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Oggy Knob fail sandwich on Z750

Discussion in 'Riding Gear and Bike Accessories/Parts' at netrider.net.au started by Grimmelkin, Sep 26, 2010.

  1. General heads up on possible damage due to Oggy knobs on a Z750 (07 - 10 model)

    I had Oggy knobs fitted on my Z750 when I bought it as eventually I figured they would come in handy...

    SO a couple of weeks ago I got to test them out when a woman pulled out in front of me (obviously didn't look) then stopped (across my lane) when she saw me.. I opted for trying to make around the front of the car instead of flying across the bonnet but the act of turning while still breaking too hard resulted in the bike taking a gentle slide down the road...
    Thankfully it was pretty low speed by the time went down.. And she admitted fault.

    Aside from some minor scratches on the bar ends, mirrors lever, foot pegs, axel etc. The engine cover (left side ) was ground through enough that there was a small matchhead size hole and the oggy knob was ground down a bit. Bike probably slid 5 meters in total and despite loosing a bit of oil I was able to ride it home

    The woman admitted fault and her insurance covered the damage.

    Brighton kwaka did the quote.. and picked up that the engine mounting bracket snapped due to the weight of the bike on the Oggy knob.... WTF... It is slightly hidden where it cracked so I didn't see it before I took it in..

    Apparently they have raised this with Oggy knobs AU as while it may have protected the tank and the cowling it snapped the engine mounting bracket in the process.. The mounting brackets are cast and obviously not designed to take that sort of stress as it just snapped clean through...

    then..



    Last night the universe in it's infinite wisdom decided to unleash disgruntled AFL muppets loose on the street and my bike was knocked (deliberately, it is leaned against a wall it would take a good amount of force to knock it over.)) over and now the bracket on the other side has cracked in the same place..
    Not happy to say the least, the scratches (muffler, bar end and under side of footpeg) are one thing but needing to replace an engine mounting bracket for a stationary drop... Bracket for the left hand one was just over $230 not including labor..

    So... For those people out there with Z750s, if you drop or bin the bike... You will likely end up with a cracked engine mounting bracket (the cast arms that the Oggy knob is mounted on).. The crack appears near where the upper and lower brackets join .. It is not obvious unless you go looking for it. It is not a primary mounting point so it isn't the end of the world the bike is still ridable but you will obviously want to get it fixed at some point...
    These are the knobs in question... http://www.promotomelb.com/pdfs/OK670-671.pdf

    I'll add pics once I get some.


    Hopefully I got this in the right section...
     
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  2. Glad all is ok...
    Yeah i have read on here before somewhere the pros and cons of oggys.
    Things like sure they help save the fairing and the like, but transfer the impact to the frame, and as is shown precisely in your case, thats bad!
     
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  3. I've seen some oggy's that are connected at two locations on the frame, about 250mm apart so they don't overload the frame in one location but the load is spread. Great idea (y)
     
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  4. Yep, Oggy's that mount via a "plate clamp" are the better idea. I don't trust these engine mounted oggy's purely because I shudder at the possibility of a bolt snapping off in there and the expense of having it drilled out.
     
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  5. I've heard about them damaging frames and other structural parts as well too.. I hadn't imagined that a simple tipping over would do it though...

    I think ultimately what was worrying with this is that has I not known about the first break, I probably would not have noticed or known to look for the other break until I next washed the bike or got my head right up close to the engine as it is only visible from certain angles...

    I'm still weighing the pro's/con's of the Oggys bur it would be likely that tank and the front cowling being damaged would be much more expensive to fix...
     
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  6. These ones are mounted via a bracket that attaches at two points about 25cm apart but the knobb is at one end of that bracket so the impact isn't distributed evenly over the two points. The design of the oggy bracket results in all of the weight of the bike going onto the weakest bit of the engine mounting bracket.. I can definitely see what they were aiming for with the oggy bracket, but it probably needs to be mounted onto something that isn't just cast alloy...
    The in the case of z750 oggys the result is the same as using this style of frame slider except that it sticks out a lot further and thus protects the tank/cowling a little better.. http://www.twinshack.co.uk/prods/174.html
     
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  7. I've been thinking of swapping out my knobs for an engine cage. Other expenses take priority, though.
     
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  8. Damn, that is troubling! Sorry to hear you've found out the hard way.

    I've bought R&G Racing Crash Protectors for my Z750 that mount at a different point to yours. It only attaches to a single engine mount, the one with a bolt head rather than hex head which I think is much sturdier... the bolt is about 20cm long and over 5mm thick. But I've haven't successfully attached it yet because I need to lift the engine block ~3-5mm for the engine block mount to align with the frame. But now I'm having second thoughts about them... I guess like most aspects of biking it's all about risk assessment!
     
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  9. If i had a cruiser id probably get them, better the frame damaged then the entire side of the bike. On the sports, thats half the reason the fairing is there i think :p.
     
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  10. They do look a lot nicer too.. As far as I can tell from their pics it looks like they attach to the one of the same points as the oggy bracket but having the knobb at that spot looks like it would have a lot more structure behind it.
    I've been looking at some of the R&G engine case covers, they are pretty cheap and don't require much to install. The left engine cover ground through so quickly I'd hate to see what would happen if it slid an another 5 or 10 meters..
     
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  11. interesting read... I've always been skeptical of crash bungs... But look at it this way, insurance was going to repair the bike with or without the crash protectors so in my case I figure thats what insurance is for. I understand the odd drop, but still it could be more hassle than its worth as you found.

    I think the R&G engine cases would definitely be worth while... Thats the first thing to hit the ground on any fall, and the crash bungs from where they're positioned would concentrate the slide on them I think?

    Let me know if you start looking into the engine cases, im seriously looking to invest in those!
     
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  12. I'll be getting a new Z750 soon and was thinking whether to put oggy knobs on it or not but after reading this I think I'll pass...
    I'm buying the bike new from the dealer and getting comprehensive insurance on it so I'd rather pay the excess than close to $300 for the knobs only to cause more damage than they are meant to prevent.
    thank for the heads up though!
     
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  13. This is what I like about this forum and the people here

    Grimmelkin - even though you have suffered a loss so to speak - you are willing to share your experience and warn other members of the possible pitfalls in using these oggy knobs
    for this I commend you
     
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  14. There you go then - plus it saves you one of the lives you get with most insurance policies. I'd be annoyed as well however but as you have identified, at times of annoyance it's better to be saddled with the cheapest outcome ;)
     
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  15. I know not a Z750 but this is the same reason I don't have crash knobs on my CB400 (They mount to the engine) despite me being a bike noob and statistically pretty damn likely to drop it at some point soon :/ (Hopefully not though!)
     
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  16. I put them on my cb600f because I figure a broken bracket is better than a ****ed radiator, frame and tank. Weighed up the pros and cons and decided to go with it.
     
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  17. R&G crash protection are the way to go - pricey though, however, I swear by them. On my 9R they mount directly onto the engine mounting bolt points and there's very little lever arm so the bolt and the bung take the hit.

    Any frame slider that needs to be mounted via some kind of cantilevered arrangement should be viewed with suspicion. The mounting arrangements needs some seriously good engineering - I don't think I've seen seriously good engineering from Oggy or Ozzy knobs.

    Frame sliders are there to protect an instant write off from a damaged frame... the rest of the bike is fair game in a prang.
     
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  18. my Hornet has ugly (but very effective (y)) engine protection bars, bought from www.renntec.co.uk

    cost $200; $100 for the bars and $100 for freight :LOL:

    Still cheaper than ANY of the engine cases, however.
     
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  20. I bought mine through AMC too.
     
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