Honda Twins banner

1 - 6 of 6 Posts

·
Registered
Joined
·
589 Posts
Discussion Starter · #1 ·
How do

Two questions about the 450 cush drive bushes - or whatever they're called 'cos that's the best name I can give them; item #6 on this diagram:

honda-cb450k5-1972-usa-rear-wheel_bighu0029f6016_6cdc.jpg

- are there any tricks to removing them? Mine seem to be very solidly in their sockets and before I start applying any force, I want to make sure I haven't missed anything. I've had a go with a blind bearing puller, but right now, it's not happening, so I'm soaking everything in PB Blaster.

- is there any point in me removing them? I'm assuming that replacing the bushes with something newer than the 1972 parts that are in there will make the drive a little softer/less jarring because the newer rubber will be more malleable. It's not like the rubbers in there are busted or torn up, and the ride's not terrible, but they look pretty tired.

For a little more context, the bike only has about 10k on it, but AFAIK it stood for a v-e-r-y long time before I got to it. I've had it for around ten years and it's only now that I'm now using it pretty regularly.

Thanks all.
 

·
Registered
Joined
·
13,085 Posts
Well, now that they're soaking in penetrant you might have to replace them... but as for the "cush" part, they're pretty stiff when new and in my experience, unless they're rotted or disintegrating I'd leave them alone. They're pretty tough - both in durability and in difficulty factor to remove. Many here have used a saw to cut into them to eventually split them in order to get them out. The ones in my 450 are probably original, as the rear sprocket seemingly is (after all this time until 2+ years ago when I bought it, what's the chances someone replaced the rear sprocket with an OEM part that has the 35T stamped on it and the original lock tabs unbent?)
 

·
Registered
Joined
·
589 Posts
Discussion Starter · #4 ·
Oooh, bloody hell. I knew they were a bit of a pig to shift, but I hadn't figured on needing to break out the drill press. That takes it to a whole other level as far as I'm concerned.

If they fall out by themselves over the next day or two, I'll replace 'em but failing that, they can stay where they are. Might douse them in wintergreen/isopropyl alcohol for good measure, but I don't really fancy going the destructive route right now. Too many other things going on . . .

This all came from curiosity over how different bikes with different cush drive arrangements feel under load. For example, the CB750 feels very smooth when changing gears under acceleration, in part because it's got a whole set of cush rubber parts damping the force being applied to the back wheel through the chain. It's the same with one of the modern bikes I'm on, and I was kinda wondering whether the effect would be similar by swapping the ones in the 450. Having said that, given that the rubber in these bushes covers such a small surface area, I wasn't expecting miracles, but in view of your comments (?!) I'll probably leave well alone for now.

Thanks fellas.
 

·
Registered
Joined
·
395 Posts
You know what, you would probably never know the difference between brand new ones and 50-year-old ones. Just leave them in. I've even heard people powder-coated with them left in to no I'll effects.

Sent from my Pixel 3 XL using Tapatalk
 

·
Registered
Joined
·
108 Posts
So the way I got them out was tapping the inner bushing with an appropriate thread and then jacking it out..the rubber on mine was cracked so it came out..i then used a file on the outer bushing to make a small relief after which i got behind it with a pick and slowly started bending the edge over...I put in a 1/2" extension drive and smacked it..came out...mine were originals. have a look at the pictures I am attaching...looks comical almost but it did the job....

IMG_20190803_1554410.jpg IMG_20190803_1618361.jpg IMG_20190803_1619594.jpg
 
1 - 6 of 6 Posts
Top