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How are the FCR's in mid to light throttle, like in traffic? How are they to tune?
Just thought of something worth mentioning on that point; Trials bikes are used mostly for slower speed riding and rarely need to achieve maximum capable speed, manufacturers typically fit them with smaller bore carburetors compared to their motocross counterparts. The reason is because they can achieve better low speed fuel/air control with the smaller carburetor. If you want to avoid problems at mid to light throttle operation and don't mind giving up some land speed record performance, you would probably be advised against going too over-sized on the carburetors.
 

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Both sets of carbs are smooth throughout full operation as long as your throttle handle is smooth. Neither has any issue in traffic.

You can order the FCRs from Sudco already set up. They're listed for 1995 Speed Triple. I just had to tweak the air/fuel mix. Jetting was fine.

If cost is an issue, it'll be easier to find a second hand set of CVK36s.
 

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one of the issues tuning (edit - i should have said "data logging and making sense of said data log with") cv carbs is that there's no measurable relationship between throttle opening and slide position. do the cvk have a tps? that will help to some extent. i used manifold vacuum when i was logging my monster 38 bdst carbs, but even that is just guessing. in terms of needle you make a change and relog and see what happened to get a feel for what did what. collect enough data though and it will help to compile a knowledge base.

fcr have everything the cv carbs have but plus one - pilot jet, slow air screw, mixture screw, needle, needle jet and main jet. the slow air screw overlaps with the mixture screw and i don't really get why it's there, or made adjustable anyway. seems like an added complication to me.
 

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fcr have everything the cv carbs have but plus one - pilot jet, slow air screw, mixture screw, needle, needle jet and main jet. the slow air screw overlaps with the mixture screw and i don't really get why it's there, or made adjustable anyway. seems like an added complication to me.
FCRs also have an accelerator pump.
 

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CV's are for those too numb handed to use FCR's

Quite often a slow air screw is used to provide better bottom end pick up and weakens off the mixture at WOT if it bleeds into the emulsion tube.

As trialsrider said: small carbs for low end torque at the expense of outright powah and big carbs sacrifice bottom end torque and flexibility for maximum airflow at high rippums.

Either way, unless you are doing serious tuning work on the engine, the stock carbs are right for the bike and would just benefit careful setup and tweaking in to the lump and pipe.
 

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If it looks anything like this


it shouldn't need a lot of hacking. Not sure how a TBird or Legend tank would fit in the scheme without custom everything else as far as bodywork...
 

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If it looks anything like this


it shouldn't need a lot of hacking. Not sure how a TBird or Legend tank would fit in the scheme without custom everything else as far as bodywork...
Since all the first gen Hinckley Triumphs shared frame/engine architecture, should create few, if any issues. Hacking off the rear subframe shouldn't do anything but remove some weight. Those frames were very robust.

Good project. But as has been mentioned, you coulda bought a Tbird sport...
 

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Discussion Starter #29
I have been looking into the FCR's a bit more, sounds enticing. My goal is to have the bike assembled with the stock 885 engine for 2017 riding season then go through it with a finer tooth comb in the winter of 2017 and refine things and go through the engine. I will probably do the FCR at this time with a jump in displacement and head/port/valve work.

The Trident pictures is the same color as the one I have.

The idea of getting a Tbird did cross my mind but I wanted tubeless tires, better cams, 6 speed, Keihin Carbs, 3 to 2 header, Improved rake and trail for performance riding, and a few other differences. The Trident was 600 bucks, a T bird in similar state was over a grand in my area.

For now Im getting some parts while I am waiting for the tank. I have the seat pan already and the two together will determine the sub frame location.
 

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I have the bearing codes for the rear linkage if you decide to rebuild yours. Pretty much all the bits for 'em are available from Triumph still but you can shave off a few dollars by buying quality bearings from cheaper sources. The guy who I'm doing the Trophy for is looking to cafe racer either the Trophy or his Sprint so I'll keep an eye out here. I have quite a bit of tech info and cross reference stuff on Hinckley Trumpets so let me know if you get stuck with owt.
 

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Discussion Starter #34
Pwalo, thank you for the info offer, I will most likely need that at sometime.

there is loads to do still and just gathering parts for right now, and figuring out the sub frame alignment.
 

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The good thing about the early back boned Hinkley frames is that the sub frame doesn't support the shocks or much else than the seat. So, even though I don't really like your inspiration bike, it won't suffer from compromised handling just with a different subframe.
 

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Keep going......

The big challenge is that the rear sub frame is welded to the frame, and has the footpegs attached to it.......and the whole thing looks butt ugly

I'm constructing a sub frame in aluminium, using the existing subframe as a jig which I will cut off when I'm finished, and have bought 675R rear sets to bolt to the side plates of the frame. It's getting more complex as we go.....

image.jpeg

image.jpeg
 
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