FRACTURED STEEL ROADSTER TANK

Status
Not open for further replies.
79x100 said:
Unfortunately, I spent a lot of dosh on a white / blue / red paint job so it's going to have to stay on for a while yet (unless L.A.B. decides he wants a quality white two pack painted tank & panels and makes me an offer I can't refuse
Click to expand...

79x100,

Thanks for the kind offer, but I think I will continue to use my symmetrical non-rubbing seamless tank for now, as I much prefer the black & gold pinstripe colour scheme in any case!
 
I just checked the OD of the frame and it measures 2.253" so it must be an Imperial frame. Placing a straight edge on top of the backbone does reveal a slight hump at the point where the two side frame rails join the backbone. This hump, however, does not appear to be excessive, so I don't think the frame has been wrecked.

I suppose it's just "another mystery of the sea", as they say.
 
I know the Ross Thomson near London Ontario fixes Interstate tanks around the mounting studs all the time. Seems the stock set up doesn't hold up to the weight of all that gas well. He welds in a large washer making the thread insert and the washer one. Spreads the forces out over a larger area.
I would never use the stock set up, that long stud right into the tank is flirting with a gas disaster. They are just 3/8 fine thread, good old USA type and all the industrial supply's have Iso rubbers with a stud out each end to replace the old system. If you have ever seen what even a small low side does to the tank mounts you would be changing them fast to this system. True iso mounts like these never have a stud going right through. Instead two elevator bolts are cast into a rubber puck. You still run the old rubber washers on the bottom side of the frame. Wick-in lock and brass nuts work well here. Hey do what you want you will anyway.
 
79x100 asks "Does yours also come close to the small diameter cradle tubes at the rear due to a lack of properly formed cut-outs ?
Click to expand...
The rear cutouts seem to clear the tubes OK. My problem was the front offside but I glassed up the nearside as a precaution. Don't seem to have any issues at the rear which seem solid but to reduce the load on rear mounts I added 3/16" spacers under the cotton reels to part compensate for an extra rubber at the front.
I'm wondering if those experiencing problems are using the correct thickness (and density) foam pad at the rear of the tank?
Click to expand...
LAB suggested this. I have the correct thick pad on the rear which sits just inside the lip over the main tube as LAB outlined. I actually lost the front pad on the road many years ago because I did not glue it in.
As for the frame source it must be Italian and with the powder coat they come out at 60,4 and 25,4 average. It is quite rippled in the mid section which several members put down to accident damage but when the frame was being set up for the dimensional check (ISO/cradle alignment) it was not significantly out of square or with excessive rake. Looking at the bare metal it looks more like many years of wear from cable ties chattering way etc.
I would never use the stock set up, that long stud right into the tank is flirting with a gas disaster. They are just 3/8 fine thread, good old USA type and all the industrial supply's have Iso rubbers with a stud out each end to replace the old system
Click to expand...
Norbsa's comments are right on track with what I would do and replace with the cotton reels which can be adjusted for height with spacers etc. I guess I got away with my bodged repair as it's only a Roadster with 33lbs of fuel and tank on board. Interstates must be under a hell of a strain with 60+lbs. Like he says we will do what we want anyway!! but since my tank no longer matches the fairing (same paintjob as 79x100 but a budget homespray) I may do proper repairs this winter (if the 8 yr old fix lasts that long!) only problem I will have is how to remove the POR 15 I put in prior to welding. The Petseal rubbish came out with Nitromors paint stripper. Any guesses if that will work on POR? I have some left over so will see if the runs on the can will give in to Nitro'.
 
Hi Norbsa,

Couple of questions please:

What is an "elevator bolt"?

Are the tank mounting studs merely threaded into the tank? If so, are they easily removed with double-nuts?

Thanks,

Jason
 
Jason Curtiss said:
Are the tank mounting studs merely threaded into the tank? If so, are they easily removed with double-nuts?
Click to expand...

Jason,

My parts book shows the studs as being replaceable and even lists a part number for them, so it should be possible to remove them.

Good info about the rubber mounts! The old master lets slip another of his secrets! You've probably forgotten more than I'll ever know about these bikes, Greg :lol:

I'd better do that to my steel tanks as well. The Interstate tank needs some serious cleaning though, so it may be staying on the shelf for a while. I'll probably put the Roadster tank on the 850, but it sounds like it could use the muffler mount upgrade too.

Debby
 
An elevator bolt is a stud with a plate formed on it's end, that gets cast into the rubber puck on each end. See Granger catalog or Mc Master Carr for details under vibration dampeners.
 
Debby and Norbsa,

Thanks for the info. Perhaps the iso mounts on the rear of a steel tank could and should be used on the front of the tank in lieu of the studs? Do you know if the threads are the same in both places?
 
Status
Not open for further replies.
Back
Top