High Speed Rear Blowouts

Charged-Reacter · #1 (**permalink**) 10-25-2009, 07:56 AM

I am using a GEBE Tanaka 40cc belt drive with a expansion chamber exhaust
and a high performance carburetor and I am having trouble with rear blow outs.
I was going 35mph for about 9 miles with throotle left to spare. The tires , tire liners,
and slime tubes and wheel set are of decent quality. The trouble is at the valve stem,
either the tire and tube is slipping causing this. Does anyone else have this problem
while going at higer speeds? How can a person fix this issue? I am using about 60psi
in both tires. The front tire seems to be doing ok at these speeds. Will I have to go to
clincher style rims?

bandito · #2 (**permalink**) 10-25-2009, 08:29 AM

Whats the max tire pressure for your type of tires? It seems the tire is slipping with the tube and tearing your valve up. Whats your rim size and the size of your tube and tire? These answers will help folks to address your problem. How wide is your rim? If the tire slips it will take the tube with it.

HoughMade · #3 (**permalink**) 10-25-2009, 08:53 AM

How close to the maximum recommended pressure are you running (60 psi, i know, but what do the tires say). I think it would be advisable to run closer to the max than the min.

Charged-Reacter · #4 (**permalink**) 10-25-2009, 08:55 AM

The tire size is 26x2.0 with maxium 65 psi.
The tube size is 26x1.75-2.125.
The wheel measures outside at 1 inch.

akeyma · #5 (**permalink**) 10-25-2009, 09:09 AM

How about drilling out the stem hole in the rim to acomadate a rubber grommet and then install the stem through the grommet?

upsrogue · #6 (**permalink**) 10-25-2009, 09:10 AM

My fix and so I don't even worry or think about a blow out is at Walmart they have a solid rubber tube for less than $20.00 each, they are hard to put on (and to take off) but that means to me they will stay on under extreme conditions. I don't go over 20 mph because I like to cruise and enjoy the ride and also be able to look around and see who is about to hit me in a car and the solid tube takes away one more worry.

Charged-Reacter · #7 (**permalink**) 10-25-2009, 09:47 AM

I am real happy about how this mb performs riding wise. I can
narrow in on a small strip of payment without reducing speed and
not drift out. The bicycle is a Firmstrong CA 520- 7 SPEED. The
valve stem did seem tight when installing with the rim tape. I will try
akeyma suggestion. Thak you for the replies.

Retmachinist · #8 (**permalink**) 10-25-2009, 09:52 AM

Find out what the speed rateing is on your tires. Most all these cheap bike tires are NOT high speed tires. I have been buying only high dollar tires, such as Maxxis, Michelin, & Continentals since talking to a friend of mine that has been into bicycling all his life.
I think the most important part on the bike for safety is the tires.

John

lilhog · #9 (**permalink**) 10-25-2009, 11:57 AM

duct tape......

bandito · #10 (**permalink**) 10-25-2009, 01:42 PM

You have the right size tire and tube on the rim. You might try increasing the pressure by say 10lbs. Does the valve stem fit real tight in the rim hole when you install the tube? Mine just drops in on my rim and fits very loosely in the hole. Is the rim hole jagged and may need to be filed smooth?........."Q: What is the deal with rim locks?
A: Rim locks are used on wheels to prevent your tire from slipping around the rim. This can occur if you are running your tires at very low pressures. Common when riding off road. If your tire turns on the rim it can pull the valve stem through the wheel or tear it off completely leaving you with a flat. They are fairly simple to install but it requires removal of the tires and tubes and this can be more work than the rim lock installation. The rear is the more critical wheel to lock as it is subjected to the forces of driving the bike forward. Install them opposite the valve stem to minimize the affect they will have on wheel balance.
Riding Tips FAQ for Tips on Riding in Sand or Off-Road."