This project has been a long time coming.
I am not an expert, nor do I have an engineering back ground I have just brought all this information together to make it all happen. This is my adventure…..
I finally got a final drive from a VS1400 Intruder installed. The hub ratio is 2.66 vs the 3.09 of the VX. Approx 14% taller gearing throughout all gears.
Top speed is not effected, as it is now too tall to rev beyond 7200 rpm (or 110ish mph). This is with a new Avon Storm 150/80 on the rear.
The rpms are lower in all gears. At 60mph I turn 4200ish rpm and 70 comes at just about 5000 rpm. I have only had it on for 2 tanks of gas so I have not memorized exact speeds. These are approximate.
So far I have seen a consistent 220 miles per tank, on mostly highway riding at 65--70 mph. Normally 180 miles per tank is common.
It does require the modification of your swing arm as well as the shortening of your drive shaft. This is how it all came about
A while ago I was looking at fiche on Alpha sports web site and I surmised that a GV 1400 Cavalcade may fit (it will fit but there are fitment issues), it looks eerily similar to the VX hub. It took me a while to track one down, only to discover that the axel is 2mm bigger, as well as a shock post that is out board by almost a full 2cm more than stock, and the hub splines are deeper (15mm vs 10mm), and the splines of the hub are further out beyond the inner face of the hub too.
I had first read about a modified drive shaft/hub swap on the Intruder forums Different rear drive ratio/highway cruising - Suzuki Volusia Forums : Intruder Volusia and Boulevard Forum
)(theres over 40 pages to the thread, so if you have nothing else to do read on....). ***I dont know how the Volusia/boulevard riders get 3100rpm at 65 but they do (so they say)***. We (VX’ers) are supposed to have the same transmission. I would like some help figuring that out if anyone knows what to look for.
I had ordered and received my first modified drive (from the originator of the idea, Dan Hillis) back in May of last year. I took a day off from work to install it. It was my first time opening up the drive hub of the VX. Its not hard. I quickly found out that the modified drive shaft I had gotten would not fit. Misinformation from the seller, but its not his fault. VX has its own drive shaft length. It is not shared with any other Suzuki that I can figure out (I have one from the GV1400, 2 VS800, 1 VS1400, 1 VS700). So I had to get my drive shaft shortened to make it a comparable length to the hub as with the stock hub.
Let me explain. Where the drive shaft mates to the hub is at a different height in the hub in relation to the axle on the VS1400 hub compared to the VX800 hub. This is important to maintain so that when the suspension is in compression and the drive shaft moves in the hub (there is a small amount of play for this to happen as it is supposed to). What I did was measure the shoulder of the drive shaft (where it meets the U joint beside the output gear) to the face (including the bearing retainer) of the old drive hub. Then I measured the same distance from the shoulder to the drive hub face (including the bearing retainer). I had to shorten it by that much (at this point it was last September so I dont recall what it was exactly). I think it was 3/8". This link shows some of the engineering that has gone into the mod (not just this one, there are several versions of it) up to today. How to guide: VS1400 drive on a VL800/C50 - Suzuki Volusia Forums : Intruder Volusia and Boulevard Forum
That was only one of the problems I had to overcome. The other is the shock post on the VX is shorter than any of the other Suzuki Models I have found (including, GV1400 Cavlacalde, VS700, VS1400, I have purchased one, or more, from each of these so that I can take measurements of them, as well as axles and spacers). It is shorter by about 1.2 cm. This is an issue because the axel will not go through the right side of the swing arm as there is a parallax that occurs with the shock in the VS1400 hub (the shock base is now out of line by 1.2 cm). I tried to follow in the foot steps of Ferenc Kovacs, a fellow VX forum member that has successfully swapped in a VS800 Intruder drive hub (geared the same as the stock VX hub). He had the shock post unscrewed and machined down the appropriate amount. To make the VS1400 hub fit I didnt really want to machine it down. Unlike the VS800 drive hub the VS1400 hub shock post is not as much of an actual post as it is just an area of the case that needs to be machined or shortened. I was acutely aware that I may machine through the case, destroying it. Having looked at pics from other on the intruder forum, I decided against machining the hub.
My machinist had the idea of doing this. Shimming the shock post OUT, at the top, so the bushing rests on the treaded part of the shock post (remember we are talking about the top post here), and securing it with a bushing with a threaded insert so it is very secure. In fact it has more threads securing it on now than it did in its stock configuration. OK I think its question time.....---