Tyre Pressures

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Psamathe
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Tyre Pressures

Post by Psamathe »

Before setting out today for some reason I squeezed a tyre and it felt a bit low. They were all similar. On pressure gauge 2 bar of less (not so accurate/clear down there). Sitting on it (ICE Sprint X Tour) tyres looked fine but I inflated them up to 3.5 bar and .. it was an uncomfortable ride! Schwalbe Marathon Plus and on UpWrong I use same (but narrower) and run them at 4 bar - which is a bit low.

The rear suspension is probably a setting is probably one setting too firm and no front suspension. It wasn't pothole issues but poorly resurfaced roads felt really "rough".

Edit: With hardshell seat but it has a decently think cushion.

Do people tend to run their tyres at lower pressures? Any reason not to run e.g. 2 bar?

Ian
UpWrong
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Re: Tyre Pressures

Post by UpWrong »

What width Marathon Plus? They are renowned for a hard ride. Marathon Greenguard are better.
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n0ct0
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Re: Tyre Pressures

Post by n0ct0 »

I’m running my regular Marathon Greenguards at 75PSI. 406 on the front and 559 on the back of my Scorpion, all 1.5”.

I didn’t use the Marathon Plus after reading how harsh they are.

I’ve ran them as low as 60PSI, but the ride was no better and the rolling resistance increased.
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squeaker
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Re: Tyre Pressures

Post by squeaker »

The only 406 tyre I would (intentionally!) use at 2 bar on the front of a trike would be a 50mm Big Apple. 40mm tyres get 3.5+ bar.
I agree wrt to the effect of lowering the pressure on a M+: much slower and little, if any, increase in comfort.
"42"
Psamathe
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Re: Tyre Pressures

Post by Psamathe »

UpWrong wrote: 18 Jan 2022, 7:09am What width Marathon Plus? They are renowned for a hard ride. Marathon Greenguard are better.
20x1.75 on front, 26x1.75 on back.

1st time I'd taken the route (on the bent) yesterday so maybe I was just unlucky with the road surfaces.

Ian
Jdsk
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Re: Tyre Pressures

Post by Jdsk »

I suggest doing the pressure experiments single-blinded: write down the list of pressures of interest, get someone else to randomise and inflate accordingly, record your experience. And repeat.

That way you'll remove a whole lot of biasses in finding your preferred pressures.

Jonathan
belgiangoth
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Re: Tyre Pressures

Post by belgiangoth »

Would you not expect to run lower pressures on smaller tyres?
If I had a baby elephant, I would put it on a recumbent trike so that it would become invisible.
DaveReading
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Re: Tyre Pressures

Post by DaveReading »

belgiangoth wrote: 18 Jan 2022, 12:39pm Would you not expect to run lower pressures on smaller tyres?
I would expect the opposite.
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simonineaston
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Re: Tyre Pressures

Post by simonineaston »

I aim for the front tyre on my Brompton to run at around 3 bar, whereas on my Moulton I aim for 5, 'cos the former has no front suspension.
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
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al_yrpal
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Re: Tyre Pressures

Post by al_yrpal »

My memory says Brompton tyres 100psi?

Al
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Tigerbiten
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Re: Tyre Pressures

Post by Tigerbiten »

I'm running out a set of 40-406 Trykers at ~60psi on the front of my ICE trike.
If I'm only doing an only on-road route with known good tarmac I may up them to ~70psi.
If I'm doing a mainly off road route or a route with known bad chip and seal then I may drop them to ~50psi.
The trick I used to find that pressure range was to run a short loop with a stretch of bad chip and seal multiple times with a range of tyre pressures.
I soon found what was comfortable and what rattled my fillings out ........ :lol:
I tend to just match the pressure in the 50-406 Big Apple on the back to the pressure in the front tyres.

Luck ........... :D
Lodge
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Re: Tyre Pressures

Post by Lodge »

I use Schwalbe Marathon Plus on my ICE Sprint (unsuspended), 35-406 front and 35-559 rear. I spent some time playing with pressures and am now down to 2.5-3 bar to get a degree of comfort. Much lower and I would risk snakebite punctures if I happen to hit a pothole. I'm just over 60 kg with perhaps 5 kg luggage regularly carried.

Before the M+ I used a set of Kojaks for 5205 miles. Down at 2.5 bar they did suffer a snakebite (only the once - lesson learned) but were otherwise acceptable. The M+, with their heavier sidewalls, appear more resilient. I swapped to M+ after moving from France to Staffordshire and suffering too many thorn-induced punctures from the regularly trimmed roadside hedges round here.
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pjclinch
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Re: Tyre Pressures

Post by pjclinch »

al_yrpal wrote: 18 Jan 2022, 2:02pm My memory says Brompton tyres 100psi?
They are rated to that, which means you can physically inflate them that far and not expect a loud bang, but that's not the same as it being a good pressure to run at.

I generally prefer tyres like bricks, but after a brief flirtation with 100 on the front on the Brom realised you can have too much of a good thing. The back (which is suspended) I tend to run 80-100 but have the front a bit softer.

Pete.
Often seen riding a bike around Dundee...
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pjclinch
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Re: Tyre Pressures

Post by pjclinch »

The Streetmachine (fully suspended, standard 40 mm Marathons) I run at 100 both ends and let the suspension take the strain. Same on the Moulton (Duaranos, 28 mm).
Often seen riding a bike around Dundee...
Psamathe
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Re: Tyre Pressures

Post by Psamathe »

Update: I've been doing some experiments and observing a bit more.

Tadpole has rear suspension but I've always left it set too firm (for a rider about 20Kg heavier than I am). So I've adjusted the suspension and it made no difference.

But observing the roads it seems it's due to poor surface dressing. Where the surface dressing is "pitted" or with small patches missing so you are over smooth 2 inches later on slightly raised surface dressing, 2 inches later back on smooth then 2 inches later back up to surface dressing, etc. all creating something of rumble strips. Unfortunately much of the road surfaces round me are like this so "that's life".

Ian
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