Topic: 79' CB650 (674) Project with a 550 tank and CBR front end.

[Sigmund]

After gaining some info and support here, I have decided to start a build thread to maybe help others out and gain ideas for my build.

I'm in no rush, this is not my first build and I know how much time it takes, money it costs, and how everything that can go wrong, will go wrong. - A life lesson there, don't let small things stop motivation for your goals.
As I get older, I just expect things will cost more than expected and people will make mistakes...
For example, I just got my Dynoman pistons and they sent the wrong gasket... No big deal
Other things like the barrels getting bored out .02mm too big is a harder and more expensive fix! 
You just have to not care too much about losing a few $$$ here and there.

Anyway, I'm over a year into this and it doesn't look like much yet, but I'll update with some pics and detail asap.

[Sigmund]

One of the first things I did was buy a CBR600rr front end. I wanted good brakes and decent forks that were worth rebuilding - Unlike my other old bikes. Here is the CBR600RR front end, from an 08' model. 
This is the fun measuring/engineering/problem solving stuff that enjoy about being out in the garage working on a project.
The stem length on a 450/550/650 is 10mm shorter than a CB750 (sohc or dohc) so you don't really need to get a custom stem made or buy one from cognito IMO.

I didn't need to do too much to get it ready:
Pressed the stem out and machined off about 3mm from the shoulder at the bottom of the stem.
Pressed it back in and then had enough thread when it was all back together.
Make a spacer that was 6mm thick to space out the bottom CBR triple so it doesn't foul.
Steering stops are better spaced than a GSXR and I just welded a tab and cut to size.
You just need to use normal sized CB bearings- They are mostly the same in my experience. That is, models above.

[Sigmund]

This was the mock up with the CBR front end from a year ago... Been collecting parts and building the motor up over that time.
It will have spoked wheels. Probable 18" rims (at least on the front) cause 17's just don't suit these IMO.
I also have a late 550 tank to go on... The 650 tank does look nice with the stance of the CBR bull dog look though

[Sigmund]

Where's the 650 front end? - I hear you ask...
⚠️  Warning: only a twin! It is sohc though
 On my 77' CB400t. Bored out to 450, ported head, custom air intake and exhaust. Jetted to suit and goes like crazy for a little bike.

[SOHC4 Cafe Racer Fan]

Nice looking front end.  I was going to go with a CBR600RR front but changed course.  I still have a spare clean triple tree if anyone needs one, PM me.

[Sigmund]

Yes they are, thanks.  Love your Thruxton blacked out, it looks mean.... I had trouble deciding whether to paint my 650 engine black or silver. Went with black and I might try to get the side covers powder coated in textured black. Is that what you did?

[SOHC4 Cafe Racer Fan]

Yes they are, thanks.  Love your Thruxton blacked out, it looks mean.... I had trouble deciding whether to paint my 650 engine black or silver. Went with black and I might try to get the side covers powder coated in textured black. Is that what you did?

Thanks.  My entire 650 motor is painted in VHT Cast Iron. 

IMG_4002_zpsbeu2iuu0 by Donald Leonhardt, on Flickr

image_zpscdxixbph by Donald Leonhardt, on Flickr

I like your idea of doing a wrinkle black for the side covers.  IF I had to to re-do over, I'd vapor blast the entire motor and cerakote all the exterior parts.  Cerakote is applied like paint BUT is not like ceramic powder coat -- it is as durable or more durable than powder coating, and helps disburse heat.

[Sigmund]

That's nice. I like that between silver and black tone. What about the Thruxton side covers though?

[Sigmund]

I did a little to the frame today:

[Gurp]

Following

[Sigmund]

For those who have a Motogadget M-unit Blue...
Can you convince me I need it?  I want it, I like what it does, with phone connectivity, an alarm and possible RFID etc($200 more!?), but I'm good at Electronics (Worked in the field) and I can't quite work out the cost vs what it does. ($500 here in Australia)

All I get is that it: "Makes for a tidy, efficient and reliable electrical system"
I can make the original loom (or a new one from scratch) tidy, efficient and reliable with new connections, new modern fuse block and front connections hidden perhaps under the tank and NOT inside the headlight, and the rear under the seat.

I get that it ends up with new cabling and it's neat etc, but you are making a new loom with it anyway....  If you make a new loom without it, then the result would be the same, just $500 cheaper!  Would really like an alarm though... What? $100 or so?

[calj737]

Im not a fan of Bluetooth enabled features on the new units. Yes, it offers a phone-based speedo app (I prefer gauges), all of their units have an alarm (only Blue has remote warning) but it all comes down to what you want vs what you prefer. Want features? Spend the $. Prefer to save money, build a loom.

You can get a v2 or a newer non-Blue unit for less, get all the embedded features, and save $. So what's your design intent on the gauges, indicators, and build design language?

I've got a v2 unit, still fresh in the box I'd part with as it was an extra for a build that the guy walked away from. Non-Blue, but all the goodies of the original.

[seanbarney41]

I think spending money just makes people confident that they can do it themselves or that everything is fixed.  When it is pointed out that spending money does not necessarily do that, people can get upset.  That is all I have to say about the m-unit.

Have you figured out what kind of rake and trail numbers you are gonna have with the cbr front?  USD forks are generally too short to work with the geometry of 1970's frames.  No one ever seems to solve this problem, they just claim it handles fine as I don't ride it hard anyway...

Build looks really good so far, though.

[DaveBarbier]

Hey Tim, glad you made a build thread. Very nice front end. I was thinking of the inverted forks for my build too but I didn’t want it to look too modern so I went with the 1999-2002 R6 with conventional forks. Maybe next time I’ll do inverted because it looks great.

For the mUnit, I do like mine and the fact that it minimizes the wiring and mess. Plus that it has short protection built in while keeping circuits isolated. I don’t need the features of the Blue so even if I were to get another one it would be whatever they call the equivalent to the v2 now. I don’t use the alarm but plan to and I really like the flashing rear brake option. I don’t really know what else the Blue has to offer, I just don’t keep up on it.

As for ignition, I’m getting the Dyna S for the 550 to work. It ran today and my timing is spot on but I wasn’t able to go for a ride. I think you’ve seen my C5 troubles so I can’t recommend it though others like it. For the Dyna S on the 650 it just takes making a new ignition plate and turning down the ID of the rotor to fit over the advance shaft. Also, the advance shaft is longer than the 550/750 so the rotor has axial play (in and out) so I made a spacer to take up the slack. Might be hard to explain but I’ll do a write up later once I actually ride and feel that it’s the right move for the 650. I wish Dyna would just make one for the 650 but talking to their tech support guy Larry he said he only got like seven 650 requests in like 3 years, haha.

You have any ideas what you want for ignition or just letting me do all the R and D? Haha

[Sigmund]

I got a good price on the CBR600RR front end. I also like the period correct look of traditional but things are not as easy to find here.
Why not the the Dyna 2000? Hmmmm.
Thanks for all the info guys, I'll respond later when I have time.

[DaveBarbier]

I got a good price on the CBR600RR front end. I also like the period correct look of traditional but things are not as easy to find here.
Why not the the Dyna 2000? Hmmmm.
Thanks for all the info guys, I'll respond later when I have time.

Price

[Sigmund]

Im not a fan of Bluetooth enabled features on the new units. Yes, it offers a phone-based speedo app (I prefer gauges), all of their units have an alarm (only Blue has remote warning) but it all comes down to what you want vs what you prefer. Want features? Spend the $. Prefer to save money, build a loom.

You can get a v2 or a newer non-Blue unit for less, get all the embedded features, and save $. So what's your design intent on the gauges, indicators, and build design language?

I've got a v2 unit, still fresh in the box I'd part with as it was an extra for a build that the guy walked away from. Non-Blue, but all the goodies of the original.

Ah right, thanks for the detail on the m-units.  If I preferred to save money, I would buy a new bike! This old #$%* never ends with $$$  I enjoy the tinkering though.

[Sigmund]

I got a good price on the CBR600RR front end. I also like the period correct look of traditional but things are not as easy to find here.
Why not the the Dyna 2000?

Price

What do you mean!? It's only the 3rd ignition you have bought? 

I'm thinking of just using the original ignition first and see how I go. I may try a programable ignition I made, but it only drives 1 coil, so I'd have to make another one and run a pair for it to work on a Honda 4. It's fully adjustable with a hand controller against rpm and load. Load *If you have an air flow sensor or pressure sensor etc somehow. 

Hondaman's HD springs on the advance unit might be worth while....
Or spend on a Dyna 2000. There are a few around s/h too.  I read the same mods to the plate need to be made from your thread Dave.  I feel like it may be better money spent than a cam as far as drivability goes.

As far as cams go, do you need the rockers hard-welded for say, a Web 358a? And springs I guess are just more likely to break if they are old hem ones?

[SOHC4 Cafe Racer Fan]

I have an m-unit v2 on my 1975 CB550.  It works well but since I always have my phone on me, the bluetooth would provide more convenience when powering up/shutting down.  At present my, m-lock is mounted behind my side cover and I have to hold it until the RFID sensor picks it up.  It's not too finicky, but all things being equal, I'd rather have the convenience of one less key to lose.

[Sigmund]

Have you figured out what kind of rake and trail numbers you are gonna have with the cbr front?  USD forks are generally too short to work with the geometry of 1970's frames.  No one ever seems to solve this problem, they just claim it handles fine as I don't ride it hard anyway...

I'm not sure how much you know about rake and trail but for others who read this, I'll put in some detail:
There is no "problem"  to solve.  CBR/GSXR front ends have less offset in the triple tree, and therefore have enough trail (stability) on these 1970's frames.

If you have shorter forks with the same offset, (like half arsed cafe builds that just raise the forks in the triple) then you don't have enough trail and can get some fast turn in, but the negative is unstable at speed/dangerous tank slapping fun times.

I'm expecting I will be using the CBR triple with a 30mm offset, and an 18" front and rear rim so it will be super stable and I will raise the rear to suit...
I can get the trail to be what ever I want with different rear shocks, rim sizes and custom triples if needed.

I will run some numbers, and more importantly do some testing when it's together before settling on exact rim sizes and rear shock length etc.

[DaveBarbier]

I was going through some rake trail stuff for my front end and since I was getting my triples from Cognito Moto, I decided to have them custom with the factory 550 offset. I just don’t know enough about that stuff to play around. Bike feels great though!

[Sigmund]

I was going through some rake trail stuff for my front end and since I was getting my triples from Cognito Moto, I decided to have them custom with the factory 550 offset. I just don’t know enough about that stuff to play around. Bike feels great though!

It would be interesting to know if you have got the fork length the same as the original 550 forks?

[DaveBarbier]

I was going through some rake trail stuff for my front end and since I was getting my triples from Cognito Moto, I decided to have them custom with the factory 550 offset. I just don’t know enough about that stuff to play around. Bike feels great though!

It would be interesting to know if you have got the fork length the same as the original 550 forks?

They are the same within a small tolerance. I need to keep the bike the same height because I’m a short bastard. I kept the bike level as it sits. The R6 forks are a little longer but the new triple is taller on the bike so they’re pretty much flush on the top.

[SOHC4 Cafe Racer Fan]

More m-unit blue features using the app:

New features of the m.ride app (m-Unit Blue Only):
 pairing via an encrypted Bluetooth LE (Low Energy) connection; thus a secure and extremely
 low power consumption for both vehicle and smartphone
 Keyless-Go, unlock your bikes electrical system when approaching with smartphone
 Reporting of alarm events (date, time, vehicle ”down” etc.)
 Real-time fault indication via audio voice to head-set
 Manual switching of outputs (except starter)
 Firmware updates from any location
 Configuration of m.unit setup menu
 The m. Unit’s speedometer input for storage and matching of vehicle's odometer allows for
 vehicle management with automatic notifications of maintenance tasks and status of wheels,
 chain, brake pads, oils, operating supplies, spark-plugs, etc.
 Status, alarm, driver and maintenance logbook
 Display of parking position and ”ping!” feature for locating your vehicle

The last feature is akin to LoJack. Also, there is a way to remotely disable the bike using the app in the event of theft.

[Gurp]

^^^ WOW!