motorbike inner tubes lose air

[papa al]

Help!!!

My motorsai tires lose ~5 psi/week. Spoked wheels. 80/90 & 70/90x17.

Where/what are the best tubes available that might hold air? Pattaya.

Thanks

[paz]

Any new tube that is not slowly leaking like the ones you have.

Next time post in "bikes in thailand".

[Rooo]

Moved to bikes.

[papa al]

Paz: Thank you for your insightful response.

When I recently purchased new tires the shop put in new tubes that cost maybe 90 baht each...Camel I think.

They leaked.

I went to a different shop and they put in "better" tubes which cost maybe 130 baht each...Vee rubber I think.

They leak too.

[paz]

I've seen this before, a strong need to be blown periodically.

You can upgrade yourself out of that destiny with mag rims and tubeless tires. Throw in a bigger size while you're at it.

Edited December 23, 2013 by paz

[papa al]

I've seen this before, a strong need to be blown periodically.

You can upgrade yourself out of that destiny with mag rims and tubeless tires. Throw in a bigger size while you're at it.

Bike in question is an 8-year old Suzuki Raider which I love.

I'd like to upgrade to alloy rims/tubeless for sure, but the Raider mags mount a larger diameter brake disk than the spoked version.

If I switched, I think remounting the caliper pot on the fork might be problematic.

If I knew a good mechanic who spoke English I might attempt mod.

On other bikes I have installed bigger tires, but have seen limited benefit.

Mounting wider tires generally exceeds industry standards of rim/tire match.

Although they look cool, larger tires also reduce braking and acceleration performance.

I think in future I'll stick with sizes recommended by manufacturers' engineers/designers.

I do admit to a strong need to be blown periodically, but that is off topic.

Edited December 23, 2013 by papa al

[paz]

You should be able to find a relocating caliper bracket if not an entire caliper for cheap.

Thai small bikes come always with undersized tires. As the chart you posted shows, you have a choice of multiple sizes for a given channel. Get the largest one that meets the specification. Also it is true that a larger tire affects braking: always positively.

[namdocmai]

I also think that larger tires will break better, there is more rubber on the tarmac so more resistance between rubber and tarmac.

I changed for alloy rims because i had punctures all the time. Also the Thai pump the tires to hard but that seems to help because the roads are very bad. It drives like wooden wheels though. My punctures were always at the side of the inner-tube because of friction between inner- and outer tire.

I ordered Dunlop tires but they never arrived at my dealer and after being there for about 5 times to get my ordered tires i decided to buy the local brand again. Now i pump them to hard as well and didn't have punctures yet but have to pump them about every 2 weeks. I noticed that Vee-rubber tires crack at the sides after 1-2 years, my dealer said it was no problem but i don't want to risk my life on crappy tires. The spoke wheels from Honda are oval-shaped (assembled in Thailand) and the spokes are not covered well by a rubber band.

In Europe i never had punctures as far as i can remember.

[Nickymaster]

I have the same problem with my Yamaha Spark. Have to inflate the tyres every week or so. Already changed inner and outer tubes and still same issue.

[moe666]

Tubeless magwheels lose air as well, all tires will lose air. When you have something under pressure its just natural for it to seek lower pressure.

[papa al]

The standard equation for determining the resistive force of friction when trying to slide two solid objects together states that the force of friction equals the coefficient friction times the normal force pushing the two objects together. This equation is written as

F

r

= μN

where:

• F_r is the resistive force of friction
• μ is the coefficient of friction for the two surfaces (Greek letter "mu")
• N is the normal or perpendicular force pushing the two objects together
• μN is μ times N

Paz, Nomdocmai:

Odd as it may can seem, contact area is not part of the friction equation.

In theory a smaller contact area will provide the same friction as a larger one.

The softness of the rubber affects μ the coefficient of friction for the two surfaces (Greek letter "mu"), which we can affect with our choice if tire.

Also, according to physics, F=ma applies to angular momentum. It takes more force to accelerate (or de-accelerate, as in braking) more massive tire.

Most small bikes (Raider, Wave, Nouvo) with 16 or 17 inch wheels come with 1.6" wide rear wheel, and 1.4" front rim.

Manufacturers fit these rims with 80/90 and 70/90 tires.

As you can see from the chart, these are the widest recommended for the respective wheels.

If wider tires are installed without increasing rim width, industry standards are exceeded.

In reality, I know someone who runs 100mm wide tire on the 1.6" rim on his Yamaha Spark up to 140kph with no problem, yet.

Any recommendations on an English speaking shop/mechanic who could help with the caliper relocating bracket?

Shops I have approached respond with 'no have,' or a confused look.

Or, failing that, can anyone point me toward some good tubes?

[papa al]

Tubeless magwheels lose air as well, all tires will lose air. When you have something under pressure its just natural for it to seek lower pressure.

Of course. Entropy. But it is a matter of degree.

My bikes with tubes drop ~5 psi in a week.

My bikes with alloy/tubeless configuration drop about 1-2 psi/month.

[JusMe]

My tubes need pumping up every week or so. I've got a pressure gauge and try to maintain the manufacturer's recommended pressure, rather than letting Somchai make 'em brick hard. I've used that gauge in their shop and shown them what it should be, but who knows if they'll follow their own brand recommendation?

Solution: just keep pumping 'em up. I've got a small hand pump which is all that's needed every week or so to keep the tires at a comfortable pressure.

[papa al]

Jusme:

Yes, I like to keep my tires at recommended pressure as well.

I keep a pressure gauge in each of my bikes, and have a manual pump.

I guess like a lot of old people (not TV posters of course) I just complain too much.

Someone please shoot me.

[ll2]

for my wave, i keep the air pressure maximum the tire can handle so pump the tires once a month.

As it does not matter too much really for my 1 - 2 km trips to the beginning of soi or 7/11.

[paz]

I can only say, that in theory, theory and practice are the same thing, but in practice, they are not.

So I don't let formulas play too much role in my braking and leaning after decades of driving experience. It is funny however too see how often those that are so good at theory then have trouble with the spanning wrench.

Anyway 80/90 is too small and in fact honda upgraded from that to the next size on the click 125.

Sent from my GT-I9070 using Tapatalk

[dogpoo]

I can only say, that in theory, theory and practice are the same thing, but in practice, they are not.

So I don't let formulas play too much role in my braking and leaning after decades of driving experience. It is funny however too see how often those that are so good at theory then have trouble with the spanning wrench.

Anyway 80/90 is too small and in fact honda upgraded from that to the next size on the click 125.

Sent from my GT-I9070 using Tapatalk

80/90 is too small, I had that size on the Suzuki Skydrive and had many flat tyres, changed to the 90/90 and had no more!

[papa al]

Paz & Poo:

The Click & Skydrive both use 14" wheels.

Also both these bikes use CVT with the engine, transmission, exhaust system all mounted on the swing arm resulting a lot of unsprung mass and must rely on the tires to absorb a lot of shock.

Thus both greatly benefit from larger tires to protect the inner tubes and wheels from damage when striking road hazards.

I think they use left sided single strut too...a sketchy design in my book.

The Wave, Spark, & Raider hang the engine, trans & exhaust on the frame and suspend with 'proper' bilateral struts or forward centerline mono-strut (like many sports-bikes) designs, and use 17" diameter wheels. These configurations obviate a lot of stress on the rear wheel/tire.

The engineers at Honda, Yamaha, and Suzuki still specify 80/90 on these models.

Ad hominum & anecdotes not-with-standing, physics is physics, and the engineers at Honda et al are the best in the world.

Edited December 23, 2013 by papa al

[Beardog]

All the scooter tires always lose air in the tires. I had 7 new bikes the first 7 years & everyone would leak air out . Get some tire slime if you can find it up here. It ends the air leaving out pretty much. Well worth it.Just put it in the filler tube & ride. end of problem barring you don't get a blade in your tire. Even on my mountain bikes in the U.S. I would only lose 3-4 psi every month with slime. And 20psi without. And it stops a puncture if you do get one.

[BSJ]

Tubeless magwheels lose air as well, all tires will lose air. When you have something under pressure its just natural for it to seek lower pressure.

Of course. Entropy. But it is a matter of degree.

My bikes with tubes drop ~5 psi in a week.

My bikes with alloy/tubeless configuration drop about 1-2 psi/month.

That's about the strength of it! Changed our Fino wheels to alloy but kept the tubes. Lose about 5-6psi/month.

[papa al]

Bear: I'm hearing you man.

When I lived in Albuquerque, the goats-heads were brutal on the mountain bike tires.

I used thorn resistant (thicker) tubes, thorn resistant liners, & Slime.

Haven't seen Slime here.

A buddy is coming over in January and maybe I'll see if he can bring some.

Thanks for the excellent suggestion.

Why didn't I think of that?

I swear, I'm getting dumber every day!

[papa al]

I dunno BSJ.

Doesn't retaining the tubes defeat the advantage on slow leakage with tubeless/alloy?

Seems like there would be no seal where the tube stem penetrates the rim, and thus leakage.

You got me scratching my head on that one for sure.

[CBR250]

I share the OP question - what are better tubes, and where can I get them? I don't want to change wheels or get non-standard sizes on my Wave. I just want to avoid pumping up the tyres so often.

The guy I bought the bike from had used Japanese inner tubes that didn't leak air so much. But over a few years I had punctures and eventually had to replace the rear tyre, and did so with IRC tube, as I couldn't find Japanese brands. I now pump the IRC tube much more than the Japanese tube, so believe the problem is the rubber used in the tube.

I have put GlobX (a Slime-type substance) in the tube. Makes no difference.

[papa al]

Checking Slime website, they warn agains use with chromed rims, which I have...darn.

Also contraindicated for speeds > 100kph for some reason.

Also, I suspect that slime might not cover all the tube, rather only outer area where it would be deposited by "centrifugal" forces.

I think air would still leak through on inner area.

Thanks for warning CBR 250. I'd hate to add the extra weight of gel for naught.

Tubes thru Ebay would run ~$50 each with shipping...ouch.

[Issanman]

In the US many tire shops are now filling the tires with nitrogen because the larger nitrogen molecules don't seep out nearly as fast. Probably unheard of in Thailand so far.

[pastafarian]

Actually nitrogen has been available in Thailand for a while now and is available at many tyre dealers such as Cockpit.

Sent from my GT-I9300 using Thaivisa Connect Thailand mobile app

[BirdsandBooze]

If you can find a shop that sells heavy duty Dunlop tubes you'll experience much less pressure loss. Worth the extra cost IMO.

[papa al]

If you can find a shop that sells heavy duty Dunlop tubes you'll experience much less pressure loss. Worth the extra cost IMO.

B&B: Still looking for a shop to accommodate....

If ordering from the States, looks like it would cost ~6000 baht per pair including shipping.

Ouch.

[BirdsandBooze]

If you can find a shop that sells heavy duty Dunlop tubes you'll experience much less pressure loss. Worth the extra cost IMO.

B&B: Still looking for a shop to accommodate....

If ordering from the States, looks like it would cost ~6000 baht per pair including shipping.

Ouch.

I used to get them from a now defunct small tyre and rim shop in Saphan Kwai. If you pop into any similar shops while passing you'll eventually come across one that stocks the tubes. As for Slime, I had a Scoopy with chrome rims and ran Slime in the tubes without any detrimental effect. You can buy it from Panda Rider in Bangkok.

[namdocmai]

Yes i also like the Saphan kwai shops under the skytrain station. They also sell helmets in xxxl-size. He can order the Dunlops he told me, i ordered them at my own dealer but they never arrived.

I 'm thinking of a whole new bike though, still have to decide which one but definitely with big fat tyres that can carry at least 200 kg. I don't believe in Thai tricks/quality anymore.

The problem with ordering tyres here is that i want to choose the profile of the tire, some don't have side-grooves which i want to drive in the rain.