Fastback tail & tank mounting

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Jul 18, 2004
I am turning my pile of parts into a bike... here is my latest batch of questions.

1) How exactly is the fender and tail piece supposed to attach to the frame loop?
Are they held in place by a bolt from the inside of the fender into the threaded hole in the tail (#1 below)? ....or does the tail piece just sit on the rail with the fender held on by a bracket?

There is a bracket listed in the parts book and I have one, but it seems that the bracket/fender/tailpiece all meet at one spot making a messy lump.

2) Why are there two threaded holes on the underside of the tail? (#1 &2) below.:shock:
Fastback tail & tank mounting

3) How exactly does the tank attach to the forward mounts. I have the rubber spacers.. but why such a big hole in the mounts?
Fastback tail & tank mounting

Is there a smaller rubber spacer that fits in the hole to center the bolt?

I could make something up that works but I thought I should try to make it "stock":wink:

Any help appreciated!

You and I are at similar points in the reassembly process. Though I took hundreds of pics during teardown and carefully bagged and labeled parts, I'm finding it interesting going as well.

In addition to the service manual, the factory parts book - with the exploded diagrams and part numbers - has been invaluable.

As for the tank mounting, I decided to alter the stock setup. I know you're going for stock, but its an easy enough swap for later - and no one will see it but you...

I'm using large rubber stoppers bought from the local hardware store (like the type used in lab glassware). It you freeze them overnight, they can be drilled to accept the tank studs. Stainless fender washers, stainless nylock nuts, a little silver anti-seize - and there you have it.

Mine are inserted from the below the bracket, smaller end facing up. Tightening the nuts pushes the stopper further into the mounting bracket. Seems to work as well, if not better than, the original arrangement.

Thanks for the tip.

My bike was a bit of a rolling basket when I got it, so the nitty gritty details are missing.

I am not hell bent on stock but would like to know if the original ideas are better than my own. Having had several bikes, I often shake my head when I see how things were done back then.

I recommend that you use the rubber washers shown in the parts book to mount your gas tank. These washers are "stacked" on the gas tank studs and will rest against the bracket on the frame. You can adjust the quantity of washers to achieve the desired tank height - make sure the tank is high enough to clear the backbone of the frame.

The big holes in the mounting bracket allow you to find the optimum lateral position of the tank. For instance, I've pushed my tank as far forward as the holes will allow, providing sufficient seat clearance at the rear of the tank. Once you find the optimum position, anchor the tank with large fender washers, matching thin rubber washers and Nyloc nuts. It all actually works quite well.


The tailpiece mounts on the rear frame loop with between the two holes numbered 1 and 2. It should have two threaded studs going into each hole and a loop bracket (I assume thats the one you have) and then nuts holding it in place tight against the frame-the loop has one direction its supposed to face in order to fit. With it mounted at this point the two front holes should line up perfectly with your top shock bolts.

The front of the tank is mounted by "pinching" the mount between the rubber washers. When compressed they squeeze into the holes slightly holding it steady but still allowing for cusion from vibration. The big hole also allows for some adj. to the final position of the tank to get it where you want-ie push it back or forward to allow for fit against seat/clearing headlight mounts.
Wow, guess I was typing as jason was replying...anyway, like he said! :lol:

I should add that the stud in position 1 should also go through your fender to hold it to the frame loop-but that should be pretty obvious once you cram it all together.

Thanks guys for the info... that clears it up!
The great weather we are having here (Toronto) has put me into panic mode.

Seems like you have lots of info on the tank mounts...but everyone seems to have forgotten the simplest solution. The rubber mounting blocks with the threaded bolts sticking out on both ends, that hold the mufflers to the little mounting plates, back by the rear axle, will screw right into the holes in the tank , front and back, and replace all those stacked rubber washers just fine. My interstate tank has been mounted that way for years, just add the big washers/nyloc nuts in front, and put the tank holding strap/small washers and nuts, over the bolts in back....and it's done.
This is true. Granger industial supply sells a slightly larger diamiter isolastic rubber that works even better than the exhast pieces. Real handy when doing the full forward tank mount that most Fastbcks require. These are a good thing for any of the models because if you have to lay the bike down the rubber can break away saving the tank from major damage. The larger rubber woun't fall thru the back of the large frame hole when using the far forward mount up. norbsa
Dyno Dave,

Thanks for the “adequate” check. But I thought the stock tank mounting setup was more than adequate?

Dave C,

Great to have you back stateside. We were sorely missing your wisdom and sage advice.

How was your trip?

Feel like turning out a few Roadster tanks? Not for the general public just for forum members? :D

Fuel-resistant resin, color in the gelcoat - sounds pretty good to me. Any standard Norton color would be fine - black, yellow, red, orange. I have black sidepanels, any of those colors would look great. I'd probably buy a couple of different colors :D :D

Dear Dynodave......
I would hope not to have to take your comment about lack of knowledge (Post subject: subject matter knowledge or lack of), as the official entry in the Norton Bible under....."He who knows and is so proud of it".....but some of us just don't own a Fiberglass tank. Advice about a steel INTERSTATE tank seems perfectly fitting for a steel Interstate tank. Forgive me that I didn't stop to think that the fellow had a Fastback. If you know all the ins and outs of the wonderful world of fiberglass tanks...may the force indeed be with you. But if the rest of us are expected to know every little detail about every little thing, on every body elses little bike...that's cool too...but I don't, and you won't catch me trying to act like I do. I know my bike better than I wish to, and certainly better than I would expect you to....but I wouldn't spend my time distracting from any bit of halfway intellegent input you might care to make in this forum, and I would expect the same from your side. Might be true that the bolts are molded into a fibreglass tank...I have to assume you know what you are talking about..but I can't remember. I put mine in a dipsty dumpster over twenty years ago.
Well I have two Fastback tanks but they are not stock, one from Norvil and one from Evan Wilcox they both have female threads. I made the mistake of assumption that the studs were removeable. And now stand corrected. norbsa
Between you and me.....I wouldn't now touch a fiberglass tank with a ten foot the risk of "lack of knowledge", I still think the steel ones are more than "adequate"......and at least no one will get into a tizzy about them...or?
So, what's wrong with the stock tank mounting system? I've had good results using the stock rubber washers and hardware to mount both fiberglass and steel tanks. Sometimes I think we invent problems just for the sake of having something to fix.

Don't think anyone has said there is something wrong with the original system..or the fact that you prefer it, but rather only pointed out there is indeed an alternative which functions but as was so kindly pointed out, evidently only with a steel tank. Actually it doesn't matter how the tank gets attached, but it apparently does matter whether perfectly valid information gets labeled as a "lack of knowledge", at least to the person who bothered to waste his time and experience offering it. I bet the person who made this comment would feel a bit different, if the shoe was on the other foot.
Enough said.....send us some pictures when you have mounted all this stuff on your bike......
Opinions, Opinions, everybody's got one-even the nameless.

Personally I wouldn't hesitate to use a fiberglass fact I do :lol: I do think it's a good idea to properly coat/seal the inside so it can better stand up to modern fuels. What's more I'm a big believer in coating the steel ones as well, albeit for different reasons. Have to admit I really like the idea of a tank made out of a more fuel resistant gelcoat, but I'm too much of a purist to every replace my original.

Phil-I just took a tour of your site-nicely done. Hope you tracked down a fastback fender somewhere or you'll have a tough time mounting your lic. bracket. (assuming you're intending to license it)

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