technical question for bikers

Skybird · 10-24-09, 07:51 AM

In early Spring I got myself a new bike. Amongst some minor other things (lights, saddle) I exchanged the tires for fail-safe tyres by Schwalbe, these have a operation pressure range of 3.5 - 6.0 bar. Adjusting the air pressure for my weight and the luggage I sometimes transport, I operate the wheels at 4.5 - 5.0 bar.

The inner tubes have Presta/Sclaverand/French valves. And since Spring, today I ruined the third such valve/tube while pumping the tire up and removing the cap of the pump. That cap of the pump'S hose is lined with a robber coating inside.

Three breakdowns in 8 months due to failing valves when removing the pump (I tried three different ones now, all suited for Presta valves, they say). To say I'm pissed would be a mild description. More fun, these damn hypersensible things cannot just be replaced like Dunlop valves (taking the old valve out, putting the new one in, pumping up the tire and that'S it: one minute's job if you work slowly) - no, Presta is integrated into the tube: you always have to replace the complete inner tube, taking out the wheel and the wires and the chain for that. Merde.

Before, on my old bikes, I always had Dunlop/Woods valves (on a side note: it is also called English valve while in Germany it is called German valve

or Blitz-Ventil). Not a single of these ever failed me in the past 30 years. The tubes may got punctured, but the valves I never needed ro replace. they worked for a decade without ever causing troubles.

why are these Presta valves even sold on regular touring bikes today? What makes them so special that they have taken over even on bikes where you do not use to run narrow-sized high-pressured racing wheels at 11 or 12 bar? with air pressure around 4.5-5.0 bar, is it recommended to go back to an inner tube using Presta valves, and kick these damn Presta valves into the bin? what speaks against it? I mean there must be a reason why these Presta things now dominate the market. Is it just marketing? Three beakdowns in 8 months does not speak for the robustness and quality of these Presta valves. And I cannot remove the pumps from the valve any other way then putting them off, right? Or is there a trick or a hidden magical spell I need to use?

Steel_Tomb · 10-24-09, 08:05 AM

...

I could ask my dad, I ride a gsxr-600 but not clued up on technical things. I'll get back to you. My dad knows way much more than me lol.

Skybird · 10-24-09, 08:13 AM

Any input is welcomed. I googles a bit in the past minutes and found MANY complaints about the Presta Valves. And these were complaints not owing to the valves being called "French". It seems they are pretty much hated outside the racing bike community.

I thought about getting tubes with Schrader valves, but it seems these are low pressure only, up to 4 bar at max.

CaptainHaplo · 10-24-09, 11:09 AM

I could be wrong - but I think Skybird is talking about what we call a bicycle. Not a motorcycle.

Sky, here a "bike" is first thought of as the motorized kind.

Most motorcycle tires don't have tubes.

I ride a bike (or used to, don't have one anymore) but again, it was motorized so I can't really provide any input.

Skybird · 10-24-09, 12:21 PM

Yes, a bicycle I mean, like "bike" in "mountainbike"

. Tricky language. Mine is a "touring-bicycle-bike".

Shearwater · 10-24-09, 12:50 PM

I actually like them, though on my new bike (-cycle) I have Dunlop valves. On my old one I've never had any breakdown, and my impression is that they're a bit tighter because you have to screw them twice (valve + cap). Maybe that's the reason why they're so widespread since I don't think that you can reach pressures over 6 bar with a regular bycicle pump.

TLAM Strike · 10-24-09, 01:50 PM

I use a Shrader valve on my on inner tubes and have never had it fail, usaly the tube it self runs out of self sealing goop first or I get a really big hole poked in the tube. I use them at around 50 psi not sure what that is in bars.

Have you considered the foam type tubes? They are a solid block of dense foam so you don't inflate them. They are expensive but I've heard they last a long time.

Skybird · 10-24-09, 03:09 PM

The thing with fail-safe ("pannen-sicher") bicycle tires is that you need to run them with higher pressure than many touring bikes usually operated with, the lower the pressure, the smaller the security benefit from that tire is. That's why I have them at 5 bars, which is not little for touring bikes. Dunlop valves are described to hold up to 6 bars. Presta valves originally were only used for racing bicycles, since the tires are narrower and are put under much higher pressure (10-13 bar). Dunlop valves cannot hold that. so in racing sports the Presta has it's meaning, but why they are being used for touring bikes as well is beyond me.

The Schrader valve is described for pressure up to 4 bar (max), it is often used for car tyres, too. You find it on mountain bikes where the tires are wider and higher pressures are not so much wanted.

I will give the bike to a shop on Monday and ask them, my thoughts are to go back to Dunlops valves. I am needing the thing for it is my only means of mobility, and I travel up to 120 km away from my home town by bike. Getting caught by a technical failure in some forsaken area and 50 km away from home may not be life-threatening, but it is NO FUN nevertheless and means only trouble and discomfort.

Until Tuesday evening, Skybird is grounded.

Sailor Steve · 10-24-09, 05:48 PM

I have a bike.

I pedal, it goes.

And you say you're not technical!

Skybird · 10-24-09, 06:11 PM

Ask me to maintain and readjust a hub gear, then get popcorn, cold drinks, a chair and enjoy the afternoon-long show.

10-24-09, 07:51 AM	#1
Skybird Soaring Join Date: Sep 2001 Location: the mental asylum named Germany Posts: 42,602 Downloads: 10 Uploads: 0	technical question for bikers In early Spring I got myself a new bike. Amongst some minor other things (lights, saddle) I exchanged the tires for fail-safe tyres by Schwalbe, these have a operation pressure range of 3.5 - 6.0 bar. Adjusting the air pressure for my weight and the luggage I sometimes transport, I operate the wheels at 4.5 - 5.0 bar. The inner tubes have Presta/Sclaverand/French valves. And since Spring, today I ruined the third such valve/tube while pumping the tire up and removing the cap of the pump. That cap of the pump'S hose is lined with a robber coating inside. Three breakdowns in 8 months due to failing valves when removing the pump (I tried three different ones now, all suited for Presta valves, they say). To say I'm pissed would be a mild description. More fun, these damn hypersensible things cannot just be replaced like Dunlop valves (taking the old valve out, putting the new one in, pumping up the tire and that'S it: one minute's job if you work slowly) - no, Presta is integrated into the tube: you always have to replace the complete inner tube, taking out the wheel and the wires and the chain for that. Merde. Before, on my old bikes, I always had Dunlop/Woods valves (on a side note: it is also called English valve while in Germany it is called German valve or Blitz-Ventil). Not a single of these ever failed me in the past 30 years. The tubes may got punctured, but the valves I never needed ro replace. they worked for a decade without ever causing troubles. why are these Presta valves even sold on regular touring bikes today? What makes them so special that they have taken over even on bikes where you do not use to run narrow-sized high-pressured racing wheels at 11 or 12 bar? with air pressure around 4.5-5.0 bar, is it recommended to go back to an inner tube using Presta valves, and kick these damn Presta valves into the bin? what speaks against it? I mean there must be a reason why these Presta things now dominate the market. Is it just marketing? Three beakdowns in 8 months does not speak for the robustness and quality of these Presta valves. And I cannot remove the pumps from the valve any other way then putting them off, right? Or is there a trick or a hidden magical spell I need to use? __________________ If you feel nuts, consult an expert. Last edited by Skybird; 10-24-09 at 08:03 AM.

10-24-09, 08:05 AM	#2
Steel_Tomb Ace of the Deep Join Date: Mar 2007 Location: Cambridgeshire - UK Posts: 1,128 Downloads: 0 Uploads: 0	... I could ask my dad, I ride a gsxr-600 but not clued up on technical things. I'll get back to you. My dad knows way much more than me lol. __________________ _______________________________________________ System Spec: Intel Core 2 Duo 2.4Ghz \| 4Gb Corsair XMS2 Dominator DDR2 PC-2 6400 RAM \| XFX GeForce 8800GTS 640mb PCI-E \| Creative X-fi sound card \| 250Gb HDD \| *Rest In Peace Dave, you will be missed.*

10-24-09, 08:13 AM	#3
Skybird Soaring Join Date: Sep 2001 Location: the mental asylum named Germany Posts: 42,602 Downloads: 10 Uploads: 0	Any input is welcomed. I googles a bit in the past minutes and found MANY complaints about the Presta Valves. And these were complaints not owing to the valves being called "French". It seems they are pretty much hated outside the racing bike community. I thought about getting tubes with Schrader valves, but it seems these are low pressure only, up to 4 bar at max. __________________ If you feel nuts, consult an expert.

10-24-09, 11:09 AM	#4
CaptainHaplo Silent Hunter Join Date: Apr 2007 Posts: 4,404 Downloads: 29 Uploads: 0	I could be wrong - but I think Skybird is talking about what we call a bicycle. Not a motorcycle. Sky, here a "bike" is first thought of as the motorized kind. Most motorcycle tires don't have tubes. I ride a bike (or used to, don't have one anymore) but again, it was motorized so I can't really provide any input. __________________ Good Hunting! Captain Haplo

10-24-09, 12:21 PM	#5
Skybird Soaring Join Date: Sep 2001 Location: the mental asylum named Germany Posts: 42,602 Downloads: 10 Uploads: 0	Yes, a bicycle I mean, like "bike" in "mountainbike" . Tricky language. Mine is a "touring-bicycle-bike". __________________ If you feel nuts, consult an expert.

10-24-09, 12:50 PM	#6
Shearwater Captain Join Date: May 2009 Location: SUBSIM Radio Room (kinda obvious, isn't it) Posts: 542 Downloads: 45 Uploads: 0	I actually like them, though on my new bike (-cycle) I have Dunlop valves. On my old one I've never had any breakdown, and my impression is that they're a bit tighter because you have to screw them twice (valve + cap). Maybe that's the reason why they're so widespread since I don't think that you can reach pressures over 6 bar with a regular bycicle pump.

10-24-09, 01:50 PM	#7
TLAM Strike Navy Seal Join Date: Apr 2002 Location: Rochester, New York Posts: 8,633 Downloads: 29 Uploads: 6	I use a Shrader valve on my on inner tubes and have never had it fail, usaly the tube it self runs out of self sealing goop first or I get a really big hole poked in the tube. I use them at around 50 psi not sure what that is in bars. Have you considered the foam type tubes? They are a solid block of dense foam so you don't inflate them. They are expensive but I've heard they last a long time. __________________

10-24-09, 03:09 PM	#8
Skybird Soaring Join Date: Sep 2001 Location: the mental asylum named Germany Posts: 42,602 Downloads: 10 Uploads: 0	The thing with fail-safe ("pannen-sicher") bicycle tires is that you need to run them with higher pressure than many touring bikes usually operated with, the lower the pressure, the smaller the security benefit from that tire is. That's why I have them at 5 bars, which is not little for touring bikes. Dunlop valves are described to hold up to 6 bars. Presta valves originally were only used for racing bicycles, since the tires are narrower and are put under much higher pressure (10-13 bar). Dunlop valves cannot hold that. so in racing sports the Presta has it's meaning, but why they are being used for touring bikes as well is beyond me. The Schrader valve is described for pressure up to 4 bar (max), it is often used for car tyres, too. You find it on mountain bikes where the tires are wider and higher pressures are not so much wanted. I will give the bike to a shop on Monday and ask them, my thoughts are to go back to Dunlops valves. I am needing the thing for it is my only means of mobility, and I travel up to 120 km away from my home town by bike. Getting caught by a technical failure in some forsaken area and 50 km away from home may not be life-threatening, but it is NO FUN nevertheless and means only trouble and discomfort. Until Tuesday evening, Skybird is grounded. __________________ If you feel nuts, consult an expert.

10-24-09, 05:48 PM	#9
Sailor Steve Eternal Patrol Join Date: Nov 2002 Location: High in the mountains of Utah Posts: 50,369 Downloads: 745 Uploads: 249	I have a bike. I pedal, it goes. And you say you're not technical! __________________ “Never do anything you can't take back.” —Rocky Russo

10-24-09, 06:11 PM	#10
Skybird Soaring Join Date: Sep 2001 Location: the mental asylum named Germany Posts: 42,602 Downloads: 10 Uploads: 0	Ask me to maintain and readjust a hub gear, then get popcorn, cold drinks, a chair and enjoy the afternoon-long show. __________________ If you feel nuts, consult an expert.