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carbman

Trike rearend

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Checking out rearends to build a trike with and saw on ebay, a trike rear end from American Classic Motors for $1500.00. Am I getting in too deep with this setup for the first try or if I can afford it, is this the way to go? I would imagine this setup is for hardtail, and I just build the back onto my bike. Lots to think of, need your help. John

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Are you going with a hardtail?

There's a bunch of ways of doing it, hardtail is easiest IMO, you just need an appropriate live axle that you can narrow, to suit the wheel track you want.

Any small rear wheel drive car axle is plausible depending on diff ratio.

Over here in the uk, the most common live axle choice is from some shitty old Reliant robin car, and they came with a bunch of ratios to work with. they work reall well with most prop shaft driven bike engines, and they have an offset diff so you only need to narrow one side. . Others use MG axles or old Volvo stuff.

If you want suspension, you first gotta decide if your gonna go IRS or not.

I'm using a jaguar irs on my wife's xj1100 trike... I personally find irs easy to mount, you only need to incorporate a frame for the diff casing, and shock mounts then just make sure the rest of the frame is up to handling the load off the shockers. Ok it's a bit more In depth than that, but it's pretty easy to set up.

Jag rear ends are plentiful all over the world, parts ain't hugely expensive,they'll put up with a lot of power and they're easy to narrow.

Alternatively BMW IRS etc.

Just check your final gearing and try n find a diff to suit.

There's plenty of gear calculators online to help.

1f4d985a-b08d-f027.jpg

Alternatively if you're using a chain drive motor, you can strip down lots of small diffs and attach a sprocket To it and in effect have a chain drive or belt drive diff to fit into a hardtail.

Here's an example or two of chain drive.

Regular small car diff in a housing, you'll get the idea.

1f4d985a-af4d-e8ca.jpg

1f4d985a-af62-4adf.jpg

1f4d985a-af8f-1ea2.jpg

1f4d985a-afac-51b3.jpg

1f4d985a-afc2-1a3f.jpg

Http://onebaddaddy.Wordpress.com

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Thanx onebaddaddy for the info, but this time around I have cut down a ford 8 inch rear end (slip diff) with 2:80 gears for the final drive. Yes I will be doing shocks for suspension. I am trying to make it as durable and safe and user friendly as possible.

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He doesn't come around as often anymore but BlackJack knows a lot about setting up trike rearends and could offer a ton of advice. You may want to send him a PM.

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Thanx onebaddaddy for the info, but this time around I have cut down a ford 8 inch rear end (slip diff) with 2:80 gears for the final drive. Yes I will be doing shocks for suspension. I am trying to make it as durable and safe and user friendly as possible.

silly question.... if you have the rear narrowed and have the work in your mid drive how come you are looking at other rears?

Edited by stacebg

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I take it you're looking at doing a swing arm conversion? ie axle, mounted to a frame section that pivots at swing arm mount?

Just my 0.2 but I really don't like those designs... And here's why.

A car axle is generally 'floating' on the leaf springs, with the shockers just taking the load from undulations in the road surface, BUT it can move up,down,sideways and a little diagonally fore and aft. All of which are 'normal' conditions for that setup. ie body roll in a hard corner, there is a lot of lateral force applied to the susp.

You might not think this is all relevant, but in most swing arm conversions people seem to forget that the axle is going to want to twist around with the movement of the suspension and torque load exerted during cornering, as it would in a car.

Now due to the fact that in a swing arm trike the axle is fixed solidly to the rear arm, and is no longer 'floating' on leaf springs, it can only move freely in an up/down motion at its pivot point.

That puts a lot of twisting stress on the swing arm mount, during cornering, especially when you consider The physics principle of leverage..the wider the track of your axle, the more force will be exerted at the mounting point.

Exactly the same as putting a breaker bar on a wrench to crack off a nut.

A lot of folks use the shocks as a top mount for the swing arm, in an attempt to triangulate the trikes rear frame, which IMHO is ├╝ber bad, as they actually do nothing. On a motorcycle, as it has one rear wheel,in a fixed pivot swing arm the shocks travel up & down in unison which is great.

Across an axle the shocks will want to move seperately as they load, but will be stopped by the swing arm.

You could try making a 4 link setup and panhard rod, as used on most hotrod susp. Four link mounts welded to axle and to rear of frame, 2 bars fitted either side, with poly bushes/ rose joints, diag bar from front to rear to triangulate.

That way you get a nice tubular rear end, pretty minimalist looking, and allows for susp movement but eliminates sideways movement which should stop frame fatigue.

Sorta like this.

1f4d985a-2441-baf9.jpg

And before the hardtail trike riders jump in, theyre a different story, as they tend to ride with more of a need to counter steer, which kinda eliminates some of the twisting motion and the load from the rear axle is exerted throughout the whole frame not just the swing arm area.

Like I said I ain't a pro at this but I have seen a lot of bad trikes and built enough hot rods to know when something's gonna be stressed.

Ask blackjack, he is about, I've seem him on some of the other forums recently.

Go steady

Obd

Http://onebaddaddy.Wordpress.com

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He doesn't come around as often anymore but BlackJack knows a lot about setting up trike rearends and could offer a ton of advice. You may want to send him a PM.

I have emailed blackjack with some questions on rear end set-ups and he got right back to me. Seems to be a good guy.

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If I make the swing arm, which will be attached to the pivot points on the bike, like two ladder bars and then put x bars from corner to corner, will not the swing arm unit move as almost one unit, even with the individual shocks to the frame? Does anyone have the email adress of blackjack. I am still in the process of dead centering all my drive to the rear end, and then will mock up the swing arm frame unit with some old pipe I have, before I get serious. I do want to make this bike safe and rideable.

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I take it you're looking at doing a swing arm conversion? ie axle, mounted to a frame section that pivots at swing arm mount?

Just my 0.2 but I really don't like those designs... And here's why.

A car axle is generally 'floating' on the leaf springs, with the shockers just taking the load from undulations in the road surface, BUT it can move up,down,sideways and a little diagonally fore and aft. All of which are 'normal' conditions for that setup. ie body roll in a hard corner, there is a lot of lateral force applied to the susp.

You might not think this is all relevant, but in most swing arm conversions people seem to forget that the axle is going to want to twist around with the movement of the suspension and torque load exerted during cornering, as it would in a car.

Now due to the fact that in a swing arm trike the axle is fixed solidly to the rear arm, and is no longer 'floating' on leaf springs, it can only move freely in an up/down motion at its pivot point.

That puts a lot of twisting stress on the swing arm mount, during cornering, especially when you consider The physics principle of leverage..the wider the track of your axle, the more force will be exerted at the mounting point.

Exactly the same as putting a breaker bar on a wrench to crack off a nut.

post-3819-0-97499600-1338989154_thumb.jp

post-3819-0-48069400-1338989234_thumb.jp

post-3819-0-03781700-1338989271_thumb.jp

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Are you going with a hardtail?

There's a bunch of ways of doing it, hardtail is easiest IMO, you just need an appropriate live axle that you can narrow, to suit the wheel track you want.

Any small rear wheel drive car axle is plausible depending on diff ratio.

Over here in the uk, the most common live axle choice is from some shitty old Reliant robin car, and they came with a bunch of ratios to work with. they work reall well with most prop shaft driven bike engines, and they have an offset diff so you only need to narrow one side. . Jag rear ends are plentiful all over the world, parts ain't hugely expensive,they'll put up with a lot of power and they're easy to narrow.

personally i like to leave the rear stock width handle great and less work

just me

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I hear ya stace.

I prefer stock width rear hardtail trikes, and narrowed irs trikes, as some of the stock length jag irs trikes ive rode lurch about a bit on the twisty stuff.

The first of the pics you posted is kinda how I'd do it, is that a four bar link setup? Kinda hard to see properly as I'm on my iPhone n it's not letting me zoom pics for some reason.

Http://onebaddaddy.Wordpress.com

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If I make the swing arm, which will be attached to the pivot points on the bike, like two ladder bars and then put x bars from corner to corner, will not the swing arm unit move as almost one unit, even with the individual shocks to the frame?

Does anyone have the email adress of blackjack. I am still in the process of dead centering all my drive to the rear end, and then will mock up the swing arm frame unit with some old pipe I have, before I get serious. I do want to make this bike safe and rideable.

not sure if I follow you here, but I'll give it a shot....,

If you put the x's between the ladder bars they will in effect be rigid again.

The whole idea of the four link, is that each bar is able to pivot. ie the two left bars(upper and lower) can pivot independently of the two right hand bars. The panhard rod between the left and right links is on rose joints which allow the separate 4 link sides to move yet maintains the triangulation.

I'm at my parents with limited things to do this but here's how it works.

http://i280.photobucket.com/albums/kk195/greaserbizz/214c2587.mp4

Sorry I don't have Blackjacks contact info buddy

Http://onebaddaddy.Wordpress.com

Edited by Onebaddaddy

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I hear ya stace.

I prefer stock width rear hardtail trikes, and narrowed irs trikes, as some of the stock length jag irs trikes ive rode lurch about a bit on the twisty stuff.

The first of the pics you posted is kinda how I'd do it, is that a four bar link setup? Kinda hard to see properly as I'm on my iPhone n it's not letting me zoom pics for some reason.

Http://onebaddaddy.Wordpress.com

better pic maybe its a corvette rear has 10 links counting the axle ...

post-3819-0-10866500-1339025091_thumb.jp

post-3819-0-08581300-1339025142_thumb.jp

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Thanx onebaddaddy for the info, but this time around I have cut down a ford 8 inch rear end (slip diff) with 2:80 gears for the final drive. Yes I will be doing shocks for suspension. I am trying to make it as durable and safe and user friendly as possible.

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That was an excellent mockup for me baddaddy, and thanx guys for the info on blackjack. I have not contacted him yet, as I have just had the mid drive unit machined to fit and will be putting it in place along with mocking up the ladder bars to a swingarm pivot point and take some pics for scrutiny by those of you who are in the know. Stay tuned for some pics in the next few weeks as to where I am at. I still won't be done until next summer but the journey is where its at.

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Finally got the splined shaft for my mid drive and a 14 tooth 630 chain sprocket. Had my machinist friend mate the two together so that I can now start lining up the drive shaft to the mid drive etc. Is is necessary to tilt the rearend or have a degree of incline to the drive shaft for better performance! I need to know this before and can tack the parts in place. I am trying to leave areas for adjustment but with a swingarm and drive shaft the chain will have to take up the slack with a chain tensioner. Will send some pics as I line things up.

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Finally got the splined shaft for my mid drive and a 14 tooth 630 chain sprocket. Had my machinist friend mate the two together so that I can now start lining up the drive shaft to the mid drive etc. Is is necessary to tilt the rearend or have a degree of incline to the drive shaft for better performance! I need to know this before and can tack the parts in place. I am trying to leave areas for adjustment but with a swingarm and drive shaft the chain will have to take up the slack with a chain tensioner. Will send some pics as I line things up.

I've been taught that the straighter the line the driveshaft has, the better it's going to be. Less chance of vibration and better longevity of the parts.

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the 2 shafts need to be parallel but not in line..or offset just a tad or you probably will have a vibration and the u on each end of the shaft need to be timed the same or same result....

hope that make sence...

stace

Finally got the splined shaft for my mid drive and a 14 tooth 630 chain sprocket. Had my machinist friend mate the two together so that I can now start lining up the drive shaft to the mid drive etc. Is is necessary to tilt the rearend or have a degree of incline to the drive shaft for better performance! I need to know this before and can tack the parts in place. I am trying to leave areas for adjustment but with a swingarm and drive shaft the chain will have to take up the slack with a chain tensioner. Will send some pics as I line things up.

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I have been told that the drive shaft or rear end should be angled at about 7 degrees to each other. Is that necessary or make any sense. I will have them dead center with each other (no problem)but the mid drive is a few inches higher than the rear so will be going at a slight angle. Should I turn the rear up to meet this angle or let the u-joint do its work. In other words, can I leave the nose of the rearend level and just let the drive shaft angle up to the mid drive? And I will make sure the u-joints are in unison.

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not sure wher the 7 degrees comes from.... possibly cars have the engine at 7deg which would mean the rear should be at 7 deg

like wise ig your mid box is 4 or 5 deg the pinion should be the same angle

there is some margin for error there but not sure how much it would be...

try to get as close as posible

cant remember what if any thing you have for suspension

but if the rear can move to where the 2 shafts can possibly be in line up and down you would not want them to be dead center side to side...

so there would never be a chance of them being in line in both directions

for example the corvette rear uses ujoing in the half shafts... the hubs are an inch or two behind the differential so no matter where suspension travels the joint are aways moving

hope that clears it up a tad...

if not ill try again

can be tough without a pen and paper

stace

I have been told that the drive shaft or rear end should be angled at about 7 degrees to each other. Is that necessary or make any sense. I will have them dead center with each other (no problem)but the mid drive is a few inches higher than the rear so will be going at a slight angle. Should I turn the rear up to meet this angle or let the u-joint do its work. In other words, can I leave the nose of the rearend level and just let the drive shaft angle up to the mid drive? And I will make sure the u-joints are in unison.

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Thanx, Stace I am in the process of welding up and fitting the mid drive to the rear and will send some pics before I secure it in place,for examination.

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The 7 to 15 degrees is the range that cross type u-joints work best in. Less than 7 degrees of deflection and the needle rollers don't move enough to stir the grease and tend to wear groves in the spot that they set and vibrate. The rollers must move a full revolution. And more than 15 degrees causes early wear from extreme loading and extreme roller speed. It doesn't matter what plane the deflection is in as long as both u-joints deflect between 7 and 15 degrees. Generally in the real world you can get away with more deflection but never less than about 3 degrees.

Dusty

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