Final drive swap

[James England]

Hi Folks. I've been reading loads of previous posts/threads about swapping the final drive gearbox on the XS1100 for one from an XS750 or XS850. Like many people, I'm always looking for a non-existent 6th gear and I don't like the feel when the engine is revving high at higher speeds. So, I'm thinking that the 750 final drive swap could be for me.

Reading some posts though, people have mentioned inaccurate speedometers as if this is somehow associated with changing the FD. Unless I'm missing something, how can changing the final drive affect the speedo reading? I mean, it runs off the front wheel, right?

Also, could anyone who has done this swap and is still running it please give me an update on the copper bush side of things? Do they hold up after a long time/miles?

[crazy steve]

Keep in mind that most who do this swap have specials; they have a lower 'effective' gear ratio due to the smaller diameter rear tire/wheel combo. Not to say you won't see a rpm drop, but you'll have a little bigger performance penalty too....

[James England]

Oh, I didn't think of that. My rear wheel is, as you know 17", and not the 16" of the Specials. The rpm drop will be exactly the same though, won't it? But with the higher penalty on performance because of the larger wheel.......

[WMarshy]

Oh, I didn't think of that. My rear wheel is, as you know 17", and not the 16" of the Specials. The rpm drop will be exactly the same though, won't it? But with the higher penalty on performance because of the larger wheel.......

No, what he's saying is the Specials have a 16" wheel stock and Standards have 17" wheel sotck, both with the same drive ratio but, due to the size difference in tires, a Special turns a little more RPM over the Standard at the same speed. Therefore, they seems to experience the "where is 6th gear" problem more commonly than the people on standards with the 17" wheel... In general, changing to the 750/850 FD will have a little acceleration loss due to the "taller" gear ratio although its not very noticable according to the people who made the change (about 500 RPM). Personally, I think your all driving these bikes like a panzi! Spend a few miles riding and shifting above 6000 RPM and the cruzing RPM will seem lower.

[crazy steve]

You'll see a bit bigger drop, but you're also not starting at as high an rpm. If I recall right, if you figure the standard as the 'benchmark' with a 3.3:1 rear gear, the special has an 'effective' ratio of about 3.43:1 with the smaller tire. That's the reason the specials became the faster one of the two after they came out.

[James England]

Personally, I think your all driving these bikes like a panzi! Spend a few miles riding and shifting above 6000 RPM and the cruzing RPM will seem lower.

Nah.... I'm riding mine like a 31 year old bike that I'd like to use with a certain consideration/care so that it lasts as long as possible.... preferably another 31 years It's fast enough and powerful enough for me at revs below that. I mean, these bikes are old and can't take the punishment they did when they were younger. For high-revving, high performance, I would just go and buy a modern bike. I can't see the point of pushing an older machine too far......

[WMarshy]

Nah.... I'm riding mine like a 31 year old bike that I'd like to use with a certain consideration/care so that it lasts as long as possible.... preferably another 31 years It's fast enough and powerful enough for me at revs below that. I mean, these bikes are old and can't take the punishment they did when they were younger. For high-revving, high performance, I would just go and buy a modern bike. I can't see the point of pushing an older machine too far......

LOL Im just ribbin ya man. Each to their own when it comes to riding style.

...
these bikes are old and can't take the punishment they did when they were younger......

Well that part might be open for discussion.

[James England]

I know you were! I must be quite a hypocrite... if you read some of my previous posts, you'll see I fitted nitrous oxide injection to my last XS11 and added an extra 90bhp. It burned off virtually any bike in a straight line. And I still didn't manage to blow it up. It's just with this latest one, I've got it looking and working so well, I'd hate to snap a camchain or whatever just through overdoing it. What I really need is a less restored example that I can thrash and not care about too much. It's the downside of lavishing too much time and money and energy on one bike..... you end up being too careful with it....

[cywelchjr]

Oh, I didn't think of that. My rear wheel is, as you know 17", and not the 16" of the Specials. The rpm drop will be exactly the same though, won't it? But with the higher penalty on performance because of the larger wheel.......

No, the drop will be larger. That said, having done the swap, I don't even notice it anymore, other than the fact that around town I now run in 3rd or 4th instead of 4th or 5th, and when I get onto the freeway (would be autobahn in Deutschland, not sure what it's called in England) 5th gear leaves me at a much more comfortable RPM. Since I'm not a hot rodder, I find I really don't miss it, and my driveway is pretty steep, so I thought I would notice it pulling into the garage at night if nothing else, but it's so much the non-issue.

I'd have to say, I've seen nothing from it but positive so far, no negatives that I've seen so far, but as I said, I'm not the type the tries or even wants to pull the front wheel up anyways (even though I have a couple of times.) With my riding style, I've seen a few MPG increase around town as well, but haven't gotten out on any distance riding as of yet to really get a feel for what it's done for my cruising mileage yet, I'll be doing a couple of rides this summer that should give me an idea though.

[DGXSER]

Hey James,

I had the 750 FD on my first XS11. I made the swap and loved it. I tend to ride highway quite a bit and backroads where speed limits are pretty much highway speeds around here. That 750 FD made the big beast feel more like the cruiser I was after. And with the massive amounts of torque these engines produce, you will never notice that either. I once took off in third gear (forgot to downshift), and other than having to throttle up a bit and feather the clutch just a tad, it still took off for a dead stop and ran right up to speed.

I also did this swap on a fellow XSives machine who had his bike since brand new (an 80 model). We just did it about 1-1/2 years ago, he still talsk about how nice it is.

As to wear, I had about 7k miles on mine and it showed no signs of wear. Reality is that the driveshaft, and the coupling that fitting goes up against turn together, so there is no real wear to occur.

[jetmechmarty]

Nah.... I'm riding mine like a 31 year old bike that I'd like to use with a certain consideration/care so that it lasts as long as possible....

I believe the FD swap will put more strain on your transmission, and more wear on your clutch. Don't be afraid of a few RPM.

Marty (in Seattle)

[Pat Kelly]

On my E, after the 750 swap, my RPM dropped by 800 at 65 MPH

[cywelchjr]

I believe the FD swap will put more strain on your transmission, and more wear on your clutch. Don't be afraid of a few RPM.

Marty (in Seattle)

I can see where you might can maybe see a little bit more wear on the clutch, but there is no way it can cause more strain on the transmission, it's the same horsepower, the only difference is the final drive ratio. It's like changing the rear end on a car, that doesn't affect the strain on the transmission one bit. It can affect wear on the clutch a bit, but that's so easy to change out when it wears it's not worth worrying about. Even I can change out a clutch in a couple of hours max (this does not include the oil soak time, but I don't figure that time counts).

[SFSPECBIKER79]

swap

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 2 it will be harder on transmission 3 more riding clutch 4 causeing more pressure on the rod bearings, which is harder on the engine, than the 5-800 more rpm higher it runs now, 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. i have a couple spare engines. i just don't see where the swap would be worth the trouble to do it. but thats just me. goodluck with the swap if you feel you need it.

[Bonz]

See the new thread in this section that I started today, "Final Drive Swap, finally" about finally doing my FD swap. With all respect, the "time and effort" is about a half day of having the bike apart, once the donor FD is set up to go on the bike.

I was a lazy butt for not doing it sooner, as I had my donor FD sitting around since last fall.

No extra strain on the tranny, like it was said, the engine isn't putting out any more power, so how can the tranny be strained? I can promise there is no extra "strain" on the clutch, as that would only happen leaving a stop, and it pulls away even more smoothly now, since it's not geared so dang short (softens driveline "lash") and the clutch engagement is flawless and smooth as always. As far as more strain on the rod bearings, you can do the same thing with the stock final drive if you are in too tall a gear for the conditions and no amount of reasoning will convince me that turning 4700 rpm at 75 mph with the FD swap is any harder on the engine than turning 5300-5400 rpm at the same speed with the stock FD. This bike was made to do one thing, and that was be the fastest production bike of it's time, and was geared crazy short. Plus, speed limits were 55 mph everywhere, so running at 65 mph wasn't that high of an rpm. Things are different now, speed limits are 75 mph and you can easily run 80 mph for hours many places, and the FD swap makes total sense for that in this day and age. Heck, 4th gear at 60 mph is about 4100 rpm now, vs in 5th gear with the stock FD I was turning an even 4000 rpm. Using the shifter once in a while ain't a bad thing, and if I'm paying attention, I won't be shifting any more than I was before because I have already learned the new gearing and make it work for me.

You can think of many non-starter reasons not to do it, OR if you are inclined, JUST DO IT, you won't regret it.