A couple of Q's...suzuki related..more of a cousin

[Vishnu]

HI All!!

My name is Alan. I currently ride a VX 800.

I want to say initially that I am not 100% sure where to post my Q's, so if the mod/admin moves this I completely understand....

I love my VX, its a blast to ride and I love it....oh did I say that twice? I am here because I get alot of "dont do that or why do that " on the VX800 forum. My local mechanic, suggested I come here...he said it s a knowledgeable forum. Even though its a GS forum I have learned alot just reading random posts. Cheers

OK, really. I have been toying with the idea of putting a final drive from a GS 1000 (2.90) on my rear. I currently have the stock final drive, with 3.09.

I have read lots of posts on the VX800 email list about swaps of this nature, and surprisingly enough no one has done one. rpm at 70 mph are 5200, or there abouts, same as the 80 gs850 glt.

So my questions are these;
1. Is the drive shaft coupling a Suzuki standard?
2. If I was to find a GKD, GLD,GKE (2.91)rear end would my engine be powerful enough to take a 6ish% taller gearing? It only makes 50 ish ft# of torque.
2 a) I am looking at a set of mega cycle cams in the next 12 months...so I am also looking for a set of carbs. I was thinking of a set of 32mm (stock are 36mm). I am looking for more torque ie useable power, I dont want top end, I want a better cruising speed (ie lower rpm). If I can get the engine rpm down to 4500 it would cruise along at its peak torque.


Why? simply I am an Iron Butt wanna be, I dont want a bigger bike, I would like to make my bike more....me!

PLz feel free to redirect me to a better resource, so far I havent found one...and I have looked for over a year.

Cheers

Alan

[Nessism]

The 2.90 rear end will only take about 300 rpm off your highway crusing speeds so it's not going to get you were you want to be. I put one on my 850 and the bike has plenty of torque to pull the gearing so I suspect your 800 would be fine as well. Of course that assumes the rear end would fit, which I have no clue about.

Regarding changing the carbs and cams, sounds like you are going to fuss aorund endlessly and spend a bunch of money with very little gain. I wouldn't do it. Enjoy your bike for what it is and be happy. The grass is always greener but unless you have limitless cash, your green will flow out of your wallet and the bike will be only different, not better.

[bwringer]

I happen to have both a VX800 and a GS850 in my garage. We seem to think alike...

The rear ends will mate to the wheels just fine. I tried it with a spare 850 rear end (which is interchangeable with the GS1000 final drive, and all other '79-'83 850+ Suzuki shafties). The bolt pattern attaching the final drive to the swingarm is also the same.

However, the driveshafts are set up totally different. The VX800 driveshaft stays attached to the final drive (it's a spring-loaded coupling that allows for slight variations in length), with a splined coupling at the engine end.

The GS850 driveshaft bolts to the engine with a splined coupling at the final drive end.

Assuming you could solve that conundrum somehow, I also haven't measured the offset. The VX800's stock 150/70-17 tire size is wider than the GS850's 130/90, so it's possible that the VX800's final drive is wider. I don't know about that yet -- the incompatible driveshafts are the real stopper.

I suppose a custom driveshaft shop, as used by the Jeep crowd, could weld together the rear part of a GS driveshaft with the front part of a VX driveshaft. However, the spring-loaded variable length function (which is part of the VX final drive) would have to be added somehow.

I have a spare VX800 final drive sitting on my work bench... it'll be a couple of days before I can get pictures, but you can look at the microfiches to see what I mean.

The Euro models of the VX800 also had taller transmission gearing -- it might be possible to order the parts, but you're talking about a complete engine disassembly.

[Vishnu]

Ringer,

Many thanx for the 411, I am glad to hear that I am not the only one that seems to think like that. I am a little saddened to hear that I would likely see only a few hundred rpm difference.

How ever I was up to the wee hours last night and I had a thought to look on the Intruder forums to see about any advice/mods they may have made.

Long story short, I'll post some links and let you read what I found.

http://www.volusiariders.com/viewtopic.php?t=84658

I was looking at a couple of fiche for the c90 and the vx800, and yes they are similar, but I see the different mount/attachment you mention.


What are your thoughts?

Might a cut and weld with various vx and c90 drive shaft and final drive be feasble? Plz what are your thoughts?

[duaneage]

It might be easiest to install a larger tire, that would cut the RPMs down. I went from a 110 to a 130 and it dropped the RPMs about 500

[bwringer]

There are a few people on the VX800 forum who have installed a 130/90-17 rear tire, which is a bit taller than the stock 150/70-17 and drops RPM slightly.

The rim is 3.5 inches, so it stretches the 130 out a bit, but not too badly.


I'm currently using a 140/80-17 Avon Distanzia on mine, and it's a tiny, tiny bit taller than the 150/70.


I'll need a little more time to look at the mod on the Volusia board, but in general please be aware that you're trying to solve a "problem" that doesn't exist. The VX800 will happily drone along on the interstate at 85mph and 6,000 rpm all day and all night. The engine is designed to safely turn that fast, and really doesn't care if you think it's supposed to sound like a Harley or have similar power characteristics.

Yes, a VX800's powerband takes some getting used to if you're expecting it to work like other V-twins. And indeed, it does have excellent low-rpm torque as expected. But with 4 valves per cylinder and overhead cams, it is also perfectly capable of revving hard -- there's a good bit of power above 6,000 rpm.

Newbies always ask the same thing about the GS850G, too -- they all think it "sounds too busy" at highway speed. I don't know what "sounds too busy" means, really. I do know that if high revs (6,000 to 9,000 rpm) hurt the GS850 engine, I'd never make it back home. 6,000 rpm (about 80-85mph in fifth gear) is just where the fun starts.

[Vishnu]

I understand what you mean about it not really being a problem, I know the engine canrun at 6000 rpm all day. I have done Toronto to Vancouver in 3 days...so I have lived it. I just feel that for my type of higher speed and longer distnce reducing the rpm would make things a) cheeper, and b) potentially faster (through the praries I know 120 is a good all day speed). If I could reduce the highway rpm by say 1000 I figure it would take less than a year to recoup my costs. That is based on 500$ USD. Since my bike has just broken the 21K miles barrier I thik I have the potential for lots of life yet...and many adventures.


As it stands I have been reading lots about the C90 drive mod for the Volusia. It usese a 2.66 ratio final dive, and there do seem to be quite a few guys with it, and they all say it does make long distance riding a bit easier (my guess is it reduces some of the buzz the 800 motor starts to get around 6k rpm). I am looking at fiches and trying to loctae the various parts I ould need from a GV1400. Has a 2.66 final drive, just needs a drive shaft chop/mod...I'll know more when I get the parts in my hand.