Topic: Chain Replacement

[Jakoba]

Just a quick background first;
I have a 1978 750K running a stock 630 chain with the 15T/41T sprockets. The current chain has 84 links.
I am going to a 530 chain with 17T/40T sprockets.
My question:
Logically you would place the axle to its forward most position in the frame and over time as the chain stretches I would move the axle away from the frame.

Is this where I should position the axle on the frame to remove excess links when first installing?

Would there be a standard number of links to start with on a 530 chain with this sprocket combination?

Thanks for  "The Rock"

[coyotecowboy]

You're thinking right, you should have the wheel as far forward in the4 adjusters as it will go before you cut your chain.

On another note, why the 17/40 combo?

[BobbyR]

You're thinking right, you should have the wheel as far forward in the4 adjusters as it will go before you cut your chain.

On another note, why the 17/40 combo?

You may want to rethink that. The best chain adjustment technique is to have a person sit on the bike and then check the tension. This means you may want a bit of forward and backward adjustment.

[eurban]

110 is more than enough if you don't mind cutting off the excess yourself.  I can try and find time to count my 78Ks links this evening as I have converted it to 530 but I don't remember off hand what sprocket sizes I chose.  Remember that the late bikes have longer swingarms so the number of links will likely not be the same as an early bike running the same sprocket size.  If you end up cutting down a chain, do yourself a favor and triple check your work before you cut.  I am shamed to admit that I have an expensive oring chain with two master links due to a miscalculation on my part.  If your new chain fits well with your axle all the way forward, your chain will we worn out long before you run out of room to adjust it!  I also found that the alignment marks on the swingarm where not accurate when compared to a careful front to back alignment done with string lines.  Leave yourself some room to play with.  Oh, if you are into high speed cruising over canyon carving the longer the wheel base the more stable the bike will be at speed. . . . .

[cafe750]

I too ask, why the 17/40 sprocket combo...

[Jakoba]

First off, thanks for the replies.

As for the 17/40 combination, I'm new to the game and I'm trying to get a good ratio for highway and cruising gears. I thought that this would be a "middle of the road" set up.

Suggestions are "Greatly" appreciated.

[moham]

I, too, have a 78 750k, and am also replacing chain with 530 ek x-ring. I went off the advice found in this thread:

http://forums.sohc4.net/index.php?topic=372.0

Ordered a 110-link chain, 18t front and 48t rear sprocket, all from dennis kirk for right at $150...Hope this helps...

[Jakoba]

Hey Moham,
           thanks for the reply and the link.
You don't happen to have the part numbers for the sprockets and chain do you?

Cheers

[moham]

Sure:
(these are dennis kirk part nos., the sprockets are JT and have JT part nos. also, those are in the thread if you need them...)

Part# 119922110
530 SRX Super Sport Series Chain

Part# 8111618
Sprocket

Part# 8106048S
Sprocket

mo.

[Jakoba]

Thanks Mo,
                   greatly appreciated.

[Bodi]

You have to factor in the longer pitch length of the 630 chain - a 40 tooth rear sprocket will be pretty small in 530 chain. You want a reasonably large front sprocket as well, I wouldn't want to go below 16t with 530 chain. 17/48 is a 2.823 final drive ratio, your original 15/41 was 2.733. That will give you slightly higher RPM on the highway. I would go with 18/48 for slightly lower highway revs, if that's what you want - this is 2.667. These differences will be pretty minor, anyway (about 300 RPM change at 5000 RPM between 2.667 and 2.823).
Going for a major highway RPM drop will leave you with no passing power and sluggish performance from a stop in first gear. The gear ratio steps are designed with the final drive in mind, too - going far the from stock final drive ratio will give you too-close or too-wide ratio steps for comfortable riding.

[Jakoba]

Hey Bodi,
                   it's all starting to come together and make more sense now. Thanks for the response. 
           Like someone told me "It's a sad day, when you don't learn something"
That 17/48 combo seems to be pretty popular. I think I may go with that.

Again you will have to excuse my ignorance I'm a somewhat mechanically inclined "Midlife Newbie".... not a good combination. but you have to start somewhere!!!!

I never had a motorcycle until I bought this in Oct 2007.
So far I have had both wheels off, replaced rear shoes, front pads and added a SS brake line. Replaced fork dust seals, Headlight stays, 2 signal lights, air filter, oil/filter. Added a center stand, pinstriped the tank and side covers. I'm having a blast and I'm so glad that when it comes to stuff I need help, you guys are here to answer all my somewhat dumb questions.

Thanks again.

Cheers 

 

[eldar]

Wait till you start that sucker up!

[Jakoba]

Oh man Eldar,
                     I had it running on Sunday OOOOOHHHHH.
After sitting there since November, I put the gas in, opened up the bowls to make sure she was flowing, choked her off and I couldn't get my finger off the start button fast enough. When she came to life it was like music to my ears.
Now if the snow would only go away but just my luck we have more dirt coming on Thursday.

Oh well I'll just have to sit on her in the garage...again

[eldar]

Really is something isnt it. I am waiting to get rid of the snow too. I was ready after it snowed back in november!

[ruliera88]

I have a 71' cb750k1, I am running the original oem sprocket.  I know i need a 100 link chain, but does anyone know what link size i should  use on the original sprocket?

[cafe750]

530 chain. I would install new sprockets too, so that your new chain lasts for a while. 17/48 for a little more pep, 18/48 is stock.