Topic: The Hot Mess - 1975 CB550F1 Frame/1981 CB650 Engine

[SOHC4 Cafe Racer Fan]

I think Jim may have "found" the exhaust system for this project -- Hindle 4-2-1 in stainless.  The quality looks nice in the pictures and produces 54 hp and 35 ft/lbs torque at the rear wheel with a stock, used 650 motor.  I imagine it will make more with the 674cc kit and 126-20 cam.

http://www.ripplerockracers.com/product/honda-cb650-hindle-stainless-steel-exhaust-fits-1979-82/

[Restoration Fan]

Ooooh, I like it.  That bike is going to be one awesomely fun bike to ride.  That light 550 frame with the HP from that 674 is going to make it a lot of fun!

[bwaller]

It sounds like you'll have a good engine to play with Don. There are subtle improvements including primary chain tension and the clutch speed. That cam is a good choice. I'm sure you'll be pleased with this exhaust too.....good pedigree!

I don't know Lang Hindle personally but followed his race career years ago. It just so happens that the US/Phillip Island race bike project Denis Curtis had been working on involved Hindle for exhausts. Denis was thrilled with how Lang took this on and the professionalism sounds top shelf. Hindle built CB750 pipes previously, and Kemp has done a good thing with these new SOHC exhausts, good on him. 

[FunJimmy]

I think Jim may have "found" the exhaust system for this project -- Hindle 4-2-1 in stainless.

I'm looking forward to mounting one up on the Interceptor too Don and like Brent said, it comes from good pedigree. I just wish I had the bottom end you've got to push things over the top.   

I like the fact that a SOHC4 member (Kemp) is involved in these too.
Great guy!

[brandEn]

Those Hindles look sweet! I would like to try one on my K4 but it looks like filter access won't work.

Jim, you need a 750......

[SOHC4 Cafe Racer Fan]

Those Hindles look sweet! I would like to try one on my K4 but it looks like filter access won't work.

Jim, you need a 750......

That's why I have both -- or rather why I have this project!!

I think Jim may have "found" the exhaust system for this project -- Hindle 4-2-1 in stainless.

I'm looking forward to mounting one up on the Interceptor too Don and like Brent said, it comes from good pedigree. I just wish I had the bottom end you've got to push things over the top.   

I like the fact that a SOHC4 member (Kemp) is involved in these too.
Great guy!

Jim: I didn't know Kemp was a member.  The frame brace looks like a nice piece, too.  The curved cut-outs look like they avoid the filter, too. 

The exhaust has many great things going for it.  Pedigree, lighter weight, great materials and construction, and it even allows for a center stand.

Kemp says that the 12" is more quiet than the MotoGP system, but I assume he is talking about the non-baffled pipe.  I don't want to wake the whole neighborhood.

[CBGhia]

I think Jim may have "found" the exhaust system for this project -- Hindle 4-2-1 in stainless.  The quality looks nice in the pictures and produces 54 hp and 35 ft/lbs torque at the rear wheel with a stock, used 650 motor.  I imagine it will make more with the 674cc kit and 126-20 cam.

http://www.ripplerockracers.com/product/honda-cb650-hindle-stainless-steel-exhaust-fits-1979-82/

I would be curious to know what that same bike tested at on the same dyno with a stock exhaust to see the comparison.  They said stock engine, but there are obviously pods. 

[bwaller]

It is typical for Lang Hindle to have a dyno on the premises. The good builders know what works but the dyno's aren't there for decoration.  Kemp might not know that engine's output because there may not have been a stock exhaust system available, too bad. We know numbers produced & shared on this forum for stock engines are always pretty similar, 36-38RWHP with the odd really good one a bit higher.

The filters can be changed with this exhaust.

[SOHC4 Cafe Racer Fan]

A 5-6 rwhp gain is nice.  A 9 lb. exhaust is nice, too.  That's much lighter than stock and lighter than the Yosh 4-1 replicas out there.

I just ordered the 12" Reverse Megaphone model -- $637.60 CAN or $488 USD SHIPPED!!  That's an outstanding value!

Along with the engine mods (674cc, Megacycle 126-20, headwork), this will increase performance and also reduce weight!

[SOHC4 Cafe Racer Fan]

Good news.  Buzz/Dynoman is sending me a replacement ring set out right away, so the engine build will not be stalled long.

I got the replacement ringset for Piston #1 yesterday. (Thanks, Buzz!!)

The Megacycle 126-20 cam is resting and awaiting deployment!  A putty test will be required to make sure there is sufficient valve-to-piston clearance.

[SOHC4 Cafe Racer Fan]

Some pictures of the Hindle CB650 Stainless Exhaust (with the Classic exhaust tip as opposed to the reverse megaphone).  The design allows for removal of the oil filter while keeping the header on, and for retention of the center stand.

cb650_bike_zpshza6vhcs by Donald Leonhardt, on Flickr

cb650_hd_zpsz5bzcjrt by Donald Leonhardt, on Flickr

cb650_hm_zpsopaqzq8q by Donald Leonhardt, on Flickr]

cb650_m_h_zps7sqjyyam by Donald Leonhardt, on Flickr

cb650_pretty_zpsj7ueengy by Donald Leonhardt, on Flickr

Here's the reverse megaphone muffler

9795_zps5ukjshro by Donald Leonhardt, on Flickr

[MessnerMoto]

Some pictures of the Hindle CB650 Stainless Exhaust (with the Classic exhaust tip as opposed to the reverse megaphone).  The design allows for removal of the oil filter while keeping the header on, and for retention of the center stand.











Here's the reverse megaphone muffler

I like when you can see welding spots. Beautiful Stainless look!

[FunJimmy]

I just ordered the 12" Reverse Megaphone model -- $637.60 CAN or $488 USD SHIPPED!!  That's an outstanding value!

I know. It's a crazy good deal. I ordered the billet frame brace too.

Brent. The primary tube diameter is 1  1/2 inch. This diameter is what Hindle
prefers for the SOHC4 models.

[SOHC4 Cafe Racer Fan]

I just ordered the 12" Reverse Megaphone model -- $637.60 CAN or $488 USD SHIPPED!!  That's an outstanding value!

I know. It's a crazy good deal. I ordered the billet frame brace too.

Brent. The primary tube diameter is 1  1/2 inch. This diameter is what Hindle
prefers for the SOHC4 models.

The frame brace is a nice piece of design, too.  Bolt in frame bracing and it does not interfere with the oil filter. 

Frame-Brace-5_zpsjhfgqyzg by Donald Leonhardt, on Flickr

Frame-Brace_zps37nqudqy by Donald Leonhardt, on Flickr

[Bigsam302]

Don,

I really like that frame brace.  I wanted to get it when I was shopping for parts, but they don't make it for the 750.  That's why I ended up having a bar welded in the same location instead.

Sam

[SOHC4 Cafe Racer Fan]

I am debating on whether to weld a cross-member for this build or use that brace.

[slikwilli420]

Don,

I really like that frame brace.  I wanted to get it when I was shopping for parts, but they don't make it for the 750.  That's why I ended up having a bar welded in the same location instead.

Sam

Could probably come up with something for the 750, but you might have to weld in a couple of bungs on the left side since there aren't holes there like on a 500/550 frame.

[SOHC4 Cafe Racer Fan]

Don,

I really like that frame brace.  I wanted to get it when I was shopping for parts, but they don't make it for the 750.  That's why I ended up having a bar welded in the same location instead.

Sam

Could probably come up with something for the 750, but you might have to weld in a couple of bungs on the left side since there aren't holes there like on a 500/550 frame.

That might not be a bad idea for the 750!

[Bootsey]

Looks like you're putting together the makings of one killer bike here CB750!

Are the 550's thought to have significant amounts of flex in the frame at the front motor mounts, or is the brace as much for looks as it is for additional bracing?

[SOHC4 Cafe Racer Fan]

Looks like you're putting together the makings of one killer bike here CB750!

Are the 550's thought to have significant amounts of flex in the frame at the front motor mounts, or is the brace as much for looks as it is for additional bracing?

The 550/750/650s all have abundant flex in the tube steel frames.  The factory welds are not the best.  Some flex is good. 

Many folks who choose to reinforce their frames add gussets to the triangular points where the tubes meet each other, frame rails or the head stock.  Cross brace welds are also used to prevent frame twist, especially when a cross-member is removed.

Some frequent areas for gusseting/cross-members
Framegussets_zps50735415 by Donald Leonhardt, on Flickr
Additional gusset/bracing examples





I have seen welded cross-members on the front of the frame between the downtubes but this billet brace is the first bolt in brace I have seen offered as a turnkey, no weld solution.

[MessnerMoto]

Maybe I will say something stupid... But I think that engine is stressed member of chassis(I am talking about cb750 but it is same for 550 650...). Not completely like in modern bikes but... Front of the engine is acting like the bracing for the front part of the frame.

[calj737]

Maybe I will say something stupid... But I think that engine is stressed member of chassis(I am talking about cb750 but it is same for 550 650...). Not completely like in modern bikes but... Front of the engine is acting like the bracing for the front part of the frame.

I think you're right, but the way the 500/550 mount with plates between the engine and frame on the down tubes, the engine is somewhat isolated from supporting the frame there. Beneath and behind, I definitely see your point. But because the engine is set back from the down tubes, there is flex there. How much? No clue. Is it detrimental? Again, no clue.

[SOHC4 Cafe Racer Fan]

This might be why most "X" bracing that I have seen is on the rear of the triangle, where there are no engine mounts traversing the tubes.

[calj737]

This might be why most "X" bracing that I have seen is on the rear of the triangle, where there are no engine mounts traversing the tubes.

I speculate that the X in the rear is mostly to attend to the driveline stress from the swingarm/sprockets and rear suspension. Theres lots of stress forces occurring right thru there, and that X and other gussets probably make huge differences. I've been trying to arrange time with a local guy that builds race frames (he made my 550 hoop) to discuss my 500 frame. I'll be interested in his input on what modifications I should add given the subframe change.

[MessnerMoto]

The biggest gain in chassis stiffness would be achieved if you could brace engine head(somewhere in the line of carb mounting position) and frame in the line of airbox mounting holes... And engine head in the line of exhaust openings and frame at the neck. That would crete 3d boxed structure. But I am not sure if engine head/studs/etc can handle that without leaking oil...

This might be why most "X" bracing that I have seen is on the rear of the triangle, where there are no engine mounts traversing the tubes.

I speculate that the X in the rear is mostly to attend to the driveline stress from the swingarm/sprockets and rear suspension. Theres lots of stress forces occurring right thru there, and that X and other gussets probably make huge differences. I've been trying to arrange time with a local guy that builds race frames (he made my 550 hoop) to discuss my 500 frame. I'll be interested in his input on what modifications I should add given the subframe change.

I think you are on good path of thinking. I can see some benefits from bracing back of frame...