Forks and trikes and other bits of cutlery.

One question I am asked a lot is “How heavy is the steering going to be on a trike?” The answer is that “it depends”! Not a lot of help is it but there’s a reason. Many trikes have aftermarket “Raked Yokes” or “Raked Triple Trees” fitted to them. Often also referred to as easy steer (EZ) yokes and “it’s like power steering for trikes”. What that actually means is that it makes the handlebars easier to turn when riding the trike by needing less effort to push and pull them. It’s all down to the trail and geometry of the bike’s rake angle of the front forks and that is usually set by the angle of the headstock on the frame.

Raked Yokes – some call them triple trees because when fitted they have the 2 fork legs and the handlebar pivot bolt running between the top and bottom yoke don’t know about the “Tree” bit – are made usually to increase the angle of the rake of the forks and so change the trail and caster angle (one is measured in millimeters the other in degrees) of the front spindle and the tyre on the road surface. This has the effect on bikes of increasing stability at speed but can have a negative effect on handling. On a trike because the wheelbase is a triangle the stability is not an issue but the amount of effort required to steer the trike can be depending on the donor bike and the strength of the rider. Often folks would like it easier or lighter to move the steering at lower speeds.

Now the easiest way to make steering lighter is to fit wider handlebars because they are in reality the levers you are using to move the front wheel. Imagine taking a heavy box on a see saw and having the pivot point or fulcrum nearer to the heavy box. (See the diagrams below). The “effort” to move the load in diagram 1 is less than in diagram 2 because the fulcrum is nearer to the load so you have more leverage.

So wider bars than the stock bars and even bar risers, can provide you with this although it may mean you have to extend you cables, brake cables /  lines and throttle cable to accommodate this and you may also not have the room to do it is you have say a fairing on the trike. On top of that they may just look “wrong”.

Raked fork yokes do the same thing i.e. reduce the effort but you keep the same handlebars. It works by changing the trail of the front wheel usually by “pushing it forward a bit” which actually reduces the amount of trail. Take a look at the diagram below for a 4.5 degree rake on a Harley where the grey circle is the original wheel position and the dotted lines are the new potion after a set of 4.5 degree raked triple trees are fitted. By increasing the angle of the front forks in relation to the ground the trail measurement is reduced this makes the steering “lighter” and easier to steer.

Below are “Before and after” photos of then fitters to a Triumph Rocket 3. The difference is obvious.

Leading Links
Are a completely different solution to the heavy steering problem and are probably best known as the steering adaption for ‘Bikes with Sidecars and they look like this:

The whole of the forks are changed and shock absorbers are fitted to replace the  original telescopic fork legs. By relocating the routing of the fork stanchion and adding the bottom rail to mount spindle to the trail is changes and the steering becomes easier. The issue here is not that it’s a bad system – it isn’t – but the cost especially if you need the leading links to be made especially for your trike, plus they do look a little “different”. They can be fitted to bikes which do not have a conventional front suspension setup such as those with the BMW telelever system.

In the end
To sum it all up for a trike the case for raked triple trees (or leading links) is a good one where the trike is heavy to steer but will you need them or not depends very much on you, your upper body strength and the door bike. The price depends on the availability something that is batch manufactured for a “popular bike” is going to be cheaper than bespoke one-offs but if you need it you need it.

In Casarva’s case we have experience in building trikes with many different donors. Some we have don often and know that the raked yoke is necessary e.g. the Honda Valkyrie 1500 or the Triumph Rocket 111 2.3 litre whilst on others it’s a possible. The thing is if you don’t have them changed at the time the trike is being built then you can fit them afterwards BUT by pushing the front wheel away from the frame there is a chance that the attitude of the trike will be changed going nose down at the front unless you screw add extensions to the top of the fork legs to compensate (see  another article “Getting the Right Attitude / Stance on the Casarva website  covering this https://www.casarva.co.uk/mounting-a-trike-kit-height/)

This article is one of a series that are on the Casarva website. They are no technical handbooks and are solely for guidance and explanation neither are they intended to be exhaustive and cover every aspect of a topic. If you have a question please feel free to use the contact us page on the website or send an email to info@casarva.co.uk