Big crash with a bob trailer

[Andy_Roo]

Hi all,

Had a big crash the other day whilst preparing for a long tour and thought the details of what happened would make a good discussion point.

I was testing out my fully loaded Bob trailer for balance and handling, going up and down a hill. Everything was fine and I was getting up to about 50km/h with no problems. Then coming downhill again at about 50km/h I needed to brake for a car turning slowly in front of me.

The weight of all the gear on the trailer (about 20kg) caused it to jacknife and threw me over the handlebars. I survived (obviously) but was injured. Broken collarbone and ribs, but all will heal.

My thoughts on why it jacknifed are that
1. I was going round a slight bend which caused the weight to push to one side when I braked.
2. I was going too fast. Pretty obvious in hindsight.

I think the bob trailer is great and am not put off from using one. But it must be understood that heavy loads and high speeds do not mix. I will be limiting my speed to 30km/h downhill in future.

Maybe one solution would be to fit a brake to the trailer wheel. Has anybody ever seen one or tried to fit one?

Has anyone had any similar experiences? How about handling in the wet?

[il padrone]

Yes, sadly not surprised by this. I haven't had such an accident, but was put off using a BOB trailer on a long trip 6 years ago.

All packed up for a tour into the Victorian high country - 6 days away from any supply points. Loaded up the BOB (it was a squeeze) to use with my dual suspension MTB. I had to fit a handlebar bag and rear setpost rack with rack bag to fit in the gear I needed as a minimum. Test ride... it felt so wobbly!

I finally decided, at the last minute, to use the touring MTB with front & rear panniers, handlebar bag and rack top gear bag. I found that the full gear load of the BOB fitted into easily just 3 of my panniers. I could actually carry considerably more gear on the tourer, and it felt much more stable to turn and brake.

As it turns out the BOB would have been a horror on some of the steep descents we did, and on the pushes up steep climbs (walking).

I've stuck with panniers ever since. If you use the BOB I'd recommend using panniers as well - front panniers at the minimum to load your front tyre, and preferably rears too. Use the BOB for extra gear space, and load it with your light but bulky items.

[heavymetal]

I ride with a BOB trailer and have found that fitting a low rider front pannier rack and putting the front panniers as close to the ground as possible helps.

I have found from experience that the geometry of the bike has a lot to do with it.

A mountain bike tends to get twitchy steering, but my road tourer is fine with a heavily loaded BOB trailer.

I tend to use both brakes when braking with a loaded trailer, with more emphasis on the front.

[Aushiker]

G'day

Aren't Bob trailers speed rated? Don't have the manual with me so can't check.

Also I am confused as to how the trailer resulted in the accident. Based on my limited use of the trailer up and down some pretty nasty and rough hills behind a Giant XTC 2 I couldn't see the trailer actually pushing me around enough to result in a jack knife. It seems to take a lot of angle to get the trailer to jack knife.

Ahh, saw this comment

I was going round a slight bend which caused the weight to push to one side when I braked.

. Was the load properly packed and secured? I could cause a similar outcome with panniers if I packed badly.

Oh, I learnt to pack light as a bushwalker and find I can easily carry a week's worth of food and gear on the BOB. My only gripe is the design of the sack. I am considering using my backpack instead.

Andrew

[rustguard]

I assume that like any trailer, when you brake the weight goes to the front, making the back very light and easy to jack knife. I have had the same problem in trucks with light aluminum trays while towing car trailers. I used to strap a water tank on top of the rear axle when I was towing heavy trailers.
Theoretically it would be more stable with weight on the rear wheel while braking. I too have thought about a rear brake on trailers, my idea was to use a cable splitter from one of the stunt bmx bikes. it would be fiddly to do but with ingenuity I know it could be done.[/img]

[il padrone]

I assume that like any trailer, when you brake the weight goes to the front, making the back very light and easy to jack knife.

The problem with the BOB is complicated by the fact it is a single-wheel trailer. Years ago, when I first got my child trailer (2 wheels) I tried to use it for the family shopping. Riding home with 6 bags from the supermarket when I braked it had a distinct and disturbing tendency to jack-knife, so yes, I could well imagine a loaded BOB at 50kmh will do it too. However the BOB will begin to topple as it jack-knifes, pulling your bike over! I have also had problems with this when man-handling the BOB at slow speed. A heavy trailer load turned off-centre will just go 'clunk' and you stop. Weight placed towards the front will worsen this.

I too have thought about a rear brake on trailers, my idea was to use a cable splitter from one of the stunt bmx bikes. it would be fiddly to do but with ingenuity I know it could be done.[/img]

Despite the heavy weight you may have inthe BOB, 30kgs is really not enough to make a trailer brake work. Too little tyre load - it will just skid. But maybe it will help the trailer stay in line.

[geoffs]

sorry to hear of your injuries.
This is the reason that I've never even contemplated using a trailer.

We use a full set of ortleib panniers on our tandem and find them convenient, easy to carry, well balanced and waterproof.
When we were in France last year we came across a mobile home cutting the corner on our way down a mountain. We were only doing 40kms/hr and even with the tandem fully laden, I locked the rear wheel while breaking front and rear as hard as I could. The back of the bike swung out, I released the rear, straightened up, grabbed it again, skidded and released again to straighten and squeeze through the small gap. The back of the bike with my terrified stoker on just missing the front of the vehicle. If we had had a trailer, the weight of the trailer would have pushed the rear of the tandem around and we would have crashed for sure.
I like our panniers.

edit.
Just had a look at your page on crazyguyonabike an and a couple of comments:
Saw the pics of the helmet and shoulder - ouch!
I've toured around western Europe a couple of times and done lots of other touring so i have a bit of idea as to what works. When I first started though I had help in the form of a group of friends who had ridden from London to Sydney for ideas on what to take. They were a great help. I had met one of them in Sydney which is how i got the touring bug.
Make sure your panniers racks are steel - either Tubus or something similar.
Get a stove that burns unleaded such as a MSR Dragonfly or Whisperlite. Dont buy it here. get it from the US via ebay.
Steel or Titanium (from REI) tent pegs.
Dont take jeans or cotton clothing that's heavy and takes ages to dry.

cheers
Geoff