Long term Triumph Chopper project

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Prof
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Re: Long term Triumph Chopper project

Post by Prof » Tue Apr 30, 2019 12:43 am

Girder looks really nice. And the stance is ok. If you have to retain current frame dimensions, you could disguise the height a bit by dropping the exhausts just a couple of inches lower at the front.
Chopit'nrideit... Prof

El Skitzo
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Re: Long term Triumph Chopper project

Post by El Skitzo » Fri May 24, 2019 5:18 pm

HUGE NEWS!!!

I've heard back from the Transport Department of WA already and they've given me written "in principle" approval for ALL the modifications I want to make to this Chopper, being:
- change of wheel & tyre widths and diameter
- addition of the girder front end
- addition of the rigid hardtail rear end
- and most amazingly to chop, stretch and rake the frame!!

The list of things they want from the Engineer to prove the modifications are done safely and according to Australian Standards is long and onerous, but we'll get there.

This is the first step of many through this field of red tape, but a HUGE step. I'm so excited!!

Image
'65 Triumph Chopper (project)
'64 Triumph Chopper (project)

Prof
Founder, Choppers Australia
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Joined: Sat Oct 22, 2005 3:54 pm
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Re: Long term Triumph Chopper project

Post by Prof » Tue May 28, 2019 12:10 pm

Good news.
Chopit'nrideit... Prof

El Skitzo
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Re: Long term Triumph Chopper project

Post by El Skitzo » Fri Jul 12, 2019 9:56 am

Hey TriNortchopz, sent you a PM :wink:
'65 Triumph Chopper (project)
'64 Triumph Chopper (project)

El Skitzo
Posts: 780
Joined: Wed Sep 30, 2009 6:40 pm
Location: Perth, WA

Re: Long term Triumph Chopper project

Post by El Skitzo » Thu Oct 10, 2019 8:12 pm

Spring loaded chain tensioner is now in.

Really wished I had one of these on my first Triumph Chopper which had a 4' stretch hardtail, so an absolute must with this 6" stretch and 130 link chain this time.

Image

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'65 Triumph Chopper (project)
'64 Triumph Chopper (project)

El Skitzo
Posts: 780
Joined: Wed Sep 30, 2009 6:40 pm
Location: Perth, WA

Re: Long term Triumph Chopper project

Post by El Skitzo » Thu Nov 28, 2019 10:12 am

Big things are happening!

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'65 Triumph Chopper (project)
'64 Triumph Chopper (project)

Prof
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Re: Long term Triumph Chopper project

Post by Prof » Fri Nov 29, 2019 10:07 am

Wow! That's a high steering head. Have you considered shortening the bottom link for regio and then putting longer one back afterwards so you can have a bit more rake?

Just in case you haven't thought of it, the wheel will move forwards a bit when the bikes full weight comes onto the girder.

I would also suggest (I'm always full of suggestions! Sorry!) that you have a new steering head machined up and weld tubes directly into the back of it with the appropriate gusseting. Would be quicker than trying to align the existing tubing.

If you moved the steering head forwards 2-4" would also reduce the 'high in the head' affect. If you heat and bend the lower part of the down tube to be parallel with the top piece as set up in the pic and move the rest of the bike back until they line up would also work... and give a bit extra length.

If you did that, then cutting the seat post and pivoting the top part of the frame from the axle plate would give you an almost straight line to the steering head... It would raise your seat height though.

Just some ideas for you to consider.
Chopit'nrideit... Prof

El Skitzo
Posts: 780
Joined: Wed Sep 30, 2009 6:40 pm
Location: Perth, WA

Re: Long term Triumph Chopper project

Post by El Skitzo » Fri Nov 29, 2019 1:20 pm

A high stretched up frame with a long front end was always the plan for this bike, so I'm very happy with where the steering head will end up, and it complies with the law by meeting the 550 rule and we'll end up with a couple of inches of positive trail, so all should be good.

I have no option but to use the original neck as it has the original frame number in it and is the key to rego as a "modified bike", as opposed to becoming an ICV. The Transport Department and Engineer have given approvals for all this based on the fact that the original neck casting remains "undisturbed".

I'll be visiting the workshop to check on the bike this weekend, and to discuss the plans on how we're going to marry it all back up again.
'65 Triumph Chopper (project)
'64 Triumph Chopper (project)

Prof
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Re: Long term Triumph Chopper project

Post by Prof » Sat Nov 30, 2019 11:35 pm

Fair enough. Will watch with interest.
Chopit'nrideit... Prof

TriNortchopz
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Re: Long term Triumph Chopper project

Post by TriNortchopz » Tue Dec 03, 2019 1:44 pm

test, to see if I can post today...Yes!

I like where you are. I agree with Prof...move the bike back about 4" so the existing downtube is close to alignment with the section still attached to the neck.
Will you be able to cut the tubing off the neck and weld the neck onto a new piece of downtube slugged and welded to the lower section to keep the downtube in the desirable straight line?
The the same with the backbone; bend it up to meet the neck and remove the piece that's on the neck now so it is one straight clean piece from the seatpost.
What is the rake of the neck as it sits now?

I have a copy of the original P&P girder parts sheet, i hope you get it today:

Image

lLook in post #3:
http://www.chopcult.com/forum/showthread.php?t=54095

aarrgghh, don't know how to add a pic from my e-file, so here is a link to a thread on Chopcult where I added the image in the thread. The top shock mount is a straight, round size-on-size pin, that has a small setscrew underneath on the one side.

El Skitzo
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Re: Long term Triumph Chopper project

Post by El Skitzo » Thu Dec 05, 2019 10:28 am

The first picture a couple of days ago was just showing that we had started to cut, not how we planned it to go back together :lol:

Here you go, it might make more sense with this picture, with the rear half rolled back into place.

So we've got 33 degrees of rake now, and the down tube will have a slight kink in it to marry back up to the neck. The backbone, seat tube and cross brace will all be remade to suit.

Image
'65 Triumph Chopper (project)
'64 Triumph Chopper (project)

TriNortchopz
Posts: 72
Joined: Sat Feb 24, 2018 5:41 pm
Location: Haines Junction,Yukon, Canada
Interests: Choppers, nature, learning more about choppers

Re: Long term Triumph Chopper project

Post by TriNortchopz » Thu Dec 05, 2019 7:07 pm

Looking good. I am wondering if you can have the bend right at the tube 'sleeve; from the neck - where it changes diameter. Have your inner slug tube up into the larger OD section (same size id?) and into the bend at the join. Hope that make sense. Use same method whenconnecting the new backbone.

Not sure what your welder knows about joining frame tubes, but found this tidbit of info from the Practical Machinist site:
One comment in the thread;
"Rather than (solid) pins, I would sleeve it with tubing so there is not such a major cross section change at the repair, so that it does not break at the ends of the pins in the future. I would rosette weld the sleeves on both sides if easy to do so, with one pair of rosette welds at 90° to the other pair, again if easy to do so. Weld the tube in 4 passes, one in each quadrant, 12 o'clock to 3, then 6 to 9, then 6 to 3, then 12 to 9."

2007 Thread: Old Triumph Motorcycle Frame Repairs,
https://www.practicalmachinist.com/vb/f ... rs-132222/

And here on Chopper Compendium:
good videos,
2013, Slugging a frame;
"Nice videos, especially liked the tip about rounding the ends of the solid slugs.
I hadn't thought of it, but if a sharp edge is left on the end of a slug, it does become
a stress riser when the frame flexes. The sharp edge is in contact with the inner wall of the original frame tube."

"I have used heavy walled tube to make slugs and cut the inside down so that the tubing of the slug is the same... that way the same settings on the welder can be the same..... I 45 the joint, but I use slots on the frame tube for two reasons.... It make the frame tube "give a little" to get the slugs in and it gives you more weld area on the slug. I drill four holes and then mark the side of the hole to the end of open tube, cutting with a cut off blade. Drilling the hole doesn't leave a sharp end that might split from flexing. the same way you stop a split in flatbar or sheet metal. Haven't had a frame break in 45 years, but what do I know , I have no formal schoolin !"

"Good and accurate descriptions dude, I will sometimes use tubing machined to match the thickness of the original frame, and then bevel the inside edges so I can safely run wiring through at a later stage of the build"

http://choppercompendium.com/ccforum/vi ... .php?t=604


Thread: Cracked motorcycle frame...help!
"...a 1967 Triumph Motocycle frame."
https://weldingweb.com/showthread.php?1 ... frame-help!

El Skitzo
Posts: 780
Joined: Wed Sep 30, 2009 6:40 pm
Location: Perth, WA

Re: Long term Triumph Chopper project

Post by El Skitzo » Thu Dec 05, 2019 7:33 pm

Yes TriNortchopz we are going to try and get that bend in the downtube as close to the neck casting as possible, hopefully right at the join.

Obviously we can't slug it there with a bend nor risk TIG welding that close to the brazing inside the neck casting. So the plan is to bore the remainder of the downtube out of the neck completely, and make a new downtube section that has the slight bend in it, then slide it up into the neck and weld everything together.

And yes my Engineer and Fabricator are on the same page with joining frame tubing, exactly as you've described :wink:

BTW, thanks for the info on the top shock mount pin. We'd already machined up a new one exactly matching your description.
'65 Triumph Chopper (project)
'64 Triumph Chopper (project)

Prof
Founder, Choppers Australia
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Re: Long term Triumph Chopper project

Post by Prof » Fri Dec 06, 2019 9:51 am

All interesting information. I am often able to use hollow bar as a starting point for frame tube slugs to save a lot of boring. I always chamfer ends of slugs, but that has been to make them easier to tap in... relieving a further stress point makes good sense. People don't realise how much frames flex. I read some time back that attempts to make race bike frames with no flex resulted in constant failure due to cracking... and some flex is now built into them. May also be a reason a lot of aluminium frames fail... ally does not seem to take kindly to constant flex, especially the large angular sections.
Chopit'nrideit... Prof

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