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Discussion Starter #1
I am looking at a very nice 1969 Tr6 Tiger, and have a few questions, please: How do I tell the difference in a tr6c and tr6r, if both have low pipes on them? Also,What is the flow difference between a single 69' Tr6r Amal, and the two on a Bonnie? I know the Bonnie had hotter cams and higher compression, but was the Tiger single carb much bigger than each of the the twins on the Bonnie? Was there really much seat-of-the-pants performance difference other than top end speed, between the Tiger and Bonnie of that year? Thanks!
 

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Hi Becket. You will see if it's a 'C' or an 'R' because it will be stamped on the engine number. There is no difference in cams or pistons to the Bonneville, and yes, the T120 will (should?) have the edge on top end power. BUT the single carb bikes are sooooo much easier to live with and enjoy.
Roy.
 

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Becket -
Your post shows an unusual array of "urban folk lore", so maybe I can help set you straight.

• Please don't use the name of the model, becasue they got mixed around so much as to become meaningless. Do yourself a big favor and drop the "Tiger" bit. It simply confuses everyone.

• You can tell the difference between a TR6R (road model) and the TR6C (competition model) by the model number, as DAGAG pointed out, stamped as part of the engine and frame numbers. Other bits, which may or may not have survived, are the ex pipes, size tank, presence of a tach, handlebar mounting, fenders, and final drive gearing. Models before 1968 would have also had a different ignition system.

• The TR6 parallel port head actually breathes better than the T120 spayed port head. The ports were originally splayed becasue the Amal carbs were so very big in the early 60's. The Bonnie was finally converted back to parallel porting in 1979 or 1980. In fact, the world speed record in 1958 that made the T120 Bonneville famous, was done with parallel port heads fitted with 2 carbs. So that should tell you something.

• The T120 absolutely DID NOT have hotter cams or higher compression. The only difference between the T120R and the TR6R was: the cylinder head, the size of the fuel tank, and the color. Nothing else.

• In period road tests, the T120R beat the TR6R in the 1/4 mile by only 2/100's of a second, or some such infinitesimal difference. The dual carbs showed their largest advantage right at the end of the race, in the 90+ MPH range. So in hindsight, all the hoopla over the T120 Bonneville is almost laughable. Especially so when you consider all the extra day-to-day tuning required to keep 2 carbs in sync and working, and how infrequently most bikes get ridden above 90 MPH.

Hope this helps! ;)
 

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• In period road tests, the T120R beat the TR6R in the 1/4 mile by only 2/100's of a second, or some such infinitesimal difference. The dual carbs showed their largest advantage right at the end of the race, in the 90+ MPH range. So in hindsight, all the hoopla over the T120 Bonneville is almost laughable. Especially so when you consider all the extra day-to-day tuning required to keep 2 carbs in sync and working, and how infrequently most bikes get ridden above 90 MPH.
GABMA left out one important piece of information - Pre-71 Bonnevilles look hot! As well, its not that difficult to keep the twin carbs in tune. That being said, I always enjoyed my TR6R when I had it and the larger tank is useful if you actually ride the thing any distance.

Bruce
 

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Discussion Starter #5
Thanks for the clearer info. I first went to the web for tr6 info, which obviously led me into "urban folklore". Everyone that never owned a tr6 obviously posted in a couple of places I found; what a shock, huh?
 

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tr6r

The single carb on my 72 tr6 was the same size as the Bonneville. The difference is main jet size, throttle cut away, and needle clip position. I put a Mikuni on it after I wore out the Amal after 70,000 miles. The Mikuni is a 34mm. I would not go larger with an Amal than the 30mm. I keep up with the Bonne's and Nortons up til 85 mph. If I hit the throttle first, they can't hardly catch me. I highly recommend the easy tunability of the single carb. The single throttle cable is less problem prone too. I have cruised at a steady 85 mph in the tr6 for many thousands of miles. The biggest disadvantage is with a 40mph headwind. The tr6 takes 5 miles or so of hugging the tank to hit 100. Bob
 

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Discussion Starter #7
Thank you, that info really helps. I love my 02' Bonnie modern twin-carb, but with amals, I would be much more comfortable with a single carb setup. my bike is great, but it just can't touch the 'soul' factor of a truly classic triumph.
 

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if i was you i wood go for the tr6 ..............ive got a tr6p motor and it goes verry verry well... i have had this motor. for about 19 months now and i have not had to tuch it ... dont expect to do 90 mph allday with a old triumph motor,,,, but they will sit on 65/75 mph all day every day ..my tr6p has a sweet spot at 51 mph at 3700 rpm at that speed in top gear its right on the cam , and pulls like a 16 year old boy,,,,if you know what i mean ;),,,,,,,,,,albert the tiprat
 

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Discussion Starter #9
That was one I hadn't heard before, pretty funny :)!
Single carb TR6 seems to get the thumbs up all round', thanks everyone
 

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Hello, I've got a '71 Triumph TR6R and its great!! The singe carb is easy to work with. As I ride this bike around, it seems that its not the "Smoothest" bike for long distance. It seems to me that its a better around town and daily rider bike than a long distance hauler. It actualy feels like it'll vibrate apart after a full day of the long road. super Rad bike though!!!!
 
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