what rakes are these?

[Fowler]

I have been doing some research on Rake, Trail and Offset

I understand Trail is the most important but I would like a certain look in the rake.

I don't know whose trikes these are but I do like their rakes.

Any idea what rakes they are?

 

[vwbug72501]

Just print out the straight-on side view and use a protractor to determine the rake angle. You will be able to determine the trail this way also. Not 100% but close enough for Government work.

 

[LarryA]

just eyeballin' I'd say 30/35 deg. anyone else??

 

[Fowler]

Just print out the straight-on side view and use a protractor to determine the rake angle. You will be able to determine the trail this way also. Not 100% but close enough for Government work.

will try that tonight

 

[Fowler]

I ran out of ink so I could only do these 3

I think I did something wrong because the rakes do not look right to me

 

[LarryA]

Just by eye, if the top and bottom trikes were broadside to us,

like the middle one is, the angles would almost be the same.

the rake angles look to be about right for a front engine trike.

just my .02

 

[vwbug72501]

Yep. Pix need to be straight on sideways views not 3/4ish angles as seen in top and bottom pix. I'm thinking about 30 degrees also. Just because a trike has been built with more or less neck angle doesn't mean that it is more or less rideable. One thing for sure, more neck angle equals more stresses on the frame at the neck area.

 

[Fowler]

Thanks guys

I see what you mean. I have to have a straight side view to get a good reading.

Weather and time permitting I will set my neck this weekend.

Not sure what rake I will use yet, I will see how it looks at different rakes.

 

[vwbug72501]

I have a friend that I consider a Master Fabricator. He was once asked: "How do you know when something is right?" His response: "When it looks right."

Sometimes working with a basic set of dimensions, mocking it up, and staring at it for a while is the best course of action.

 

[Fowler]

30



35



40



45

 

[LarryA]

with the 45 deg.....the lower ball or roller neck bearing will have most of the engine wt. on one or two rollers or balls...same with the upper bearing.....not good! The rake closer to 30 would better imho. However, rear engine trike......not an issue.

That said, are there many headstock bearing failures on trikes?? I have not been around trikes long enough to know for sure.

Just speculation on my part.

 

[Fowler]

I was thinking of a 35 degree rake.

 

[stacebg]

great place to start and agree about 45 being to much... i know we see em doesn't make it a good thing..

the more important part is what you end up with for trail

personally i like about 1.5 - 2.5 inches so you need a set of raked trees or build a leading link or even a springer type.. personally dont like springers.. not much travel an imo i tad flimsy

 

[Fowler]

I was planning to build a leading link or Earles Fork

 

[stacebg]

I was planning to build a leading link or Earles Fork

great way to go

 

[grandpanystrom61]

Sugar Bears drop pivot springer front rocker arm set up is a Zero trail, that is what he found works best for his design.

Oh and he says all is designed for the 21" rim up front.

Now I have been dealing with rake and a offset neck with a twist, try to figure stuff out when that is off.

So as the front neck goes up and down in height, the rank angle will change some, more quicker on some than others.

Just so you get an idea, if I raise my neck and backbone up 2" in height, the 45 degree rake in the neck changes to 47.5/48 degrees.

Now you can get longer forks, use same small tire, or if the original forks will allow it, one can just put a larger front rim/tire on the trike and raise the front end.

but when we move things rake and other things can change, so remember one thing can effect many others.

Leading link front end set up is suppose to be a good one, if you design it and build it, all can be done up to the axle location being drilled, why, because now you can put all on the trike, weight and spring reaction on the front end, get the true ride height, and than figure out rake and trail and set the front axle where you want your trail at.

Now if you ride 2 people a lot, well at least have the passenger set on the rear seat when you do the load test, if you can sand bag the weight on each set and than set the ride height, so even setting the main tubes to soon can be bad, I say tack weld all in place, see how all set and looks, if all is as you want, than you weld all together and enjoy the ride.

What is those trikes rake, I would look at 40 degree's, want longer forks go with more rake in the neck, want short tight forks and smaller front tire, go 35 to 37 degrees. Again everyone is just offering opinions, you get to choose what sounds good.

 

[LarryA]

the only suggestions I can offer is to block up your frame at the angle and ride height that you desire. Then select your front wheel/tire combination. block it upright with a wood frame with the axle centerline marked of the base of the wooden frame. run a straight shaft down thru the neck bearings and mark the floor. then set the wooden frame c/l 1or 2 inches behind the neck bore mark. From this point on fork tube/neck bolt offset can be considered. once fork tubes are located rocker pivot points can be figured (getting into springer travel here). This is how I set up Last Winter trike. I'm no engineer, nor very good at trig. so I just mocked up using these considerations.........others here have more knowledge and better advice than I, so hope they will chime in!

 

[LarryA]

grandpany61.....I have finally remembered that I had used the fork tube/neck bolt offset of 2and 3/8 inch, copied from a harley....forgot which model?? With the fork tubes set ahead of the neck bolt.....I'm suggesting that you look in vw forum Snu's tech tech tech thread a lot of valuable fork data there! good luck on your project, I do like vwbugs saying "your mak'in that trike your own" !