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muaythaitom

anybod make their own trike rear???

18 posts in this topic

Am looking to do a custom trike project. Was told I could use a car rear with some work instead of searching and getting robbed for a old servi-car rear. It is a Harley engine and trans and I wanna run some big old tires on it so I would guess a car rear would be much stronger---any suggestions?

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Am looking to do a custom trike project. Was told I could use a car rear with some work instead of searching and getting robbed for a old servi-car rear. It is a Harley engine and trans and I wanna run some big old tires on it so I would guess a car rear would be much stronger---any suggestions?

Yeah.

First off you using a shaft bike or a chain bike as a basis?

Chain you got a couple of choices, Yamaha middle box, or chop the shit out of the axle and make it chain drive.

Shaft is mostly easier.

Next up, You need to know what size rear tires your using. Tire height is a gearing issue. Tall tires, give you tall gearing, lower tires, give you lower gearing.

You can end up with a trike that does 60mph flat the fuck out in top gear, or you can end up with a trike that fries the clutch trying to pull away and won't hold top on the flat.

Basically you need to work out how far the bike travelled for one turn of the drive shaft (tire circumference over the original bevel ratio), then you take the circumference of the tire you're planning on using and divide that by the distance the bike used to travel for one turn of the drive shaft. This gives you the final drive ratio you need to keep the gearing stock. Most people agree that 10% lower is a good plan, but if it's a single seat trike, stock gearing isn't going to hurt.

Clearly you need to know the tire dimensions as wiothout that info you've got no idea how high the axle needs to be above the ground.

So, pretty much the first thing you need to know is the tire size you're using for the finished trike.

This is a bolt on rear end I built for a V-Max. Uses a Euro ford 3-litre Capri axle.

MOST (but not all) car axles have the crown wheel to the left of the pinion gear. If the donor bike has the shaft drive on the left of the bike, then it's crownwheel is on the right of the pinion gear.

What that means is that if you install the axle the way it was in the car, you got five reverse gears. Flipping the axle over left for right sorts that out.

If the bike has the drive shaft on the right side (Gold Wing for one) then it's no problem.

If you're thinking suspension, IRS is the ONLY sensible way to do it, and that handles like shit.

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Anyone know if any other right side drive shaft bikes? I am loving this thread already and while we got blackjacks attention we can all ask many questions...lol

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yes, blackjack is a smart Mo-Fo for sure. It is a 88" Panhead with a 5 speed trans. wanna do a low seat height with a fold away 2 person passenger seat--kinda like the old hotrods had. I am basically just looking for a nice wide set of low tires--kinda like Exiles trike has. I can hit the scrap yards and get a rear out of an older Mustang or something for fairly cheap. I have access to all the steel and alum I need--for free, so cost of that wont be an issue. Basically looking for something to tote the kids to school on and a barhopper/short run bike----I have several other bikes for long runs and such---although I would like to be able to put some miles on it if need be or the mood strikes

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I'm using a Ford 9" rear, flipped upside down. I shortened the housing to 28" and had the axles made by a shop here. BTW...unless you know someone in a machine shop that will do the axles for you, it's gonna be pricey, it's probably best to go to JEGS or some other site like that to get your axles. I asked Blackjack about the ratio thing before and finally figured out that the final drive on the XS750 was about 290 and the 15" wheels and 70 series tires are real close to the same height of the stock rear on the bike, so I went with 300 gears in the rear end hoping it will compensate slightly for the extra weight and maintain a top end somewhat close to stock. I guess we'll see. :whistling:

Sorry if I got a little long winded. >.< Hope it helps.

post-7756-1244239700_thumb.jpg

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Doh!

Missed the bit about you using a HD drive train....

First off, the rumble seat idea sounds good, but if you're putting kids on the back of it then you want them sat in front of the axle line.

Drivers get blinder every year, and the chances of one of them running into the back of you is not exactly negligible.

Simplest way out is to have a rigid trike, car axle, and some sort of 90 degree bevel box driven by a chain or a belt off the tranny and driving a shaft to the rear axle.

You don't want a reduction on the drive to the bevel box, so either a custom trans pulley to accept industry standard belts, and a short belt driving to the bevel box, or move the bevel box back and use a longer chain (really short chains wear quite quickly).

The bevel box off of an XS750/850/1100 Yam is one choice, but there are industrial bevel boxes out there too. You need to watch speed and torque rating on industrial stuff...

Though a guy I know once built a Ford Pinto engined chain drive bike using a bevel box that came from a yard where they were scrapping ships. Part of the deck gear from a minesweeper apparently...

If you're any good with a decent sized lathe (or know someone who is...) this sort of set up is a better choice, but if you can't do the work yourself, is gonna be expensive...

http://www.westgarage.co.uk/forsale/kits/kit2.html

But as I said, if you can make it yourself...

http://www.100-biker.co.uk/forums/showthread.php?t=38944 (pics around the second page?)

Then set it up either as an IRS set up or build a rigid "truss" to locate the diff and hubs like I did with that XJ650 Maxim trike frame.

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or a toyota corolla rear..its like a mini 9in ford w a removable center carrier..

If you're using shaft drive to the axle and not converting it to chain drive, then the available diff ratios are the main consideration.

RWD Corollas being small motored cars AFAIK, you're likely to find that the ratios are all too low to be comfortable.

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Am looking to do a custom trike project. Was told I could use a car rear with some work instead of searching and getting robbed for a old servi-car rear. It is a Harley engine and trans and I wanna run some big old tires on it so I would guess a car rear would be much stronger---any suggestions?

Yeah..

If you're thinking suspension, IRS is the ONLY sensible way to do it, and that handles like shit.

Here's some pics. and a link to my Photos.

cameraapril06153small.jpg

I used a rear bevel drive from a triked V65 Sabre to turn the drive 90deg. The ratio was approx 3-1. The Reliant axle ratio was approx 1-3, result!

If I'd not decided to use the standard rear axle position, but fabricate a new swingarm, then it would've been much shorter. As it was I could use the stock drive belt and pulleys. (cheapskate)

cameraapril06132small.jpg

Made on a steeply sloped and uneven driveway!

http://s132.photobucket.com/albums/q25/cho...%20fabrication/

cameraapril06044small.jpg

Hey Blackjack, I have the utmost respect for your work and advice, but I beg to differ with your opinion that an A frame type swingarm is no good. Mine worked just fine and the only time it was a handful was on a badly potholed dirt track that would've done for any trike.

Cheers, Mick. :cool:

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using a live axle and torsion tubes will give you a more stable ride too. you can get lightweight trailer ones for very cheap

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Hey Blackjack, I have the utmost respect for your work and advice, but I beg to differ with your opinion that an A frame type swingarm is no good. Mine worked just fine and the only time it was a handful was on a badly potholed dirt track that would've done for any trike.

Cheers, Mick. :cool:

Mick, most people are hanging a car axle (and bear in mind the the US isn't exactly dripping with Reliant axles...) off the end of a stock, bendy, jap swing arm.

The swing arms break, the frames break round the swing arm pivot, and about a dozen other things.

You know, and I know, that it's possible to engineer your way round all that.

Trouble is, by then you might as well have built an IRS set up.

That's without even looking at the attributes of it as a "suspension" set up....

So, no, I don't think it's any good.

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A good way to go is use a Frankenstein trike rear-end. www.frankensteintrikes.com They are not cheap, but you will be spending some bucks anyway if you do it right.

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Im wondering why an ATV/4wheeler rear wouldnt be a good start? You have a choose in shaft and chain, theyre tough as fuck and if the bearing arent hiway speed worthy, swap um. The shafty ones like out of a Polaris should have roughly the correct offset to match the power plant's

This one is a full setup with swingarm/carrier. And all for less than 100 right now. (disclaimer: not mine)

ATV_rear_axel.jpg

Use the swing arm from the ATV, the bearing carrier from the motorcycle swingarm, relocate the shock mounts, a little over and under bracing and bang. To get a rim/tyre combo more road worthy, a quick trip to somewhere like a junkyard for a good set of small Ford/Chevy/Whatever Hubs and a drop the whole lot off at someplace like a driveline shop for them to replace the ATV hubs for the aforementioned hubs. Now Ive never done this, but as soon as Im working agin, plan to. So if this is a bad idea please explain why. Id hate to die for lack of knowledge. Oh the donor will be a 1983 GS650G shafty.

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I've seen a handfull of homebuilt trikes with ATV rear ends. I think, beyond the speed difference they're meant for, the main issue is that most ATV's run a solid rear axle, with no differential. Kinda like driving a truck on the street with a locker. When you turn, the outside tire needs to be able to move faster than the inside, since it's traveling a greater distance. With a "locked" rear end, you get wheel hop, which beyond being annoying, stresses axles and other driveline parts, and things break....quickly. It's not as much of an issue on the dirt, where the tire can slide across the ground a bit easier, but on pavement, with a street-worthy tire, you really need something with a differential.

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I've seen a handfull of homebuilt trikes with ATV rear ends. I think, beyond the speed difference they're meant for, the main issue is that most ATV's run a solid rear axle, with no differential. Kinda like driving a truck on the street with a locker. When you turn, the outside tire needs to be able to move faster than the inside, since it's traveling a greater distance. With a "locked" rear end, you get wheel hop, which beyond being annoying, stresses axles and other driveline parts, and things break....quickly. It's not as much of an issue on the dirt, where the tire can slide across the ground a bit easier, but on pavement, with a street-worthy tire, you really need something with a differential.

Pretty much what he said....

Plus that sticky out, unsupported, axle bit is designed to deal with something that weighs a shit load less than a biggish jap four, and deal with it on dirt where you can't develop anything like the same lateral loads because it's dirt and getting tires to stick to it is tricky.

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A good way to go is use a Frankenstein trike rear-end. www.frankensteintrikes.com They are not cheap, but you will be spending some bucks anyway if you do it right.

Plus they don't seem to have much of an understanding as to why cars spin tires, or why that wouldn't apply to a bike where the crank was tranverse....

If you take the trouble to look up there somewhere, I posted a link to the 100% Biker forum where some guy just made his own set up like that out of a Ford Sierra/Merkur IRS diff. I'd guess you could buy a used, full size lathe, have the three phase installed to your house, buy the material, the tooling, and a second hand diff, and STILL spend less money than that...

Not saying you have to, just saying you could.

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