Author Topic: Did the CB750K2 have a front brake rainguard?? (Read 2541 times)

andy750 · « **on:** March 05, 2006, 06:15:44 PM »

Hi all,
Assembling the K2 front fender (which is specific to K2 and below as the caliper hinge is different on later bikes) I couldnt see an obvious place to put the front brake rainguard. Since I am doing a ground-up restoration I cant recall if it had one or not...does anyone know if the K2 had a front brake plastic rain guard?
Thanks
Andy in Boston

Clyde · « **Reply #1 on:** March 05, 2006, 06:25:27 PM »

From memory no. My parts list does not show one for a K2 or earlier. My K6 parts manual definitely does show one.

TwoTired · « **Reply #2 on:** March 05, 2006, 06:32:16 PM »

According to the Honda Motorcycle identification guide, the K2 didn't, the K3 did.

Cheers,

andy750 · « **Reply #3 on:** March 05, 2006, 06:53:01 PM »

Thanks Clyde and Lloyd thats what I thought. Id also checked the K2 parts manual and it doesnt show it but just wanted to make sure. Both my K4s have one so now I have a spare from somewhere! Thanks for clearing that up.

Ah one last question for K2 owners....on mounting the brake caliper to the forks (on rigt hand side when standing at front of bike facing backwards)- are 2 bolts required or 3?? The parts manual only shows 2 but I think I have 3 holes to fill?? And on the fnder attaching to the lower fork legs are there supposed to be rubber grommets between the fender "legs" and the fork (as in later models) - when attaching those small 10mm bolts there is a rubber grommet inbetween?? Anyone know for sure?

Sorry for all the simple questions but trying to get it right...the K2 has all these small differences from K4s (which I also have)
Thanks for the help,
Andy in Boston

HondaMan · « **Reply #4 on:** March 05, 2006, 07:03:15 PM »

There are 2 bolts (I think they are 10mm) that mount the caliper bracket to the fork leg and one more 6mm flathead screw (with a spring between the caliper lever and the fork leg) and a washer and nut on the outboard side. The stock 6mm screw also had a screwdriver slot cut across the end on the outboard side to aid in locking the nut down without turning the screw.

These are used to adjust the clearance between the static (inside) brake pad and the disc. I used .020"-.030" on mine.

TwoTired · « **Reply #5 on:** March 05, 2006, 07:23:03 PM »

The stationary pad to disk clearance on the CB550s is .006 inch. I find that if I adjust this to a larger gap, more lever travel is required to engage the front brake. Perhaps .020-.030 is okay for the 750. But, if you feel your brake lever travel is excessive, reduce the stationary pad to disk gap.

Cheers,

andy750 · « **Reply #6 on:** March 05, 2006, 07:41:30 PM »

Thanks Hondaman (and Lloyd) for the info on the mounting bolts - much appreciated.
Cheers
Andy

Ted Nomura · « **Reply #7 on:** March 09, 2006, 01:51:11 PM »

1972 CB750K2 was the first year that had the front disc rain guard. I have two stock CB750K2s, plus factory brochure and parts books that also have them.

Whoops, my mistake! CB750K3 built in 1972 was the first year that came with a rainguard, not CB750K2. I was typing from a memory and it slipped on me that none of my early stock CB750s I have have rainguards but my 1974 CB450, 1975 CB550K and 1976 CB400F all have rain guards. Sorry for the mix-up!

andy750 · « **Reply #8 on:** March 09, 2006, 02:01:40 PM »

Hi Ted,
Can you take a photo of your K2 raingaurds please as I cant see how it fits onto the caliper arm/bolt. Or even scan in the parts book info if you dont mind.
Thanks,
Andy

eldar · « **Reply #9 on:** March 09, 2006, 02:31:53 PM »

is there any real reason to have this guard? I mean, if you are in the rain, your brake is going to get wet anyways.

Bob Wessner · « **Reply #10 on:** March 09, 2006, 02:57:55 PM »

Quote

is there any real reason to have this guard? I mean, if you are in the rain, your brake is going to get wet anyways.

I think the intent was to prevent the disc from flinging water up towards the rider.

eldar · « **Reply #11 on:** March 09, 2006, 03:06:10 PM »

kinda funny if you ask me. You got this treaded tire grabbing loads of water to soak you with, you are in the rain and they worried about a small smooth disk!!!

Clyde · « **Reply #12 on:** March 09, 2006, 03:52:12 PM »

Ted,
I am interested in your K2's.
Can you let me know the frame numbers?
Honda changed the K2 in late 72/early 73 when they changed the front forks (and I think introduced the rain guard) as well as changing to the later bolt on instruments. This was known as the K3 in some places, but also called the K2 in others
I have seen a parts manual many years ago that stated the change around 2093???. unfortunately it was in a bike shop that is now closed.
My parts book is dated December 1972 and does not show a rain guard. Looking at the rain guard on my F1 which has the same fork lower pattern as the K3-6, it would not fit on the earlier forks.
My K2 has the early forks and clamp type gauges and has the VIN/Frame number CB750-2076130
Regds Clyde

mick750F · « **Reply #13 on:** March 09, 2006, 04:04:53 PM »

I remember once hearing that people removed the rain gaurds because they ended up collecting grit which would then drop into the brakes. Also that they actually direct water back onto the disc rather than allow it to be thrown off and away. Urban myth or fact?

Mike

Bob Wessner · « **Reply #14 on:** March 09, 2006, 04:36:50 PM »

Both seem plausible.

TwoTired · « **Reply #15 on:** March 09, 2006, 05:37:29 PM »

A wet tire or disk will throw off water in a 360 degree pattern around it's circumference.
The fender its used to keep the thrown off water in an area away from the operator or at least away from his vision.

The disc guard has the same purpose.

If you have ever riden a bike without a front fender, you know that water picked up by the wheel gets tossed up in front of the rider and the forward motion allows the rider to move into the water spray.

The front fender and the disc guard are there to reduce the amount of water that gets to the rider. Improving the rider's vision is a good thing, IMHO.

eldar · « **Reply #16 on:** March 10, 2006, 07:58:09 AM »

Of course vision is important. the actual question was if the guard actually DID anything. Things are always being put on ALL vehicles that turn out to not be needed.

So those of you that do not run one, does it really throw up much water or not?

Bob Wessner · « **Reply #17 on:** March 10, 2006, 08:52:45 AM »

Quote

So those of you that do not run one, does it really throw up much water or not?

Mine doesn't have one, never did. I currently don't ride in the rain if I can help it. Years ago on long trips when you couldn't control the weather or when you rode, if it rained I never noticed much from the disk because I was otherwise drenched anyway.

mick750F · « **Reply #18 on:** March 10, 2006, 11:37:11 AM »

Quote from: eldar, Master of the K8 Thunder! on March 10, 2006, 07:58:09 AM

Of course vision is important. the actual question was if the guard actually DID anything. Things are always being put on ALL vehicles that turn out to not be needed.

So those of you that do not run one, does it really throw up much water or not?

Honda didn't put them on the '77-'78F models with dual discs so they may have figured something out. The strange thing is they DID put one on the rear disc. Is it to keep the passengers leg dry? Maybe the budget only allowed for one so they put it on the rear.

I've never noticed spray coming off my discs but then again it's raining when you ride in the rain so would you even notice? It's not like the tire which is in contact with a wet surface and pulling water up as it goes which must account for the majority of the water it throws off. I'd think that any water coming off the disc would be blown back before it reached the riders face area. Just my HO...based entirely on unscientific reasoning.

Mike

Ted Nomura · « **Reply #19 on:** March 11, 2006, 01:37:34 PM »

Quote from: Clyde on March 09, 2006, 03:52:12 PM

Ted,
I am interested in your K2's.
Can you let me know the frame numbers?
Honda changed the K2 in late 72/early 73 when they changed the front forks (and I think introduced the rain guard) as well as changing to the later bolt on instruments. This was known as the K3 in some places, but also called the K2 in others
I have seen a parts manual many years ago that stated the change around 2093???. unfortunately it was in a bike shop that is now closed.
My parts book is dated December 1972 and does not show a rain guard. Looking at the rain guard on my F1 which has the same fork lower pattern as the K3-6, it would not fit on the earlier forks.
My K2 has the early forks and clamp type gauges and has the VIN/Frame number CB750-2076130
Regds Clyde

My mistake. I got mixed up with CB750K3 built in 1972. My friend's CB750K3 built in October 1972 have a rain guard but my own twin CB750K2 doesn't. I was typing from my faded memory, which is ironic because I often warn people not to designate the year model by date of manufacture but by the frame number. Honda did change the forks for the CB750K3 to adapt the new rainguard.

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Author Topic: Did the CB750K2 have a front brake rainguard?? (Read 2541 times)

eldar

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