Frame sliders/engine guards

[2017EX_imp]

Speaking of the sw motech bars, the instructions suck. I had to go back through old posts on here to find the torque specs for the 2 stock engine mount bolts on down tubes being reused for the bars(36 ft/lbs). The supplied swm bolts(one on each side) are torqued at 28 ft lbs. I think/ hope I did it correctly.

Yes the SWM instructions are lacking. Yes you used the correct torque values and bolts. Post #s 12, 14, and 17 in this thread [url=http://cb1100forum.com/forum/showthread.php?tid=8360&page=2]http://cb1100forum.com/forum/showthread....360&page=2

[peterbaron]

Well-spotted, Max.
I think these CB engine mounts are disgraceful for thesereasons...
1. They are placed too far to the outer edges of the crankcase where they are very vulnerable to being struck
2. They are grossly insubstantial. If I recall, my '72 CB750 mounts were bigger affairs that went right across the engine from one side to the other, with one big long bolt securing the two sides.
3. This is from a world-leading manufacturer, so you wouldn't expect these sort of errors.

As a result of 2017EX, Houtman and other's observations on crashbars (my preferred protection) I have switched my intentions to buy from Hepco&Becker to the SWMotech offering - very similar bars but with two main differences - an additional metal strip between engine mount and bar mount on SWM, that allows a little flexibility in an accident and reduces "shock", and a different attitude to the mounting bolt - rigid and inflexible on H&B or "sacrificial" in nature on SWM.

Here are my own broken engine mount pics:

For this problem, I would use a two pice clamping collar ( not band) to brace the crack and prevent from further destruction. Perfect would be custom machined collar, which must be installed in crack squeezing manner. Do your repair right, so it will last forever.
I used JB-Weld for fixing car's broken transmission housing/mount...never came back with any complaint at all.

Here is a good collar example/idea:

https://www.globalindustrial.ca/p/motors...gIjR_D_BwE

Good luck

[Bazbro_imp]

Many thanks for that, PB, and for the link too.

[Dover_MA_imp]

Can you weld that broken mount ?

Yes, I could, John.
The best course would be to...
1. Take the engine out of the frame and replace the lower engine block. Or
2. Next would be an engine-out, strip-down alloy-weld repair. Or
3. Then an in situ alloy-weld repair, and finally
4. A JBWeld repair.
Removing the engine is out of the question - it would ALL have to be done at a dealer and the cost would be prohibitive! It ain't gonna happen, 'cos I can't do it myself.
I spoke to my welder (who coincidentally owns an old Honda Four!) and whilst he was prepared to look at the job and maybe have a go, he was unsure about doing it in situ because of the heat generated by the weld
. At that time I was going to take the 'bike for him to have a look, on my way bringing the 'bike home. My 'trailer plan' failed when the hitch broke so the 'bike was brought straight home here and the welder hasn't looked at it yet.
I decided to at least TRY the JBWeld - I'll be keeping a VERY close eye on it. If the product is as good as the reports, it'll be fine. If it's not, I will have to deal with it then.
The crack itself is UNDER the weight-supporting part of the bracket. It is totally supported on either side by big penny washers, clamped and torqued up, then clamped to the frame. The weight is downwards, onto the unbroken part and I can only see it breaking again if it gets an upward whack like last time. Of course, it may fail through vibration, heat, whatever but all reports suggest that will not be the case. No weight is being taken by the weld - just holding the loose underneath part UP onto the solid top part.
It is what it is and although not ideal, I'm keeping my fingers crossed. (And toes, and arms, and eyes!).

Please don't think I'm a naysayer, but isn't engine torque going to pull the front of the motor up?

[Bazbro_imp]

Can you weld that broken mount ?

Yes, I could, John.
The best course would be to...
1. Take the engine out of the frame and replace the lower engine block. Or
2. Next would be an engine-out, strip-down alloy-weld repair. Or
3. Then an in situ alloy-weld repair, and finally
4. A JBWeld repair.
Removing the engine is out of the question - it would ALL have to be done at a dealer and the cost would be prohibitive! It ain't gonna happen, 'cos I can't do it myself.
I spoke to my welder (who coincidentally owns an old Honda Four!) and whilst he was prepared to look at the job and maybe have a go, he was unsure about doing it in situ because of the heat generated by the weld
. At that time I was going to take the 'bike for him to have a look, on my way bringing the 'bike home. My 'trailer plan' failed when the hitch broke so the 'bike was brought straight home here and the welder hasn't looked at it yet.
I decided to at least TRY the JBWeld - I'll be keeping a VERY close eye on it. If the product is as good as the reports, it'll be fine. If it's not, I will have to deal with it then.
The crack itself is UNDER the weight-supporting part of the bracket. It is totally supported on either side by big penny washers, clamped and torqued up, then clamped to the frame. The weight is downwards, onto the unbroken part and I can only see it breaking again if it gets an upward whack like last time. Of course, it may fail through vibration, heat, whatever but all reports suggest that will not be the case. No weight is being taken by the weld - just holding the loose underneath part UP onto the solid top part.
It is what it is and although not ideal, I'm keeping my fingers crossed. (And toes, and arms, and eyes!).

Please don't think I'm a naysayer, but isn't engine torque going to pull the front of the motor up?

Please don't think I'm a naysayer, but isn't engine torque going to pull the front of the motor up?
Yes, and there will be all sorts of other minor stresses too, in all directions. But the major stress, the sheer weight and bulk of the engine, is downwards. The engine torque also has to fight against that not-inconsiderable weight and it's also lessened/softened by the movement of the 'bike itself.

Thanks for your thoughts, Dover. We shall see how the joint stands up over time. It will certainly be checked before, during and after every ride!

[Lambchops_imp]

There are many different ones but I like the ones from Over from Japan.

I have the OVER RACING ones too. I really like how they mount directly to the frame instead of the engine and have 3 points/bars. Also, they don't touch the road like the Kijima ones in the twisties... Haven't had a chance to crash them to say if they're up to it.

I don't think any of these crash bars are meant to hold up in a high speed crash anyway.

[flynrider]

There are many different ones but I like the ones from Over from Japan.

I have the OVER RACING ones too. I really like how they mount directly to the frame instead of the engine and have 3 points/bars. Also, they don't touch the road like the Kijima ones in the twisties... Haven't had a chance to crash them to say if they're up to it.

I don't think any of these crash bars are meant to hold up in a high speed crash anyway.

I have crash tested the OVER Racing guards. After a deer strike I went down on the left side at around 25 mph. I was amazed that it not only protected the engine, but the whole left side of the bike (except the handlebar) stayed clear of the pavement. I didn't even scratch a turn signal. Right after I got home from that road trip, I immediately ordered another set from Samurider.

[chopperrockets_imp]

i just bought the same guards, they dont quite match the frame color. is it distracting?
also can you put your feet on them and lide for a bit like fwd foot pegs?

thanks

[Cormanus]

I think some members may have mounted pegs on their engine guards to use as highway pegs. Start here http://cb1100forum.com/forum/showthread.php?tid=5175

[Wisedrum]

I did.



Wisedrum