Author Topic: Crash bars  (Read 510 times)

Offline billywingnut

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Crash bars
« on: November 06, 2019, 05:03:00 PM »
I'd be interested to know what members think about fitting crash bars to 400/4

Offline Nurse Julie

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Re: Crash bars
« Reply #1 on: November 06, 2019, 06:25:19 PM »
I have the proper ones fitted as supplied by Honda back in the day on my 400/4. Look great, very useful if you just have a stationary or very low speed drop as they would protect the engine and some other sticky out bits but I am fully aware that if I came off the bike at any decent speed and the bike hit the deck quite hard, the bars would bend, if not snap the engine mounting lugs and possibly the frame.
« Last Edit: November 06, 2019, 06:27:15 PM by Nurse Julie »
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Offline MCTID

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Re: Crash bars
« Reply #2 on: November 06, 2019, 06:44:12 PM »
I recently bought a 1979 Suzuki GS750 (yes I know - but it's still a rather nice machine for being 40 years old). On stripping the 'bent' crash bars off it, I found that one of it's mounting lugs underneath the engine was snapped off. No structural damage was apparent to the rest of the bike, and it's obvious that the material used in the Crash Bar is designed to be 'sacrificed', along with the fittings being to the Frame rather than the Engine Block.

On cleaning up the Crash Bar to prepare it to have the broken lug re-welded, I was surprised how soft the steel is, but I'll be quite happy to refit it knowing that it will fail first if it has to do its job in a slow speed slide in the future (God forbid).

I would be wary of any Crash Bar which was bolted to an Engine Block, but I suppose you have to weigh up Crankcase damage which could be prohibitively expensive whereas fitting or replacing a Crash Bar might cost £100.
Now: CB750K4. 1970 Bonneville. 1979 Suzuki GS750E. Various other 1960's 650 Triumph T120's/ TR6's/ TR6C's. Previous: CB1300 (2). ZXR1200S. VFR800. CB750 Nighthawk. CX500. XS500 Yam. Suzuki GT500. BSA A10. Various Lambrettas. Zundapp Bella (honest).

Offline mattsz

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Re: Crash bars
« Reply #3 on: November 06, 2019, 10:15:08 PM »
I have the proper ones fitted as supplied by Honda back in the day on my 400/4. Look great, very useful if you just have a stationary or very low speed drop as they would protect the engine and some other sticky out bits but I am fully aware that if I came off the bike at any decent speed and the bike hit the deck quite hard, the bars would bend, if not snap the engine mounting lugs and possibly the frame.

Got a pic handy, Julie?

Offline Nurse Julie

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Re: Crash bars
« Reply #4 on: November 07, 2019, 11:15:54 AM »
I have the proper ones fitted as supplied by Honda back in the day on my 400/4. Look great, very useful if you just have a stationary or very low speed drop as they would protect the engine and some other sticky out bits but I am fully aware that if I came off the bike at any decent speed and the bike hit the deck quite hard, the bars would bend, if not snap the engine mounting lugs and possibly the frame.

Got a pic handy, Julie?
You can see the fixing points on these Rickman bars. They come in 2 halves and are a complete tube pipe design, unlike what DS sells now which are only half a tube, if you get my drift

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Offline mattsz

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Re: Crash bars
« Reply #5 on: November 07, 2019, 11:48:08 AM »
Thanks!

You can see the fixing points on these Rickman bars. They come in 2 halves and are a complete tube pipe design, unlike what DS sells now which are only half a tube, if you get my drift

I don't, but that's ok!  The ones currently offered by DS are rather... busier than yours:


Offline Nurse Julie

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Re: Crash bars
« Reply #6 on: November 07, 2019, 12:01:12 PM »
Thanks!

You can see the fixing points on these Rickman bars. They come in 2 halves and are a complete tube pipe design, unlike what DS sells now which are only half a tube, if you get my drift

I don't, but that's ok!  The ones currently offered by DS are rather... busier than yours:


If you look at the top pic, you can see the vertical bars are only ½ a tube, so in effect they are ornamental.

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Offline Nurse Julie

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Re: Crash bars
« Reply #7 on: November 07, 2019, 12:07:05 PM »
Edit...sorry, the horizontal bars, when fitted to the bike, not the vertical bars  ::)
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Offline mattsz

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Re: Crash bars
« Reply #8 on: November 07, 2019, 12:10:07 PM »
If you look at the top pic, you can see the vertical bars are only ½ a tube, so in effect they are ornamental.

Ah-so!  The entire "web" structure within the outside tubing is indeed half-round - horizontal and vertical, I think.  I initially thought you meant all of the tubing.

I wonder if those extra half-round bits would do anything at all if called upon to help provide protection in any kind of fall.  I think yours look better; less is more to my eye...

Offline Nurse Julie

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Re: Crash bars
« Reply #9 on: November 07, 2019, 12:15:08 PM »
If you look at the top pic, you can see the vertical bars are only ½ a tube, so in effect they are ornamental.

Ah-so!  The entire "web" structure within the outside tubing is indeed half-round - horizontal and vertical, I think.  I initially thought you meant all of the tubing.

I wonder if those extra half-round bits would do anything at all if called upon to help provide protection in any kind of fall.  I think yours look better; less is more to my eye...
I don't think the half round bits will do anything at all in a drop, that why there is no need for them there. Yes, I like my basic design ones.
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

 

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