Sidehack handling/braking

[rodekyll]

There's another topic that has touched on this, but I thought I'd start another thread rather than continue that drift.

Since I've been building my trike I've been curious about things like brakes and handling.  I'm that perpetual week away from actually driving mine, but seeing the front end failure on this other thread, I'm wondering louder about std forks v trailing/earls/leading link/whatever front wheel geometries, handlebar choices, steering dampers, and silly things like which brake is used more and why.  Input from any 3-wheel drivers welcome.

[sidecarnutz]

What is the question?

IME, earles front forks handle much lighter at low speeds and ease the steering. They give  feel of power steering compared to regular forks. But the laws of physics must be paid. No free lunch. They can feel twitchy at higher speeds.

Regular forks will feel very heavy at low speeds with a sidecar. But they shine on the freeway with better stability and no twitchiness compared to earles.

I prefer regular forks with a sidecar for the stability. Use a wide handlebar for leverage. Be prepared for a good upper body workout and DO learn to shift your weight from one side of the seat to the other when cornering. It'll lessen the load for steering.

[oldbike54]

 The only trike I have ever really ridden was a home built Volkswagon powered thing . The builder was quite proud of his design, the engine placed in front of the transaxle for better weight distribution . The only problem , he installed a springer fork that was long enough to need a separate zip code , so the thing wouldn't steer . My best guess ,  keeping enough weight on the front end , proper geometry , and a steering damper will keep things under control . Knowing that you have designed this thing from scratch , and thought out weight distribution , handling should be fine . Doubt if the stock Guzzi forks will give any trouble .

  Dusty

[Bisbonian]

My experience is that trikes and side cars aren't really comparable with regard to riding dynamics.

Sure, the both have 3 wheels but react completely differently to steering and braking inputs.

[fotoguzzi]

show some pics of your fork set up..

[fatbob]

I concur with sidecarnutz about lower steering effort with leading link forks, but not about high speed twitchyness. I don't have any of that with my Unit Fork on my R100. I think leading link is better in every way. Costly though.

[rodekyll]

The question is open-ended.  Given the engineering solutions for steering and handling, what combination of forks/dampers/bars/tires do you 3-wheel folks like and why?

The brake question is an aside, but interests me -- do you use your front or rear as your primary?

show some pics of your fork set up..

MY forks are std EV at this point with no steering damper -- not much exciting to post pics of.  The little I've ridden it suggests low speed road feedback (bumps and holes) will be noticeable.  Since I'm going to hit every damn thing in the road with one wheel or another, I'd like to minimize that feedback and the steering effort.  Explained pics of other folk's front ends would be nice.  How are dampers mounted and why?  What's up with your front tire choice?

[JoeW]

My first sidecar rig was a 78 Harley with a factory chair. I bought the sidecar and bike separately. The sidecar came with a servicar adjustable trail front fork. The reasoning behind the adjustable trail was, little trail for around town and more trail in the "highway"  setting. Besides the mechanical advantage of the unit forks, there is also reduced trail that helps with steering effort. But, the trade off is stability. My leading link fork has two settings for trail, I've been running my rig for 19 years on zero (or close to it)  trail. Easy steering but, a little squirrelly at speed. I have a friend with an EML that runs in the "more" trail setting and finds the increased effort not a too high price to pay for additional stability. It's a trade off between stability and ease of steering, maybe a balancing act would be a better description.

[BillinPA]

I use modified triple trees on my sidecar rig. Last rig was stock steering. It worked but was tough at tight turns with speed. Now that I have the mods, I wish I woulda done it to the last one. Less bump steer, easier steering and rig feels less stressed in the tight stuff. 

[wrbix]

My experience is that trikes and side cars aren't really comparable with regard to riding dynamics.

Sure, the both have 3 wheels but react completely differently to steering and braking inputs.

Yeah, that ^^^^^^^.
Question is not really applicable to your trike-in-progress

[Chuck in Indiana]

Gotta agree. Trikes and rigs are completely different animals.

The brake question is an aside, but interests me -- do you use your front or rear as your primary?

I did a fair amount of research before building the Jack-All rig. I noticed many of the high performance rigs in Yurp use the sidecar brake tied to the front bike brake, so.. I added another front disc to the Jackal,got a Gixxer brake pump to handle all the pistons, and plumbed the sidecar brake to it. Worked very well, you could grab a handful (and footfull) of brake and stop pretty darn straight with the tires howling. 
As far as I'm concerned, the Unit front fork was much sturdier, and gave much lighter steering. I never did high speed with it, though.. I'd say we were seldom above 80. No twitchiness up to those speeds.

[John A]

Besides stability at speed, a problem with either three wheeler can be that the front end can loose its ability to steer the damn thing. I found that both problems are helped by useing square profile tires. Two hunnerd miles ago I put one of these on http://www.lucasclassictires.com/400-425-17-Longstone-BW-Long40017.htm. It's the first time I've had a square profile on all three corners and it definitely helps. I've been testing the stability and so far it's good to an indicted 105. It turns better too, it's on a '99 Bassa with stock forks. At parking lot speeds it takes effort to turn it but above that it seems ok but maybe that's because I don't have anything to compare it to. I use a T3 wheel and brake on the car and the car brake is operated by a second  lever above the clutch lever and is completely separate from the unmodifid bike brakes. It fun to use to maneuver and does not operate the brake lights. Plus I did all the normal stuff like Hagon shocks, fork springs, Matris damper, bump stops on the car shock limiting its travel and overly sturdy construction. The only time it shakes it's head is when the front tire is locked up and skidding like on oil at an intersection. I haven't wadded it up yet.....

[rodekyll]

If you were looking to reduce the overall effort required to steer a 3-wheeler (hack or conventional trike) would you want to play with flat profile tires or steering angles first?

[Ted N]

I would go with steering angle first. When my triple tree was modified by Steerite, they changed the caster 4 3/4 degrees and the camber 1/4 degrees [probably would not need the camber on a trike]. My hack handles great up to  98.9 mph[top speed per
GPS] and I only use the crappy factory damper.

Ted

[oldbike54]

 Trikes and hacks are two different breeds of cat . Decreased rake might make a trike plow in corners . Dunno , seems like a slightly increased rake and a slightly reduced trail might allow the trike to turn easier .

  Dusty

[rodekyll]

I agree that some of the discussion won't be entirely relevant to my project, but I'm coloring way outside the lines on this one, so I'm not trying for "what to think", I'm trying for "how to think".  Understanding the choices people make and why they make them helps me identify what's important to consider and what's nonproductive fretting.

[oldbike54]

 Oh , sorry , wasn't trying to stifle the discussion . Still , seems as though increasing the rake a bit would allow the tire to roll onto its side a bit when turning , and decreasing the trail would reduce steering effort . Or , you could design some weird looped handlebars that allowed for increased leverage , although on second thought , maybe not 

  Dusty

[Rich A]

I would go with steering angle first. When my triple tree was modified by Steerite, they changed the caster 4 3/4 degrees and the camber 1/4 degrees [probably would not need the camber on a trike]. My hack handles great up to  98.9 mph[top speed per
GPS] and I only use the crappy factory damper.

Ted

My rig has the Steerite mod, too. I think it works quite well.

Rich A

[John A]

Going after effort I agree angles first, flat profiles won't reduce the effort but will put a bigger contact patch on the ground with all the benefits that brings

[cleatusj]

Moving the axle 1 3/4" forward on my 'vert when I built the LL made all the differance in ease of steering, with no twitchyness at any speed.

[Shorty]

I now have a year or 2 under my belt of using a sidecar to commute part time. Mine is the second rig for me. (Wrecked the first, then got tired of constant tinkering on my Convert tug). Mine is a 790 Triumph Bonneville with a 250 pound Dnepr all metal sidecar. Stock steering, with progressive fork springs. Stock rear shocks on sidecar and tug. I have a VW steering damper on it, it will still tankslap if I remove my hands.  Steering effort is heavy. Stock bars, slight forward body lean to drive it. Keeps my back straight that way. Mine tracks straight at about 35 to 60 mph. It is rather like an aircraft in accell and decell, substitute your upper body for rudder pedals.  . It needs to have a sidecar brake installed. It will try to buck left if you use the front brake too hard. Back brake more tame, but less effective. Part of the problem is the 3 different spring rates that is going on:  the (unbraced) front forks, rear shocks and sidecar shock. Future mods for me? Flat profile tires. Sidecar brake. (hopefully a disk) Gonna try to use 3 FLH air shocks on rear of bike and car.    Floorboards would be nice.  I seldom exceed 60 mph, so the little Triumph is plenty. I had an earls LL fork on my Ural, but it was kinda flimsy, so I did not care for it. I would love to try to drive a more professionally set up unit, as mine is definitely mom and pop.  Just guessing, but I would think a trike easier to drive. Sidecar keeps you on your toes...

[dsrdave]

I use the VW steering damper also.  Added a fork brace and welded some tabs to it to mount the damper to the forks and a bracket on the brace going to the hack.  MUCH improved stability, especially in the 25-40 mph range.

[Chuck in Indiana]

I had no steering damper on the Jack-All.. didn't need one. Don't know why. I never drove it with telescopic forks, so maybe it was the Unit front end. Something that worked quite well was electric lean on the sidecar. Basically a linear actuator that moved the sidecar shock up and down. Toggle switch on the bars so I could trim for hands off on various road cambers and side winds. Made traveling much more comfortable.

[rodekyll]

I like the idea of the vw damper.  Does anyone have pics of theirs on the rig?

[Chuck in Indiana]

I like the idea of the vw damper.  Does anyone have pics of theirs on the rig?

It's pretty commonly done. There should be a ton of pix on the web..

[Eric]

I haven't any experience building as many here have, but I've put a lot of miles on my urals with most of it in the dirt. This doesn't really fit your situation but, as you say, coloring out of the lines. The leading link on my ural shortens the trail and makes it turn more quickly. That much is clear. So it can feel twitchy at speed on pavement, speed being a relative term when it comes to ural. But all that disappears on dirt roads where steering becomes a process of throttle control more than turning the handle bars. When I turn the front wheel right, for example, my body shifts to the left and, eventually the sidecar comes off the ground and, now on two wheels, the lean of my body  and the, now, countersteered (is that a word?) front end requires that the motorcycle change directions and go to the left. To prevent this from happening in the dirt I have to apply enough throttle to move the back end to the left fast and far enough so that the line from the back of the bike begins to fall in line with the front wheel and follows the front wheel around the corner. On a trike, this would tip the vehicle over. On the ural, it has the opposite effect. At least experience would tell me this. Not sure if it's good geometry though.

[dsrdave]

I can get you a pic next week.  At Daytona now, our race is the last one on sunday.  Should be home tues.

[rodekyll]