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Discussion Starter #21
The one in my profile? I did...it's showing up for me at least...?
 

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You didn't fill out your location, at the very least state or province. Not everybody knows Purdue is in indiana.

It is nice you filled out all the other stuff, but being that we are a board that focuses on real life community, we urge people to fill out location so they know who is local to them and vice versa.
 

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Discussion Starter #23
Okay, it's updated.

On a more motorcycle-related note, new bars are in the mail, and I'll probably be picking up some bar end mirrors as after looking at the factory ones, I think my sightlines will be so far gone I won't be able to see much behind me.

I also recently discovered that the comstars on the black bike are set up for tubes and the Custom comstars are tubeless. Apparently the changeover was 1981.
 

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The comstars on the black bike are regular comstars supposed to be painted silver, the other bike has "reverse comstars".

What caliper so you have on the other one?
 

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Discussion Starter #25
Are you sure they're supposed to be silver? CB400tii's have silver comstars, but those are 19" front and 18" rear. These are 18" front and 16" rear. I've actually never seen these in silver, in pictures or otherwise. Plus these are powdercoated and there is no overspray anywhere, and the insides of the spokes are also powdercoated a nice even black. I'm pretty positive these are the correct comstars.

All disk-equipped CM's came with single piston calipers, except apparently for '81-on CM400c's, which have a larger diameter (by about an inch) rotor and a dual-piston caliper. It has much greater swept area and the hub has a slightly better venting design, at least to my eye, and in addition to being twin piston, the caliper also has heat-sink ribs on it. When I actually swap the parts I'll take pics and measurements for size comparison.

I thought about using a CB750 Comstar on the front with the dual disks along with the correct forks, but for the improvement and my planned use for the bike, that money could be better spent elsewhere.

EDIT: this is the only pic I have that shows the front brake at all.

 

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yup:



C models or customs have 18"/16" wheel setups. It could be the 'merican market had painted ones but I have never seen them. you can bolt on the dual piston caliper to the brake setup you have on the 1981, you just need the fork leg bracket as well. It is a better caliper, honda still uses it on some of the dirt bikes.

if you want to do a wheel swap - go find a boomerang comstar that was on cx500 turbos and canadian/european/japanese cb1100Fs (you will need the rear off the cb not the cx to match). Way cooler looking.
 

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Discussion Starter #28
Well blow me over and buckle me down...sounds like I could probably get an 18" rear off of a Hawk; I'll have to do more research on that. All of the CM400's I've come across had the 16" rear, and both of the manuals I have only list the 16".

That picture also shows a kick start-only the '79s had that to my knowledge, fwiw.

I looked at boomerangs, but spending that kind of money on a CM just seems ridiculous to me. I want to make sure that I can get the suspension working really well and make it handle better before I spend that much money on wheels. Definitely cooler looking though.
 

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quote:Originally posted by gearheadE30

True, shims are reversible. Once I get it all apart I'm going to check the rest length (I know it isn't tension but its as close as I can get in my garage) and see how close it is. I'll have to see what it looks like and then go from there on shimming/cutting. The ride height and sag are about right though right now, and the last thing I want to do is raise the front end more with shims. But yeah, you're probably right. I may just try shims as first and see how that goes. I can always take it apart again later.

And no, you can't weld a spring. The heat will cause it to lose tension, thus making it not much of a spring anymore.
You've got the right idea with the springs. I used to have a link to using a bathroom scale and tape measure to rate springs. Thought it was from offroad.com/dirtbike. Maybe you find.

Keep in mind if you substancially stiffen springs may need to modify damper rods. If I were doing it, just talking out my ass, if the springs are stiffened 20% I'd enlarge the compression holes and decrease the rebound holes 15%. You get why right?

Stay single disc. Unsprung is your enemy.
 

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The three valve 400/450 motors were in tons of bikes cb400t, cm400, 450sc nighthawk, 400 nighthawk...etc. Plus a lot of bikes had different setups, I think Honda sold the hawk like a car setup with "options". I owned a "base" model hawk from 1979 that had a drum front brake and a kick only, and a same year bike that was an e start only and front disc, so anything goes with these motors.
 

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Discussion Starter #31
Huh, good to know. I knew the engines were pretty prolific, but that's interesting that they were sold that way. Too bad the 450's with the 6 speed aren't more common, at least in my area, or that could be a nice upgrade.

And Ken, I do understand damping and such. I haven't had a motorcycle fork apart before so I have a bit of learning to do, but it seems pretty straightforward. From the sound of it, I'm getting the impression that there is no valving difference for low versus high speed damping? For now I'm just going to work with the springs, and once I get it all back together and ride it I'll be able to tell what changes I'll have to make for damping. From riding so far, I'm getting the impression that with 15w fork oil and stiffer springs, compression is actually pretty close and rebound should be stiffened up a bit. Again though, I'll have to ride before I can actually see and feel what the difference will be. I get out of school May 7th, so that's when the fun will begin, haha.
 

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Correct, no low speed damping in your forks. You get why that makes unsprung even more your enemy?

I'd quess, just making shit up, your stock springs are in the .4- .5 kg/cm3 range. Depending on your weight, you'll end up in the .8- .9 kg/cm3 range.

Seems like you understand. This'll be fun.
 

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Discussion Starter #33
Yeah... I had no idea how primitive these forks were haha. Now I understand why emulators come so highly recommended. Out of curiosity, I may end up weighing all the brake hardware I'm swapping to see what the weight change is.

Also, it turns out that the fork travel stop (the one that keeps the bars from hitting the tank) was bent at some point and the tank was repaired with Bondo. Well, the thickness is ridiculous and cracked in the sun the other day, so it looks like I'll be reconditioning the tank. the sheetmetal doesn't seem terribly thick, so maybe I'll be able to pop the dent out with compressed air or maybe even one of those glue-on dent removal tools. I want to keep the paint job relatively cheap and somewhat subtle, so I may keep the flat black and add gloss black accents, or perhaps vice versa. regardless, it will be simple.

Can't wait for summer to start wrenching again...
 

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Discussion Starter #35
Yeah, I saw the half-writeup on the tank. It doesn't seem to bad, I like the looks, and the extra capacity is nice. I'll be keeping my eye out for one of those tanks.

Also installed 'superbike' bars today. I still have some work to do shortening controls and tidying it all up, but holy crap is it a huge improvement over the stock bars. Makes the bike so much more comfortable and controllable, and riding is a ton more enjoyable. It still isn't fast, but at least it's fun to ride through curves and such now. Now to figure out rearsets to compete the riding position... Pics to come.
 

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Discussion Starter #36
And as another little update, my car started to overheat on the way back to college (suspecting something to do with a 250k-mile head gasket, 10:1 compression ratio, and a turbo...) so I limped the car home after cooling it off and bleeding the system on the side of the road, and then loaded the bike up with 2 big backpacks and rode 2 hours to Purdue. the bike handled the highway just fine and cruised at 70mph with no issues. It was actually really comfortable, except for my ankles....need those rearsets. People always seem to say these bikes don't have enough power on the highway... I never had an issue. I never had to downshift, even. Just crank the throttle and go. That said, more power is always good, but this seemed adequate.

Only minor issue: both screws in the tach managed to vibrate themselves loose, and the faceplate came off while riding. I pulled the cable off so that I wouldn't catch one of the screws in the spinning bits inside the tach, but looks like I'm gonna have to repair that soon.
 

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they only place they don't have enough power is the highway on ramp.


by the way, what e30 parts do you have? I am in need of a few things.
 

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Discussion Starter #38
clusters, US ellipsoids, buttons, a few head units, seats, speakers, door cards, dashboard (that might be sold) Konig rims, facelift tail lights, HVAC panels, cruise retrofits, airbag parts, full OBC retrofits, a toolkit, US grilles, marker lights...lots of stuff haha. Let me know what you need. If I don't have it, I might be able to get ahold of it for you.
 

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Well my car is a 1991 vert with diving boards ( rare, I know) in bronzit beige metallic. Right now I need a left door card (same as 2 door) in that light tan color. I also need a left taillight as some schmuck cracked mine while pulling out of a parkIng space with his dodge. Also I need a set of rear coil springs.

I actually need a lot more but these are the initial things.
 

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Actually more than anything I need a good lowmileage fully assembled 325i head that I can just bolt on. A couple of came followers in my head have gone bad and the car is noisey as a mother. Need it for cheap too.


By the way, which bike did you actually ride, the black one or the red one?
 
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