750fd

[Bamper]

So why does everyone want the 750FD? is it a lower gear ratio or somthing? Also how much does one of these run used and what models fit the XS1100SF?

[TopCatGr58]

750 Final Drive mod tech tip on Beta Site, complete with photos!
T.C.

[dbeardslee]

Bamper - 1100 FD is 3.3:1 gear ratio while the 750 is 2.9:1. The main reasons I wanted one (can't speak for everyone else) are better mileage, and lower cruising rpm's. Pretty sure all xs11 and 750 rear ends will swap. Everything I read said the '79 or later rear ends are an easier conversion - not sure why, but why tempt fate. They're all over e-bay. Saw one for $9.95 but it was for a '77. I bought mine from a local guy for $50 'cause he had it right here, and he said he would guarantee the seals and gears.

I'm right in the middle of doing the conversion right now, and the hardest thing about it is getting the drive shaft back in. Plugging the spooge holes and cutting a spacer - the actual mods you have to do - are incredibly easy.

[mason79]

i bought one from ebay a year ago and never put it in

it is from a xs 850 i believe it's the same

missing the vent cap but otherwise in mint cond, pm me and make me an offer if you want it.

[Brasco18]

So any year 750 FD will swap out any year 1100 FD?

[dbeardslee]

Brasco - 79 or later 750 or 850 FD's are preferred. The word is it makes for an easier conversion. Make sure you inspect the splines on your universal joint if you make this mod. I started this mod on mine and found the end of the u-joint was chewed-up and wouldn't allow enough spline engagement to suite me. Gonna get a better u-joint and try again.

I paid $50 for mine from a local guy who guaranteed it. They're all over e-bay. Cheapest one I saw was $10, but no guarantee. The reasons I want to convert are gas mileage and top-end.

[tomatao]

I'm not sure why they say to use a 79 or later. I put one from a 77 on mine. The worst part was getting the drive shaft back into the U Joint. That had nothing to do with the final drive. I paid about $25 on ebay with shipping.

I didn't notice any big fuel milage jump, but I tend to get to speed quickly. However it dropped my RPMs by about 1k at 70 mph.

I also found it nice around town being able to stay in 3rd longer.

[dbeardslee]

tomatao - I'm not sure why either, but I checked the fiche, and the only difference I can see is the flat head screw on the fd flange where it mates up with the drive shaft housing. I think it's got something to do with the shimming of the pinion. The 77s and 78s don't have that screw. Maybe someone who knows what it does will chime in. I know when I did the modification to the fd I didn't have to mess with the pinion at all. Just took the nut off, cleaned it, gooped the big washer and put it back together. Everything I've read says you can use any of them, but they say the '79 and later is easier. Me being all about the easy way I didn't look into it much farther, and just got one off a '79.

[Brasco18]

A friend of mine doesn't seem so enthuised about this mod. He compares my bike to his dual sport, saying this bike is suppose to have high rpms, that is where the 'sport' part comes into the 'sport touring' title. I guess I am trying to determine if this mod is a good idea or not.

[tomatao]

dbeardslee,

I was able to leave the pinion in on mine as well and just goop up the washer. Anyway, it worked for me. I had missed the whole "use a 79 or later" when I bought mine. Oh well, I've got a few hundred miles on it and it seems to be fine.

IMHO the mod was definitly worth it. The bike just feels better on the highway. I didn't notice any difference in power, just that the shift points are a little different. Like someone else said, I'm not searching for another gear on the freeway anymore.

The nice thing about this mod is that it's pretty easy other than getting the drive shaft back into the u-joint so if you put it on and don't like it you can easily switch back.

[trbig]

If you want high RPM, downshift and ride it in high rpm. 4th gear after the mod is almost identical to 5th gear stock.

Here's a posting from another thread I wrote in concerning this mod... don't know if you caught it.

"One of the things I like about the 750/850 mod IS the way it is in the other gears, but 1st gear especially. The bike still has enough torque to do wheelies off the line if I choose, but feels like it now has a COMPLETE first gear, not a granny gear. Racing guys on other XS bikes, 1st gear is generally where you get them the most. I can rap it up to a much higher speed in 1st than they can. When they go to hit 2nd and shift, it looks like they hit the brakes compared to you. When you finally hit 2nd, they can't make up the ground they lost because they are soon shifting into 3rd."

SO... just because you'll cruise at a little lower RPM in 5th, doesn't make your bike less "Sport". If you are in 5th gear... if you go full throttle, you'll feel very little difference in the take-off whether it's in the stock 5k range, or the after-mod low4k to high 3k range.

Truly... the only downside I can see for this mod is if you take off from a stop going uphill and you regularly haul a trailer or a sidecar. Other than that... it's an awesome mod.

Tod

[Brasco18]

So say I live in a very hilly area (which I do), would this mod be a good idea? Duluth, MN is like a mini San Fransisco, hill-wise

[dbeardslee]

Brasco - Duluth, MN. My little brother was born in Hibbing, up on the iron range. With or without the mod, man, you've got some great places to ride, not to mention the fishing.

[John]

The real skinny

I was one of the first to do this mod after Maximan first posted it, and it is the best thing I have done for the bike. I also have an 80 Special that hasn't been modded yet, and I can tell you that the results are amazing. Your engine speed will lower by 6-700 rpm at speed, and you can really wring it out if you want, and you'll still have plenty of nuts for any up hill climb. I have been riding in the Ozarks a couple of times this year, and I have had no problem with the gearing at all. I will never switch back. I didn't have any real MPG gain, but I was looking to get a taller gear anyway. I already have an F/D all modded up and ready to go on that Special, but it has been too damn hot here to do anything in the garage. We have had temps like 102-105 the past few days, with more in the forcast for next week.

[trbig]

Tell ya what...

Find a good price on one and pick it up. It's a pretty straight-forward swap to do. Try it out for a while... if you don't like it, throw the original one back on and sell it to someone here. This isn't a huge decision like you're buying a home or getting plastic surgery. It's easy enough and cheap enough to try out.. no big loss if you don't like it, but I'm betting you will.

Tod