Larger Tyres on Ro...
 

  You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more

[Closed] Larger Tyres on Road/Gravel/CX....What Pressures?

39 Posts
29 Users
0 Reactions
120 Views
Posts: 10539
Full Member
Topic starter
 

I'm currently running 35s on my roadbike, and have historically ran 60psi, but have been advised that this is waay too high...is this right?

I'm 77kg (currently with my XMAS/PhD weight) and would usually run 90/100 on 23s or 25s.


 
Posted : 01/01/2016 5:50 pm
Posts: 0
Full Member
 

Anywhere between 45-60 i'd say.

Depends on where you are riding though.


 
Posted : 01/01/2016 5:51 pm
Posts: 1398
Full Member
 

I tend to vary mine between 45 and 60 depending on the ride. If it's mostly on road I'd ride higher pressures, if there's a fair bit of off road I'll drop them to 45. Lower rolls better off road but punctures become a problem with tubes if they're too low


 
Posted : 01/01/2016 6:05 pm
Posts: 10539
Full Member
Topic starter
 

I'm running mine tubeless on Crest rims, so the upper pressure is...tightly constrained. I've had a tyre blow off the rim whilst trying to seat it.


 
Posted : 01/01/2016 6:18 pm
Posts: 17187
Full Member
 

Similar weight here. On Croix De Fer with 35c Cross Speeds I have around 65psi for road use and 55 off road. On Defy I have 25c GP4000's at 90 back and 80 front


 
Posted : 01/01/2016 6:19 pm
Posts: 0
Free Member
 

I've got SCHWALBE Marathon Plus on this week as i've been mostly riding road, 32C and tend to run @ 50PSI as i find 60 is just too harsh over pot holes on the B roads


 
Posted : 01/01/2016 6:24 pm
Posts: 4359
Full Member
 

I run my 35mm CX comp at 65 psi on the road but drop them to 45 when there will be off road involved. Tbh I only notice the difference on road, where the lower pressure is more comfy but slightly slower.


 
Posted : 01/01/2016 6:25 pm
Posts: 80
Free Member
 

i'm currently 78Kg and running 38s @35-40/40 F/R and 35s @40/45

the wee bit more front variance is if I have the panniers on the front.

FWIW, I run 23-25s@80/85 (and 28s @75/80 ish)


 
Posted : 01/01/2016 6:26 pm
Posts: 1
Free Member
 

I use Vittoria XN Pro's (31's) on my CX bike and weigh around 160lbs, if I go offroad (Quantocks) with much less than 80psi I can guarantee pinch flats.
I really don't understand how people get away with such low pressures.


 
Posted : 01/01/2016 6:34 pm
Posts: 43345
Full Member
 

31s though. We're talking higher volume tyres here.


 
Posted : 01/01/2016 6:38 pm
Posts: 41395
Free Member
 

Road? Or gravel/cx? Very different, 15% rule for former, latter dependant on circumstances.


 
Posted : 01/01/2016 6:39 pm
Posts: 5626
Full Member
 

115kg and run my 32c at 60psi off road. TBH it's a bit to much. Never had a problem with pinch flats. I'm not the most elegant rider. You could drop down to below 35psi no bother.


 
Posted : 01/01/2016 6:41 pm
Posts: 10539
Full Member
Topic starter
 

Mostly road if I'm honest.


 
Posted : 01/01/2016 6:44 pm
Posts: 6829
Full Member
 

I ride Surly Knard 41mm @ 35-40 psi on 23mm rims and never pinch-flatted. OK I'm only 60kg but some of this includes the likes of GT and Inners black runs and off-piste riding, hucking my way over drop-offs, taking air - learning to unweight the front of the bike and riding 'soft' . For CX I'll run as low as mid-20s with tubulars where I know it's just soft. On the road I'll ride 25mm tyres at 60-65psi.


 
Posted : 01/01/2016 6:45 pm
Posts: 1014
Free Member
 

i start at 50 psi. marathon racers have to go up (60 ish) to avoid pinches (particularly rear) as they are very thin sidewalls. CX tyres a bit less.

I weigh a bit less than you...


 
Posted : 01/01/2016 6:50 pm
Posts: 15068
Full Member
 

Personal preference between so low you get pinch flats or so high it becomes skittish.

Also as above depends on your weight and what sort of terrain..

I bought myself a topeak d2 digital pressure guage for Christmas.. Great bit of kit.. I can finally easily give myself a point of reference to experiment from.


 
Posted : 01/01/2016 7:14 pm
Posts: 0
Full Member
 

I use this guide from one of Jan Heine's blogs which calculates for optimum 15% sag.

[img] [/img]


 
Posted : 01/01/2016 7:36 pm
Posts: 5626
Full Member
 

Going by that chart I'd need about 600psi in road tyres.


 
Posted : 01/01/2016 7:55 pm
Posts: 6856
Free Member
 

Unless you weigh 200kg I suggest you probably need to read the small print. I agree it's not very clear.


 
Posted : 01/01/2016 8:31 pm
Posts: 6317
Free Member
 

Fail to see the need for the silly low pressures.
For gravel with some cobble like going and single track my rough stuff bike is set at 60 both ends. Seriously don't think I have ever had a compression puncture but equally grip isn't an issue. Can't say that comfort is but I did notice how slow things felt at 50psi when I tried it. I must admit to not running big tyres though. Usually 38mm or sometimes 40mm. Mix of CX knobblies and good road tyres. To be honest the latter are way better. The very few times that grip has been an issue on off camber slime is way outweighed by the speed and comfort of a fast rolling tyre. Gravel is just tarmac with a tendency to throw up more spray.
Weight sub 80kg.
My mileage may well be less than many of you though , about 4000 a year on the gravel.


 
Posted : 01/01/2016 9:56 pm
Posts: 43345
Full Member
 

[quote=mattsccm ]Gravel is just tarmac with a tendency to throw up more spray.
Isn't that just a [i]tiny[/i] bit dependent on the grade of the gravel? 😆


 
Posted : 01/01/2016 10:14 pm
Posts: 15261
Free Member
 

Ordered a 32mm Hutchinson Toro (Tubeless) to try on the rear, currently using 35mm schwalbe Rocket Ron's at between 55-65psi which ain't the best tyres ever...

The Toro is apparently a CX race tyre intended for muddier conditions, which sort of suits my expected winter use, my reasoning was simply that the Toro couldn't be much worse than the Ron's and has a reasonable chance of being an improvement in ride and flat resistance, I am expecting to have to run it at a higher pressure than My MTB tubeless tyres say ~45 psi? just for general duties...
The "black mamba" was also available but looked a little shallow in tread for offroad winter mud use...

If the Toro is any good I might get a matching one for the front... And possibly try the mamba over summer, but I would prefer to find a single all year round tyre.


 
Posted : 02/01/2016 1:17 am
Posts: 0
Free Member
 

I use Vittoria XN Pro's (31's) on my CX bike and weigh around 160lbs, if I go offroad (Quantocks) with much less than 80psi I can guarantee pinch flats.

Have they tried to kill you yet in damp conditions - I loved mine until, they spat me off on a damp road.

Changed to Panaracer Gravel Kings in 28s after which tell me they should be 105psi on the sidewall, no ranges.


 
Posted : 02/01/2016 2:55 am
Posts: 6317
Free Member
 

I was thinking more in the terms of how to ride on it.
Must admit that I see gravel as FC type of stuff which is rougher than the Yank version in many cases.


 
Posted : 02/01/2016 9:17 am
Posts: 1
Free Member
 

Have they tried to kill you yet in damp conditions - I loved mine until, they spat me off on a damp road.

I've been using them for 4 or 5 years now, so I suppose I've got to know their limitations. There's a few tarmac climbs round here where I get wheel spin when they're due for a change and they're not the best on mud/wet grass but that's just a case of choosing your route. Most of the Quantocks is sandy/rocky where they're fine.


 
Posted : 02/01/2016 10:51 am
Posts: 6829
Full Member
 

Latest tyre manufacturer research shows that rolling resistance of lower pressures is actually better than high pressures, never mind the fact that you get more grip. Seems counter-intuitive, but let some pressure out and enjoy the grip!


 
Posted : 02/01/2016 3:19 pm
Posts: 6317
Free Member
 

Yeah but that pressure data is all about 23v25v28 mm on the road. There is a point where it doesn't apply. Even I am riding below the pressures that are talked about.


 
Posted : 02/01/2016 3:24 pm
Posts: 0
Free Member
 

Hi Daffy,
Have'nt got a clue about the tyres but I thought I'd say hello and let you know that Iain's moved to France and got engaged.

Cheers, all the best for 2016

G


 
Posted : 02/01/2016 4:46 pm
Posts: 4331
Full Member
 

I have 35c SB8s, on a road ride somewhere about 75psi, I'd guess 40ish for gravel.


 
Posted : 02/01/2016 4:51 pm
Posts: 10539
Full Member
Topic starter
 

Gordon!!! How're you doing?

Can you send an e-mail to my address in profile? I'd love to catch up.

ATB,

Martin


 
Posted : 02/01/2016 8:03 pm
Posts: 0
Free Member
 

Check the tyre and rim manufacturer guidance and go from there?


 
Posted : 02/01/2016 8:14 pm
Posts: 3167
Full Member
 

Interesting reading, this thread. Seems I'm running much too high a pressure in my tyres.


 
Posted : 02/01/2016 8:25 pm
Posts: 0
Free Member
 

If I'm racing cross it's generally in the 20-30 psi mark, conditions dependent. Riding mountain bike trails (on a cross bike) 30-40 psi, and on-road 40-50 psi. I don't feel any benefit from more pressure on road.

That's on tubeless, and I don't weigh much more than 60kg. Tyre guidelines are set far too high in order to avoid lawsuits.


 
Posted : 03/01/2016 9:58 am
Posts: 0
Free Member
 

This ^^^^^


 
Posted : 03/01/2016 10:13 am
Posts: 6317
Free Member
 

Why increase rolling resistance? Grip isn't an issue on the road or gravel. Go and try the same tyre at 40 and 60 psi and tell me that you can't tell the difference.


 
Posted : 03/01/2016 11:32 am
Posts: 13330
Full Member
 

45psi in 33mm tyres for mixed road and towpath work.


 
Posted : 03/01/2016 11:59 am
Posts: 0
Free Member
 

35psi in 40cc wtb nanos


 
Posted : 03/01/2016 12:29 pm
Posts: 10539
Full Member
Topic starter
 

Well,

I ran my 37s (with tubes) today at 40 front and 50 rear...I can't say I noticed much difference.

If the weather holds, I'll try the tubeless fellas tomorrow.


 
Posted : 04/01/2016 8:49 pm
Posts: 0
Free Member
 

I run about 80-85 psi in 28c tubed tyres for pure road riding.

On my CX/gravel/gnarmac thing I run about 35 psi tubeless with 35c tyres.

Seems to work for me.


 
Posted : 04/01/2016 10:05 pm
Posts: 0
 

I've been using Rocket Ron's (35's) on my crosser this year and I've settled on 50 at the back, 40 at the front and that seems to cover most bases for me, including racing. I'm no real lightweight at 13 stone though.


 
Posted : 04/01/2016 10:16 pm

6 DAYS LEFT
We are currently at 95% of our target!