Misc: Everything Else Series 'D' The Series 'D' Stand

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Peter Holmes

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With the help of Rob Staley and AVO I sourced and fitted an AVO Series D coil over shock to my D Comet, when I did this I chose to have the shorter shock with the benefit of a lower ride height, perfect for me, but at the time Rob did warn me it would make the stand a little harder to pull onto the stand due to the stand legs engaging with the ground surface sooner, and changing the initial angle of operation.

I did not find that too much of a problem, better than purchasing a one armed Bullworker, but in June I managed to hurt my shoulder, and it is still not right yet, I remember when the standard Armstrong shock was fitted the pull lever was very easy to operate, and I would like that ease of use back.

I need to shorten the stand legs accordingly, currently when on the stand the rear tyre sits 70mm above the ground when on a flat surface, I am aiming to get that distance somewhere around 20mm above the ground, but I only want to take a hacksaw and arc welder to the stand legs the once, would anyone like to suggest an accurate dimension for me to achieve this.

Thanks in advance

Peter Holmes
 
bmetcalf

bmetcalf

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Get successful dimensions as a first choice!

But, if the tyre OD is 26”, the radius is 13” or 330mm. Then the present distance of the axle to the ground is 330mm + 70mm or 400mm. You want it to be 330mm + 20mm or 350mm, a difference of 50mm. Measure the distance from the front axle to the stand pivot, divide that by the wheelbase, then multiply that by 50mm. Maybe prudent to cut a bit less from the legs to be safe.
 
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Peter Holmes

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Yes I take your point Robert, but I do not think the calculation is as simple as "I want the rear wheel to be 50mm lower, therefore I will cut 50mm off the stand legs" there is clearly a correlation between the wheel height and the stand leg length, I was just enquiring whether it is a known formula, and Bruce's answer seems to suggest there is.
 
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A Nut

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Message directed to Peter Holmes,
Hi Peter, I tried to fit a standard length D rear unit but realized that because of the position of the RFM pivot on a Comet compared to a twin it resulted in the bike being quite a bit higher than a D twin. I had to have the the damper rod shortened (I can't remember by how much, 10mm seems to ring a bell. I am using a Protech shock ) . I then had to shorten the legs on the stand. I can show you when you come to collect your seat frame. By the way could you please email me with your contact details as I don't have any way of contacting you.
Brian
 
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Andys998

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Hi Peter,

I've done exactly the same as you. I fitted a short version of the Rob Staley AVO rear coil over shock to my Open 'D' with a standard centre stand. The rear wheel was about 2 1/2 inches off the ground. To work out the right stand length I did the following. If you can imagine the stand is the hypotenuse of a triangle with a straight line from the stand pivot point to the ground as the opposite side. Measure the distance from that vertical line to the stand foot and then you can reduce the vertical height and calculate what the ideal stand length ( hypotenuse) should be.

If that is confusing - PM me a telephone number and I'll talk you through it.

Cheers

Andy
 
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Peter Holmes

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Andy, Thanks for your input, I did not study that well at school, so words like hypotenuse are somewhat of a mystery to me, but I am sure I could understand it if I really put my mind to it, and I thank you for your offer of assistance in that matter. Another member has suggested a method that might be simpler for me to understand, and the suggestion seems to be this, use a string line by trapping a string line under the front tyre, and with bike on the stand in the current position, mount the string line onto a piece of wood or any substance directly under the lowest point of the rear tyre at a height that I would like the rear tyre to be above ground level, say approx 20mm, mark off the position of the tight string onto the stand leg, and cut off what lies below that line, allowing also for the thickness of the stand feet to be welded back on the stand legs, I am sure this will work fine, does everyone agree?
 
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