Triumph Rat Motorcycle Forums banner

How do I identify what I have?

3K views 11 replies 7 participants last post by  KADUTZ 
#1 ·
Hi, all. The motorcycle bug bit me a couple of months ago. Did I go buy a new starter bike? Noooo. Did I buy a good used bike for a newbie? Noooo. I went and bought two rolling basket case Triumphs. I convinced a friend that he had more project bikes than he would ever get around to fixing, so he sold me two. I went this route just because I have always liked Triumphs. Or more exactly, I have always liked the people that I knew who rode Triumphs.
Anyway, to the point:
The bikes are Frankenstein creations. They are hardtails that have not run in 10 - 20 years. By the engine codes, one is a 71 Bonneville, the other is a 71 Trophy. The Bonneville has a single-carb head on it. That is just the start of the non-original parts.
My question is this: is there a good resource for identifying the year and model that the various parts came from? Maybe a photo guide? I think one of the frames is an older Triumph (definitely not a 71 OIF) with a hardtail welded on. I think one of the forks is a standard 71 set, but the other set is different. You get the idea...
The exploded parts diagrams do not seem to show enough detail to make a positive ID. Any suggestions are welcome.
Thanks --
-- Jim
 
See less See more
#2 ·
Probably the on-line parts books is as good a place to start as any.

The specs in the front of the manuals will help you with things like carb ID. Your two engines should both have had Concentrics on them when new. There should be a number on the non-OIF frame that will help you to date it.

A lot of parts are the same across mutiple years. A lot are interchangeable. Single carb engines are easier to tune and tend to have a little better bottom end. Although I've never had an issue tuning a dual carb bike, myself.

If the hardtail is truly a bolt-on, you may be able to bring it back to standard form and build a nice bike with it. I'm sure you could sell the hardtail, expecially a vintage hardtail.

Your bikes are both bitsas so don't spend crazy money on correct year parts if the parts you have work well. Build the bike(s) to be reliable and suit your tastes and riding style.

Also keep in mind that some of the parts may be valuable and even if you do not want to use them, could help finance the build.

Good luck and welcome.

regards,
Rob
 
#6 ·
Thanks for everything so far, guys. As luck would have it, there is a Brit car and bike show in town this weekend. Hopefully, I can see some good bikes, rub some elbows, and get some answers.
As for pictures, let's start with the forks. Here is one set, which matches what I see in pictures of '71 Bonnies (except for the ridiculously long tubes on this chopper).




Here is the other set, which is the correct length. Notice that there is no ridge along the outside. Can anyone tell me what this set is from? I need to make sure that I order the right parts, because there is a problem with them, as shown in the bottom pic.




 
#7 ·
Front wheel is from a 71 or 72 650 both years used the same one. However the fork sliders are from 2 different years. The Driveside one is from a '71 while the Timing Side one is from a '72.
As I assume you know the fork tubes are trash.
 
#8 ·
1972. Thanks. I had looked at the 72 brochure located here http://www.classicbike.biz/Triumph/Brochures/1970/72TriumphBrochure.pdf, and the cover bike clearly has the ridges. I guess the brochure was put together before the final design changes were made. :D
Yes, I know the tubes are trash. Now that I know the year, I can go ahead and get the rebuild parts on order. By the way, this set of forks stinks - literally. They smell like 90 wt gear lube. Is adding 90 wt an old trick to squeeze a little more life out of forks that are shot?
-- Jim

Next up: pictures of the head.
 
#12 ·
1972. Thanks. I had looked at the 72 brochure located here http://www.classicbike.biz/Triumph/Brochures/1970/72TriumphBrochure.pdf, and the cover bike clearly has the ridges. I guess the brochure was put together before the final design changes were made. :D
Yes, I know the tubes are trash. Now that I know the year, I can go ahead and get the rebuild parts on order. By the way, this set of forks stinks - literally. They smell like 90 wt gear lube. Is adding 90 wt an old trick to squeeze a little more life out of forks that are shot?
-- Jim


You will find Triumph sales brochures at times leave a bit to desire (from a historical point). Air brush changes, maybe early in the season photo shoots, and running model changes all come to mind. Also note the brochure you show is headed "Advance Program Announcement". While the main photo shows ridged sliders all other photos in the same brochure show smooth sliders. On the same classicbike site if you look at the 71 brochure all sliders have ridges. For what its worth 71/72 fork tubes,seals and all other small parts are the same.
As far as the 90wt gear oil I suspect it was used as it was what was at hand. That thought comes to mind seeing the quality of the work in your other photos. At least 90wt has lubricating qualitys.

K
 
#9 ·
Here are a couple of pictures of the top of the engine that is supposed to be a Bonnie. It has one carb. Is there anything that the head could be from besides a Trophy? More importantly, will the internals be the same as the Bonnie, or could there be differences? And, yes, the excess gasket sealer makes me think that just as much squeezed into the inside of the engine. :eek:
Thanks --
-- Jim



 
#10 ·
Looks like a pre '71 top end to me. No inspection holes on the side of the rocker boxes, and the inner head bolt are the style that go all the way through the rocker box and head, with threaded extensions on them for the head steady bracket. Which by the way, is awol. in the pic. What is the Engine # prefix. That will give a clue to the bottom end.

Alan.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top