Rocker cover "protection"

1077 Views 15 Replies 9 Participants Last post by bahn88, Nov 11, 2021

bahn88

Discussion Starter · Nov 6, 2021 (Edited)

There appears in my opinion a weak point on the engine bars where they mount ...happy to upload breaks pics courtesy of other forum members....
There seems to be no viable mounts for a metal guard on the rocker cover as done on sone Guzzis as there is only the 2 mounting bolts....is there enough clearance on the inside to weld some extra strength ala what racers did on the alternator/crank covers of inline 4s....
Or simply a carbon fibre jacket atop with industrial adhesive.....thoughts?

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CXPHREAK

· #2 · Nov 6, 2021

Anything is iffy.

The valve cover bolts are only 6 mm and screwed into the head. easily damaged.

The Hondaline crash bars can break the front engine mounts off of the engine block with the transfer of force from a drop.

In view of these things I consider the valve covers disposable.

Not ideal I know, but I'd sooner lose a valve cover than a head or block.

Reactions: 2

bahn88

Discussion Starter · #3 · Nov 6, 2021 (Edited)

Welds/extra alloy on inside or carbon fibre externally the most "likely" to work ....?

reclinedrelic

· #4 · Nov 6, 2021

CXPHREAK said:
The Hondaline crash bars can break the front engine mounts off of the engine block with the transfer of force from a drop.

Motor vehicles became safer in crashes due inpart to the introduction of crumple zones. Could someone with enough engineering knowledge design a set of crash bars with crumple zones to protect the cylinders and the mounting points from impact forces?

CXPHREAK

· #5 · Nov 6, 2021 (Edited)

The issue arises from the mounting stud taking the transferred force at a right angle roughly two inches {the approximate thickness of the hanger mounts} from where it emerges from the block. This allows additional leverage to be exerted on the stud compared to if the mount was connected level with the block mounting surface - which is itself elevated an inch or two dependent on side..

Perhaps the section of tubing connecting to the head and block mounts could be a sleeve fit - tube inside tube secured by one or two small plug welds that would break away with enough force applied. The tubes themselves would need to be an interference fit so they too resist sliding into each other, but allow movement which would then come up against a positive stop collar..

The issue here is limited space.

How far can it move? An inch? Two?

There would be other ways of arriving at a similar end but this seems low tech.

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The lost Dane

· #6 · Nov 6, 2021

one way to fix the problem
Don't ride off road

Reactions: 2

Gerard

· #7 · Nov 6, 2021

Or stay, Shiny side up, rubber side down.

bahn88

Discussion Starter · #8 · Nov 6, 2021 (Edited)

As an aside...Not only are mounts questionable in these bikes but in Bmws K100 the top bar mount was an engine mount..well shield from impact..the lower used a thread into the sump.....
Nothin worse than losing the 3L of slippery stuff(oil) at urban speed infront of the rear tire.......yup experience it by clipping a Vw beetle wheel arch?... that turned on me...

MCReviver

· #9 · Nov 7, 2021

Motorcycles are disposable. You are not, so worry about your own crumple. BTW, I have a spare pair of rocker covers.

bahn88

Discussion Starter · #10 · Nov 7, 2021 (Edited)

MCReviver said:
Motorcycles are disposable. You are not, so worry about your own crumple. BTW, I have a spare pair of rocker covers.

Im ok for rocker covers....i am more thinking prevention of damage of whats undermeath....and keeping mobile if a "mishap" if on a trip(motorcycle journey not the chemical one...).....
Yup i know you can patch it with a araldite steelwool mix.....

rcw3586

· #11 · Nov 11, 2021

I believe the "crash bars" are designed to protect your legs not the bike.

CXPHREAK

· #12 · Nov 11, 2021

I'm pretty thin. I doubt they would give my legs any clearance if the bike fell on me.

But you may be right. They may prevent you from taking the full weight.

bahn88

Discussion Starter · #13 · Nov 11, 2021

rcw3586 said:
I believe the "crash bars" are designed to protect your legs not the bike.

Probably very true of those wide bars on in-line fours-they also helped with picking the bike up in a minor parking lot drop......
On the downside....At speed (crashes) they provided a pivot point for the bike to go somersaulting down the road......

Sidecar Bob

· #14 · Nov 11, 2021

I think the idea is to minimize damage to the bike if it falls over, not to prevent any damage in a major crash.

LC8Adventures

· #15 · Nov 11, 2021

What are you trying to achieve by reinforcing a valve cover? This seems like a response to a very hypothetical question, the same way BMW adventure bike riders end up with 50 lb steel cages wrapped around their bikes and a winch mounted on the back.

The Hondaline crash bars are not strong. They are good for taking light tipovers but will bend up into the cylinder head. They are very thin wall. At the end of the day, this isn't a bad thing because I'd rather have them bend than crack the front engine mount bosses off.

The valve covers will take a pretty good hit with no problem. I would hazard a guess that I have crashed my CX500 much more frequently and much harder than most people on this site, and so far the main weak point is actually the ignition coil boots. I always seem to break the top off somehow, I guess because they are all brittle after 40 years. Does that mean I think I need a cage around my plug boots? No, it means I need to crash less but be prepared to fix a plug boot when I go ripping around off road. I have cracked the hondaline crash bars and scratched the valve covers (and broken 3 rear brake levers and bent a shock) but overall it is a very durable engine.

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bahn88

Discussion Starter · #16 · Nov 11, 2021

LC8Adventures said:
What are you trying to achieve by reinforcing a valve cover? This seems like a response to a very hypothetical question, the same way BMW adventure bike riders end up with 50 lb steel cages wrapped around their bikes and a winch mounted on the back.

The Hondaline crash bars are not strong. They are good for taking light tipovers but will bend up into the cylinder head. They are very thin wall. At the end of the day, this isn't a bad thing because I'd rather have them bend than crack the front engine mount bosses off.

The valve covers will take a pretty good hit with no problem. I would hazard a guess that I have crashed my CX500 much more frequently and much harder than most people on this site, and so far the main weak point is actually the ignition coil boots. I always seem to break the top off somehow, I guess because they are all brittle after 40 years. Does that mean I think I need a cage around my plug boots? No, it means I need to crash less but be prepared to fix a plug boot when I go ripping around off road. I have cracked the hondaline crash bars and scratched the valve covers (and broken 3 rear brake levers and bent a shock) but overall it is a very durable engine.

All your points are relevant....
I was thinking about what could be done to keep the bike mobile/lessen damage.....I for one dont own a car, so in the event of a get off having a rideable bike is a plus...
Maybe I was over thinking it..(happens on non-riding days)..and those rocker covers are less of a issue than the crank ends on the inline 4s......

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