# Why does my bicycle steer funny and feel unstable when I have a heavy load in my Bob Yak trailer?

I have an Electra Townie 7D Tall which I use to pull my Bob Yak trailer. If I have say 30 lbs (16 kg) in it, my steering will be shaky and not feel very stable, especially at slow speeds.

Why and what can I do about it? I have used the trailer on other bikes with the same sensation.

• How does the trailer attach? What's the weight distribution (i.e. is there some weight on the towbar)? Feb 20, 2021 at 18:41
• Can you add a photo showing how your bike and trailer are connected? I'm suspecting the coupling is aft of your rear axle. Also - how accurate is your idea of weight? Is the Center of Mass of the trailer loading the nose or evenly positioned over the axle ?
– Criggie
Feb 20, 2021 at 22:08
• bobgear.com/yak-bike-trailer Feb 21, 2021 at 1:12
• The trailer is inherently going to pull the bike to one side or the other as you make turns or go over bumps. Unless you are riding perfectly straight the trailer will determine how much the bike tilts. Feb 21, 2021 at 1:15
• The other source of instability in this design is the position of the steering axis: It is located behind the rear wheel of the bike, and right in front of the load. This gives the load in the trailer a lever on the bike: Any sideward force of the load translates to an opposing sideward force on the bike's front wheel. And this is bad. Consequently, the further back you place the weight in this trailer (= reducing the lever of its mass on the bike), the more stable your steering should become. Feb 21, 2021 at 19:29

I suspect Chris H is on the right track with his weight distribution question.
You may have too little weight on the front wheel. An easy way to test too little weight on the front wheel is by shifting your body weight forward when the bike feels unstable.
Experiment with the trailer load to find the best handling.
You may find that adding front panniers with some weight helps.
It's all about experimenting until you find the right distribution.

Looking for other people who are having problems with stability using a Bob Yak trailer has led me to some advice that might help.

In a thread on campfirecycling.com Jacob says:

I’ve been a bike messenger (in The Netherlands) for some time, using a Bob Yak professionally. Since my positive experiences with this handy one-wheeled-trailer I own one myself now, mainly for use as a vacation trailer.

When loading a Bob Yak/Ibex trailer you should keep a few things in mind. 1. Always distibute the load evenly along its length-axis 2. place the heaviest load nearest to the trailer’s wheel 3. When you overload a Bob trailer (which is fairly possible), never make the load ‘top heavy’.

I’ ve handled loads of over 50 kilograms with the Bob Yak and have had no stability or handling problems with it.

Tip: A bike without shockabsorbtion is most ideal (in terms of handling/control) for towing a one-wheeled-trailer like the Bob Yak.

Another problem some people had with the Bob Yak is high speed stability wobbles. cara2u posted this warning on forums.adventurecycling.org:

Please be very careful if you decide on a one wheel Bob. If they are not loaded correctly they can cause your bike to completely lose control at the most inopportune time, downhill.
On our last TA tour we met an Aussie gal that had that very thing happen to her on a downhill. She was unconscious for two hours down in a drainage ditch until someone found her. She had to fly home to convalesce for two months before she could continue her tour. She was East to West and the accident happened the first week or so of her trip.

There is a lot more conversation about stability at speed in this thread.

• The Bicycle mentiones (Electra Townie) should exacerbate the problem, due to its relaxed riding position (almost sitting on top of the rear axle). Feb 22, 2021 at 10:14