Rear Shock Adjustment - C-Spanner size?

jfheath

jfheath

John Heath
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Ilkley, W Yorkshire, UK
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Can anyone help please ?

This may seem like a stupid question, but I've booked in some time to fettle my Brother's ST1100 AV. I no longer have a C spanner, and the one I used to have didn't fit and the tooth was on the point of breaking off. I never got the Honda toolkit with the my bike, and he doesn't have one either. Its been a long time since I worked on an 1100. 17 years.

So does anyone know what size I need to get his suspension sorted please. I guess it is the diameter of the adjusting section of the suspension that I need to know ?
 
Have you considered a suitable size channel locks? Depending on the tightness of the nut, you may mar the nut with the pliers' jaw teeth. Maybe wrap, a rag around the nut?

If you want to pay postage from Florida, US, I'll send you a wrench (from an ST tool kit).

UK ebay?
 
Whenever I used channellock pliers on something that I did not want to scratch, I wrapped the jaws with several layers of electrical tape. Works well.
 
John:

Attached is a true-size scan of the spanner. I traced it out on 8.5" x 11.5" paper and then scanned that using 8.5" x 11.5" set at 100% scale. If you print it out full size on 8.5" x 11.5" paper it should be true-to-size. The two parallel lines represent the thickness of the spanner. It is the same thickness throughout.

If you remember your geometry lessons you can calculate the diameter by measuring the width and height of the circular segment that is present. You will have to look it up as I don't remember the formula.

If you want a specific measurement let me know.
 

Attachments

  • ST1100 Shock Spanner.pdf
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jfheath said:
Can anyone help please ?

This may seem like a stupid question, but I've booked in some time to fettle my Brother's ST1100 AV. I no longer have a C spanner, and the one I used to have didn't fit and the tooth was on the point of breaking off. I never got the Honda toolkit with the my bike, and he doesn't have one either. Its been a long time since I worked on an 1100. 17 years.

So does anyone know what size I need to get his suspension sorted please. I guess it is the diameter of the adjusting section of the suspension that I need to know ?
Click to expand...

89202MT3000 Spanner, Pin Part Honda - MSP

MSP is Europe’s most popular online parts supplier, buy new Honda manufactured Spanner, Pin from MSP, worldwide shipping using DHL
www.motorcyclespareparts.eu www.motorcyclespareparts.eu
 
Wow - many thanks folks. I never thought that places would have these in stock still, so I never bothered to look.
And many thanks @Andrew Shadow for the outline drawing - that will be extremely useful for locating the correct size.

I don't remember ever learning a formula for that - but then I always preferred to work thing out from scratch.
So a quick chord and a couple of measurements as you say - and pythagoras is your friend *. And checked with a springbow compass. (which surprisingly, I still have and could put my hands on). 78mm diameter.

(* He has to be somebody's. I would not have got on with him. A most irrational person. Ho! Ho!).

The spanner is a minor requirement, but his suspension certainly needs sorting out. (My brother's, not Pythagoras'). I suspect most of my time will be spent on that weird 3 point ace-of-clubs pivot bracket for the SMC behind the left grey shroud, and on checking the rear drive and the rear caliper - as well as teaching him how to take the wheels off and put them back again.
 
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jfheath said:
78mm diameter
Click to expand...
I didn't bother doing the math because @Sunday Rider had already stated that the diameter is 64mm. Since he has an ST1100 I assumed that he either measured it for you or has previously measured it at some point and already knew. The difference between the 64mm that he listed and the 78mm that you came up with is a substantial difference, so something needs to be rechecked.
 
Andrew Shadow said:
I didn't bother doing the math because @Sunday Rider had already stated that the diameter is 64mm. Since he has an ST1100 I assumed that he either measured it for you or has previously measured it at some point and already knew. The difference between the 64mm that he listed and the 78mm that you came up with is a substantial difference, so something needs to be rechecked.
Click to expand...
I was wondering about the difference as well. I have an OEM shock as a spare, and that's what I measured (the adjustable ring). I will pull out the C spanner in the tool kit and take a picture and edit the post later.

Measured 64mm
IMG_4987.jpeg
Spanner around adjuster ring
IMG_4988.jpeg
How Spanner fits in the 64 mm measurement
IMG_4989.jpeg
 
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Hmm.

Yes -I was expecting 64mm, but may maths came up with 78. My measurements could have been slightly off - but the 39mm radius arc fitted the drawing perfectly. The 32mm radius is very close but a gap opens up towards the tail end of the arc.

But it could be a software issue or the paper has changed size coming through the laser printer (it usually shrinks a bit with the heat though). I didn't allow for the 'pencil width' of the tracing around an object when I measured either. But it was only a bit of maths fun. I was going to take your (@Andrew Shadow's) drawing with me if I visited a hardware store and anything I found of about the right size, compare it with the drawing. But now I know that I can order online.......
 
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Andrew Shadow said:
I didn't bother doing the math because @Sunday Rider had already stated that the diameter is 64mm. Since he has an ST1100 I assumed that he either measured it for you or has previously measured it at some point and already knew. The difference between the 64mm that he listed and the 78mm that you came up with is a substantial difference, so something needs to be rechecked.
Click to expand...
well, I wasn't going to mention it because I wasn't sure anybody cared, but in my boredom I did a little photoshopping on your drawing and I came up with 64mm diameter as well. My technique wasn't perfectly accurate, but favors the 64mm vs. 78mm measurement. Didn't want to argue with a man holding a compass, he could poke my eye out!!!
 
Hard to argue with a vernier caliper.
Sounds like John failed geometry and that his friend Pythagoras pulled a fast one on him.
 
dwalby said:
well, I wasn't going to mention it because I wasn't sure anybody cared, but in my boredom I did a little photoshopping on your drawing and I came up with 64mm diameter as well. My technique wasn't perfectly accurate, but favors the 64mm vs. 78mm measurement. Didn't want to argue with a man holding a compass, he could poke my eye out!!!
Click to expand...
Andrew Shadow said:
Sounds like John failed geometry and that his friend Pythagoras pulled a fast one on him.
Click to expand...
Report:
Maths: Perfect. Pythagoras was also correct (on this occasion). A**
Eyesight and Measuring: Could do better. Z--

That'll teach me to use a flat steel ruler. I took a shortcut. Placed ruler at one end and moved the other until it met the curved line at 5cm - so I had a 5 cm chord. And marked the mid point.
Problem is - the flat steel ruler I was using was hiding the notch next to the pin, so failed to spot it - So 5cm chord measurement was not a proper chord. :doh1: (Blames tools).

64mm it is.
 
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