USCA Sidecar Forum

For some extra information about navigating the forum you can go to Forum Tips

WE ARE NOT ASKING FOR GIFT CARDS. IF YOU RECEIVE AN EMAIL TO THAT EFFECT, IT DID NOT COME FROM THE USCA. IT IS A PHISHING SCAM. DO NOT REPLY!

Please or Register to create posts and topics.

Raked triple trees

12

Being fairly new to sidecar rigs, i have a question for the pro's out there. When i was riding 2 wheeler Harleys back in my younger days, i had the front ends raked way out there and was able to ride them with no trouble as they were just easy to steer. Now i am reading that once i rake my front end on my Harleys to put a sidecar on i can no longer ride it again as a 2 wheeler as it becomes too dangerous, what's up with this and what is the difference between now and the past? Heck, we had Harley's with the front wheel a foot farther out than stock and had no problems. Can anyone of you tell me something here that i am missing or don't understand?

A REAL expert will be along soon to give you a technical explanation. All I can say is be sure you aren't confusing the terms "rake" and "trail". To reduce the steering effort of a sidecar (or trike) you want a trail near zero. A zero trail on a two-wheeler will make the steering very twitchy and prone to the handelbars going hard-over followed, of course, by the rider going over hard!

https://www.cycleworld.com/2015/05/22/cycle-world-tips-and-tricks-understanding-motorcycle-rake-and-trail

First off, we are NOT raking the front end! What we are doing is changing the angle of the forks in relationship to the steering head angle of the bike. This looks exactly like we "raked" the bike but in fact that rake has not been changed. Companies and people that tell you that the tree's are raking the front end either do not understand what they are doing or do not care as such I recommend staying away from any company that tells you they are raking the front end with tree's as they clearly do not understand the basics of what they are doing or they do not credit you with enough smarts to understand what they are doing.

By changing the angle of the forks in relationship to the steering head we are reducing trail. Reducing trail lowers the steering effort by taking some of the stability out of the front end. We can get away with this as we have added the stability that a third wheel has to offer. When you turn the handle bars you are swinging the front wheel through an arc, lower the trail and the arc is shortened as such you end up moving the sidecar (and or trike rear wheels) less when you move the bars.

To change the rake on the front of a bike the angle of the steering head needs to be changed. This can be done many ways including changing the ride height at the rear of the bike, lower the rear and the rake angle increases. Raise the rear end and it decreases. You can cut the frame and weld the steering neck at a different angle or there are companies that have special steering stem bearings that allow the steering stem's angle to be changed in relationship to the head stock on the bike. This does change the rake but does little to change the trail but people try these bearings anyways as they are fairly cheap and they think wrongly that it will help lower the steering effort as a three wheeler.

In an ideal world we would have less rake on the front end for sidecar use as the more rake, the more you are causing the front of the bike to raise and drop when you move the bars.

I have people often ask me about putting sidecars on cruiser type bikes as they figure that they usually have a lot of rake on the front end that they should steer better with the sidecar. Again people are confusing rake and trail. Rake is often all about creating a certain "look" But when manufactures set the rake, they also adjust the trail to where it needs to be.

"Chopper" type bikes often have a lot of rake to give the look they are after, I would venture a guess the most of the companies building chopper type bikes do not have a clue about trail, looks are far more important then function. These bike seldom are ridden far and there is pleanty more about them that makes them cornner poorly, often stop poorly, ride poorly and in general really not work all that well. Again, looks are more important then how it works. I suspect in your youth, how it looked was more important then how it worked and more then likely your standards of "safe" where not what they are today.

One nice thing today is we have lots more options for triple tree's that reduce trail due to the current fad of stupidly larger diameter front wheels that require a change in at the tree's in order to end up with the proper trail on the front end. When you change to a larger diameter front wheel you are increasing trail making it necessary to reduce trail with the triple tree's. And before any one jumps in and tells me that the larger wheel is not "stupid" I suggest doing a quick study of gyroscopic progression and its effects on handling.

Of course another way to reduce trail would be to put a smaller wheel on the front which we some times do with smaller diameter automotive wheels, but this also brings up another set of issues.

If you reduce trail on the front of the bike for easier steering, if you then ride it with out the sidecar you will find that it does not really want to turn. Turning takes more effort to get the bike to lean, once leaned you must maintain pressure on the handle bars to keep turning as if you let up pressure the bike will stand up and go straight. With stock trail once you start a turn if throttle positions stayed the same you could let go of the bars and the bike would continue going in a circle.

So in short. We are NOT raking the front end for sidecar use!

Jay G
DMC sidecars
http://www.dmcsidecars.com
866-638-1793

Jay G DMC sidecars www.dmcsidecars.com 15616 Carbonado South Prairie RD Buckley WA 98321 866-638-1793 Hours Monday - Thursday 6-4:30

I was typing my reply when the first replay came in from old school.
NO you do not want the trail near zero! It would not be safe to ride. You need some trail. How much depends a lot on where and how you ride your bike. The least we ever go is 1.2 inches which makes for extremely light steering that is quite twitchy to ride. We did this on my wife's old R100S rig. Fun bike for a few hours at a time but I would not want to cross the Midwest on it. For most people in most conditions we find that we want to end up with about 2 inches of trail. Perhaps a bit more if you live and ride in the plain state most of the time as more trail gives you more stability which on the highway can be nice when passing or being passing a semi.
Jay G
DMC sidecars
866-638-1793
http://www.dmcsidecars.com

Jay G DMC sidecars www.dmcsidecars.com 15616 Carbonado South Prairie RD Buckley WA 98321 866-638-1793 Hours Monday - Thursday 6-4:30

Thanks for the correction Jay. That's why we wanabes rely in you experts so much!

So, I think you are telling me that it is dangerous to disconnect the sidecar and ride the bike as a 2 wheeler. Would we be better off not changing the trees in the build so we can ride the bike both ways or will it be a handful riding with the sidecar attached?

Your best bet would be to build it to be the best sidecar bike you can and chose not to ride it on two wheels for pleasure. The bike can be ridden with reduced trail and no sidecar however you have to have your head in the game, no day dreaming. People often do this to take their bikes in for service. The bike will not handle well which is the reason to not ride it for pleasure. And of course do not also attempt to ride it with an automotive tire on the back. People do it, but I feel that it is not wise. If you find that you still wish to ride on two wheels from time to time then buy a second bike. For a second bike I often recommend a much smaller bike. People forget how much fun a smaller lighter bike can be. Also keep in mind the mathematical formula for the perfect number of bikes to own. X+1
Jay G
DMC sidecars
866-638-1793

Jay G DMC sidecars www.dmcsidecars.com 15616 Carbonado South Prairie RD Buckley WA 98321 866-638-1793 Hours Monday - Thursday 6-4:30

^like

Jay, your formula for bike ownership is quote-worth! As is the rest of what you said, but there is only so much room on the quote line! 🙂

The big danger in riding w/o the sidecar and reduced trail comes when you unexpectedly have to get on the brakes hard for what ever reason. Or you top a hill onto a fairly steep decline. In both of these situations the bike can and will probably go into an instant tank slapper and spit you down the road just like GP riders and their twitchy steering bikes.
This happens because the front suspension collapses and the rear suspension elongates reducing the already reduced trail to near nothing or beyond. Thunk grocery cart front wheels flopping side to side!

My next project will be to rake my grocery cart. I'll look badass with the apes I already have on it.

Rogue

12