Tube = Grip ???? – OLD Bull Trailriders

This topic contains 7 replies, has 0 voices, and was last updated by pete 13 years, 8 months ago.

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July 27, 2011 at 7:36 pm #100249

pete
Member

Whanny’s post about tyres got me thinking.

Does a tube make any difference in grip? ie. a standard tube verses an ultra heavy tube run at the same pressure, does the heavier tube act as extra strength to the tyre? giving you that feeling of a higher presure when riding.
If so, what do you do? I have found that if you drop the pressure in an ultra heavy tube you can tear the valves off ( I did that a the OBT birthday ride ).

I have been running the ultra heavy tubes lately and I usually run 12 – 14 pound in my rear but with the UHT it feels different to what I’m used to.
I recon a couple of pound can make a big difference, if my pressure was at 14 could the tube make it feel like it was at 18 pound ( does any of this make sense? ) and could this be a factor, or is my mind playing tricks on me?

PTW

July 27, 2011 at 7:39 pm #205614

Mick D
Member

Good question Pete.

My answer is…………….Dunno :blush:

Never gave it a thought, a fair question indeed.

July 27, 2011 at 7:50 pm #205616

Greg
Member

Dont know about the grip, the extra weight of an ultra heavy duty increases your unsprung mass but no one on this site me included would notice that I reckon. I don’t agree that dropping the pressure in an ultra heavy duty tube rips the valves stems out that’s normally a rim lock problem. For example I run down as low as 8 psi in the rear of my bike at Wauchope and Coffs last year with an S12 and they grip like shit to a blanket added that the 650 has the power to tear a valve stem out it has only done it once. I tore a valve stem out at Hampton in Jan this year and was running 10 psi but was using a new billet rim lock and they are shit. Put ol faithful back in and haven’t looked back.

I say more traction with an ultra due to the extra weight of the tube increasing the unsprung mass pushing the tyre onto the ground and the ability to run lower pressures without pinch flats increasing your tyre contact patch

IMO

TB

July 27, 2011 at 7:56 pm #205617

scott bocking
Member

Hey PTW

Your valve tore because your rim lock was not tight, not due to pressure. Lower pressure will get you better grip to the point where the tire starts to roll on the rim. Depends on sidewall integrity but this would start to happen below 8psi.
Mountain bikes have successfully gone tubeless and you get better grip at the same psi as a tube. The tire is able to deformed perfectly to match the terrain without the added resistance of a tube. This is even more relevant as the pressure is lower or the tube is thicker. By that reasoning tubeless is the ideal and thin tubes give better feel than HD which give the least. It is like wearing three condoms. You will have less feel but will go for longer without getting soft (a flat). 😆
Tubeless is the future.

STM

July 27, 2011 at 8:35 pm #205618

Greg
Member

All hail the king !! You are right about pressures and foot prints. But I am not convinced re tubeless being the future right now I think it’s a way of for trail bikes compared to say MX track bikes.

My example Birthday ride

54 bikes

5 flat tyres to speak of

2 standard tubes :pinch:

1 ultra ( loose rim lock spun and tore valve out ) :whistle:

2 bikes with tubeless systems and both scored flats ( one found flat the next day bit still flat from the ride ) that’s a 100% strike rate. My question is anyone using them for racing sprints or enduros? ( I will try and find some answers out there through some people I know, motocross and enduro )

Now I am not saying tubeless won’t work etc but I have many unanswered question regarding them in rocky terrain against a loamy motocross track with rocks and tree roots etc side walls getting pinched, tyres not designed to be run as a tubeless

Again just my jet lagged ramblings or some food for throught

TB

July 27, 2011 at 9:24 pm #205615

pete
Member

On the OBT birthday ride I was running an s12 with a ultra heavy tube, both were a first for me and things didn’t feel right and so dropped the pressure and as a result the valve tear was my fault. :blush:
Now I’m back with the trusty 404 and an ultra heavy tube but it still doesn’t feel right.

STM, so basically the ultra heavy tube will feel harder than a standard tube at the same psi, and if I make sure the rim lock is all good I can drop the pressure and hopefully get close to what im used to.
This is good cause I do like the tubes.

PTW

July 27, 2011 at 11:50 pm #205626

drew
Member

you must be a more in touch rider than i Pete.

i went from std. tubes to UHD on the 640 and didn’t notice any difference. but i run my tyres art around 18psi..

yeah i know, not what everyone would choose to ride on. but 18psi and UHD means i ride confident that for my style i will be less likely to get a flat, and it’s where i feel most comfortable at. i tried 10-12 and didn’t feel right to me plus i got flats too easily..

next ride i do i’ll see how pressure affects feel. i’ll start off at 18psi and drop it to maybe 15 then 12 and maybe 10 depending on how the lower pressures go.

July 28, 2011 at 1:43 am #205646

pete
Member

xy-transit wrote:

you must be a more in touch rider than i Pete.

i went from std. tubes to UHD on the 640 and didn’t notice any difference. but i run my tyres art around 18psi..

yeah i know, not what everyone would choose to ride on. but 18psi and UHD means i ride confident that for my style i will be less likely to get a flat, and it’s where i feel most comfortable at. i tried 10-12 and didn’t feel right to me plus i got flats too easily..

next ride i do i’ll see how pressure affects feel. i’ll start off at 18psi and drop it to maybe 15 then 12 and maybe 10 depending on how the lower pressures

You know how something feels comfortable and then sometimes it just doesn’t, well that’s what happened and through process of elimination I could only think of one thing that was different, the tube. :S

When I learnt to operate harvesters it was flogged into my head that there are three levels,
A steering wheel attendant. :side:
A driver. :silly:
And an operator.
An operator can hear all noises and can notice all the different vibrations of a machine to the point where you can notice a change and catch a blockage or break down before it turns to shit.
Maybe I am more in tune with my bike than I thought, and maybe I did learn something when Rod was yelling at me cause I wasnt paying attention and blew a hydraulic hose and just about emptied all the hydraulic fluid. :blush:
Or maybe it’s all in my weird little head. :blink:
To be honest i think when I hop on my bike next it will all feel fine. :woohoo:

PTW
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