Motorcycle stability question?

Discussion in 'Cars, Bikes 'n AFVs' started by issac_hunt, Jan 17, 2009.

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  1. Hello fellow bikers, I have recently taken delivery of an FJR1300 (2008 model) and very happy I am with it too. The manual states that the panniers should not be used in conjunction with a topbox. I asked the mechanics at my dealership and they didn't see any reason why the topbox (givi 51 litre case) should be incompatable with the panniers.

    Are there any arrsers out there who use both on an FJR or know someone who does and can offer me advice. I am loathe to try it without hearing other biker's experiences.

    Many thanks,

    Issac Hunt
  2. I suspect its a weight thing.
    At a guess, if you were to load up two panniers and a top box then add a pillion you will probably go over weight?
  3. I would have though both weight and distribution as the panniers look to be behind the rear spindle an a top box would be further back than that. It'll probably be like a little hatchback with a boot full of concrete (if you've ever tried that) when fully laden. You could always suck it and see.

    Edit: Careful mind. You don't want to break the rear subframe, that could be bad ;)
  4. Too much weight behind the rear axle will affect the bike's stability and steering by making the front lighter and reducing the front tyre's contact patch smaller. Aim to distribute the weight with as much of it forward of the rear axle as possible, use the top box for spare lids, sleeping bags, light clothing, etc.

    Best plan is to experiment and see for yourself how the weight affects the handling without, one hopes, lofting a minger of a wheelie and flipping the bike.
  5. I've been riding big bikes over long distances for over 25 years and I've covered over 1,000,000 miles, thats not a brag. I've been through many bikes my first big one was a Yamaha XJ900 which lasted 200,000 miles, though it did break the frame 4 times, why? Top box and panniers were too heavy, over time they fractured the frame, Yamaha paid up on the first one, but I had it welded from then on. Next up BMW R100RT, came with big panniers and a small top box, I switched it for a large fibre glass one, all was well, unless you passed HGVs big wobble, no problems with a pillion on, I guess it is to do with the disturbed air passing over the rider and then being disturbed again by the box, no top box, no wobble. I needed to use as much space as I could so I knew there was an issue and adjusted my riding to suit. I guess these days maufacturers don't want a court case! As has been said above, it will always alter the handling, either through wieght distribution or aerodynamics, more wieght or speed bigger effect.

    Last point, some police forces, Surrey and Thames Valley IIRc have had very experience riders killed on Police spec BMWs and Hondas due loading issues, if you do fit a top box, take time to see what effect it has, remeber when empty it may act as a wing and lift the wieght off the rear wheel! IIRC this is what happened to Honda!
  6. Hang on, FJR 1300 is a sports touring bike...what is the use of a bike designed to tour if you can only take enough luggage for a weekend away? Bit pointless in my mind, these bikes should be able to carry enough luggage for a protracted stay away from home.
  7. Sure it's not just because you'd have to ask for assistance from passers by when you drop it at traffic lights? :twisted:
  8. I had a cbr 1000 with 3 x 50 litre givi boxes. Did 3000 miles round europe 2 up fully loaded, and could still do 150mph on the autobahn without the slightest glimmer of a wobble! Likewise, could get the pegs down going round the swiss alp passes.
    Top honda!
  9. I'm not slagging off any replies on here but to cast your net a bit wider try The Rev Counter:

    There's a lot of experience on there and you may get some definitive answers.

    Like London_Lad I too had an XJ900 and put 226,000 miles on the clock. Top bike although a bit dated.