What you have to remember about top boxes is they tend to overhang the rack at the back. That increases the leverage and bending moment on the frame. The 5kg weight limit will be a conservative figure, but even so, rough riding together with this additional leverage will push this limit. Work hardening over time is also the issue here.

 

Unless you are carrying a pilion, strap everything to the rear seat, it is designed to take up to 100kg and good for fuel consumption too.

 

As for the rest of the frame, you cannot count direct impact damage, that is called a "crash" and and outside the design remit. Riding the bike without direct impact, 95% of the shock load is absorbed by tyres and shocks. That is why shock absorbers, often ignorred, are so important.

 

Many of the 4 wheel off-roaders ignor this at their peril, when the go to places like Africa without OME shocks, some don't think to carry spares. Result, the entire vehicle falls apart. Then they blame the vehicle.

 

I assume there is an OME (Old Man Emu) equivilent for bikes?

I agree, using a top box when going off road or across country probably isn't the best idea. As you suggested, too many stress points that will take a hammering.

 

I've actually not heard of that acronym OME before....OEM (Original Equipment from Manufacturer) is quite a bit more common tho.

20 hours ago, CMKiwi said:

I agree, using a top box when going off road or across country probably isn't the best idea. As you suggested, too many stress points that will take a hammering.

 

I've actually not heard of that acronym OME before....OEM (Original Equipment from Manufacturer) is quite a bit more common tho.

OME is an Australian manufacturer and amongst the Off-roading community their shocks are (or were) considered the best. Everyone who goes to challenge the Africa corrugations fit them, if not on their first attempt, they do on the second.

 

My last trip to north Africa a guy taught me to fast drive and drift the corrugations, which takes the load of the suspension by skipping over the ruts. Had OME shocks on my 1971 Range Rover and everything was fine and great comfort given the conditions. Not sure if I would do that on a bike though with two wheels missing.

 

I guess if you live in the dirt-road capital of the world you learn something, either that or have a long-long walk.

 

On the subject of small bikes, we carry a 50cc Peugeot scooter on the back of our campervan, gets us right into town, even through some of the narrow streets where bigger bikes wouldn't fit. I have a lived with a buggad left knee for ten years now, so walking isn't easy, this little bike and the Vespa makes life really easy.

 

Riding a scooter around these streets is totally accepted by the locals, big bikes would not be at all welcome. 

This is the most important part of ANY motorcycle trip....

 

 

On 24/04/2018 at 10:16 AM, AllanB said:

I assume there is an OME (Old Man Emu) equivilent for bikes?

Race Tech, Öhlins and YSS to name but a few...the original suspension fitted to the 250L is fine for 'light' off roading, but if you weigh more than 60kg and want to push on a bit then forget it...it doesn't take much to bottom out the rear shock and blow the front fork seals.

 

It's one of the main reasons why the KLX is more expensive...they chose to fit much better adjustable suspension to that bike.