Why do you think I had a wobble?

[ihorator]

I was travelling on a dirt road with a passenger at low speed and suddenly I started to be thrown very hard from side to side and after 2-3 turns of the steering wheel I fell over. 

In the past, I could sometimes feel very light swaying when I was driving on a bad road, but it didn't affect the steering and I could easily get out of these situations. But here it was all sudden and much stronger. When I got into the wobble, I did absolutely nothing, but then I fell. 

What do you think I should have done and what were the reasons for this? I want to analyse the situation. As I understand it, I should have gradually increased my speed.

I've attached a video of the trajectory of my fall.

 

[Nick the wanderer]

Hi,

Check everything is tight on the bike, forks loose etc and check you have air in your tyres.

[bonio]

If this were me, I'd be looking to see if my suspension is set up right. 

[AstronautNinja]

Strangley to get out of a speed wobble on a push bike you gently start to pedal whilst braking if needed.

[RideWithStyles]

Ground is mixed conditioning at varying points- firmish with some packing and very soft (very fine sand).

Vid quality isn’t the greatest but tyre tracks doesn’t hint at anything greatly untoward with tyres as they are biting and not ploughing, no major step outs or overly dug ins. maybe I’d say the rear preload too low, the rebound too fast as it’s reacting noticeably later on…

checks and changes should o been made with pillion.

point at the rider error, weight and after effect of pillion placement of them being moved about from the bike while your doing what your asking the bike At 9,15,23 time stamps.

if you have inverty shut the throttle off ( easy to have whisky throttle when surprised, loose and pillion on) when throttle and steering application would have been needed (how much of each varying) you would have reversed what was needed, and vice versa. 

shut throttle - shortening wheel base, forks compress and weight thrown forward so steering is more prominent turns , lifts rear up which depends on where the weight and angle of the rear wheel is depends on if it actuates or twists the yaw of the bike, then the rear lowers and digs the rear in (helped by pillion) helping it to turn and power forward (bucking bronco), rinse and repeats to the point your slowing down for lack of momentum.

[Trooper74]

Don’t ride on dirt roads with a pillion ….

[RideWithStyles]

You can do, just you need to be very aware of what implications such things it has to the bike, what needs to be adjusted or changed and what you need to do differently with your inputs when you do dirt and have a pillion etc. 

[keith1200rs]

I ended up on a dirt road on my BMW R1200R with my wife on pillion (dodging massive traffic jams on a bank holiday). It was ok but hard work keeping in a straight line. Luckily it was a wide track so I had plenty of room to manoeuvre. 

[AstronautNinja]

I remember "blasting" down a tarmac path when I was a kid on my 50cc supermoto kinda bike and suddenly hitting a deep AF gravel pit. A lesson I've always remembered. I remained rubber side down luckily. 

[Steve_M]

What tyres do you have on your bike?  Road tyres aren’t ideal, I’d expect semi-trail tyres would work better.  

 

I once rode my VFR800 wearing road tyres on a slightly rutted dirt track and experienced similar symptoms. The same track on a borrowed Honda Transalp with more appropriate tyres was fine. 

 

 

 

 

[RideWithStyles]

These are knobbles the video shows the trail on the track along with the knobbies indents in the sand at various points so they are biting/digging. Also the very half sec in the back ground of the bike and tyres.

[AstronautNinja]

Surely in these situations "you pays your money and takes your chances"