Bike Forums

Bike Forums (https://www.bikeforums.net/forum.php)
-   Touring (https://www.bikeforums.net/forumdisplay.php?f=47)
-   -   Dropping the tire pressure and avoiding pinch flats (https://www.bikeforums.net/showthread.php?t=971107)

Walter S 09-11-14 06:34 AM

Dropping the tire pressure and avoiding pinch flats
 
Heading for the mountains Saturday morning. I'll be doing a lot of riding on dirt/gravel roads. My tires are Continental Travel Contacts. I usually keep about 40 pounds in them. Some of the roads I'll ride on are real bumpy at that pressure though. It's especially bad in places where there's these ripples in the dirt separated by a few inches and the bike goes blam blam blam across that and is just brutal on my spine. It helps a lot to get out of the seat but that also wears me down if it goes on for hours.

I'd like to soften the ride but not overdo it and have pinch flats. Any thoughts on that?

vik 09-11-14 07:01 AM


Originally Posted by Walter S (Post 17120366)
Heading for the mountains Saturday morning. I'll be doing a lot of riding on dirt/gravel roads. My tires are Continental Travel Contacts. I usually keep about 40 pounds in them. Some of the roads I'll ride on are real bumpy at that pressure though. It's especially bad in places where there's these ripples in the dirt separated by a few inches and the bike goes blam blam blam across that and is just brutal on my spine. It helps a lot to get out of the seat but that also wears me down if it goes on for hours.

I'd like to soften the ride but not overdo it and have pinch flats. Any thoughts on that?

You can set your wheels up tubeless so there is no tube to pinch flat and run lower pressures. You'll also find the existing tires feel more supple without a tube inside.

I setup my touring bike tubeless this year. Faced with tires and rims that weren't designed specifically to be run that way I used the split-tube method which was easy to setup and has been totally reliable.

Walter S 09-11-14 07:13 AM


Originally Posted by vik (Post 17120428)
You can set your wheels up tubeless so there is no tube to pinch flat and run lower pressures. You'll also find the existing tires feel more supple without a tube inside.

I setup my touring bike tubeless this year. Faced with tires and rims that weren't designed specifically to be run that way I used the split-tube method which was easy to setup and has been totally reliable.

Thanks. I might try that sometime. But no time to experiment with something like that before my departure on this​ trip:(

mtnbud 09-11-14 07:57 AM

40 psi is already pretty low. What is the recommended pressure listed on the sidewall? Tire size?

I would be cautious of going below 35.

I'm interested too, as I would like to start utilizing dirt and gravel roads for touring myself.

Washboard is one of those frustrating things you'll have to put up with when using gravel roads. The less used roads will have less of it. Look closely to see which side of the road has less - use both sides of the road to minimize the frustration when no cars are around.

cyccommute 09-11-14 08:14 AM


Originally Posted by Walter S (Post 17120366)
Heading for the mountains Saturday morning. I'll be doing a lot of riding on dirt/gravel roads. My tires are Continental Travel Contacts. I usually keep about 40 pounds in them. Some of the roads I'll ride on are real bumpy at that pressure though. It's especially bad in places where there's these ripples in the dirt separated by a few inches and the bike goes blam blam blam across that and is just brutal on my spine. It helps a lot to get out of the seat but that also wears me down if it goes on for hours.

I'd like to soften the ride but not overdo it and have pinch flats. Any thoughts on that?

You could go to a wider tire, although how wide you can go is dependent on your frame. You don't say what width tire you are using so it's hard to give you much advice. There are lots of 700C tires out there for mountain bikes now that are up to nearly 60mm wide. You could easily run that width of tire at 40 psi without worrying about pinch flats. I do it all the time on mountain bikes.

40 psi on a tire that is less than 40mm is asking a lot of the tire and risking damage to the rim. That goes doubly if you are carrying a load and even triply if you are carrying a load on a rough surface. Any less than 40 psi is just asking for a blipped rim with a touring load.

My suggestion is to either find wider tires, plan a different route or choose a different bike. I know there is this whole thing about riding rigid bikes everywhere which you can certainly do. But if it hurts, why keep doing it the same way? There are better choices out there.

Jim Kukula 09-11-14 09:32 AM

Here is my nifty table for bike tire pressure: Interdependent Science: Bicycle Tire Pressure

It depends on how much weight you're carrying, along with the width of the tire.

It's fun to think about how a wheel reacts to different sorts of obstacles. If you are cruising fast on the flat and then encounter something like a rock, I doubt the bike has much time to get lifted above it by the tire pressure etc. That is a very tough situation and I think it is mostly just having a tire fatter than the rock that saves you. Of course if you see it first and can lift up on the handlebars and unweight the bike, well, you can just hop over most anything. It's when you hit something fully weighted that a pinch flat is easy to get.

Walter S 09-11-14 09:48 AM

Right now width in the front is different than width in the rear. I didn't set it up that way intentionally, just using what I have on hand. The front is 1.5" and I normally give it 50 pounds. The rear is 1.75" and I normally give it 40 pounds. The rear is a Travel Contact, the front is a City Contact (not as good for dirt, but "OK" unless it's very muddy).

fietsbob 09-11-14 10:14 AM

Tire torque creep, around the rim, carries the tube with it, then the stem shears out of the tube..

high enough pressure will prevent that .. though I got Recommendations, suggesting sew-up Glue on one tire bead
would also stop the tire from creeping , that use was in Ice studded tires .. increases contact patch.

Rolling resistance noticeably goes up on soft tires , I've found .. YMMV..

ThermionicScott 09-11-14 10:22 AM

I like this calculator: Bicycle tire pressure calculator

It gives a good starting point, if nothing else -- if you have trouble with pinch flats, go ahead and add a little.

Since you generally have more weight in the rear of the bike, I'd recommend [strike]swapping the front and rear tires[/strike] to put the bigger one back there -- that may help with comfort. :thumb:

Leebo 09-11-14 11:52 AM

So, your weight, bike weight, inside rim width? 26" tires? Can you fit 2.1" tires? Got a mountain bike?

Walter S 09-11-14 12:36 PM


Originally Posted by ThermionicScott (Post 17121065)
I'd recommend swapping the front and rear tires to put the bigger one back there -- that may help with comfort. :thumb:

Rear is 1.75, front 1.5. 26 inch. Lhdt is my only bike.

ThermionicScott 09-11-14 12:43 PM


Originally Posted by Walter S (Post 17121480)
Rear is 1.75, front 1.5. 26 inch. Lhdt is my only bike.

Whoops, somehow I misread your post to think that you had the narrower tire in the rear. Anyways, I stand by the rest of that post. :)

cyccommute 09-11-14 03:54 PM


Originally Posted by Leebo (Post 17121373)
So, your weight, bike weight, inside rim width? 26" tires? Can you fit 2.1" tires? Got a mountain bike?


Originally Posted by Walter S (Post 17121480)
Rear is 1.75, front 1.5. 26 inch. Lhdt is my only bike.

Like Leebo asked: Can you fit a 2" tire in there? Continental (not my first choice but never mind) makes the Travel Contact in a 2" size. There are other options as well. A mountain bike knobby with small blocks would probably work without rubbing. Going from your 1.75"/1.5" tire to a 2" tire may not seem like much but it does make a difference both in pinch flat protection and in comfort.

Walter S 09-11-14 06:29 PM


Originally Posted by cyccommute (Post 17122040)
Like Leebo asked: Can you fit a 2" tire in there? Continental (not my first choice but never mind) makes the Travel Contact in a 2" size. There are other options as well. A mountain bike knobby with small blocks would probably work without rubbing. Going from your 1.75"/1.5" tire to a 2" tire may not seem like much but it does make a difference both in pinch flat protection and in comfort.

Yes, 2" tires will fit. I'm sure you're right. I can tell the difference going from 1.5 to 1.75. I'll try that in the future. No time to make the change for this trip though. Thanks for the help.

SparkyGA 09-13-14 07:47 AM

Can you install on front suspension fork at some point in the future? Geometry would be a bit funny using a LHT but it would work.

Personally just run bigger tires. I run 2 to 2.25" tires on my Troll for rough roads. Slow on pavement, but rolls pretty fast relatively speaking on the rough sections. You be amazed on some of the stuff you can go down with some bigger tires on a loaded touring bike.

fietsbob 09-13-14 09:32 AM

20 pounds of gear in front panniers dampen a lot .. Consider a fatter front tire rather than the 1.5"

LeeG 09-13-14 06:44 PM

1.5" simply isn't big enough for for washboard and a medium heavy load/person


All times are GMT -6. The time now is 04:56 PM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.