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Discussion Starter #1
still finding bits i need for my project
my 650 engine has 4 studs coming up from rocker boxes for the 4 twisted stays, but the 80 frame has nothing for the twisted stays to attach to
the 80 frame uses the single straight bar that attach to the 2 studs coming up from the centre of the later engines' boxes bolted to the box on the underside of the main frame tube - this setup wont fit the 650 engine
am thinking i will make up 2 flat bars that run back from the 2 studs on each side and run another bar laterally bolted to the frame box and bolt that bar to each of the 2 bars coming back (making the steady a 3-piece U - I_I)
has anyone else already invented this wheel? or have a better idea?
thanks as always
rory
 

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Hi Rory, Yes that works good. Also what looks like a double crossed T/t . Whatever is easier to make.

I feel you are correct in tying both rocker boxes together. I feel it gives a more stable connection.

There is one bolt in the frame bracket. It seems to hold & work good so that should pose no problems.

T140 stay is 3/16" thick & 7/8" wide. I would use that as good size to work from.

Depending on the year of oil frame there is a spacer or washer as needed to line up with frame bracket so stay is fit tension free. Both styles hold well. I found I needed a thin washer to fit stay to frame tension free. The stay is straight & stiff. Putting Z bend would probably be ok, but straight & spacer might be stiffer. But... you have to do what will fit.

Please post some photos of what you do. Thanks.
Don
 

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Discussion Starter #3
thanks for your encouragement Don, it spurred me to action
bought a 5mm x 25mm piece of flat steel bar and made up the bits in the pix
a couple of things emerged
the T140 brace seems to sit directly on the top of the rocker covers, but the 4 studs on the 650 engine have a large hex where they screw into the covers (because they're head bolts?)
this means that the 650 brace sits about 1/2" higher than it does on the 750 engine (the 750 engine brace has a spacer between the top of the brace and the bottom of the box to bridge the gap)
this also means that the 650 braces won't sit underneath the box on the frame - when fitted to the head, the underside of the braces are the same height as the bottom of the box on the frame
so my solution to this was to offset the holes in the braces so as to splay them outwards at the rear so they'd clear the box and then bolt a lateral bar to the box and run it under the 2 braces
when all bolted up there is about 0.015" gap between the top of the lateral bar and the bottom of the 2 braces from the rocker boxes - can't find a washer that thin so am wondering whether it would be ok to take up that gap by just tightening the bolts (have read in other posts that the braces shouldn't have tension on them as a result of not shimming the gap)
admit it doesn't sound or look that pretty, but am wondering if there are any significant issues?
any comments welcome
thanks
rory
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Hi Rory, I personally wouldn't leave a .015" gap. I understand that .015" washer could be hard to find. I have various shims left over from work, which gave me an easy solution.

However, If.... you could find some flat washers of .015 difference, you could put some under the head steadies & bring the cross bar down, then add a .015 thicker washer top of crossbar to fill gap.

Grinding .015" off flat washer is practical solution if needed. I know you're not supposed you grind on side of grinding wheel, but... Sometimes we need a flat surface. Might spoil a few until you get the feel of it.

On the other hand putting a .015 dog leg in stays is so slight, I doubt it would effect stiffness. I've found a small dog leg is very hard to bend. Grinding washers may be easier. Really mechanic's choice.

Your are correct, on this engine, the stays are bolted to top of actual head bolts that go through rocker boxes & head into cylinder. So, the rocker box gaskets are taking head bolt torque in this case, which is different from the cly that uses long studs coming up from cyl. on '71 & later engines. Both work fine, but the studs allowed easier fitment of rocker box with motor in frame with the fat top frame tube.

On a side note, the T140 frame is a good riding bike. With the 650 motor, maybe the best combination?
Don
 

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Hi Rory, Been thinking about oil filters etc. Came to mind, what are you doing with oil feed pipe. Frame sump is 3/8, motor would have been 5/16. Sometimes you can force 5/16 hose over 3/8 steel pipe/nipple. Or get T140 feed pipe to motor.

I've some experience with T140 motor in dry frame. Easiest there is put T120 pipe from year of frame on motor.

Just curious. Thanks.
Don
 

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Discussion Starter #6
Don
thats the purpose of the dry fit - to find out the issues and get them fixed
haven't run any oil/breather lines or fuel lines yet, so haven't identified the issue you raise
i have a Motao filter ready to bolt in (just like my T140), so assuming the outlet from that is 3/8, is the connection to the motor your referring to the 'oil junction block' - if so is it straightforward to fit a later part to the 650 motor?
if i've missed the point, please correct my assumption
btw, great piece of lateral thinking with the different thickness washers - pulled my collection out and got a great fit in minutes - wouldn't have thought of that myself
thanks again
rory
 
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