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Discussion Starter #1
So I wanted to swap a set of newer 35mm forks onto my CB450.
Here are some things I've learned over the past 3 weeks:

CB750f forks are 1.5" too long, but that can be worked around.
ebay forks were rusty but cheap ($40 for everything)
now I have to find a 2nd pair of legs
bellows won't work with DOHC dust seal
have less offset than K forks
stem too long
I bent stock CB450 stem pressing it out so now I need another
wider axle than drum front so I need to make spacers
no brake rod mount
fender prev. spraypainted so it reacts with lacquer primer.
broke new lower steering tapered roller bearing while test fitting so have to buy another set
no known stock-type fork ears work
CB750f upper triple has no stem pinch bolt, but CB450 stem has not enough thread for locknut
polished upper triple then dropped it.
then discovered pinch bolts are 7mm not 8mm like the ones I ordered in SS
no known dual-disk front wheel works with CB750f legs
legs are black so a PITA to sand/polish by hand

There's more but I can't remember it.

The lesson for next time?
- Don't bother with 35mm forks unless you're racing or unless it's a bolton swap like CB500t. It's just as much work as doing a bigger, modern setup.

- If you're going to do a swap like this just go straight for GL1000 forks with 39mm legs, dual disks, polished legs and a spoke front wheel. Then call Frank and have him make shorter tubes. Then call someone and have them build you a billet upper clamp. Then order a brand new fiberglass fender on ebay. Yeah, it'll be $500 by the end, but it will WORK.

This job has turned out to be a way bigger hassle than I expected, especially considering my own blunders.

There is so little interchangeability with this stuff, why is that?
 

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the sliders are the longer parts. pull them through the top clamp. of course you need axle spacers, the tubes are further apart in the clamps. fork gators are your issue. personally, unless its british, i hate them. they have less offset, thats what makes them desirable for a racebike. we went over the stem issue here about 2000 times. you could always drop a spacer on the bottom of it to make the difference up. its how other people do it. i dont know how you bent the stem on the 450, ya must have ham hands or something. the brake rod mounts to the caliper mounting holes. throw that old pos fender out. im sure the cb750f fork ears work. big deal, 2 sets of nuts and bolts that dont fit. like you dont have a box of spare nuts and bolts already?? to run a dual disk, you need to pull the speedo drive. then bolt the disk carrier on there. magic, dual disks. yeah, you dont have a speedo, maybe you should say no stock speedos work with dual disk fronts. yeah, they come from the factory black. thats what makes them cool looking. that and they are wing shaped.

now stop breaking shit, complaining, and get to work. alot of people here have done that swap. its not that big of a deal.

jc
 

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Discussion Starter #4
Yeah, I know I'm just whining but it helps.

Anyway, I bent the stem by pressing from the top like an idiot.

And you're right, the boots are no big deal.

I'll be done soon.
 

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and please put pictures. the stem presses from the bottom. but i guess ya figured that already. keep going, you'll get it. you didnt mention how many times youve knocked the bike over. (i always do.)

jc
 

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Discussion Starter #6
I have it on a jack so luckily not once. I'll post some pics if I can get my act together.

Actually in real life I get paid to photograph things so it makes me unmotivated to take them for fun.

I'm brazing up the rebound holes in the damping rod and cutting a few inches off the springs too, just to add to my workload.

Almost finished sanding the lowers today, so I should have them polished up by next weekend. A set of non-pitted tubes is on the way, too. With any luck I'll be bolting it together next weekend but I've been saying that for weeks.

I still need to borrow a lathe to make a couple of spacers.
 

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when my shop was down i took the entire bike to a machinist and had him do it up for me. i was actually on my way up to new hampshire from maryland and i unloaded it from my truck, he made the spacers, then we loaded it up and i went to new hampshire to race. i had a wheel laced, a brake made up, and a new front end put on in a week after i crashed it and bent the front end.

jc
 

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joe, sorry to dissagree with you, but you can run dual disks with a speedo drive. the cup shaped drive needs to be hack sawed into a plate with two tabs that fit into a recess into the hub. i have a picture to prove it, but i have no means to attach.

scott from chicago
ahrma #527
 

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I just used XL350 forks and reamed the stock 33mm triple clamps out with an adjustable hand reamer. That way the fork spacing is the same and everything bolts right up. I used a cl front fender and it bolted up too. I didn't polish anything, but I did try some primer on the chrome front fender before I squirted it black. Paint still doesn't stick very well to chrome.
Ken

AHRMA 412
Vintage racing - old guys on old bikes
 

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just email it to me. id like to see it and ill post it up. the old goldwing has dual disks and a speedo drive. not saying it cant be done, just on older stuff i had never been able to figure out a way to do it with the disk carrier mountd there. meaning, using 350/550 stuff.

jc
 

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Discussion Starter #11
Just figured out what the problem with the steerer stem is. I've been using CL450 lower triples as donors. They aren't welded, but they aren't just pressed, either. The little bracket/tube for the friction steering damper is pressed into the end of the stem after it's assembled, and it's tapered so it swedges the tube between the lower triple and the tube. Anyway, it makes it almost impossible to disassemble them because you have to press the heck out of it. It also means that the end of the stem is expanded too big to fit into another (welded) stem. Finally figured it out after the second bent one.

I need to find a welded CB450 lower triple to make this work. Or possibly a CB550 triple assuming it's the same length.
 

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Discussion Starter #12
Got some other crap I won on ebay, but now I've got two sets of useless tubes. One pitted and one bent.

I'm about one weekend away from calling "Forking by Frank" and ordering some new shortened tubes.

On the plus side I have the damping rod modified and the spring shortened.
 
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