Topic: dream upgrades?

[francesb]

Hey all,   

After a longish hiatus, I just remembered that spring is coming and I'll get CHIKbike (73 CB750) out of storage (she's in a Brooklyn warehouse, watched over by a guy named Frankie).

Now, I *had* been sort of planning on upgrading to a newer bike this season. But, I decided to stick with the CHIKbike after all. Given that, I have some money to throw at her (that I would have put towards the other bike). So, what are the dream upgrades? Last season I installed a 4-2 exhaust, fork springs, fork seals, tapered stem bearing (is that what it's called? Installing was the second worse motorcycle experience of my life), new brake pads, and SS brakelines. I've read about all the front brake upgrades, but don't want to go there.

On my list thus far:
newbrake pads since I think my (new) ones are contaminated by fork oil (the old ones leaked)
electronic ignition
rebuild drum, since I'm totally out of rear brake

bore out engine?

Whenever I ask my friend A.  the Mechanical Genius, he suggests rolling CHIKbike off a pier and getting a SV650. Blech. So, CBGeeks, what would you do with a CB and a couple US thou?

[Sam Green Racing]

First roll your Mechanical Genius off a pier

Get 836cc big bore/megacycle cam, have Mike Rieck work your head, burn rubber,    easy.

Sam.

[bill440cars]

Are you referring to your bike as a CHICK bike, like as to attract chicks (girls)? Just wandering if that was why you were attracted to it? Are you talking about boring it out because it need to be bored out? Or are you talking a bore job to enlarge the engine? Personally, I wouldn't bore it unless a rebore was needed. There would be only 1 reason (to me) for an unnecessary rebore and that would be with a spare cylinder. There's bound to be more to do on the bike. What type of a bike are you building?
I don't think I'll have any (that I have) that'll be completely stock. Most of mine will be leaning towards either, bobber, slightly chopper (No hardtails, no drastic mods to the rake and I DO NOT want a huge belt
driving the rear wheel), or cafe racer. I'm mainly driven towards Bobber cafe racer.  Later on, Bill

[francesb]

It's CHIKbike because I'm CBCHIK. (CBCHIK being my license plate, and an ironic reference to my gender) Also, I refer to it as CHIKbike because I was out wrenching one day last summer, and some guy came over to me and told me he had seen my bike on the street and assumed that it belonged to a woman (he might've said "girl") because men ride bigger bikes. He might've said Harleys--I posted about it when it happened, I'd have to go back and look.

I'm not trying to attract chicks, although I am always looking for more women to ride with.

Bore job to enlarge the engine, give me a little more to play with.

I'm not really building any sort of bike. CHIKbike is more-or-less standard, except for the exhaust. I'm replacing the bars--NYC seems to ask for a more aggressive riding posture.

samcr, what's a "megacycle cam," I've established that Mike Rieck is a well-respected forum guy, is he also a mechanic? Based where, if so. Can't roll the Mechanical Genius off the pier. He once spent nine hours talking me through the fork seal/tapered head bearing rebuild. Of course, it wouldve taken him two hours, but then i woulnd't have gotten to build all that character.

One other thing I've been contemplating--I'm ready to replace my chain and sprocket. I know sometimes people change the sprocket size for reasons I don't exactly understand. is that something worth doing?

[Glenn Stauffer]

I'd certainly spend the money to get your braking systems in order since you know the rear needs to be re-done.  Check your swing-arm bushings. How's the engine?  If you have the common oil weeping at the head, spend some money to have the top-end rebuilt.  Are you concerned about cosmetics?  Get the bits to make it right; it'll prove to be a good investment.

[Bob Wessner]

Also, I refer to it as CHIKbike because I was out wrenching one day last summer,

I think I remember this earlier post. Just the thought of dodging NYC taxis, buses, pedestrians and whatever, well, my hat's off to you. 

[Jonesy]

I'm going through the same ponderings as you RE upgrades. The two on my list are Dyna-S electronic ignition and a clutch assembly from a post-'76 CB750. I'm tired of fiddling with points and would like my bike to idle better and more quietly. (The '76-on bikes had an improved clutch basket and special clutch plate that eliminated the rattling that would develop after a few thousand miles. My '73 750 could almost put a Ducati to shame it rattles so bad!) FYI, Z1 enterprises has the best price anyone has found for Dyna-S ignitions ($120).

RE your back brake. You have a '73 K3, right? You might indeed need now brake shoes. However, since you say it's "out" of rear brake, you mean no more adjustment? The K3 debuted a wear indicator. There is a chrome ring behind the lever coming out of the rear brake drum with an arrow on it. There is another arrown on the side of the drum. If you press on the brake pedal and the arrows line up, the shoes are worn down to the limits. If they wear any more, the cam that forces them apart can twist far enough that it locks the shoes open, causing rear wheel lockup. I'd attack that one first. You're most likely only looking at new brake shoes, which are cheap.

836 Kits are fun, but lots of folks complain about oil leaks at the head/cylinder interface if it's not done properly.

AS for the chain, folks change the sproket ratios for different reasons. Honda changed it from the earlier 750's because the front sprocket was so small it had chain jumping issues. Honda changed it from a 16 to an 18 tooth sprocket for more chain wrap. If you have a smaller front sprocket in relation to your rear sprocket, it improved the mechanical advantage of the engine and you will have more torque to deliver to the back wheel, making for a faster snap off the line. The downside is that at cruising speeds the engine revvs higher. Some people who do extended cruising elect for a lower ratio so the engine turns less RPM's. The benefit here is less wear and tear on the motor and better gas mileage. But, if you need to pick up speed in a hurry, the lower ratio lowers you rate of acceleration. Seeing that you bike around the city, if you're happy with the performance (the acceleration is snappy enough to get you out of trouble in traffic and you're not constantly changing gears) I'd leave the ratio the same. BTW the K3 had an 18-tooth front and 48-tooth rear. I got a DID O-ring chain ($110 but well worth it) so I could shut off my chain oiler. The bike's MUCH cleaner now!

Good luck with it!

[Sam Green Racing]

Chick, have a word with Mike, send him a PM outlining what you want from the bike, as these motors can be improved no end in the head department.

They can be made to go a lot faster but like Glenn said, get the brakes sorted you will need them.

Sam.

[francesb]

hm. Clutch top-end rebuild, drum brake, electronic ignition, and the electrix. That should take care of my money-spending impulses. thanks, all. I'm paying Frankie to do most of this. I spent all last season working on the damn thing, and this summer i want to play.

[bill440cars]

CBCHIK,

          My apologies, I had no idea, I applaud you! Now, in case no one's clued you in, changing the sprockets around changes the gear ratio. Example: if you had an 18 tooth sprocket on the engine and
                                                          dropped to a 17, you'd gain a little power and lose a little
                                                          speed. If you could put alittle larger front sprocket on and
                                                          have the opposite effect. That same goes withthe back
                                                          sprocket. If you installed a rear sprocket  a (say) 2 less teeth                           
                                                          on it, you'd get some increase in speed and your power would
                                                          drop.
 Gearing depends on a lot of things. What do you want out of it Speed, Power or a compromise of both? Everyone has their own opinion about what they want out of their bike and when you should approach the subject. Anyway, I'd better get out of here.  Later on, Bill