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bruteforce

Slingshot racer- where to put crash bobbins?

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I've an '89 Slingshot 750 to do trackdays on. Since I've crashed it at Spa last year, I'm looking into fitting crash bungs-bobbins-protectors or whatever you call them. Reason is that I've enjoyed seeing a H*nd* being ridden off the Zolder track, and that stayed undamaged surprisingly well due to strategically placed protectors. 

Now there are several sellers that sell kits for newer GSXRs but not for the '89. What I'm looking for is advice to how- and where to fit them? I'm thinking big ones at the engine mounting points in front of the engine, some smaller on the passenger footrests to protect the exhaust and some on the front cam plug aside the engines' head. I've ordered the set pictured below.

Pictures please?

 

 

GSXR_crashbobbins.png

s-l300.jpg

crashpads.jpg

Edited by bruteforce

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I had mine thru spindle on front wheel, one's that fit to the cam end bolts & some on the swinger that i Avdel nut'd & doubled as paddock stand pivot/lifters.

You could put em thru original lifter holes on underside ;) 

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56 minutes ago, CockneyRick said:

I had mine thru spindle on front wheel, one's that fit to the cam end bolts & some on the swinger that i Avdel nut'd & doubled as paddock stand pivot/lifters.

You could put em thru original lifter holes on underside ;) 

As Rick said. The sticky out ones on the front engine mounts are ok in slow speed crash's if you want to protect your bodywork. But when its a bit faster it can wreck the frame and crank cases. (I have done it)

Front spindle, rear spindle and fairly big flat ones on a plate secured to the rocker shaft plug caps help the bike slide and not trash the important bits at the expense of the bodywork

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In my experience sliding down the road does little damage anyway apart from snapping off the ally bits that stick out which you then unbolt and bolt new ones on.  However if anything that doesn't give or snap off catches and digs in then it's going upwards and no bobbins in the world will save it.  As our OSS GSXR frames are relatively light and fragile, I'd take heed of warnings above about breaking frames and engines as a result of having crash bobbins.  I hit a stationary bike lying in the track at about 80 mph at the start of a race in 2015, destroyed all the bodywork, snapped the fins off the block and caved the (pristine) tank, but the frame, bars, exhaust, engine, etc all survived intact ready to race a few months later at the Manx.  

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I've seen too many bikes dig in and flip because of bobbins, wrecking both sides. Mind you that was on the soft stuff (gravel traps and run offs). If you only crash on tarmac I'm sure you'll be fine.  If you launch a bike skywards they're not much use.

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They're great on your road pride and joy for when you drop it in a car park or slide off on diesel, but as some of the winged hammers point out can cause more problems on track.

If you check out bikes in WSB they only have engine covers and maybe an exhaust slider plus other bits designed to break away when dropped which are quick to replace in the pits, I reckon they know the score.

I used to run a non-suzook track bike which I put loads of sliders on, crashed it at Cadwell and snapped the sub-frame, convinced it was due to the sliders as I had crashed previously at the same place without them and other than cable ties and some duck tape the bike was still ok.

Lesson learned....the hard way, although I do have them on my road bike for when I fall off in a car park or outside the pub....O.o

Edited by Simbec1863

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I'd stay away from fitting any sliders etc to the head's sides. It's way too delicate and you'd probably damage the head severely even in a relatively light crash.

Just my two cents,

Nik

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Having some experience of WEC can I pop in some notes.

It's worth remembering that the bars and pegs are integral crash protectors, that you can't actually do without, so best use them to the max.

You want them to deform slowly, absorbing energy as they bend. The trick is all in the type of alloy used if you want to survive.

7075 is very strong and is often quoted as the material used, but it's brittle on impact, 6082 is a better choice as it is much more elastic. Can be a good choice for Yokes as well, better to have a set of yokes that can bend as opposed to a really stiff set that just leaves you with forks that have snapped off at the bottom yoke. It makes getting the bike mobile again a lot more difficult.

Is worth looking at your lock stops, a nylon bung mounted on the headstock casting that stops the fork leg is better than a lump on a yoke and a stop on the frame. Nylon to metal will distribute the loads and impact energy a lot better.

Next trick is to make a triangle of the contact points,so that the bike can slide on it's side. You also want to protect the oil cooler, so set of bungs mounted off the front mount is what I would do. I think the trick here is to fit a set of tough engine covers and then match the length of the bungs to make the o/all width the same, not sticking out to protect the fairing.

A long/strong lever that sticks out of the side, is just begging to hook into a kerb and start the bike flipping and cartwheeling.

Oh and those bits of hose around the end can, just fashion. The original idea of these is that you have a couple of loops of  fencing  wire wrapped around the can with the hose to stop it destroying the finish on the pretty can. The wire is twisted into a rope and tied onto the subframe, in an off that trashes the exhaust hanger you can keep going for a while without the can going walkies.

 

 

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Of course you may still end up needing some T cut.

iTPZXiOl.jpg

Culprit here was the sticky out bit, 

TmE2XRUl.jpg

This on came down from a very great height.

It cracked the tyre.

8Z1byhDl.jpg

:D

 

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I have NRC engine covers on one of my bikes. Pretty near indestructible

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I was looking at them too. How many times have you crashed with them?

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OK thanks for your comments guys, I just got the bobbins in so will make a start.

 

I'll place them on the bike as in my first picture, and for ease of fitment loose the bellypan as per red GSXR. I already have welded alu plates on the standard crank end covers so the combi with the bobbins should make it a little more crash resistant.

 

I'll keep you posted!

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