My Trike

grandpanystrom61 · Aug 5, 2018

No real update today, other than I got lost a bit. I did try the reverse Triple Trees and liked how lined up and looked, but I would have to relocate foot pedal assembly and brake MC, so I will not be doing that.

What I drew on paper is not exactly what I am getting physically out in the garage with the trike. I have something wrong, maybe how I am finding angles, time will figure it out, I think it is how I am doing the rake angle, short on paper and yet longer in the garage?

Need to read things again, right down all the key points and tips that apply to this.

Wow, took a bit, but I got it figured out, the 47.5 degree angle is to be at the top of the neck, when I went from the ground line to get the 47.5 degree angle I actually shorted myself, so all was off, but it matching up now.

grandpanystrom61 · Aug 6, 2018

Never get in a rush to buy things, especially when you are doing a large project, best to take the time and double check what is needed is correct and shop around for the better price and product, maybe even ask for members input on it.

Okay, almost broke all those rules when I thought I needed a new 18" wheel setup, also ment going to disc brakes at a cost near 1K.

So damn as glad I did not do it........, turns out that I have a choice to make, spend near 1k on 18" front wheel assy., or use the 16" wheel with drum brake that is if all checks out true to keep using it.

Just a heads up, we owe it to ourselves to step back and look everything over a few times, once confirmed "good to go" get what is needed. Actually you can save time and money this way. Have a great week everyone

DeathBySnuSnu · Aug 6, 2018

Yep.....gotta stay on the right side of the 90.

Easy mistake to make.

IF you are going to make a new front end then use whatever size tire suits your fancy.

You must have been stuck on that larger rim when trying to use the original fork.

Practical and what looks cool are not necessarily the same thing.

A shorter and wider tire with more contact patch. Even a flat tread tire. All will be more stable, more forgiving, more breaking potential.

A tall skinny just looks cool. It can be made to be an acceptable ride.

There is a reason why the big cruiser with 16 inch wheels and a fat tire are the popular thing to trike kit.

I went to a skinny 19 inch and it looks cool. But I can push it around more.

Pick what you want to do.

grandpanystrom61 · Aug 6, 2018

correct drawing

It is a good feeling when the drawing match's up with what is in the garage.

The tires on the trike are old and weather worn at best, so I will need a new front tire and should get it mounted and on the rim before I get set on tube length or set on rocker arm length.

I have not completed the 18" rim drawing yet, but started it.

I can not find it now, but I read a chart (a guideline of rakes and wheel placement ) and it was for chopper's, so keep thinking " Chopperhandbook " but have not found it, anyways there was the 3 1/2" off set pivot to axle point with a 1 1/2" trail, like in my drawing, but I do believe it was for a 45 degree rake, and the next rake in the chart was 50 degrees. It was a guide to find the rocker arm length and pivot points with a specified rake. Once one has the pivot point location on the fork tube one can determine the tube length needed. Created by years of experience and data, at least that is what my mind remembers.

I will have to check again for it, but I remember the 3 1/2 to 1 1/2 configuration because that is how I got the idea of the 5" rocker arm length. Each rake angle gave a different configuration of figures for the wheel placement.

Now if we have to allow for expansion and compression of the shock/springs with the movement of the rocker arm, it is said that one should allow 32.5 degrees exp. and 32.5 for comp. for a total of 65 degree rocker arm swing area.

With that said, full expansion leads to a zero trail point and full compression would create a 3" trail, estimates made off the drawing, and I found a weight felt on the front end to rake ratio that was for choppers, not the same as a trike, but a estimate of 35% of the over all trike weight should be on my front end. Figure this out in lbs. and one gets a idea of what strength material is needed to be used so the new front end meets the need of the trike and one gets adequate braking power on the front wheel. I do like the bullet design to finish of the end of the fork tubes, and I seen them on Sugar Bears site if I remember correctly. A project for sure, even if you have someone else make them for you, but nothing good ever came easy.

stacebg · Aug 6, 2018

grandpanystrom61 said:
It is a good feeling when the drawing match's up with what is in the garage.

View attachment 60014

The tires on the trike are old and weather worn at best, so I will need a new front tire and should get it mounted and on the rim before I get set on tube length or set on rocker arm length.

I have not completed the 18" rim drawing yet, but started it.

I can not find it now, but I read a chart (a guideline of rakes and wheel placement ) and it was for chopper's, so keep thinking " Chopperhandbook " but have not found it, anyways there was the 3 1/2" off set pivot to axle point with a 1 1/2" trail, like in my drawing, but I do believe it was for a 45 degree rake, and the next rake in the chart was 50 degrees. It was a guide to find the rocker arm length and pivot points with a specified rake. Once one has the pivot point location on the fork tube one can determine the tube length needed. Created by years of experience and data, at least that is what my mind remembers.

I will have to check again for it, but I remember the 3 1/2 to 1 1/2 configuration because that is how I got the idea of the 5" rocker arm length. Each rake angle gave a different configuration of figures for the wheel placement.

Now if we have to allow for expansion and compression of the shock/springs with the movement of the rocker arm, it is said that one should allow 32.5 degrees exp. and 32.5 for comp. for a total of 65 degree rocker arm swing area.

With that said, full expansion leads to a zero trail point and full compression would create a 3" trail, estimates made off the drawing, and I found a weight felt on the front end to rake ratio that was for choppers, not the same as a trike, but a estimate of 35% of the over all trike weight should be on my front end. Figure this out in lbs. and one gets a idea of what strength material is needed to be used so the new front end meets the need of the trike and one gets adequate braking power on the front wheel. I do like the bullet design to finish of the end of the fork tubes, and I seen them on Sugar Bears site if I remember correctly. A project for sure, even if you have someone else make them for you, but nothing good ever came easy.

drawing look good...

if you dont have access to a drawing program auto cad or master cam or similar i would be happy to draw that up ... makes it real simple to change any thing to see what it will do to the trail....

in case you didnt know the shorter the rockers are the more your trail will change

DeathBySnuSnu · Aug 6, 2018

Download the free version of.

Draftsight

You can do all the 2d flats in that and also save it in a format that the machine shop can use.

For instance.... you save a rocker as a .dxf

Take the dxf file to the machine shop. And presto....a plasma, laser, or waterjet part without the engineering fees for drawing it in.

grandpanystrom61 · Aug 14, 2018

Good morning to everyone, well I have spent some time trying to get the drawing program to work for me. I have what was required to run it, but I think I lost patience with age, or like other programs a short course in how to use them is needed. Not giving up, just not making head way as fast as I wanted.Okay, tire size, wow, been going back and forth on what I should do, what is best for the trike.I remember on this 3speed bicycle I had, chopper it was called and had a little front wheel with lots of trail I am sure. It was great until high speeds down the step hill, front end would wobble uncontrollably. Usually a spill on the pavement followed.So does the design of the drop pivot with a tighter trail eliminate this with a small tire ? or does it still happen?Finding a 18 x 2.5" Harley rim has not been easy on ebay. 19" rim size seems what stock was on a lot of them, but can not go past 12 1/2" axle height. Okay seems house is up, need to take care of things.

DeathBySnuSnu · Aug 14, 2018

If you are making the front end.....then you can make any tire diameter work. You will have to re-work the math.

19 front tires are very common.

I have a 90/90-19 on mine.

Have you looked at bike rear wheels? The wheel dont know any difference front or rear.

grandpanystrom61 · Aug 17, 2018

Correction, I do not want to exceed the 12 1/2" front axle height. I would like the same rolling diameter on all 3 tires if possible, and I have gotten it real close to that now.2004 Triumph Thruxton 900cc 18 x 2.5 " steel spoked rim that should be here today. It will mean going to a disc brake on the front end, so more work for that and $.Tire size, getting that all figured out and ran into a issue, could be me.Rear are radial tires, on the front was a Metzeler tire which is bias ply type. Tire shop said it is okay to run tires like that on a trike, hummmmmOkay I always was told to run all radial or all bias ply on the car, yes it is different than the trike, but does this rule apply to trikes and bikes ?????Does one run radial on the rear and bias ply on the front, or do we want radial tires all the way around, or just bias ply ??????Just want to confirm info here, tires are not cheap and I do not want to make a mistake again. Guess I over did the thickness of my extension piece and welding things together will be a bit tricky I was told, but doable.Thank you everyone for the input and help that has been given, it kept me from giving up to getting things done and still have my trike, Happy Camper for sure.

DeathBySnuSnu · Aug 20, 2018

I dont think it will matter much, the tires are so different anyway.

I would be more concerned with a good tread pattern at the point of contact. Not to worried about a very round section profile as it wont lean much.

LarryA · Aug 21, 2018

for what it's worth..... I'm using a Dunlop 4.00x18 bias up front, nitto 225x40x18 radials on the rear..... the o.d. of the rears is near what the original tire dia. was, I wanted to keep the same gearing as the Datona. That said, the combination, in my opinion, works great. Now, this is the only trike I have ever ridden, but, at this point in time, I see no need to change anything.

grandpanystrom61 · Aug 22, 2018

Thank you for the feedback, I just wanted some rider input and not a salesperson input.

I have to decide on pivot plates, make my own and weld them in the down tubes, or purchase a set of machined pivot tabs that insert into the down tube and are welded into place. I have to locate them first if I can.

So the triple trees take a 39mm down tube, not but a hair larger than a 1 1/2 pipe, that is what I am using in the mock up, and the trees seem to tight down nice on them.... am I wrong...

Should the down tubes be thicker than stock, to me they look like 1/8th thick, and I was thinking they should be at least 1/4" thick down tubes due to the rake and stress felt below the lower tree area, or the thinner stock with stronger pipe inserts in the triple tree area for that added strength ?

LarryA · Aug 22, 2018

I would be a little concerned about tubes of only 1/8 in. wall. I used 1/4 wall drawn over mandrel tubing, which is I believe, just mild steel that is welded and sized od and id. , maybe chromemoly or more exotic materials would work in 1/8 wall??? I was wanting to accumulate front end weight also, maybe you have the same thoughts? the fork tubes are sprung weight anyhow. I suppose some, or all of the rocker weight is unsprung? If I remember, Rex used solid stainless on his down tubes? Hopefully he will share his opinion on this subject! just my 02.:xzqxz:

grandpanystrom61 · Aug 22, 2018

I want a solid front end, one that can withstand a few wheelies, not that I want to do them, but they do occur, LOL

The rake is just enough that spring tubes and hydraulic tubes will not function properly, all I have read says they have a 45 degree limit, and that is pushing them at or beyond their limits.

It will come together.

DeathBySnuSnu · Aug 22, 2018

Whew....

Ok....that is around a .035" difference in diameter. That is as good as a mile in a machinist world.

Even though the bolts tighten up you will probably only be contacting in two points solidly in the bore.

Weld them to the yokes or make new yokes or make the legs much closer to your mm.

Bought forks typically are chromoly or some related alloy that is hardened. Harder and thinner. Most anything you can job shop will be plain soft A36 to 1018 mild steel. It will need to be much thicker to have the same strength. I would think anything from .200 wall and up would be good.

I started making mine from stainless tubing machined on the outside. But they did not turn out right. I then went to solid stainless bar. I did drill them deep into the ends.

grandpanystrom61 · Aug 23, 2018

Interesting how I keep learning new things.

I would love to have all that is needed for in house springer build, but I do not and by the time I get it all I will out price myself, if I even had room for it in the garage.

I am going to see what FranksForks will charge for made down tubes, if they will even make them for me. Get a qoute from them.

On the other side, might have to do it myself, so what can I do, well I can get the end of a solid stainless steel tube milled so the pivot tabs at the end of the down tubes are as needed. I was thinking 3/8" thick fork pivot plate and 5/8" thick rocker arms.

Is being milled out of a solid piece better strength than cutting the slit in a tube and welding a pivot plate into place ?

My mind says the milled fork would be stronger, please correct me if I am wrong.

Rex, see your point of the 1 1/2 in the 39mm clamp jaws, wow, hope all works with these trees, but now is the time for change if it needs to happen.

grandpanystrom61 · Aug 23, 2018

There is a lot of grades of stainless steel, finding the right size is my secret.

303 solid stainless steel bar with a 1 9/16"OD, cost for 38 inch's 153.68, or the 1018 solid cold rolled steel rod at 1 9/16" OD at a cost of 61.18, not sure if either is what I want, the spec's on both read like they are good, tolerance on how straight is probably the more important factor along with strength.

I got a little lost and confused on fork design, figured out my mess and now working the plan for the mock up.

I want to center the rocker's width with the fork tube center, cut the 5/8" wide slot down the center at the end of the bar, drill the pivot hole dia., shape the ends for the bullet look, or do it first before cutting the slot out, machinist decision.

I am still looking over metric size suppliers, fun stuff, LOL

DeathBySnuSnu · Aug 23, 2018

Mine are 1-1/2 diameter 304 Stainless.

Way overkill, but my tubing would not stay straight as I welded and machined on it.

The eyes are welded on.

I really wanted something I could make shiney, so mind was set on SS.

But mild steel would be a lot more forgiving and easier to work with.

grandpanystrom61 · Aug 24, 2018

So thought I was onto something, the 1 9/16" thick would work, NOT, wow, a tight as fitting clamp on the tree.So even a 39.53 mm dia. metal flash light would not fit into the tree clamp, removed the screw from clamp thinking I could spread it open, not much give at all and thea flash light would still not slide inSo the larger than 39mm is not working. I do not think getting 1 1/2" stock chrome plated will equal 39mm's, getting a fine hair closer, but not the exact size.Oh why not weld the down tubes to the trees, these 39mm trees are aluminum, begining to feel I screwed myself again.