View Full Version : Triumph T140 71-74 OIF frame specs - neck

11-22-2017, 10:46 AM
Hey all.
I have the basic dimensions page from a manual, but, it doesn't have any neck dimensions.
I need to replace or re-position a neck on a race frame I have. The one that's on it is a bit beat up too.

Someone either didn't have a frame jig when this frame was built or, they set the neck at a little bit of an offset for racing.
BUT, I don't like it... So, I'm putting it on my buddy's frame jig and going to either replace it, or straighten it up.

Also, does anyone happen to recognize the frame? It was a barn find in AZ, the shop said it was built as a flat track racer and they got the frame, wheels and a pile of flat track parts...

And - I have no idea why the pics are upside down, it's something with the bbs formatting I think... Sorry.

11-23-2017, 4:04 AM
what are you looking for exactly??? (Unclear) Rake? Blue print of the frame? (I think I have one) I recognize it, but not much to go on here.
Its likely a 1971 Triumph oil in frame, designation P39,, in mid 72 the relocated the rear section lower. But someone has done a LOT of surgery on it. (Hope it was not sandblasted,,if it was In MY Opinion then its a static display only, one does NOT sandblast oil tanks or frames with oil inside)

Lots of welding and the oil filler cap and routing of oil lines were changed. Original designs of the frame called for the oil filler in that location, but it was relocated just in front of the seat.. Looks like its also got the BSA B50 Oil tank mod as well. (Rerouting of oil lines for better circulation) There is a webpage with details on how thats done.

Just casual observation, but its rather amusing/ironic that someone totally welded the crap out of it and added more braces and welds but failed to brace or beef up the one area that actually cracks on these. (Swing arm pivot area where it joins the downtube, and where the down tube joins the bottom base plate & Top side of the sump plate) Because of the thin wall tubing and stresses its not uncommon to see cracks (and leaking oil seeping out) in those areas. Does not look like that was addressed.

Those frames were designed by non biker engineers recently hired from Aerospace jobs at Triumph circa late 69 and 1970 in what was known as Umberslade hall,, AKA "Slumberglade" and it was not a smooth engineering/design change. MANY problems which eventually killed Triumph originated in the poorly executed launch of the new models in 71.

But the forks were copies of Cerranis and were quite good, and the frame was partially copying what Trackmaster, Redline, Champion and others were doing and so, they DO have merit. OIF bikes were not worth Crap,, but now popular to make them into race bike replicas or copys of Trackmaster and paint the frames shiny silver to look like it. Some come out quite good.

BSA A65 in 71-73 used these same frames as well with only the mount holes different and some bodywork changes.

Not worth restoration, but they make good riders, or cafe or street tracker donor bikes.


11-28-2017, 11:58 PM
Sorry, got hammered with work and family stuff... Yeah, I read all about BSA bringing in Aerospace engineers on in 70ish and them coming up with the OIF stuff, it's too bad they had to mess with Triumph's design team. I have a sneaking feeling they were trying to tank Triumph to save BSA...

This whole build isn't starting off too well, too many goofy things going on...

I'm probably going to have to replace the neck on this frame and was trying to figure out just what was supposed to be on it in the first place. And I do want to see what the neck angle should be.

The frame has two distinct fabrication times. The original one was done pretty good for the most part and was MIG welded. The newest stuff was very well done and TIG welded. Which is the seat tubing area and rear fender area being added. There is no sign that there ever was an oil fill bung in front of the seat.

From what I have found out, the frame has either been ground up built using some parts from a factory frame or extensively modified factory. But, the down tubes have no sign of ever having a VIN number on them, the neck is not on straight. Looking straight on, it cants to the left at the top by about 1/8". That is why I was asking about neck dimensions. This bike will either be just a flat track racer only, or a home build. So, putting a good neck on doesn't bother me any.

I am very grateful to you for pointing out the weakness on the swingarm pivot, I will look into that upgrade for sure. I'm 220 lbs and am hard on my bikes as is....

Oddly enough, I was able to figure out that the neck bearings for the 71-74 is the same ones used in Harley wheels for their 3/4" axles. But, I was told the neck post was supposed to be 1". I have Ceraini trees with no stem, was told the tubes are Ceraini, but sliders are stamped Betor... Talk about a total head scratcher. The dude also gave me another set of sliders, but there aren't any stamps on them.
I also found that the Harley 35mm neck seals are the same ID/OD, but are superior to the doubling up of seals I found on the Betor sliders.

I'll post a pic of the other sliders if I can tomorrow.
Thanks again...

11-29-2017, 1:16 AM
Ive got a bunch of off road and flat track stuff I need to ID,, Same deal all kinds of one off stuff that is hard to figure out. A friend had a big pile as well from a well known flat tracking legend and fabricator. (If you have ever been to Sidewinders or Castle Rock in the Pacific NW you would have run across him)
I told my friend to be careful on selling stuff. Some is not worth much, and some goes for a small fortune. Check out the listings on VFT and you will see what I mean. But you gotta know what things are. I got some Street tracker projects and setting aside parts for them to make them viable builders. (Got some chrome moly race frames too)

As to your frame, dont know about your situ,, but PROBABLY better to just start over with a clean frame (Stock) as the OIF frames dont go for much money usually. As the Vin number that does not surprise me as they are stamped on that triangle sheet metal neck plate, and they are usually stamped really light. Easy to miss and possible that plate has been replaced or modified with all that fab work.

The STOCK trees are way different, they look the same in some ways, but the 1970 and earlier are a 1" stem, the OIF trees are a small OD,, 7/8" I think and use tapered bearings as opposed to the early style cup and balls.

(There is a superior taper bearing and replacement races kit for 1970 and earlier frames and I fit all bikes with those kits,, I hate the stock cup and balls)

As to the filler neck, I have modded a couple bikes similar to yours and will be again on some OIF projects here and modding the tanks to match. I bet if you ran a probe/camera down the back of the spine on the ID you will see where the original filler neck originally was. Pull the sump plate on the bottom and flip the frame over and look down the inside with a strong light and you might be able to see it as well. Regardless with unknown history I would be inspecting the ID of the main spine very carefully as you dont know what grit, sand, blasting media, welding spooge, dingleberries or other nastiness might be inside your main oil cavity.

I can take some pix with some stock frames and stick an angle finder on some if you like. The BSA frames were identical except for 3 things. #1) the mounts for the engine are slightly differnt #2) Some, but not all were painted grey for inexplicable reasons
which was not popular,. Some dealers painted over this #3) The BSA ran different tank which looked like a big breadbox, but all the rest of the parts were same as Triumph

Because of height issues which was really only an Inch,, but it pissed off nearly everyone, sometime in mid 72 they went to what was called the "LOWBOY" and its easy to spot. Where the stock filler neck is (See drawing above) the early frames had the rear section come in just below the filler neck. later frames you can lay 2 to 3 fingers between the filler neck and rear frame rails.

There was a lot of good ideas that went into these OIF bikes, but it was poorly executed. I tell people if you want a cool and good riding classic,, just buy a OIF bike. They are cheaper and ride nice, plus if you make changes nobody gets their Knickers in a twist over it. If you want investment value,, 1970 and earlier.

As I said, they were really close to Trackmasters and other frames and it seems to be quite popular to modify the stock OIF frames to look like a Trackmaster which pencils out to thousands of dollars less to build. But as I said,, that oil spine is thin metal and mounting the swing arm pivot the way they did invites problems. Its a good idea to brace and beef that up. I have had a few that spring a Oil leak around where the Oil spine backbone goes down vertically INTO the baseplate where the sump plate is also. They totally changed how they built frames from the early version,, Castings and Mild steel tubing brazed into place to a more modern all welded construction.

There was issues with the welding on the production line, some of it deliberately defective. Theres a book out now written by the guys who tried to keep Triumph going "Save the Bonneville!" and they talk about this as well. Plus the strike, sit in, and workers
co-op. By the late 70s Triumph was terminally ill so every day they faced bankruptcy.

11-29-2017, 1:46 AM
Heres a picture of a Stock OIF Triumph, and trick question. The guy riding this bike, Who is more powerful,, God or this guy?? (No cheating now) How many can get this right?


Plus, Bonus pic... Bad Ass Clint in Magnum Force,. SFPD and a OIF Triumph. Anyone can answer WHY they used this bike in the movie?


Of course, Even Uncle Fester knows what the best motorcycle in the world is....


11-30-2017, 7:09 AM
That looks like Lemmy from Motorhead. All I would say is God is more powerful but I think there may be another answer. Why is Clint on a Triumph here? Just a guess, Triumph agreed to comp them bikes and Harley wouldn't? I'd like to see "Lurch" on that Triumph! He was 6'9"!

11-30-2017, 3:34 PM
That looks like Lemmy from Motorhead. All I would say is God is more powerful but I think there may be another answer. Why is Clint on a Triumph here? Just a guess, Triumph agreed to comp them bikes and Harley wouldn't? I'd like to see "Lurch" on that Triumph! He was 6'9"!

Correct, that IS Lemmy, and Lemmy IS God, so trick question, Although in 1982 I saw a really stoned looking teen chick walking around a concert hall with a huge sign saying Joe Elliot was God (Def Leppard), but I am sure it was just confusion and a lot of drugs. Some say Jerry Garcia was God too,, and the CIA finally killed God after many tries, but we all know about those Dead heads.

As to Clint, He owned a couple Nortons, and rode Triumphs in a number of films (See Coogans Bluff, cheesy but good, great chase scene of a wacked out LSD psycho and both are on Triumphs riding thru NY Central Park going down stairs, paths, jumps and a crash..
But the story of that Triumph in Magnum force was kinda sad.
Officially there is THIS version, which might be partly true:

See: http://www.imdb.com/title/tt0070355/trivia

" The motorcycles used by the "death squad" cops through most of the movie are Moto Guzzi Eldorado police bikes. However, Triumph 500cc T100 Tiger motorcycles were used during the scenes on the aircraft carrier at the end. These were favoured by the stunt riders as they were lighter and easier to handle than the Moto Guzzis."

But the version I heard, and told to me by a former stunt guy who worked in a lot of movies was at the time, The Police edition Guzzis were not cheap and tossing them into the bay (And perhaps multiple times as sometimes movies do when the shot needs to be refilmed) it was thought too expensive, But at the time the Triumphs were purchased really cheap, and it was felt it was no big deal to toss a few of them into the bay.

A fun fact I didnt know was on that site though,..
" Directly after the scene in the garage where Callahan is threatened by the motorcycle cops, the cycles drove out and every single one of them crashed. Clint Eastwood said, "I've been threatened by the Keystone Cops."

I guess I hijcacked this guys thread enough, I will post some frame pix tonight though to help him out.
But not before more Clint Eastwood pix,, "This here Norton will blow your head clean off kid!"

80110 80111 80112

11-30-2017, 10:40 PM
Clint on a bobbed pan in hiway patrol?

12-04-2017, 7:40 PM
If it was mine and I didn't care for those fucking frames (mine cracked at the bottom and oil tanks you can't clean properly are heinously stupid so I don't care for them) I'd pick up an older style used or aftermarket frame. I consider OIF frames shipping containers for everything else on the motorcycle.

I've not looked in so long I don't know who does quality Triumph chopper frames. You can also get an earlier front frame loop and hardtail that cheap.