Hello Paul, I very sorry to hear that, it's most unfortunate. I regret to say I think it unlikely AVO would update your damper as only the smaller parts are interchangeable, but you could ring and ask if there is any way they might help. One other suggestion. The set up you have is the same as mine was for 3 years, it provides a very comfortable but well controlled ride. Before producing these new units I anticipated that many owners would not want the greater cost or the noticeably non-standard appearance of the coil-over, so I think you could probably re-sell it.
New AVO coil-over for B and C series, plus damper update.
- Thread starter ClassicBiker
- Start date
Paul, PS, If it's any consolation, I have sitting on my shelf a brand new D series engine shock absorber which I bought last autumn to fit the next time the primary drive was apart. This year, the Spares Company announced a new and greatly improved ESA. Rob
The finishing off part now comes if one wants to make the rear end look more standard. This involves making telescopic inserts that fit inside the original spring box's to replace the redundant springs, but keeps the box's in alignment so they don't "Cock" and jam given they will now be further extended, if the rear has more travel like the coilover Thornton does. And also because the coilover is wider than an original shock absorber, the front and rear attachment through-studs need to be longer with additional spacers (About 8 mm wide from memory) placed either side so as the spring box's clear the coilover unit. I have done this to two (2) Black Shadows at the request of the owners to try hide the "Look" of the modern coilover, though I must say the AVO unit looks less modern than the Thornton unit. This may become an issue to those who have luggage racks that bolt on to the forward seat through stud, as the spring box's are now a bit further apart, but still possible as per one i have done. All just a thought, and works very well whilst keeping the looks a bit more standard. Cheers................Greg.
Hi Greg, I started reading and I thought you were joking! Interesting solution, but a fair bit of work and added complexity for cosmetic purposes. I think doing the same with the AVO coil-over would not be a good idea. Firstly the AVO spring is probably a fair bit larger in diameter than the Thornton spring, secondly the offset rear mounting requires that the damper and spring case not be locked together by the front through bolt. It could be done, but at the cost of some lost rigidity in the front mounting and considerable width.
One point of information. I have the standard Vincent extended length down as either 10.19" or 10.25" and the Thornton as 10.25". The AVO "short" units are 9.65" fully extended, and the "long" units are 10.12". These shorter lengths help the bike remain a little more upright and stable when on the standard propstand.
Rob
One point of information. I have the standard Vincent extended length down as either 10.19" or 10.25" and the Thornton as 10.25". The AVO "short" units are 9.65" fully extended, and the "long" units are 10.12". These shorter lengths help the bike remain a little more upright and stable when on the standard propstand.
Rob
Some guidance on choice of spring rate.
In thinking about suitable spring rates, it’s useful to look at what was fitted to other bikes. I have a copy of the Girling suspension units catalogue that was published around 1970.
To compare like with like it is necessary to allow for the suspension lever ratio and the suspension travel. The majority of these ‘50s and ‘60s bikes had the suspension unit close to the back wheel and so they all had about the same (low) lever ratio.
The great majority of the Girling units permitted about 2.2” to 2.6” of movement.
So most of these bikes can be compared directly one to the other.
One thing that immediately stands out is that there is a minimal relationship between the size of the bike and the spring rate chosen. Bantams and Cubs got the same 100lb/inch spring rate as some of the top of the range 650’s.
There is also a clear overall pattern.
The most common “general purpose” spring rates were 100 or 110 lb/inch.
Police and “Comb” (sidecar?) bikes tended to have 134 to 150.
Some competition bikes used 75 or 90.
So how do AVO coil-over spring rates compare?
I have guesstimated two equivalent numbers.
The first is the spring rate that would give the same spring rate at the wheel as a Girling unit.
The second is the load carrying capacity. I have assumed that load carrying capacity is directly proportional to available suspension travel. And the AVO units provide much more wheel movement than the Girling units.
So, the 275lb/inch AVO spring is approximately equivalent to a 75 lb/inch for comfort and equivalent to a 110 lb/inch for load carrying capacity.
And the 350lb/inch AVO spring is approximately equivalent to a 90 lb/inch for comfort and equivalent to a 135lb/inch for load carrying capacity.
You can therefore see that the 275 spring is much more comfortable than the great majority of classic British bikes, but has a similar load capacity.
And the 350 spring is a little more comfortable than a typical British bike, but has a load carrying capacity similar to Police and sidecar bikes.
In thinking about suitable spring rates, it’s useful to look at what was fitted to other bikes. I have a copy of the Girling suspension units catalogue that was published around 1970.
To compare like with like it is necessary to allow for the suspension lever ratio and the suspension travel. The majority of these ‘50s and ‘60s bikes had the suspension unit close to the back wheel and so they all had about the same (low) lever ratio.
The great majority of the Girling units permitted about 2.2” to 2.6” of movement.
So most of these bikes can be compared directly one to the other.
One thing that immediately stands out is that there is a minimal relationship between the size of the bike and the spring rate chosen. Bantams and Cubs got the same 100lb/inch spring rate as some of the top of the range 650’s.
There is also a clear overall pattern.
The most common “general purpose” spring rates were 100 or 110 lb/inch.
Police and “Comb” (sidecar?) bikes tended to have 134 to 150.
Some competition bikes used 75 or 90.
So how do AVO coil-over spring rates compare?
I have guesstimated two equivalent numbers.
The first is the spring rate that would give the same spring rate at the wheel as a Girling unit.
The second is the load carrying capacity. I have assumed that load carrying capacity is directly proportional to available suspension travel. And the AVO units provide much more wheel movement than the Girling units.
So, the 275lb/inch AVO spring is approximately equivalent to a 75 lb/inch for comfort and equivalent to a 110 lb/inch for load carrying capacity.
And the 350lb/inch AVO spring is approximately equivalent to a 90 lb/inch for comfort and equivalent to a 135lb/inch for load carrying capacity.
You can therefore see that the 275 spring is much more comfortable than the great majority of classic British bikes, but has a similar load capacity.
And the 350 spring is a little more comfortable than a typical British bike, but has a load carrying capacity similar to Police and sidecar bikes.
It looks like we can start here http://www.vincentownersclub.co.uk/index.php?media/dsc01869.44/#media and click on the right arrow above the photo to see them all.
Hello Rob, Just got my Coilover, The 4 bushes you talk about have not come, Not a problem, The top Bush is a bit too wide But can fix that too.
To me looks ,Very Smart, Just like a "D", I don't think "D"s had a Rubber cover from Standard. Many Thanks, Bill.
To me looks ,Very Smart, Just like a "D", I don't think "D"s had a Rubber cover from Standard. Many Thanks, Bill.
Hi Bill, Sorry about that, I will have a word with AVO on Monday.
It was just for your info' Rob, Don't worry about me, I want to use other bolts anyway. I am well pleased with the look of it, Cheers Bill.
Hi Alyn, Are you coming to the rally in Parks........?.......Cheers, Greg.