No Such Thing As Correct Tyre Pressure
Well, that's an attention grabbing headline :laugh2:...... but it is true enough.
The owners handbook will quote the vehicle's maximum loaded pressures for solo unloaded use just because they are afraid of legal liability issues (eg 36F 42R).
Track guys will use lower (but not "too low") pressures like 32psi, because they ride on a closed racing circuit and can 'keep' their hot pressures consistently at optimum grip levels (eg they are prob 36psi hot anyway).
So stop writing about what is correct and start thinking about your climate & riding requirements and factor in the brand of tyre you are using...... not all tyres are happy at the same pressure the handbook recommends :wink2:.
I do not run "too low a pressure"...... I run a cold set pressure of 34psi F and 36psi R on my light (233kg wet) SDGT and that translates to hot pressure readings of +2 to 3psi after a good 5-10kms of warm-up on public roads. i ride solo only and for a long tour with panniers loaded I usually up the rear to 37/38psi from habbit and might run the front at 35-36 but it really doesn't have that much effect..... just gives a few more days touring before I need to check/top up (and accounts for cooler temps at altitude over the otherside of our Great Dividing Range......).
So if you think you need max 2up +luggage (ie set for the maximum load capacity of your bike) then fine - just be careful on wet roads if you are only solo + no luggage.
Your tyre will not collapse and dent a wheel rim with 34psi cold (ie 36psi hot) - though if you hit a bad enough pothole (one with "teeth") you may damage a rim/crash regardless of tyre pressure choice (depending on angle of hit/bike lean angle/depth of hole/etc).
Also, each brand of tyre has a temperature that gives optimum grip-life balance. A Michelin tech once told me for Pilot Road 4's I should be running with 35F & 37R..... he was correct as I have had safe wet weather grip and 20,000km tyre life for many many sets of PR4's on my Blackbird.
The SDGT with Angel GT's likes 34F & 36R for solo unloaded work here in the Aussie climate (I currently have 11,300kms and expect to get to 15,000kms before changing to PR5's). A mate over the ditch (in New Zealand) tossed his SDGT down the road due to 'too high pressures'..... he now runs 34f 36r and has no problems).
Others (on SDR's) run even lower pressures, but they are all over 30psi and they ride hard enough to heat them up and keep them in their optimum temp ranges...... I am a mere street-road rider and have to share the road with traffic so I compromise for wear and grip and feel (and I don't have snow/cold conditions unless I travel 2,000kms south.....:wink2
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Don't forget the old days - cross ply tyres - the pressures used to be (if I can recall correctly) in the mid 20psi ranges........ so if you are a slacko riding around on tyres bulging at the side and squirming around with 20something psi...... then you have "too low pressures" and are in danger of tyre failure/bead separation/crashing.
Thanks for putting up with my raving rant eh? :grin2: hope it clears the issue for some, and stay rubber side down:wink2:
Ps The mention about the TPMS being inaccurate....... I'd be wary of the gauge you are comparing it with (I once had a gauge that was 8psi in error)....... to get around this I have three gauges - A "PCL" english made engraved stick type, a "Bluepoint" US made dial type and Michelin digital battery type..... they all agree with the TPMS (which naturally only reads hot pressure which correlates to +2 to +4psi depending on how fast and how long you have been riding before testing - eg 100kph+ will see +4psi over cold temp reading).
It's a personal choice but so long as you have pressure around the 32-36F and 34-38R mark you will be fine - obviously choose the higher range for 2up riding with luggage.
One thing to adapt to these days, tyres have more silica in them than in past decades so they offer great grip and long life without the old style need to run very hard maximum pressures on soft compound tyres...... in fact that may cause rapid wear.
Ps nearly forgot...... not all tyres are constructed the same - eg michelin PR1-2-3-4-5's are all Kevlar Belted Radials, whereas Metzler/Dunlop/Pirelli/etc are Steel Belted Radial's....... a kevlar belted tyre will run cooler than a steel belt radial (and last longer) but will take longer to heat up from a cold start........ choices choices..... no right or wrong.... just gotta select the right bike & tyre combo for the individual's needs/preference/etc........ easy eh ? :wink2:
