Tyre pressure & suspension

[MatBin 5,105]

I haven't checked my tyre pressure since buying the bike in January, it was 2nd hand and I asked for new tyres, so I assumed the pressure was correct.

Anyway after the comments about what to run them at 36/42 and many people saying less 10% for more comfort and less 10% for winter I thought I might check them. When I connected my car pump the front appeared to be less than 30psi, more like 27, so I pumped it up to 32. Rear pumped up to 38psi.

I thought this would make an already "hard" suspension unbearable, but I kept an open mind.

Went for a ride this afternoon and surprisingly it actually felt better, almost as if the tyres are now taking some of the impact rather than passing it straight into the suspension.

So for me 32/38 seems a good setting.

 

[outrunner 4,457]

Overkill for some I know, but I check tyre pressures at the very least once a week. My NC 750 XDCT 34 front 38 rear, but the suspension has been played with.

 

 

Andy.

 

 

 

[Andy m 23,669]

Tyre gauges are notoriously poor for calibration and everyone's routine varies in terms in terms of load and temperature. You'd lose 10%/4psi just in that. Finding the routine and reading on your gauge that works and sticking to it makes perfect sense. 

 

Andy

[wjvh 999]

I would have thought that higher pressure in the tyres, so that they are harder, would mean that the suspension does more of the cushioning work, for which it is better designed than the tyres. I run my own tyres at the recommended pressures, occasional checks reveal very little loss of pressure. Seems to work OK for me but I'm not a terribly discerning rider.

[poldark 1,546]

Just to add another variable to this, sidewall stiffness is quite a factor in my experience.

 

There's several major tyre manufacturers now offering "A" or "GT" versions of tyres especially for heavyweight bikes (GSA et al).  I know the NC is no lightweight, but I have a preference for sportier side of Sport Touring tyres to try to aid the harsh suspension issue.

[Andy m 23,669]

13 hours ago, wjvh said:

I would have thought that higher pressure in the tyres, so that they are harder, would mean that the suspension does more of the cushioning work, for which it is better designed than the tyres. I run my own tyres at the recommended pressures, occasional checks reveal very little loss of pressure. Seems to work OK for me but I'm not a terribly discerning rider.

Its a black art and above my pay grade. 

 

A lower pressure increases the size of the contact patch (although you need to be down to single figure PSI to get the caterpillar track effect). This means steering will be slower and available braking will be over a wider range of control positions. The downside is the tyre also deforms more sideways which introduces unexpected control inputs. The tyre conforming to bumps does give the suspension less to do and as air springs naturally change rate will give a comfortable ride. 

 

It would take a lot to convince me 10 psi either way made much difference to the physics, but perception is important so dial them in if it suits you. 

 

Changing the tyres would be more noticable. If you want something to keep you awake fit a 160 section to the front 😈

 

Andy

[embattle 332]

I tend to check mine every time I wash my bike, I set the electric pump at 37/43 simply because I lose some pressure removing the pump.

[Reckless 945]

In recent years I’ve checked the tyre pressure when I take the bike out of the garage for every ride, pressure set to 2.5 bar and 2.9 bar, the pressure may only be down by 0.1 or 0.2 bar but it gets done

[The Postman 3]

On 30/10/2020 at 18:31, wjvh said:

I would have thought that higher pressure in the tyres, so that they are harder, would mean that the suspension does more of the cushioning work, for which it is better designed than the tyres. I run my own tyres at the recommended pressures, occasional checks reveal very little loss of pressure. Seems to work OK for me but I'm not a terribly discerning rider.

 

I agree, tyres should not be used as add on suspension units. The OP should try Honda's recommended 36F 42R, strangely enough you might find a big improvement in ride.  

Edited November 2, 2020 by The Postman

[Dunnster 1,650]

I was a 36F 42R man, religiously.

I now use 34F 40R I find riding solo a lot better.

[MatBin 5,105]

1 hour ago, The Postman said:

 

I agree, tyres should not be used as add on suspension units. The OP should try Honda's recommended 36F 42R, strangely enough you might find a big improvement in ride.  

Strangely enough 32/38 which is harder than what was in there feels a lot better than a lower pressure, might try a bit more to see if it's even better.

On the other hand my car label says 2.2 bar all round, it came with 2.0 so I upped it to 2.2 and found that too firm, we definitely felt the difference so dropped it back to 2.0 bar.

[DaveStewart 267]

Note to self.

Must check my tyres.

 

[electric_monk 270]

On 10/30/2020 at 18:27, outrunner said:

Overkill for some I know, but I check tyre pressures at the very least once a week. My NC 750 XDCT 34 front 38 rear, but the suspension has been played with.

 

 

Andy.

 

 

 

I wouldn't call that overkill, unless you're sensitive enough to know by the feel of the bike if the pressure is off you should be checking at least a week.

[shiggsy 529]

I found 38 for the rear tyre makes a noticeable difference.

[Spindizzy 7,109]

Set them to the book and just ride.

 

But that's just me 

[Trev 18,865]

On modern bikes, I set mine to the book and only adjust if I really don't like the feel, since I stopped riding sportsbikes (or at least only occasionally to scare myself) then I can't remember the last time I strayed from that. I do check them regularly as find some bikes do lose a psi or two over time, strangely the newer bikes seem worse the older ones for that? I have an accurate gauge rigged up to a Lidl USB rechargeable compressor, super handy and quick enough for topping up a few psi on a bike.

 

The exception to 'going by the book' are older bikes (70's and 80's for me) as the tyre tech has moved on hugely, usually the manual pressures are way too low for modern tyres.

[Scootabout 2,277]

I never ran the NC far from recommended pressures, but it did seem to me that the best ride came at spot on or even a pound above the recommended 36/42. I never hugely liked the NC's suspension, but somehow lowering the pressures by say 2 psi  didn't improve it. If anything it was harsher. I'm finding the same - stock, best -  with the Tracer, albeit the odd thing there is that the recommended pressures are 33F 36R, for the same tyres (PR4).  

I expect the experience varies depending on rider weight, other loads, and maybe other factors, too. 

Edited November 2, 2020 by Scootabout

[outrunner 4,457]

Tyre pressures like tyres are a very personnal thing in as much as what suits me might not be to your liking. I have tried the factory pressures when I got the bike new and changed pretty quickly, mind you, I did change the tyres after 310 miles as they were sh*t. Dropping the pressures made the bike feel better, for me at least, so I kept them at 34/38 as I reckon if it feels right then it is right for me. Others may not like the way my bike handles but it is set for my style of riding and I am sure others have done things to their bikes that I may think strange, funny lot us bikers. 

 

Andy.

Edited November 2, 2020 by outrunner
Ghost in the machine.

[Xactly 5,465]

11 hours ago, Trev said:

On modern bikes, I set mine to the book and only adjust if I really don't like the feel, since I stopped riding sportsbikes (or at least only occasionally to scare myself) then I can't remember the last time I strayed from that. I do check them regularly as find some bikes do lose a psi or two over time, strangely the newer bikes seem worse the older ones for that? I have an accurate gauge rigged up to a Lidl USB rechargeable compressor, super handy and quick enough for topping up a few psi on a bike.

 

The exception to 'going by the book' are older bikes (70's and 80's for me) as the tyre tech has moved on hugely, usually the manual pressures are way too low for modern tyres.

That’s pretty much my own philosophy on tyre pressures. I usually go to the manufacturer’s website and use their recommendations once I’ve changed the original tyres. I have a Royal Enfield C5. Although it’s a 2015 model the owners handbook advises pressures in the teens, even though it has modern RoadRiders fitted from new. The correct pressures are significantly higher.

I find pressure loss is minimal on modern tubeless bike and car tyres, though the bikes I’ve had in recent years with tubed tyres lose pressure and need more frequent checking. I always check them cold at home, never at a garage pump because they are notoriously inaccurate and the tyres cannot be cold if the bike is ridden. I find also that pressures vary with ambient temperature.