Neck height?

[Eggman]

After looking at a lot of trikes, I am tending to like the lower overall of the designs. I'm not wanting to sit real low, but not as high as some are. What are some of the neck heights that are typical (if that even exists) that ya'll are running?

My trike build will be a rear engine setup using a front wheel drive out of an 89 Olds Trofeo.

Thanks.

 

[grandpanystrom61]

Okay, to me a few things help determine one's neck height, but that is me.

My neck rake angle is real close to being 48 degree's, but the neck height is measured a few different ways.

Some go from the ground to the bottom of the lower tree, some go from ground to the lowest point of the bottom neck bearing cup.

Or there are those like me that did not see the issue and I measured from the ground level up to the top of the the upper bearing cup of (basically to the top of the neck ) or one might say from the bottom of the top triple tree were it meets the upper neck bearing.

How far is this distance, 28" 3/4" while on blocks. This distance may settle lower once the new front end is installed and if I get the correct shocks installed than I should still be at this distance, oh and as long as I calculated the main tube length correctly. Like I said a few factors can effect or create the neck height.

Ideally the idea I followed was that of " center of gravity". The idea was the lower the rider weight is to the wheels axle line the harder it is to flip a 3 wheeler, so my Ed Roth designed trike has the rider at about 12 1/2 " above the ground. I did adjust this a bit higher as I extended the tube length of the forks and I raised the neck height up a few inchs so the rear mounted VW engine is more level, almost truely level, but not 100%. I think this is a good match, and now I will sit about 14" above ground level.

Hope this helps you.

 

[Eggman]

That sure does help, thanks. I want to be lower to the ground than riding my Road King but not dragging my ass down the road. Plus the roads here in Illinois suck!! Quite a few places also have the pesky speed bumps. I was looking at 8" of ground clearance with the bottom of the seat around 20" or so. The neck height I was initially contemplating was around 36", which I thought was too high. After your info, I'll probably start looking around 30".

 

[stacebg]

That sure does help, thanks. I want to be lower to the ground than riding my Road King but not dragging my ass down the road. Plus the roads here in Illinois suck!! Quite a few places also have the pesky speed bumps. I was looking at 8" of ground clearance with the bottom of the seat around 20" or so. The neck height I was initially contemplating was around 36", which I thought was too high. After your info, I'll probably start looking around 30".

personally i like to stay same height as an average bike lower u r the easier u r to be missed.. and there is not much chance of flipping a trike unless it is really narrow ,,, as for the neck, all but on of mine have used a pretty much stock mc front end so the neck height was very close to average stock height... an if you are building a LL the height can be most anything

 

[TomyJ]

Neck Height

Neck Height, Fork angle:

Are you building your frame from scratch? Like me or modifying an existing frame? I am building from scratch with forks from a Honda 250 Rebel, check out the fork angle of 30 and 35 degrees in the side car threads, mine is called "HackHer". If you need more info or photos le me know...

 

[Eggman]

Okay, to me a few things help determine one's neck height, but that is me.

My neck rake angle is real close to being 48 degree's, but the neck height is measured a few different ways.

Some go from the ground to the bottom of the lower tree, some go from ground to the lowest point of the bottom neck bearing cup.

Or there are those like me that did not see the issue and I measured from the ground level up to the top of the the upper bearing cup of (basically to the top of the neck ) or one might say from the bottom of the top triple tree were it meets the upper neck bearing.

How far is this distance, 28" 3/4" while on blocks. This distance may settle lower once the new front end is installed and if I get the correct shocks installed than I should still be at this distance, oh and as long as I calculated the main tube length correctly. Like I said a few factors can effect or create the neck height.

Ideally the idea I followed was that of " center of gravity". The idea was the lower the rider weight is to the wheels axle line the harder it is to flip a 3 wheeler, so my Ed Roth designed trike has the rider at about 12 1/2 " above the ground. I did adjust this a bit higher as I extended the tube length of the forks and I raised the neck height up a few inchs so the rear mounted VW engine is more level, almost truly level, but not 100%. I think this is a good match, and now I will sit about 14" above ground level.

Hope this helps you.

I'll be building both the frame and the forks myself. How tall are your blocks? I'm measuring the neck height from the top of the neck down to the ground. Mine is currently at 36". I'm just trying to figure out the approximate Rake Angle that looks pretty decent with a Leading Link front end. So far, what I have read, the trailing numbers should be between 1.5" and 2.5". So I've been laying the forks out to be a 2" trail. Here are a few pics of what I have so far. Let me know if I am in the neighborhood. 16" rim, 26" rim, bottom rail is 8" off of the ground and the top rail is 20" from the ground.

 

[stacebg]

I'll be building both the frame and the forks myself. How tall are your blocks? I'm measuring the neck height from the top of the neck down to the ground. Mine is currently at 36". I'm just trying to figure out the approximate Rake Angle that looks pretty decent with a Leading Link front end. So far, what I have read, the trailing numbers should be between 1.5" and 2.5". So I've been laying the forks out to be a 2" trail. Here are a few pics of what I have so far. Let me know if I am in the neighborhood. 16" rim, 26" rim, bottom rail is 8" off of the ground and the top rail is 20" from the ground.

View attachment 71676View attachment 71677

i would suggest keeping the links longer.. with the short links you dont get much travel and there is a lot of trail change with the short swing of your arm / link.... if i am building a LL i bend the tubes and run a tube side to side "linking" the two arms together. with out that link you have a springer which is all wishy washy for any three wheel vehicle... if you dont want to bend the tubes you can keep a short rake on the frame... jmo but i have built a couple or 15 three wheelers

 

[Eggman]

... if you dont want to bend the tubes you can keep a short rake on the frame... jmo but i have built a couple or 15 three wheelers

A couple or 15? Thats quite a few, where would I find some pics of these trikes?

I've also seen a few front ends that have a pretty decent rake with a fairly steep LL angle. Wouldn't something like that have a fairly large trail change as it is rolling?

 

[grandpanystrom61]

What ever you do for blocking up the frame, it needs to be solid an "never" changing.

I used two 4x4 blocks, that turns out to be 6 5/8" clearance that gives me the 28 1/2" neck height.

Now when all is lowered down and the weight of the trike is felt on the front end, well depending on the style of front end, there will be some droppage in the measurments. For me, I should look at about 1/2" drop in neck height. If you want to keep that exact neck height than one needs to increase the fork length by that 1/2" so when all is on the ground it is what you want.

The tire will also give a little when all the weight is on it, some say 1/4" should be allowed, I think it depends a bit on how hard the rider runs the front tire.

Not a LL man, looked into it and just did care for it, but is suppose to be a very solid, stable type of front end for a trike.

Other's here have done much more than I, I do hope they will chime in and help you with this.

Oh the front wheel and disc brakes that I am running are off a 2001 Triumph. Yes it was a pain getting all done, but it is the size rim I needed, price was right, and the more I look at it all the more I like it, but that is me and my trike, LOL.

How one approach's it. I read some start a the wheel and work from that point, other's take a different approach and start at the triple tree's and work down. For them the rim size seemed to vary as the rider needed to achieve what they wanted.

Like I said, I wanted to keep the rear wheel axle height to match the front wheel axle height. We will see how this all works out for me.

 

[Eggman]

What ever you do for blocking up the frame, it needs to be solid an "never" changing.

Planning on using jackstands, tacked so they don't shift.

I used two 4x4 blocks, that turns out to be 6 5/8" clearance that gives me the 28 1/2" neck height.

Still kinda unsure of the neck height, will have it figured out shortly.

Now when all is lowered down and the weight of the trike is felt on the front end, well depending on the style of front end, there will be some droppage in the measurments. For me, I should look at about 1/2" drop in neck height. If you want to keep that exact neck height than one needs to increase the fork length by that 1/2" so when all is on the ground it is what you want.

Probably won't weld the top attaching point until the height is set.

The tire will also give a little when all the weight is on it, some say 1/4" should be allowed, I think it depends a bit on how hard the rider runs the front tire.

Not a LL man, looked into it and just did care for it, but is suppose to be a very solid, stable type of front end for a trike.

Not super wild about it, but I do like the looks and it does appear to be strong and solid.

Other's here have done much more than I, I do hope they will chime in and help you with this.

Oh the front wheel and disc brakes that I am running are off a 2001 Triumph. Yes it was a pain getting all done, but it is the size rim I needed, price was right, and the more I look at it all the more I like it, but that is me and my trike, LOL.



Haven't decided on the front brake set up as of yet. Going to let the tire/rim combo decide that for me.

How one approach's it. I read some start a the wheel and work from that point, other's take a different approach and start at the triple tree's and work down. For them the rim size seemed to vary as the rider needed to achieve what they wanted.



I'm going for a beefy looking front end that is safe and easy to steer. I'm hoping that the turning radius won't be too bad.

Like I said, I wanted to keep the rear wheel axle height to match the front wheel axle height. We will see how this all works out for me.

I like the same height setup, I think that will be a good look for me as well.

Thanks for your advice.

 

[Eggman]

First pic is 35 degree rake with the fork attachment inline with the steering neck. Second is with a 45 degree neck with no change on the fork location. I think I'm liking the first one a bit better.

 

[stacebg]

A couple or 15? Thats quite a few, where would I find some pics of these trikes?

I've also seen a few front ends that have a pretty decent rake with a fairly steep LL angle. Wouldn't something like that have a fairly large trail change as it is rolling?

yes

depends on the rocker / swingarm.. length too the angle of the the arm isnt the factor its the difference in height between pivot point and axle

and steep angle with raked trees or long swing arm can have short trail

while some will swear by the steep angle front end imo with a slider front (telescopic) when the angle gets steep basically no suspension until you basically hit a wall because the angle of movement is wrong

more here https://s211.photobucket.com/user/stacebg/library?page=1

also LL on sidecars which are even more touchy to set up than a trike

there were a couple sevicars, obviously didnt build them from scratch but may have well have by the time we got them so they handled well also some home brew stuff, done back in the 80s before i had the pc and most of those photos are long gone

 

[Eggman]

Cool pics. I'm always looking to learn more. Planning on the bar to go around the back side of the tire, just didn't think it was that important at this point. Kinda getting the frame roughed out. Does anyone else that has done the Front Wheel Drive engine in the back of the frame have any pics of their attachments?

This is a pic of the front frame so far.

 

[LarryA]

don't know if it will help, but a few pics of the engine trans mount in my album. used a 2.2 chrysler power train, single seat in front....maybe some pics in postings also. but a basic 3 point mount for eng/trans then for drive axle suspension made a small dropped axle with airbags, shocks and a panhard bar. the 4th from the last picture shows the rear axle details.....just layed the spindles back 90 degrees......didn't want to look at struts and springs, so did this arrangement.

 

[Eggman]

don't know if it will help, but a few pics of the engine trans mount in my album. used a 2.2 chrysler power train, single seat in front....maybe some pics in postings also. but a basic 3 point mount for eng/trans then for drive axle suspension made a small dropped axle with airbags, shocks and a panhard bar. the 4th from the last picture shows the rear axle details.....just layed the spindles back 90 degrees......didn't want to look at struts and springs, so did this arrangement.

It sure did help. I'm just not too sure on how to fully eliminate the ugly struts and go a similar route as you did. The donor car has the load leveling air shocks on the rear suspension with the compressor. I am planning on snagging the little compressor and seeing what I can do with it. Once I get the drive line assembly out of the car, I'm sure I'll be able to see things a bit better.

 

[Eggman]

I'm thinking that this is the basic front end design I'll be going with. The length of the forks may change a little depending on the neck height.

This design gives me 2" to 3" of trail depending on the bounce. I drive mostly highway speeds, probably 70-30 highway to surface streets.



Does any of the "expert" trike builders think I need more trail?

Thanks.

 

[LarryA]

there are folks around here that know a lot about trail pertaining to trikes....so search for "trail" threads, lots of info on this site.

most complaints are of heavy steering from stock road bike trails that are 3..4..5 or more inches, and are then converted to a trike.

Using the advice of folks here, I used 2in. and am very pleased with the result, front axle weighing in at 370#

I'm thinking your front end weight may be a factor on how much trail you should use....heavy front end maybe a little less than 2.....a very light front won't steer heavy with a lot of trail.

Enjoy the search!

 

[Eggman]

My gf's first bike was a honda 750 rebel. She rode the crap out of it. I thought the steering was way too heavy. She thought it was fine. Until she got her Road King. It was so much easier for her to make turns with it.

LarryA I have a few more questions for you on your elimination of the strut towers and the alignment of the steering knuckles.



How did you get the alignment straight with the steering knuckle laid down 90 degrees?

How did you figure out the panhead bar and the bar that goes between the strut tower mounting flanges?

 

[stacebg]

I'm thinking that this is the basic front end design I'll be going with. The length of the forks may change a little depending on the neck height.

This design gives me 2" to 3" of trail depending on the bounce. I drive mostly highway speeds, probably 70-30 highway to surface streets.

View attachment 71985

Does any of the master trike builders think I need more trail?

Thanks.

definitely not more

1.5 - 2.5 works for me..

as a rule of thumb start with the pivot about 1" below the axle... re dont use the minus 30 degree situation...

think of jamming you finger straight into wall.... ouch but if you bend it a little before you hit the wall it will just bent not try to break

the longer the "rocker" is the less trail will change think i used closer to 10" dont have one here to measure

oh and personally i hate the word "master" lol

 

[Eggman]

definitely not more

1.5 - 2.5 works for me..

as a rule of thumb start with the pivot about 1" below the axle... re dont use the minus 30 degree situation...

think of jamming you finger straight into wall.... ouch but if you bend it a little before you hit the wall it will just bent not try to break

the longer the "rocker" is the less trail will change think i used closer to 10" dont have one here to measure

oh and personally i hate the word "master" lol

I'm at the 2" mark for normal riding and an inch above the pivot. The 30 degree angles was to show the range of possible motion. The center to center is right at 8.5" when using a bend in the main forks. If you think that the 10" rocker will work better than the 8.5" one will, I can change it real easy at this point. Would rather have it right on paper and then for real in metal, than to have it half-assed to start with.

Point taken and changed.

Thanks for your input.