CB450x

Hey all,

This build is quite a ways along already, but I thought I would share with everyone here on DTT

I bought a CB360 for $300 that had been parked since the mid 90's. The pistons were so seized in the bore they needed an air hammer for removal, so the engine went in the scrap bin and I began hunting for and engine to transplant.
The plan was always to create a monoshock, lightweight cafe racer with inverted forks, so I wanted to buy a donor bike that could provide me with an engine and suspension.
Yamaha Banshee's were discussed, CBR's seemed a bit overkill, even considered a Ninja 250 (not sure what I was thinking). Then along came a good running '05 crf450x for a good price, and the teardowns began.

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Conceptualizing... The motor fit way to awkward in the CB360 frame, big frame modifications to come

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New bottom rails were fabbed up, as well as down tubes from the backbone. To keep the bike as light as possible, this chunky subframe had to go. Also forked over way too much money for supermoto wheels from Warp 9. Front forks were temporarily lowered just buy making new grooves for the spring stops inside the forks.

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Scored a CBR600RR shock, made some upper and lower shock mounts, and started fabbing up an aluminum subframe. Also picked up a racy tail section from airtech streamlining.

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Looking a little more like a bike. Cant even begin to tell you how much welding and notched tubing pieces went into this thing. And how many miscut notched pipes went into the scrap bin.

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Faster the better right? the engine got a fresh top end, Kibblewhite SS valves, stage 2 hotcam, but most importantly a 3 ring JE piston from a TRX450r quad for better top end life. Also got painted to look like a filing cabinet.

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Im a sucker for pie cuts, and excessive amounts of welding apparently.

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Forks needed to get finished up. Lowering twin chamber Showa's is one of the easiest mods in the world.

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Needed to get clever with the cooling system. Front rads dont look great on a vintage cafe racer, so I did my best to be discreet as possible with the cooling system. Hidden reservoir under seat, radiator mounted underneath the engine (yes i know its a terrible spot but it works and theres a belly pan going to be made soon)

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Here in Canada winter is well under way so I managed to get one ride in before the snow fell.

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Still needs a huge amount of work, but the bike us a solid runner.
Weighs in at 238lbs with a 1/4 tank of fuel
Yes, its fast.

Thanks for looking!
 
Few more closups

These are handlebar switches I designed and had CNC'd. 2a switches, can be latching or momentary contact, NO or NC, switch housing have allocations for routing through the bars or externally. Because im using clip ons I decided to just route external.

XceYxZ.jpg


Better shot of the exhaust. Muffler is titanium and feather light, pipe is made of 22ga stainless steel.

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Cut the old ugly gas cap off and welded in a pop-up style.

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Yeah it still needs some finishing touches and cleanup but its all functional right now!

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Another shot from the day I rode it

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If anyone is interested in those handlebar switches PM me, I would love some feedback on how well they work
 
futureprimitivemoto said:
Few more closups

These are handlebar switches I designed and had CNC'd. 2a switches, can be latching or momentary contact, NO or NC, switch housing have allocations for routing through the bars or externally. Because im using clip ons I decided to just route external.

XceYxZ.jpg


Better shot of the exhaust. Muffler is titanium and feather light, pipe is made of 22ga stainless steel.

sXxzGu.jpg


Cut the old ugly gas cap off and welded in a pop-up style.

hso1x0.jpg


Yeah it still needs some finishing touches and cleanup but its all functional right now!

xNGH3v.jpg


Another shot from the day I rode it

8OG25A.jpg





If anyone is interested in those handlebar switches PM me, I would love some feedback on how well they work
Motogadget offers similar switches.

Sent from my SM-G955U using Tapatalk
 
Might be better to put the radiator under the tail. You don't need one as big as the one you got now and the longer hoses will help with cooling.
 
With the added benefit of running the hoses a bit more discreetly over the head/under the tank instead of across the front
 
Putting the radiator in the tail was considered but I decided to mount it under the lower frame rails.
An aluminum belly pan is in the works, tricky aerodynamics will be the key here. Creating high pressure on top of the radiator via air ducts and fans while using the belly pan to create low pressure underneath. Once completed it will look really racy and should keep the bike cool.

These engines produce a ton of heat, anyone who's ridden a 450 knows they can't idle for long without spitting coolant out the overflow, especially with higher compression. Increased rad size is of the utmost importance and the tail did not have enough room without running a second radiator somewhere else.
 
futureprimitivemoto said:
Putting the radiator in the tail was considered but I decided to mount it under the lower frame rails.
An aluminum belly pan is in the works, tricky aerodynamics will be the key here. Creating high pressure on top of the radiator via air ducts and fans while using the belly pan to create low pressure underneath. Once completed it will look really racy and should keep the bike cool.

These engines produce a ton of heat, anyone who's ridden a 450 knows they can't idle for long without spitting coolant out the overflow, especially with higher compression. Increased rad size is of the utmost importance and the tail did not have enough room without running a second radiator somewhere else.


Putting it underneath the motor then covering it with a bash plate wont do anything to promote decent cooling. Just saying.
 
Before I start, I just have to say I'm not trying to bash. It's a beautiful start. I just wanted to say that, aesthetically, I don't really care for the long, leading-axle front end. I realize how hard they are to come by- decent inverted front ends, that is- so if it's a run-what-you-brung situation, I get it. Just saying, something less... "kicked out" would really improve the look.
 
two-smoker said:
Before I start, I just have to say I'm not trying to bash. It's a beautiful start. I just wanted to say that, aesthetically, I don't really care for the long, leading-axle front end. I realize how hard they are to come by- decent inverted front ends, that is- so if it's a run-what-you-brung situation, I get it. Just saying, something less... "kicked out" would really improve the look.

I really appreciate the response. The long term goal with the bike was always to go to a CBR front end. These forks work but the valving in them is completely wrong for the street, they're heavy, and aesthetically they're not very nice.
 
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