Final drive swap

[DGXSER]

Not trying to pick on you Rowdy, others in this thread and before have stated these same thoughts, your post was just handy to break them down.

i have thought alot about doing the swap, and figured that if i did it would be harder to start off from stops thats 1 drawback for it will cause more wear on the clutch

If you notice the difference with all the torque this machine makes, you need to check that engine out a bit. Seriously, I pulled out in third gear from a dead stop and it was not enough of a strain that I was certain it was third and not second until after I shifted to fifth and tried to shift again thinking I had one more gear to go. So it is no change to starting and stopping that I could notice.

2 it will be harder on transmission

Force transfer is a tricky beast. I will agree that the engine has to produce more force /torque to turn the wheel at the same weights and friction factors throughout due to the reduced mechanical advantage of the reduced gearing. However, unless your doing it at WOT, and dumping the clutch out as fast as it can take it, I do not think your any where near putting this drive train through more than it was designed for, or increasing the wear on it.

3 more riding clutch

that one I have to say is just not so. The clutch is designed for the torque output of the engine and it will grab and hold just fine with normal release. I have never found I needed to feather the clutch any different between the stock FD and the 750 FD.

4 causeing more pressure on the rod bearings, which is harder on the engine, than the 5-800 more rpm higher it runs now,

Again, just not so. The engine bearings and all will only see the torque the engine puts out. And these beast last for ever with proper maintenance even when beat on. IMO, the levels of force your talking about are not even in the range where this engine and its components notice. Its liek using an F350 truck to pull a Radio flyer wagon full of peanut shells. that truck does not even know it is there. So I do not see rod bearing wear or other engine wear from the swap.

besides if you get in a hard pull you going to grabb a lower gear and shoot up the rpms. these engines were designed for higher rpm and torque. thats one of the reasons i like them so much. if i want to take it easy on the engine i just slow down. if i want to go somewhere fast i twist the throttle and don't worry about the engine. because they are almost bullet proof if proper maint. has been done. mine has 43000 on it now and the 25000 i have put on it has been mostly interstate hwyway@ 70-85mph and 5500- 7500rpms and more when i wanted to cruise at 100mph.

Well said, and honestly defeats your own points No matter what the final drive ratio, you determine how much effort the engine puts into pulling up to speed. The swap just lets you do it with lower RPM required. And honestly when you get that range of higher speeds it is saving engine wear by reducing RPM for the same rate of speed. If you want to shoot up to 60 in 5-6 seconds or whatever the bike will do, well then downshift and hammer on it. And with all the grunt to spare these engines make, I think you will be hard pressed to notice.

All that said, yep I am a fan of the swap and no I have not done it on this bike just yet.

I will say that if you are planning to go carve out some canyon roads with steep hills and twisting turns, you will in that case notice the amount of shifting required that was not there with the stock FD, I can run around all the hills and twisties here in river town Ohio almost completely in 5th gear with the stock FD, I do need to shift a bit for the 750 in those extreme cases.

[Pat Kelly]

If the XS750 can handle it, why wouldn't the 1100?
(yes, I know, middle drive ratio)
Around town my bike is now a 2 speed

[SFSPECBIKER79]

swap

Not trying to pick on you Rowdy, others in this thread and before have stated these same thoughts, your post was just handy to break them down.



If you notice the difference with all the torque this machine makes, you need to check that engine out a bit. Seriously, I pulled out in third gear from a dead stop and it was not enough of a strain that I was certain it was third and not second until after I shifted to fifth and tried to shift again thinking I had one more gear to go. So it is no change to starting and stopping that I could notice.



Force transfer is a tricky beast. I will agree that the engine has to produce more force /torque to turn the wheel at the same weights and friction factors throughout due to the reduced mechanical advantage of the reduced gearing. However, unless your doing it at WOT, and dumping the clutch out as fast as it can take it, I do not think your any where near putting this drive train through more than it was designed for, or increasing the wear on it.



that one I have to say is just not so. The clutch is designed for the torque output of the engine and it will grab and hold just fine with normal release. I have never found I needed to feather the clutch any different between the stock FD and the 750 FD.



Again, just not so. The engine bearings and all will only see the torque the engine puts out. And these beast last for ever with proper maintenance even when beat on. IMO, the levels of force your talking about are not even in the range where this engine and its components notice. Its liek using an F350 truck to pull a Radio flyer wagon full of peanut shells. that truck does not even know it is there. So I do not see rod bearing wear or other engine wear from the swap.



Well said, and honestly defeats your own points No matter what the final drive ratio, you determine how much effort the engine puts into pulling up to speed. The swap just lets you do it with lower RPM required. And honestly when you get that range of higher speeds it is saving engine wear by reducing RPM for the same rate of speed. If you want to shoot up to 60 in 5-6 seconds or whatever the bike will do, well then downshift and hammer on it. And with all the grunt to spare these engines make, I think you will be hard pressed to notice.

All that said, yep I am a fan of the swap and no I have not done it on this bike just yet.

I will say that if you are planning to go carve out some canyon roads with steep hills and twisting turns, you will in that case notice the amount of shifting required that was not there with the stock FD, I can run around all the hills and twisties here in river town Ohio almost completely in 5th gear with the stock FD, I do need to shift a bit for the 750 in those extreme cases.

one of the other things i like is turning off and not shifting through the gears, i like to spend less time looking than shifting. it may better for some. with no more drop in rpms than 600 it could'nt be saving much.say the engine operated at 6000rpms @ 60mph for 1 mile. if you swapped FD your engine would turn 5400 thats saving 1/10 mile. you just saving 10 mile to the thousand. and 10000 miles in 1000000 thats just another year it would last the way i currently ride. i probally dont have 10 yrs riding left before i have to give it up. as to the way my bike is now, they are no sign of burning the engine up so the best for me is to leave it the way it was made. i'm use to getting picked on any way, i understand some don't agree with opinion.

[crazy steve]

My personal thoughts on a FD swap is, why? Mine always ran smoothly and effortlessly at any legal speed, and I usually had to go into triple digits before the bike showed any histronics...

I wonder how many bikes really just need a good tune? Don talks about that here: http://www.xs11.com/forum/showthread...182#post320182 . Sure, sometimes even I look for another gear but I don't think it's really needed. It's really about whether or not you're comfortable with motor rpm at the cruising speed you use most. There may be some miniscule reduction in engine wear, but maybe not. As far as fuel economy, I doubt if you'll see much if any improvement; it takes 'X' amount of horsepower to move the bike down the road at any given speed, and once wind resistance becomes a factor small differences in final gearing aren't going to make much difference...

JMHO....

[Joab]

How tough is it to dig up all the parts required for this swap?

[James England]

the freeway (would be autobahn in Deutschland, not sure what it's called in England).

It's called a 'motorway'. They all have a number eg M1, M6, M4, M25 (round London) etc.

I've found an FD from as 750 on eBay. He's after £50 for it.... it seems quite expensive and I doubt it will sell at that. It's done 45 thousand miles supposedly.

What I like about this modification is the fact that it's easily reversible. Based on the excellent information which everyone has responded with, I'll be doing the swap. I mean, what have I to lose apart from a few hours of pleasant messing about in the garage? Radio on. Cup of tea. Spanners out. It does look like such an easy mod. too. With fuel costing about $9 for an imperial gallon here, it should be worth it.

[cowboybob998]

Just did the swap

i just did the swap last week, have only rode it around here some but i tell ya what i am going to like it alot better than what it was befor, i like the gear spead alot better and i dont mind shifting more at all, i like it alot better when you back off for a corner, it slows down alot slower and dont throw your face into the speedo , get half way in to the corner and drop down a gear and go like hell, just the way i ride i gess, seems like i have better control over the bike to me, who knows might change my mind after i ride it more but i dought it, works for me.

[DGXSER]

Joab,

The parts needed are easy as can be. Get the 750FD, which I got one for the cost of shipping before $15, fellow was cleaning out the garage. The copper or whatever you want to use spacer is a trip to the local hardware store and less than $2. The o-rings are at the hardware store also, again less than $2.

Steve,
As I believe I mentioned earlier, I did this swap for an original owner of an SG. He is decisively more of a laid back cruiser rider and not a corner carving attack monster type rider. His bike had just recently gone through a cam chain replacement, valves shimmed, carbs cleaned, tuned, and synched by a fellow I know and can guarantee did it right. After riding the bike for almost 30 years in stock form, he has had nothing but great things to say about the swap.

Reality is this, it is strictly a personal preference thing, and the only thing it changes is the RPM level you run at, and the feel of the bike. I do not belive it does anything noticeable for engine wear, tranny wear, or even MPG. I do know that having doen the swap myself and after riding for several thousand miles with it, and now being back to stock, the change is noticable and for me it is much more enjoyable with 750 FD.

At the end of the day it is simply a matter of choice, nothing more or less.

[Bonz]

Hey, we all have pretty nice bikes in our XS's, so run what ya' brung, enjoy it and to each of us the pride in ownership no matter how our bike is set up, is the best part!

[cywelchjr]

What I find, is it feels smoother, more refined, more like a touring machine and less like a light to light rocket, so, if your not looking for a light to light rocket, or a canyon carver, I think the difference in the nature of the bike with the mod is worth the change. I was pushed into the change, since it turned out to be cheaper to replace my leaking FD with a 750 FD than find a good 1100 FD (bad left side bearing took out the seals). It really feels like this is the gear ratio it was really intended for in the first place, and then they went for a drag strip range instead to win races with it (which of course they did).

[Bonz]

Totally agree Cy, as I've siad, as you've said, as many have said, and as Yamaha said, they wanted to make the fastest production bike in the 1/4 mile at the time, and they did a good job of it... by gearing it like a 750 or similar.

In just a few short days since I did my "Franken Drive" conversion, the bike has a totally different feel to it. I've deliberately not ridden my 80 SG a lot to keep the miles off it. But also because on my commute, my 2001 ZRX 1200gets about 10 mpg better, and doesn't feel like it's wound up like a top at 75 mph. In general, most of the bikes and cars I ever owned tend to run about 40-50% of max rpm at an interstate pace, and with the XS it's spinning over 60% of redline, and it just doesn't match the bike. Now, my gut feeling is I'm going to want to ride the XS a lot more, and to heck with the miles, especially since I added a Plexifairing 3 about 2 weeks before doing the FD swap. I have a great road machine now! Even picked up a set of Fieldsheer saddle bags on closeout for the southwest rally this July, and the saddle bags along with a tail bag give the bike all the space I need for trips.

Long live the FD swap!

[cywelchjr]

Yep, if you notice, most modern vehicles cannot get to their top speed in their top gear, and in some cases must shift down two gears to get to their top speed. This is done for two things. Comfort at cruising speed (less noise, vibration and such) and economy (running at the most efficient speed for the engine at the most often run speed). This is different with the 11, where it gets to top speed in high gear, but with the FD mod, you get to top speed in 4th rather than 5th. That said, at cruising speed, it just feels more relaxed, more like a Goldwing on steroids (still the muscle man, but now with some smooth class ).

I'll never go back. I'm not sure I wouldn't even do this mod to a hack rig as well. I know more weight it involved, but most of the same issues are there, and these things have all the torque to handle the job.

[Shacknasty]

I have an 1100 and a 750. What happens to the 750's performance if I swap the FD from one to the other?

[Poprock]

My SG has a 850 FD. I carried a 210 lb guy for 135 miles on crooked, hilly mountain and coastal roads. Got 37.5 mpg with 460# of driver/passenger on board. Couldn't have had a nicer ride. Pulled fine up hills, plenty of grunt everywhere I needed it. It's nicer on the highway at 3500 @ 60. If I need to go fast, I downshift. Not a hard thing to do. It'll get me a ticket anywhere I want one.
I will say this: travel is so slow most places around here I think about putting the stock FD back in just to see what it's like, but I kinda remember, and I enjoy pushing 40 mpg rather than 32-35 like I used to get.

[jetmechmarty]

With all due respect, I'm not buying it. FD swap is more wear & tear. I'm not convinced. It won't be happening to my bike. Do as you will, but the jury is still out.

Marty (in Korea)