750 SF1 Questions

S

Scout63

Junior member
Location
Orleans, MA USA
I just bought a 1973 SF with Lucas switches and short bars. The bottoms of the switch housings will hit the tank on both sides. Is this normal? Here is a picture of the bike showing the bars. I was thinking of putting some rubber on the bottom of the switches to pad them.

Tonight I installed a new rear tire, and replaced the air filter. The filter was a pain to get to and to install. Tomorrow a new front tire and then I can ride it. I can’t wait.
 

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Scout63 said:
I just bought a 1973 SF with Lucas switches and short bars. The bottoms of the switch housings will hit the tank on both sides. Is this normal? Here is a picture of the bike showing the bars. I was thinking of putting some rubber on the bottom of the switches to pad them.

Tonight I installed a new rear tire, and replaced the air filter. The filter was a pain to get to and to install. Tomorrow a new front tire and then I can ride it. I can’t wait.
Click to expand...
This is not normal
Take a look to the lower
Fork-Clamp.
Maybe you miss this


or it is damaged.


Regards
Rainer
 
The switches were quite close to the tank with the original quite short Laverda bars on my SF2, and it could be worse on your SF1 with the Lucas switches. I have modified my steering stop to reduce how far it allows the forks to turn.
 
If the steering stop mentioned above is in place and not bent it should prevent the Lucas switchgear from hitting the tank. My orig never did - until the first time you drop it - flimsy pressed metal stop under the Ceri lower clamp bends too easily. The std low Euro bars are fantastic.

What's the blue thing around that lower clamp area?
 
It can be seen in the photo that a steering stop plate is fitted, whether it’s adjusted right or needs a tweak isn’t apparent but the piece at the bottom of the stem may be too low.
I used to make new steering stop plates from thicker material - I figured it would take a lot to bend the frame and the standard plate is so feeble that even a walking pace get off would result in a dented tank.
 
Inherent weakness by design is the section that runs fwd and circles the stub of the steerer below the clamp. Any strong sideways force will result in the thing twisting, and it only has to twist a little to allow the switchgear to hit the bars.

I highsided at a Winton trackday and the right fork leg managed to crush the tank in until the inside and outside of the tank met! Most bikes have a stop on the front of the head tube and a solid stop on the lower clamp that meets it at full lock. But no steering stop design is going to withstand a major off.
 
If the steering stop plate gets twisted it can also bind on the triple clamp shaft, making the bike steer as if the headstem bearings are notchy.
 
The steering stop on my 3c when I first fitted it allowed the triple tree to pass under the stop, it needed some judicial bashing to get it to hit square on. My bike also needed 3mm welding to its steering stop as a packer on both sides to stop any touching on its fairing-mounted dash and instruments. It's been missing that packing adjustment for the last 25 years, It's now happily just been done. BTW picking up a dropped bike with a non-functioning steering stop is not fun.
 
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