one. My link to Vincents is through my dad's boike. He very kindly lets me look at it and pat it every so often IF I behave.

That's not quite true. I have ridden it but thought it rude to mess with his existing tyre pressure settings. I will ask him what settings he uses.

 

[Peter Holmes]

I have one of those Halfords gauges but the problem I have is expounded in post #22!
It doesn't matter how accurate your gun is if you can't see the target!
Only Peter H has ventured some data, what do you use?

Currently using for the bike a Draper Digital gauge, available from Tool Station for £9.84, they claim accurate to within +/- 1%, and then claim also that it is self calibrating, quite difficult to understand how it could be, or how it could work, but anyway, it works for me.

My VW Transporter requires 58psi when fully loaded, and that used to kill my electric "RING" pump working from the lighter socket, it used to fry the plug and once repaired the whole unit died soon afterwards, I then purchased a heavy duty "RING" for vans and motorhomes etc. a far beefier unit that has given good service, you can pre-dial the required psi and it shuts of when it gets there, a really good unit.