Just to point out that Greg now has some 16.5" long 36 lbs/inch springs as well as some 15.5" long 45 lbs/inch springs. When you can get access to them that will give you some more spring rates/length to play with. This kind of feed-back is really valuable. To keep those who have been waiting patiently for me to send them their kits the latest news is that the engineers who told me months ago that they could open up the eyes in the lower links, and have promised three dates by which they would be finished, told me last Thursday that they could not actually do it so the links are now back with another company. Chris (Chrislaun) is doing sterling work on testing spring and damper settings. We think that the latest setting from AVOs is now right to use when bearings are fitted rather than Oilite bushes but Chris has now fitted an AVO coil over rear damper and finds that he needs to tune both ends to get the best results. He also found that after fitting the 45 lbs/inch springs to his twin, with bearings rather than bushes,(as found suitable by our Australian friends) he needed to pack the springs by 11 mm to compensate for his weight, 280 lbs. This is to ensure that the angle of the lower link is correct to give the maximum movement and optimum handling with the front end. A batch of four AVO dampers should be arriving this week so please keep watching this space.
FF: Forks Modified Steering Stem
- Thread starter greg brillus
- Start date
Yes the links are a difficult part to have to machine. It is a difficult part to hang onto and all the while everything needs to be kept in alignment as close as possible. Where I have had to have the eyes opened more and a steel sleeve pressed in, then the holes honed back to suit the bearing size, this becomes quite expensive. And by then the paint is suffering, so a paint strip mask up and re-paint is in order.........talk about creating a rod for your own back. The owners of these pieces can only guess at how much work goes into it
The interest is what you see now. I seriously doubt there will be any more of the stem kits made after this lot. The whole idea was for riders of their bikes to make the bike safe and handle perhaps a bit better, but the number of those kind of riders is becoming less and less. So the chance of making a batch of lower links to suit the bearing mod would not be worth it. I know this might sound a bit negative, but I feel that's exactly what it is.
I'm not so sure there will not be at least one more set to be made. The present batch worked its way up from about a dozen to 28 while things were being organised and there have been a couple of enquiries since this batch was made. The problem is that about ten have to be ordered to keep the price down but I know that there are some people who are waiting for the feedback from the present batch and different types of users before they make their minds up. We will see. At least a new batch should be quicker than this one as we should know what the correct damping and spring rates are.
Martyn,
It is quite heartening to see someone out riding and enjoying a Vinent as much as you are right now. It is also nice that those who tried out the front end are impressed.
I am impressed that you have found that the front brakes work much better. I have always written about this since the very first article I published in MPH about the geometry problem of the Girdraulic. I believed better braking to be an obvious result, but because I changed my brakes on the racer when I changed to the short springs, I was unable to quantify the better braking in any meaningful way. Your brakes must have been adjusted well and they responded to the tire having better contact with the pavement.
Thanks for the detailed analysis. The springing has been the toughest part of the project to get right. I have to say that with all the work done by Norman, Chris and Greg that nobody should be put off by the springing. It can be refined, but there seems to be workable spring set-ups at hand, even if they continue to benefit from further tuning.
I think the biggest benefit from addressing the geometry problem is the confidence it can give you when riding your Vincent.
David
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I've always wondered whether FF3 could be produced as two arms heavily keyed to a spindle which had the lower damper mounting as a welded attachment. It might be a more cost-effective means of small-batch construction. I await criticism from engineers, and I won't be at all offended. Cheers.
Prior to the 'upgrade' I was always very very carefull of corners with corrugations and/or obvious bumps on the road surface; likewise I was a timid rider on unsealed roads. Since the upgrade that has all changed. I still keep a weather eye out for those conditions however the bike is much much more stable under those conditions - confidence inspiring. And on unsealed roads it seems more planted and tracks much more accurately as bumps. loose stones, corrugations do not seem to pitch the bike off line at all. I hesitate to mention this - but ... on a unsealed road in Tassie, on which I covered around 30 miles, where in the past I would have not had the courage to do more than 20 mph I found I was travelling very comfortably, and stress free, at around 50 mph.
One other thing that needs to be called out, especially for the purists, is that if at any time you find the need to return your bike to its original state the modification is easilly reversable - all you need do is remove the upgraded headstem and replace it with your original headstem. If, like me you went to the needle roller conversion in FF3 that is also reversable as suitable oversize FF5's are available from the spares co.
Martyn
That's excellent feedback Martyn, I hadn't even thought of the loose stuff. Most all I know so far have indicated that they feel the steering damper is near redundant, as the steering now feels so much more stable. I know on the racer I set the hydraulic damper to it's middle position and never changed it, There was one corner about 2 thirds the way down the main straight at Lakeside called "The Kink" which you could take very fast and on full throttle if you had enough "Bottle" I don't know if I ever actually held it on full chat going through there, as immediately coming out the other side was quite rough I'm guessing because of ridges caused by cars. I am guessing that a stock front end Vincent would have almost certainly shook it's head Violently going through there, But I remember very well the racer getting shaken quite a bit going through, but never did it shake it's head. This was probably the track that I either raced at or held practice days the most, so I got to know the track very well. Lakeside is a very historic track here in Australia, and quite a dangerous track too, several people killed there over the years particularly on bikes. I didn't want that to happen to me, though I did get knocked off on my second ever racer there.............
