Topic: 750F Chain/Tire Question-I have read up~but still have questions.

[ladyvorlon]

Chain-Started the conversion on the chain-just wanted to know what is the average chain length, I have read some saying 104, others 107 and with mine, measure it out am sitting at 112, soo, any ideas?

Tire-How much clearance is required for the rear tire, went up one size to a 120/19/18 and was curious as to how much room is need between my rear calliper arm(think that is what it is called) I have maybe a 1/2 inch clearance with the new tire on, and everything I found on the site said that tire size would work, but the original was a 110.

SO, now what? New tire size or am OK....

[scondon]

        You're Ok on the tire width up to 130/90. 120/90 is a commonly used size on these bikes. Chain length is affected by the front/rear sprocket tooth count so you will have to post what you're planning on using in order to get a good guess at length.

[ladyvorlon]

ok front sprocket is 17 and a rear of 48, the same as the original chain on the 76 cb750's, but on the 77 cb750 they went with the 630 chain so I did the conversion...

and you are positive that the tire will be ok, the repair shop, reprimanded me on the what could happen with an oversized tire that was too big.......??

Sorry to sound so naive, but I want to do this right, first project and its been a big one!

[scondon]

 I run 120/90/18 on the rear comstar of both my 750F's, no problem. The 2.15 comstar rim width is narrower than the "recommended" width stated by most manufacturers of 120/90/18 tires but if you look closely you will find that there is a range of "acceptable" widths in which 2.15 width rims are included. The profile is a bit pinched but there is no clearance problems or safety issues. Repair shop is covering the bases by telling you it is bigger than recommended, if they "reprimand" you then ask them for the manufacturers data sheet of the tire they are selling you so they might gain a clue as to what they are telling their customers.

      17/48T 530 chain on a 77-78 750F is either 104 or 106 link. Honestly I've never counted a link, just bought 110 link chains and cut off what wasn't needed(same bike,same sprockets as yourself).

[ladyvorlon]

Thank you very much for the full explanation, so I will put the tire back on and get the chain done, check the brakes to be on the safe side and finally get ready for my first ride, farther than the end of the laneway! 

Thanks again Nita

[rbmgf7]

i think i'm running a 130 on my comstar rear. i'll have to take a look at it once i get them back from the dealer tomorrow. it's best to get a precut length of chain and then cut down. i got a RK x-ring 120 link off ebay with master clip and cut it down to length. can't remember the total number of links but it all depends on your sprocket sizes.

[quietlikeachurch]

I did the 530 conversion on my 77 750F and needed a 104 link chain (17/48).  I'm pretty sure the swingarm on late model Fs is a bit longer than the others.  Or maybe not...

-Ian 

[ladyvorlon]

Thanks to all!  Its mornin, and I want to try and get this bike done before I have to run out the door for work, day off tommorrow!  Thanks Nita