Cafe Racer Forum banner

1 - 20 of 95 Posts

·
Registered
Joined
·
1,685 Posts
Discussion Starter #1
For as long as I can remember, at least since 1970 when I learned to ride and was already into motorcycle magazines handed down from my older brothers, I have dreamed of building a Triton.

For those who are unfamiliar with the Triton concept, it takes a classic 60s Norton "featherbed" frame and mates it with a Triumph big twin engine. From that basic concept, the variations are endless; pre-unit and unit engines, old forks, new forks, drum brakes, discs, every type of header system you could imagine (mostly the swept-back style, for some reason), etc., etc., etc.

The following detailed build is a cut-and-paste that started in May of 2010:

On my way back from an AHRMA vintage roadrace at Willow Springs (north of L.A. in California), I passed through Phoenix to visit a friend who had been caught in a weird situation that played to my benefit. Mark had purchased a featherbed frame from a guy that was SERIOUSLY delaying shipping it to him (one excuse after another); he finally got frustrated and bought another one several months later, giving up on the first one. OF COURSE, the week after the 2nd frame arrived, the 1st frame finally did, too! He had called me first, knowing I'd been talking about building one since we met many years earlier. So, now I had my frame!



Very nice paint, no dents, no chopped off tabs. It is a Slimline from a '66 650ss model with the welded-on top/rear mount.

On hand:
Featherbed chassis
Ceriani forks, Arces yokes, SLS brake
Commando rear wheel assembly, drum brake
Commando rear shocks
'69 T120R Bonneville lump
750 big bore kit w/ aluminum cylinders
5-speed T140V cluster conversion
Lytedrive belt drive primary system
Finned primary cover
Amal 930 carbs w/ velocity stacks
Bonnie tank w/ parcel grid (67 Euro paint scheme
Featherbed "bum stop" cafe seat with cutout
Upswept TR6C scrambler pipes with stock muffs
Early central-mount Norton oil tank
Simple clip-ons, levers & controls
Tympanium regulator/rectifier
Smiths speedo & tach with early 70s mounting setup


Needed:

Home-made rearsets
Home-made engine mounting plates
Sparx ignition, hand-made wiring harness (I have wire & connecors)
Retro lighting
Cables, chain, bits & bobs


I figure I'll toss it together loosely and park it between my garage door and shop door, so I can look at it a dozen times a day and get inspiration. I like Bones' latest mods, I figure I can aim in that direction...

Engine, loosely assembled from parts on hand (I've got 5 engines worth or mix-n-match 650 parts)



A scruffy front end (Betor or Ceriani, not sure)



That's the basics of the project; now let's see when I can squeeze in some TIME!

 

·
Registered
Joined
·
2,107 Posts
Been on my bucket list too, but I can't seem to get my ass in gear...... and I'm a couple of years older than you. I have the frame sitting in the shed and have been half heartedly looking for a pre-unit Triumph engine. Part of the problem is my Scottish ancestry won't allow me to pay the current rates. Another problem at the moment is I'm buried in a pile of old wooden boats... there is always something in the way.
One solution to my engine quest, is the fact that my brother has a set of Vincent twin cases that he will never use. They suffered a rather rude transmission explosion and the previous owner had them welded up by someone who had no clue. The gearbox section is screwed to the point where it just isn't worth the cost to have everything re-welded and re-machined. It's amazing how badly warped they are. Much to the chagrin of the VOC, they would make a reasonable candidate to have the gearbox hacked off and then stuff the remainder into the featherbed. I know that'll cost way more than a Triumph engine, but time is running out. Anyway... enough of my thread jacking. Looking forward to seeing more of your project and the inspiration that goes with it.
 

·
Registered
Joined
·
1,493 Posts
Good to see another Triton project on here, especially a slimline. Unity Equipe in the UK can supply you the engine plates and bolt set for not a load of money. I made a set of plates for the current engine in my Slimline frame, which although enjoyable to do, took ages and if there was something I could have bought, I would have jumped at it.

They sell anyhing and everything for Triton builds and have a decent online catalogue thats worth a read, if only for reference. Molnar also supply quality Triton parts too and they have a nice rear set kit for a Manx, but the right hand peg doesnt fold. Lovely rear brake lever with bronze bushing from them, but is mounted onto the swing arm spindle which is too high for me. It was fine 20 odd years ago, but not comfortable now as my knees ache.

Take a look at the rear sets and pics on the thread of mine. If you want dimensions and where they are positioned on the gussets, I`ll give you the spec. JalSteve would also be a good point of contact as he makes nice kit and is very knowledgeable for thiis type of bike, amongst others.
 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #4 (Edited)
After paying way too much, and waiting way too long for my first set, I now make the unit Triton plate sets for under $500 delivered in the U.S. with all stainless hardware and a very nice head steady of my own design as well. Along with the swingarm spindle replacement kit for under $200, it's a decent package. I do these as a HOBBY nowdays, I have a full-time paycheck job. so if anyone is interested, you have to understand that you can't be in a hurry. I have a friend who is a custom knifemaker and he allows me to use his lathe, mill, MIG welder, band saw, drill press and belt grinders to make those bits. He taught me how to turn down the threads for the spindle kit, and I have to say, I ALMOST made a major decision to turn to being a machinist. Being able to play with high quality machinery is true joy. Just for the heck of it, E. Peña Custom Knives:



 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #5
5/12/10

Suspension & wheels-



Hollow engine block & oil tank-

Mostly mocked up. For lack of any other tank that was even close, I set the High Rider tank in place for the photo-
 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #6
Cleared a few square feet of shelf space, emptied 2 tubs and made room to walk past where I have tires & rims stacked. I donated two rolling projects to the PBTF raffle a couple of weeks ago which cleared a big chunk of space for me to move one project out of the shop and another out of the garage. So, after clearing the floor and sweeping, then rounding up all the tools and equipment, then cleaning off my workbench, I have a "clean slate".
Now, I can roll the bike lift out to the middle of the floor and have plenty of space to manever my work stool all the way around without getting a handlebar in my back or eye socket.
Here's the final mock-up, including quarter fairing, before it rolled off into the garage where the new clean space is-

A shot of the 5-speed cluster-

...and the Lytedrive kit-
 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #8
12/29/10 (yes, I know, not a lot happened in 7 months)

Scored a nice Lyta featherbed tank on e-bay. Merry Christmas to me!


Small steps.


1/6/2011


Found an e-bay deal on these hydraulic clutch conversions that have a tiny slave cylinder with a stub of cable attached to the piston. You screw the slave into the clutch cable abutment at the tranny cover and that's all there is to it! Sounds like a nice trick bit for this bike.

Since I'm doing a client overhaul on a 750 Bonnie, I'm going to hustle things up and get the engine for this bike done at the same time.


Pix soon!
 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #10
1/14/11

Engine mount conversion plates and all overhaul parts have been ordered and are on the way.
Frame and associated parts are stripped for powdercoat, those will get delivered to powdercoater next week, parts to be chromed will go in to the plater on the same day.
Engine covers will wait for polishing till conversion plates arrive; the plates might need to be polished as well (not sure of the level of finish).
Next thing I need to do is work out the fit of the wheels with the forks & swingarm, to see if I'm going to need custom spacers and/or axles.
The front wheel fit will be last to decide, depending on whether I am able to acquire a 4LS brake in a timely manner.
Humming right along...
 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #11
1/15/11 I won a 4LS Suzuki wheel on e-bay a couple of minutes ago; best price I've seen one go for in a while ($400 with laced up rim)...

1/17

MIGHTA! (How many of you remember what that means?)
I've successfully re-invented the wheel (so to speak). I've come up with what I believe is a simple, straight-forward, relatively easy to fabricate design for a swingarm bushing & half-spindle conversion for the featherbed frame.



Yes, I know, there are needle bearing conversions and other solutions already out there, I want my TriTon to be MY TriTon.
 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #12
Since I gave away the ending with the photo of the finished kit in an earlier post, it should be evident that the above drawings were my original idea, and not the final design.

I have fun thinking up things and going through the design development process as I get feedback and consider other factors i might have overlooked.
 

·
Registered
Joined
·
767 Posts
Since I gave away the ending with the photo of the finished kit in an earlier post, it should be evident that the above drawings were my original idea, and not the final design.

I have fun thinking up things and going through the design development process as I get feedback and consider other factors i might have overlooked.
I have always found the Norton Manx style bronze bush and steel bobbins are perfectly adequate. The later type of bush and bobbin fitted to the 1961 and later Manx with the hollow 3/4" pin did prove to be a problem as the bobbin shoulder was to small and would fret against the frame but easily sorted. Remember that the wideline frame is design for a solid mounted through axle not a nip up or rather you are expecting the frame to work harder elsewhere. I think you will find that few Norton frames have nice perfectly squared up gusset plates and your solution requires excellent alignment.

Most aftermarket engine plates like Converter or Dresda (not sure Degens still makes his own) put the unit engine in middle (front to back) of the frame and vertical this is 1960s thinking and looking at you plates / drawing you seem to be doing the same (are you plates copies). Moving the engine forward a bit will take advantage of modern rubber, also I tilt the engine forward a few degrees and this raises the engine sprocket and gives a better chain alignment. Fitting the engine vertical and low will have the chain dragging over the swingarm with the slightest of stretch (chain length on a unit triton is long), if you fit a 20 teeth engine sprocket this will help, I generally fit a 20 teeth sprocket on a mild tune engine or 22 teeth on a big hp engine.

The slimline is the ugly duckling of the featherbed frames as the rear subframes are horrible and a lot of builders end up jacking up the rear with longer shocks but again this leads to chain alignment problems. Below is a 56 Manx frame (welded subframe with long loop was 55 and 56 only) this is for a Manx build, attached to illustrate that the earlier wideline is a prettier frame in my opinion.

IMAG0603 (2).jpg

The barrel from an earlier post looks horrible. The liners are different thicknesses as they look to have been fitted off centre then bored to correct the misalignment, the different thickness will cause heat dispersal issues. Also are the liners stepped into the barrel the top to stop them moving or are the liners parallel? I have never had an alloy barrel that hasn't failed; ARE, Weslake (with 8v top) and some heat treated nikasil lined barrels have all cracked with expensive results. Original BIRCO castings are good for 8000rpm or 140mph.
 

·
Registered
Joined
·
2,107 Posts
The slimline is the ugly duckling of the featherbed frames as the rear subframes are horrible and a lot of builders end up jacking up the rear with longer shocks but again this leads to chain alignment problems. Below is a 56 Manx frame (welded subframe with long loop was 55 and 56 only) this is for a Manx build, attached to illustrate that the earlier wideline is a prettier frame in my opinion.


The barrel from an earlier post looks horrible. The liners are different thicknesses as they look to have been fitted off centre then bored to correct the misalignment, the different thickness will cause heat dispersal issues. Also are the liners stepped into the barrel the top to stop them moving or are the liners parallel? I have never had an alloy barrel that hasn't failed; ARE, Weslake (with 8v top) and some heat treated nikasil lined barrels have all cracked with expensive results. Original BIRCO castings are good for 8000rpm or 140mph.
I have to agree with you that the wideline is a prettier frame. In that barrel, stud hole number 9 looks to me like it's been compromised as well.
 

·
Registered
Joined
·
767 Posts
I have to agree with you that the wideline is a prettier frame. In that barrel, stud hole number 9 looks to me like it's been compromised as well.
I did notice the 9 stud issue but this is due to the poor liner installation; if the liners were fitted correctly the 9th stud would not be a problem. Another issue would be getting 18 ft lbs on the 5/16 9th stud, if 26tpi it will strip, the 3/8 outer bolts when torqued up would be on the brink. All of these barrels are utterly crap and should be melted down and cast into nose rings and neck bolts for Hipsters.

Something that pisses me off is the use of the name "Lyta" on just about every bloody Café tank made for a Norton. Lyta made alloy tanks, just alloy tanks and never glass fibre. Also the term "sprint". A BIT OF HISTORY: Lyta were a small company based in Dartford Kent in the UK, the remnants of that company became JPT or John Pearson Tanks in Swanscombe Kent (just up the road) sadly John died a few years ago and the business is still going with Steve at the helm. The so called Lyta Sprint tank was originally called the "slipper" tank because it looked a bit like a carpet slipper and they were never 2 gallon but rather the size was nominal as these things were hand made for a variety of chassis. Wideline up to 55, wideline up to 60, slimline and so on. The Manx frame went through several revisions too, although the top of the tank was largely the same (and nothing like the glass tank above) the bases were very different and some engines need carb cutaway, room for a cambox or not, room for float chamber mounting post etc.
 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #17 (Edited)
1/18/11

I went ahead and re-designed the spindle bits to be true HALF-SPINDLES. Several comments on other forums all related to the spindle stubs, so I altered the design to full-width, with a male/female joint in the center.


I don't think it lends much to the strength of the assembly, as all the load happens at the bushings; nevertheless, it will cost all of 10 or 20 dollars more to build this way, so why not...


(comment re: a few posts up - this design causes the frame webs to be rigid relative to each other, allowing just enough room for the swingarm to play through it's rotation)

 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #18
11/19

Well, the old "find the right diameter socket and use THAT to press the old bushing out with" trick paid off.


I borrowed my friend's 30-ton press and heavy duty socket set, arranged some press blocks accordingly, set the swingarm atop a socket that was sized to allow the old bits to slide out of the swingarm and into the socket's hollow, then jigged a thin socket into a 6" extension and started pressing.


It tightened up then started to resist pretty heavily, so I released it and checked everything; no worries. Re-started the pressing and got to the stiff spot then slowly pumped in 2 more pumps, feeling around the swingarm for any possible buckling, and all of a sudden "POP"! The rest was gravy, it all slid right out.


I don't beileve the swingarm tube is "stepped", I believe the second bearing's outer sleeve is lodged in there. However, it doesn't bother me or my planned half-spindle & bushing modification, so I'm leaving it in.

...besides we didn't have a socket or dowel of the exact size needed to press the thin-walled sleeve out.

 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #19
11/22

Okay, I'm now on the "Mark III" design of the swingarm spindle upgrade.


I'm going with a solid 3/4" dia. spindle, welded to one plate, then turned down to 1/2" and rethreaded on the other end where it will pass through the frame web at full 3/4" diameter and abut the second plate at it's 1/2" hole. The length of the 3/4" section of the shaft will be the exact out-to-out dimension of the frame webs.


No drawing at the moment, as my new installation of AutoCAD on my laptop is flaking out on the dialog boxes (missing a .dll file, apparently), so i only have an unfinished line drawing update.


Delivered to powdercoater yesterday:
(2) Featherbed frames, swingarms & miscellaneous bits
(2) Commando frames and all associated bits

All of the above were bolt, washer & nutted per Old Britts' spec sheet, and will be completion masked by powdercoater per the masking instructions.


About 10 days from now, should have pix of all the nice freshly powdercoated bits.

 

·
Registered
Joined
·
1,685 Posts
Discussion Starter #20
To anyone who happens to be reading this and also happens to have a plan to powdercoat a Norton Commando frame, Old Britts, Norton Motorcycle Parts, Books & Accessories has an excellent step-by-step on prepping everything for powdercoat. On the Commando it is CRITICAL that you properly mask the isolastics, swingarm pivot, and engine mount areas, or you will suffer repeated mounting bolt breakage, loosening hardware, and ill handling until you remove all powdercoat from all mating faces and hardware abutment spots.

This one hint will save you MANY hours of grief and possibly keep you from having an accident where anything can happen, including death (really).
 
1 - 20 of 95 Posts
Top