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Old 03-16-2016, 08:00 PM
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sbest sbest is offline
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Default Re: Broke another gas tank!

Also anyone know where to get cheap rear rims with the 7 gears already on them?
My rear wheel bearing just failed.
Bike shope replaced the bearing, used HD grease, tightened and trued spokes.
$24cdn, about $19us

Coming from motorcycles, ATVs and 4x4 trucks, I LOVE BICYCLES.

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Old 03-16-2016, 09:15 PM
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Default Re: Broke another gas tank!

I use four fuel tank straps, and eight nuts instead of just the two provided straps and four nuts in the kits.

Run the (four) nuts on your studs first, then two of the straps. Then mount your tank, use the two other two straps on the bottom of the top bar. Now you have straps on the top of the top bar and bottom.

Now tightening the bottom strap nuts and the top strap nuts you will sandwich the straps tight around your top bar.

Now you are still adding stress to the studs but you are not pulling on the studs causing so many leaks at the weak point at the tank.

Last edited by Dave31; 03-16-2016 at 09:35 PM.
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Old 03-17-2016, 02:56 AM
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Cylon Cylon is offline
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Default Re: Broke another gas tank!

Originally Posted by 2door View Post
You're overtightening the tank mounting studs. You are relying on them to keep the tank stationary and that usually results in tank failure. JB Weld, (glue) won't keep the same thing from happening again. And probably won't keep it from leaking again.

Take some of the advice offered and find something that will keep the tank in place and only use the kit straps/studs and nuts to act as back-up. Unless the tank is held with an alternative method, trying to keep it in place by tightening the nuts on the studs will result in stud/tank failure from vibration and shock.

Unlike the engine which should be mounted solidly to the frame, the tank needs to be isolated from the frame with something that absorbs the vibrations. There are many methods. Silicone, rubber, Velcro, thick double sided tape, etc. Whatever, don't rely on the studs to do all the work.

I think the biggest problem is the fact that Im using the stock bracket for the tank and it only bolts up to about 1/4th of the stud, so its putting more stress on the tank because of the leverage, I got double sided tape from work and I'm going to use some new strapping for the mounts to get it bolted down further.
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Old 03-17-2016, 11:45 AM
crassius crassius is offline
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Default Re: Broke another gas tank!

as one tightens the tank, the straps bend toward the center - I always watch the holes in the straps so that I can see the point at which the outside of the hole first touches the threads of the stud - stop there, as any further tightening will bend the stud

if that isn't tight enough to hold the tank, then apply double-sided tape under tank
Sometimes I sets and thinks, sometimes I jes sets.
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Old 03-17-2016, 01:27 PM
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Default Re: Broke another gas tank!

Using our 'Search' will give you lots to read on the subject of ways to mount a tank. There has been a lot of discussion about this over the years.

Look here>

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Old 03-19-2016, 10:26 AM
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Default Re: Broke another gas tank!

I would listen to 2door first. I have seen quite a few clever and low-stress ways to mount the kit tanks over the years.

That said, and keep in mind that I have no idea how mechanically inclined you might be, there is also the solution of building your own tank. Problems with kit tanks and the way they fit different frame types (or DIDN'T fit, to be more accurate) was what prompted me to make my own. Mine was made from 14 gauge sheet aluminum, using a hand-made wood buck to help shape the sides. I brazed it together. The only opening on the bottom is the fuel line fitting. My tank hangs on the frame from bolts which come through the top from inside (with fender washers for decent support) and are thoroughly brazed up top. And the tank is lined. Even if I get a deep crack and it actually manages to go through the lining, which would be a good trick, it would still be at the top of the tank. Nothing's gonna leak out. And I used Nitril rubber under the straps anyway.
Other forum members have made tanks from steel and fiberglass. I think I may have heard of a brass tank also. And more often than not, the home-made tanks are of far better quality and construction than the kit tanks. The builder has the power to make a tank as solid as he/she thinks it should be, so they often go for rock-solid.

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Last edited by Allen_Wrench; 03-19-2016 at 10:28 AM.
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