Fifth gear mod

[trbig]

5th gear would be a demon to try to make since it has the gear on one side and the dogs that engage 2nd on the other side. I'm unfamiliar with the pinion, but wouldn't there be a way to just change ONE of the gears to get what you wanted? Or close anyway so you don't have to fabricate two different gears?


Tod

[xschop]

the EASY method

and least expensive......................................... ...

750/850 FD swap

[trbig]

Yeah... but I want 'em both! (The gear AND the final drive together) I wanna cruise at 100 at @ 5k rpm! lol..

I see this gear thing making life easier on the motor, but as in the 750 FD swap I did, I never saw any difference in my fuel mileage. Dropping it a bit more with these gears... I just don't think it's going to help fuel-wise as much as some hope.


Tod

[xschop]

mpg's

I believe if you have the newer hot coils.....(MIKE's XS coils too Topcat) and your carbs are tuned properly, then you will see better MPG's with the swap.....some folks in higher elevations won't....but this is debateable.

[trbig]

I don't think that has anything to do with it. Alot of people have swapped them.. some got better mileage and some didn't. No other changes were made.. so not understanding why some do and some don't, but such is life! I'm not saying coils wouldn't help.... but I think they would help regardless of the final drive.

What I'm getting sure beats the 15-17 mpg that it got when I first bought the rusted oxidized POS!

[psycoreefer]

I'll bet the difference in why some get better mileage and some don't is the types of driving done. If your the type of commuter/rider that generally gets on the super slab and rides 60 or 70 miles to work at near legal speeds then you will probably see the better mileage.

Where if you are doing mostly secondary street driving at near legal speeds, or a lot of stop and go, or gridlock on the freeway, then I'd bet you don't see much if any difference.

[xschop]

FD swap

I helped my friend swap his and he noticed it lugging down. He went through his carbs and got even better performance that before the swap.I rode the bike before the swap and thought it was a little sluggish compared to mine. I also rode the bike after the swap and carb tuneup and was definitely better than before...this is my reasoning....

[DavesXS]

I drive a lot of highway miles for work. over 500 a week when were busy. That 5th gear will effect my mileage a lot. If all your driving is under 55 it will do no good.


I don't think we can only change one gear because if we add teeth it won't fit to the other.

The teeth can be ground off. Then a new ring of teeth made and pressed on the gear. Or welded on the gear. I'd just have to be done in a 2 piece style. That way you don't have to fab a gear, dogs and all.

Edit:
I just e-mailed a gear fabrication place "high performance gears inc" To see what they say about it.

[xschop]

diddo

that what was done to the 944 1st gear....

[DavesXS]

I'm waiting for a TCI so I can't do it. But has any one checked the rpm difference between 4th and 5th?

[DavesXS]

You might not even need an extra gear box. Here's a diagram. Forgive my drawing. I suck at PS.
All you need is 2 boards, and 2 dowls the gears slide snug on. Drill out holes in the boards so when the dowls/gears are inserted, they line up like they were in the gear box. Then pull the gears off, work on them, and test fit with out an actual extra box and gears.

[Mashermoto]

OK...I'm totally lost as to how you guys add a tooth to 5th gear, but in regard to needing to machine one or two gears I would think you could machine just one. The reason I think that is because MikesXS sells a XS650 5th gear overdrive that is just one gear with one more tooth.

I've installed one and have another on the way for another build. Some crack heads stole my bike before I got to test it out, but the install went easy enough.

Anyway, if only one gear is needed for the 650, I would think only one would work for the 1100

[trbig]

Changing the teeth is going to change the circumference of the gear. You'd keep the spacing in the teeth the same, but to take away or add, you are either going to have to make the overall size of the gear bigger or smaller.. and then it won't fit in with the other gear. You have two set shafts that are a set amount of distance apart and that can't change.

You could change just one if it had a chain connnecting the two, such as on a chain drive bike you can change one or both sprockets, but directly operating a gear off of another, you'll have to change them both to keep the spacing right.

I don't know anything about the 650 transmissions... so no idea why it would work with them??

Tod

[xschop]

gearing

Trbig is right, meshed gears are a whole diff. ballpark. This swap is doable if both gears are changed

[DavesXS]

Originally posted by DavesXS

I just e-mailed a gear fabrication place "high performance gears inc" To see what they say about it.

These guys messaged me back and said its a normal thing to do. So I explained who we are and what were looking to do and why. Told him about making a box with dowels to hold the gears and sending it and the gears to them. And asked for an estimate on what it would cost to re-tooth 2 gears. I'll get the gears, build the box, and send it to them. The person with the extra gear box can test fit and dry shift making sure they work. Then we can possibly do a group buy and get the price down.

Any thoughts?