Leading Link forks?

[OldNick]

Having just had my Valkyrie-based trike failed for leaky front forks, with a $350-ish bill for repairs, it was suggested to me that I should try Leading Link forks, withe comment it was "like power steering".

LLFs are not a cheap investment and although I have read a lot of good said about them, I was wondering what peoiple thought. Steadiness on the straight, ease of turning (for me these are a constant swings and roundabouts thing)

ATM I have 6deg raked Roadsmith triple clamps.The trike is pretty steady even on rougher highways and yeah turning is work. Mind you, just hanging on is a good part of that work!

Thanks for any help.

Nick

 

[irmagoo]

how much trail ??

hi there
if your front end has 3.5 inches of trail with your raked trees and you put a leading link on and it has 3.5" of trail it should steer the same...
I would have trail checked and see how much trail you have and go from there,, you may spend money on leading link for no improvement with out doing some leg work you wont know. sometimes a little wider handlebars make the difference,,, just say'n
magoo

 

[OldNick]

OK.I will measure the trail and see what I get. AFAIK trail is if you measure straight down the shock tunbs to a point on the ground, then take a vertical from the axle to the ground, the difference is the trail.

So am I right that basically easier steering = less straight line stability? That gels with what I know about motor bikes and road vs MTB.

I can see where easier turning might be ok, but not if I have to fight every bump and gutter on the highway. Can I overcome that with a stiffer damper? I know they say that dampers only mask problems, but a solid swing arm IS a problem; it has to cause instability when the rear hits uneven ground.

And an extra puzzler. I see guys talking about raked forks helping them turn, yet everything tells me that increased rake will add trail and make it _harder_ to turn.....at speed. I can see that at low speeds, the "grader effect", where the tilting of the wheel does the steering (as on a normal motorbike) will make a tighter turning circle...but actual easier steering at speed?

Lotsa stuff to ask and learn.

 

[clint44]

OK.I will measure the trail and see what I get. AFAIK trail is if you measure straight down the shock tunbs to a point on the ground, then take a vertical from the axle to the ground, the difference is the trail.

So am I right that basically easier steering = less straight line stability? That gels with what I know about motor bikes and road vs MTB.

I can see where easier turning might be ok, but not if I have to fight every bump and gutter on the highway. Can I overcome that with a stiffer damper? I know they say that dampers only mask problems, but a solid swing arm IS a problem; it has to cause instability when the rear hits uneven ground.

And an extra puzzler. I see guys talking about raked forks helping them turn, yet everything tells me that increased rake will add trail and make it _harder_ to turn.....at speed. I can see that at low speeds, the "grader effect", where the tilting of the wheel does the steering (as on a normal motorbike) will make a tighter turning circle...but actual easier steering at speed?

Lotsa stuff to ask and learn.

Rake and trail are two different things,altogether. Trike and bike triple trees can have the same rake but different trail numbers. Trike trees will almost always have less trail than bike trees. Installing raked trees made for a bike,on a trike,will almost always result in steering problems;i.e. severe headshake.

I would have someone knowledgeable rebuild your Valkyrie forks,if it were my trike. They will work very well,if set up correctly.

 

[peteg59]

"I would have someone knowledgeable rebuild your Valkyrie forks,if it were my trike. They will work very well,if set up correctly"

/\ What Clint said.

I know little about LL forks, but the right pair of fork springs along with a new seal kit in your stock Valk fork tubes would be a whole lot cheaper than going to a LL setup.
Besides, the riding season is just beginning down under. No sense in tearing into the trike only to disable it for unknown time period when decent weather comes?...

 

[Drpepper]

AFAIK trail is ,if u measure straight down the shock tube too a point on the ground ,,,NO!!!, A line through the stearing head bolt then squar off the floor for trail ,the stearing head bolt is how farr behind the down tubes??? I wreaked mine the other day for getting the trail on the negative side.

 

[tfdeputydawg]

Really need an education here or everything I thought I know about LLF's is wrong:Shrug:
Didn't think a rake kit was needed for LLF's?
What difference is there in a rake kit for a bike vs. a trike??? A rake kit is a rake kit and nothing is different for bike vs trike as the "bike" front is still a "bike" after triking?!
Why would one put a rake kit on a 2 wheeler anyway????
This is a typical LLF. As you can see, the usual meanings of rake and trail do not apply here, IMO.

 

[Sidecarbill]

Rake and trail always apply. Its really caster angle. Just google rake and trail. You need less angle on the frame neck or more angle in the trees. On my bikes I've found anything less than about 2inches makes the steering 2 guick.

 

[irmagoo]

well back in the day we put raked trees on bike to get "the easy rider look" screw on tube extenders/ or longer tubes if you had da money - and thought we were "cool" !!its a wonder we didn't all kill ourselves!!
ok
trail measurements = center line of steering head /neck what ever you want to call it- center line straight thought center of sheering head to floor(mark floor) then a vertical line straight down to floor through center line of front wheel axle. - measure distance between marks that's how I measure trail....
even way back in the day there were trikes and sidecars and they steered like lumber wagons for the most part!! first raked trees I ever saw were adjustable:xzqxz: and on a old Harley 49-50 something I didn't get it at that time but I kept thinking about them.. my first trike in late 60'es I put on wider handle bars to help with the steering problem. as time went on and my knowledge improved-mostly from reading a couple books about sidecar set up -I started playing around with trail and it was like a light went off lowering trial helped ease up steering back then a was strictly a springer guy- thought leading links were for old farts!! well guess I'm a old fart as leading links of all styles appeal to me now-like the industrial look of the old ones and the sleek look of some of the new ones guys come up with.
I will discuss this in rake and trail as that's what I/most of us understand. first of all I like all front end styles but springers and leading links work well at more extreme head angles- I have built 3 trike's in the past with head angle 32-45 degree and you can accomplish your trail with stock trees or raked tress .
on my current sidecar rig(2001 hd ultra) I run 3.5 " of trail I think head angle is 32 degree and I'm happy with it. this was accomplished with custom built raked trees and the bike looks great with stock front end,, the bike's stock trail was about 6.5 inches that was great for building strong shoulder muscles when I added the sidecar!!.:laugh:
I ran 2.5 " of trail on I sidecar in the 70's - I think it had 34 degree head angle that's a while back in time!! no raked tress's built springer for it. rig was easy to steer but did get some wobble in it at low speed at times(-20 mph or so and not extreme )- getting off the throttle as I recall was one of the things that could cause it??? tightened steering head didn't stop it -added steering stabilizer and greatly improved it- may have been tire issue back then,,,
so on my current trike build I'm starting @3.5 inch of trail & 36.5 degree head angle we will see how it works out...no raked trees leading link-just set it up for 3.5" not to difficult to changer if i'm not happy ... guess all I'm getting at is there are many ways to get where you want to be... not many people are happy with a motorcycle that was converted to trike and uses stock trail this is because you lean bike to steer -you want more trail- it keeps a two wheel bike going straight at speed without wobble in front end... trikes and sidecar rigs must be steered so lowering the amount of trail lower's the force needed to steer- remember you are always steering a three wheeled rig - not like a bike where you do not ever notice your leaning ever so slightly to keep bike going in the direction you want it to. there is plenty of help in choosing a set of trees now days and some of the best at it are selling them here @trike talk . so talk to someone that sells tress as they have knowledge from feedback from many many customers hard to bet experience like that!!
not much has been chiseled in stone for a long long time.... but most would agree that lowering inches of trail will improve a bike to trike or sidecar conversion
magoo

 

[tfdeputydawg]

Rake and trail always apply.

Did you notice, in the pic, the fork legs are vertical???

 

[Sidecarbill]

How the wheel is held on means nothing. Magoo explained it very well. Google rake and trail the pictures will make it quite clear.

 

[OldNick]

OK. AFAIK, the trail is what defines the desire of the steering to stay in a straight line, however you measure it. It largely has to do with the angle of the forks. If I had vertical forks then the would be zsero, and steering effort would be ...very low. But straight line stability would be shit.

I saw in all the argy bargy that leading link made no difference and I can see why that may be so. So I spoke to the LL builder and he uses a VW damper to stop head shake: he admits that low trail leads to straight line instability.

So why all the LLhype? Why do I have a raked triple tee on my trike, which yeah helps in line stability, but makes turning so physical, yet there are claims that LL stuff is so magical?

Why do I not just ask for LOW rake TTs as they would do the same thing as low rake LLs? Then damp.

 

[Flyndmc]

rake and trail

If you increase rake by raking the frame trail increases. But using trees the frame remains the same in relation to the ground and the axle is moved forward, reducing trail.