81 Goldwing 1100 cc modifactions for a Reverse Trike.

[DaveJ98092]

I have a 81 GL1100i that I wrecked back in Oct 09, wrecked me too. I bought all the parts to replace the broken bits. But The knucklehead that was rebuilding my front forks decided to just retire and took my parts along with about 15 other customers and scrapped them. I had no invoice to prove he had my parts as he is my sons wife's uncle. Enough on that part.

I have researched early GL engines and they have a few flaws.

1. Bad stator/charging system. Its stuck in the back of the engine and has HOT oil on it all the time. It is also a small amparge output, causing it to overheat. VERY COMMON!

2. Camshafts are run in the aluminum head without bearings. The cam journals get worn off center and cam timing goes to hell.

3. Carbs!!! 4 of them and always needing work.

4. Weak gear shifters and bad cable clutch issues.

5. Run hot.

6. Shaft drive with a narrow rear wheel. Limited gear and tire combo.

7.Rotten designed exhaust.

Being that it is a big engine in a small package made a naked GL1000 a hot bike of the 70's and 80's. But being in a small TIGHT package was the challenge to make it better.

So along come the idea of a reverse trike. You can build in extra room to modify things.

1. AXE the stator system and hang a GM type 1 wire alternator on the front driven by a crank pulley. Outpot is 90+ amps, over 1080 watts from a small alternator. Need more, hang a 120 Amp. That crank pulley would also have magnetic pickups imbedded for a aftermarket Ignition/Fuel injection setup, like a Megasquirt or MSD .

2. Delta Cams in Tacoma WA can cut any cam for any engine. I may have a larger journal cam cut and then have the heads machined back on center.

3. AXE the carbs, see #1 about crank pulley. Make a manifold to run 2 throttle bodys off a Suzuki Burgman 650, or 1 Hollie 350 CFM 2 bbl carb, or a 390 CFM 4bbl carb.

4. Use later GL1200 gears, shifter and hydrolic clutch.

5. A bigger aluminum radiator can be placed in a better area.

6. Shaft drive is nice, you can build a swing arm with any single side rear diff or dual belt drive from a car diff. MUCH bigger rim/tire combo will fit. Endless possibility's.

7. A tuned 4 into 1 header.

Anyone have any more input?

[westgl]

1. I agree a great fix for the charging system is to put a 5" dia pulley (from tractor supply) on the front of the engine and a v belt with a chevy alternator this will provide full charge at idle.

2. Get rid of the 4 carbs, too much work. Go to a single carb set up they are very reliable and you have only one carb. A Holley 350 is WAY TO BIG,

It wont work, it's been tried, It WONT work, A Smaller carb will work MUCH better.

3. A Cable clutch can work but the cable has to be in nwer condition and has to be routed good enough to provide a smoooth pull.

4. shifter and gears are fine on the 1100, a taller tire will give you more of a freeway flyer ratio

My thought for a larger tire, would be use available stuff it is easier to engineer,



I would go to a Motorcycle Junk yard, and get a, Swing arm, rear Wheel, and rear brake,Complete, with caliper,shaft drive from a 88'-2000' GL1500, this will accommodate more Rear Car tire choices and a wider tire too.



For my thought of a reverse trike is a VW beam axle with the Engine tucking up very close to the rear of the VW axle, with a frame built to mount to the VW front axle, Radiator in front of the beam axle, disc. brakes.



as far as the seat goes it would be mounted over the Goldwing Transmission, as i would want this trike to have a SHORT wheelbase, and be short overall. It would be a Single seat trike, to keep it short.



I also though of putting a Track system so that I could slide a single seat over on the track from the center and add a second seat side by side, (adding a storage compartments on the track to both sides of the single centered seat) tracks when only a single seat is be used

[westgl]

As far as exhaust, I used the headers from the goldwing, and put on a pair of Harley Davidson slip On Mufflers, they have many different mufflers

I bought them as take off's at the HD dealer for $30.00 a pair they were taken off before they were ever used new owner wanted them on bike before he picked up bike, So they were basically in New Condition and the Goldwing sounds excellent with them.

I took the mufflers to a muffler shop and had them spread the openings open a little more to fit the Goldwing header, then clamped them on.

[painter]

Westgl, How would you do the drive system with the GW engine in front? Also, would you have a full firewall? How about your thoughts on a wide rear tire setup.....is there anything out there to make it work with a shaft drive or would you use a right angle setup to chain or belt?

[DaveJ98092]

For a front diff, I think a Subaru rear diff with twin half shafts driven by a short driveshaft from the Wing motor. There are so many all wheel drive rear diff's that could be used.

[painter]

Am I missing something? GW front mount engine but rear wheel drive. Shaft to (diff) or right angle drive and chain to wide tire. How do you use a car diff here?

[DaveJ98092]

If you want a GW 1500 or 1800cc up front and drive the single rear wheel then a custom drive shaft would be needed. Then the GW's rear swingarm with the GW rear diff is all that is needed.

But if you want a GW engine up front driving the front wheels then a short driveshaft to a Subaru/Mitzy or any independent rearend with shafts could be mounted up front and the shafts would drive the wheels. Its just a matter of adapting the CV shafts to have enough flex for steering like most frontwheel drive cars.

Any good HP shop could make a set of shafts to mount a VW engine and transaxel up front with FWD steering knuckles and outter CV shaft ends.

[painter]

Dave, I appreciate the suggestions. However did you miss the 'wide tire' part? The GW diff will not work on a wide rim without a machined part. Looking to use a setup of a GW engine front of driver with a driveshaft back to a right angle (of some sort) that has a drive chain that would go back to a GSXR rear wheel with auto tire mounted on it.

[DaveJ98092]

Ok going from shaft drive 90 degrees to a chain drive will be a challenge. I would pick a different engine if not using shaft all the way. That said, a newer GL1800 rear swingarm will accept up to like a 205 mm tire. But swingarms can be modified for a bigger tire.

The reason I started this with a GL1100 is I have one all broken up in my shed. I would really start with a GL1500 or a GL1800 just for the reverse gear. I know I could cobble up a reverse drive setup for any engine combo.

Using an auto diff would take a bit of work. First it has a reduction gear built in so the chain/belt drive would need to be close to 1:1. You would also need to have the spider gears inside welded so both out shafts turn the same and are locked. Then a gear for the chain/belt must be fastened on to the out shaft flange. Using a "starter clutch" on the other out shaft's flange and a starter you'd have your reverse drive.

[stretchmobileski]

How about a box like a transfer case. Sprocket on the output from the trans to another sprocket on the opposite side and a chain connecting the two, them drive shaft to the wheel. Basically moving the drive shaft to the other side and making it wider. You can accommodate any width tire.

This guy has an interesting reverse setup. www.lynxae.co.uk/Products-Bikesports.htm

[painter]

Thanks Dave and Stretch. Don't want to highjack someone else's thread but since the GW modification is here I think we should include all GW's to make it simple. I already have a GW1500 and if there was a good way to right angle the drive shaft to a chain or belt driven rear wheel with something that would hold up against the torque, it would/should benefit a lot of builders out there!

Let's face it... GW engines are reliable, some have a reverse built in and they are considerably cheaper to purchase than the popular sport bike engines. They also have a clutch designed for a lot of weight! PLEASE someone put us on to a right angle apparatus that would work! This could open up many more engine possibilities for builders wanting to use a shaft drive motorcycle....and we know there are a LOT of them out there!

[stretchmobileski]

Yamaha makes a right angle drive that bolts on to one of their cruiser bikes. I've seen them on Ebay for less than $100. One side is splined and the other is a 4 bolt flange for a drive shaft.

[painter]

I have two of them. Not sure how the force on the shaft would be on the chain side without some sort of carrier bearing. Shaft input side would be no lateral force Stretch, this is exactly what I had in mind to use, however still uncertain it will go the distance!

I'm not sure, but I think that Yamaha used a shaft to the spline side via u-joint.

[painter]

Watching MTMTECH's build using an auto motor behind the seat really pushes my thinking. I thought from all that I have read that the weight had to be 2/3 front! But dealing with a forward motor is hurting my 'design' possibilities! WHAT DOES ANYONE THINK ABOUT USING A GW1500 BEHIND THE SEAT WITH A SHORT DRIVESHAFT TO THE GEARBOX ABOVE TO A CHAIN FINAL?

Also, began thinking about just using a vw front beam to simplify construction and to ease my mind on the apparent weakness of tube A-arms. Nothing against A-Arms but looking at some of them on RT's makes me wonder about hitting a curb, pothole, ect. A lot of stress on those small arms! The beam is pretty solid.

The picture is a 4-wheel but depicts my idea on frame design for the front 2/3's. WHOOOO.. GOT A PICTURE IN!

[noahkatz]

For a given cornering force, lateral weight transfer is the same no matter where the CG is.

So the less weight on the front wheels, the lower the cornering speed it takes to totally unweight the inside front wheel.

So better keep an eye on weight distribution w/rear engine, could be workable with long wheelbase and forward seating, and of course low CG always helps.

[Deleted]

Hi Dave. I built the same trike about four years ago and it drives fine. Check out the pictures in Facebook under "Eric Runyon". It has been upgraded since then. If you have any questions, I will be glad to respondt

[DaveJ98092]

I have two motorcycle engines I could go with when I build my first reverse trike. A 80 GL1100 and a 03 650 Burgman CVT'ed transmission scooter. Both would need a reverse gear setup added. Hard to say which one is a better build. The GL1100 was a full dressed Interstate and weighed about 750 pounds, the 650 Burgman weighed 627 Pounds wet as it went down the road without my weight added. They were about the same performance wise. GL1100 had maybe a bit less top speed as the 650 Burgman topped out at 122 MPH (LEO's Laser) for me once.

But if I do a bunch of the mods that the guys over on Classic Goldwings's are doing with single carbs and such, I think a GL100 would be a screamer R/T.