Topic: 1979 CB650 Questions

[PrestonNB]

Alright, I have been on here before asking questions trying to find my way on my build. I have settled on an idea and sticking to it. However, I have run into problems already (seems to always happen that way). I am looking for clip-on bars to replace the current bars.

Problem 1, what size is needed? I figured 35 mm but I keep seeing different sizes for the same bike in other builds. Which one should I be looking for?

Problem 2, with the clip-ons I know there will be an issue with placement because of the headlight mounting bracket. Any ideas on a compatible bracket that could be used to replace the stockpiece or should I just build one.

Problem 3, this isn't necessarily a "problem" in the general sense. But the gauges will look incredibly dumb sitting so high. Any recommendations for a smaller tach and speedometer? Or even ideas on how to lower the stock gauges?

Done with the problems. Now for some other things. With the clip-ons I have a feeling I will run into issues with the reservoirs not fitting. Is it wise to relocate the reservoirs? Or just find a way of leeling them off on the clip-ons?

The next thing I will be tackling is the fork springs and rear shocks. They are some squishy little things. So I am going to be getting harder springs for the front. Probably aiming for 15% harder than stock. Any ideas on which company to look at? Or better yet, a link to the site. The rear is going to be harder to switch as I can't seem to find any replacements that offer higher performance. So I may have to find a way of mounting later model shocks. Any ideas here would be awesome. I have heard a couple ideas, but would rather get them from guys that know the bikes.

On a side note, I will be getting two brackets built to move the foot pegs back (i.e. Rear sets.) and will be rigging up the shifter and rear brake to work properly. In other words, fabricating a pulley system. Which wont be a problem as I have seen several designs for it already. Probably the most exciting part so far and also the reason for hunting the clip-ons. I currently have lower bars than stock but I need a little lower.

I have been told before that the CB650 isn't a very good track bike and whatnot. But I want to see if I can change that. Where there is a will there is a way, and I intend to the way. 

I know these are a lot of questions but any help would be greatly appreciated. Thank you for reading!

[turboguzzi]

headlights and gauges on a track bike? 

in any case, a 650 can be a good track/race bike, tell us who told you it isn't so, we want to know and kick him out of sohc4.

fork and shock spring rates will depend on the combined weight of bike and YOU, but about 0.9 kg/mm is a good starting point for fork  springs....  Race Tech or WORKS can supply them if you have the dosh,

most likely 35mm clipons but dont you have a caliper to measure? if not, buy one.

TG

say hello to KR if you see him down town

[adrianm1972]

I have an 82 that I am turning into a Cafe/Track bike.  The forks are 35mm.  The geometry of the CB650 is more relaxed than the 550 due to longer forks and shorter rear shocks on some models.

13.5" rear shocks with appropriate springs for your weight and rebuilt front forks as stated above help a lot.

[PrestonNB]

    To turboguzzi. I do have one and I did measure. But seeing people putting clip ons around 37 mm was throwing me off. Not sure if they swapped forks or not. Even my handbook says 35mm. Also, good point about the brackets. I guess there is no reason to really keep them on. lol
  Thank you for the manufacturing sites. I will check them out. And the person that said that, I will go look. haha I am sure I can find them for you. Although, it may have been someone more into cruisers if I remember correctly.
  On a side note, is there any manufacturer who makes full racing body work? I mean all of it. I have found bits and pieces but would prefer to order it all at once. Saves on shipping costs.

  Adrian, you are right about the rear shocks and overall geometry. I am going to get the forks shortened I think. Or possibly just get forks off of another bike and getting parts made to fit them. I am looking at shocks for a Kawasaki that are similar for the rear. I believe it is a zrx1200. They offer slightly better ride for what I want. Either those or something on the same line. I have just about given up on finding aftermarket parts for the bike. So cramming in parts from other bikes should work. lol

Any more ideas?

[adrianm1972]

Progressive makes some great reasonably priced tear shocks.   The 12xx series. You
Can get them for ~$225 with the correct springs.

Post a pic of your fork lowers and I'll let you know if there are OE fork tubes that will work. Basically if they are the non-pressurized type you can fit shorter cb750/550 tubes.

[PrestonNB]

Adrian, I gotta go get some new pictures. My pictures got deleted a while back. I am just slow about retaking pictures. How much shorter are the 750 tubes? And what spring would I need to put in to keep it stiffer than stock? I need it to have better handling since it is in a way a cruiser right now. I am going to be ordering some rear sets from Benji's Cafe Racer. He makes some good parts. I figure buy what I need, sale what I am replacing, buy some more....and on and on it goes until I am broke. haha

[PrestonNB]

Also checked out those springs. They are nice. I sent an email to the manufacturer on what shock would best suit my needs. They are a little more than what you put. From a few sites the average is $370 for both shocks. So we shall see what their answer is. I do like that you buy springs to fit what you need. That is a bonus in my book.

[onepieceatatime]

Adrian, I gotta go get some new pictures. My pictures got deleted a while back. I am just slow about retaking pictures. How much shorter are the 750 tubes? And what spring would I need to put in to keep it stiffer than stock? I need it to have better handling since it is in a way a cruiser right now. I am going to be ordering some rear sets from Benji's Cafe Racer. He makes some good parts. I figure buy what I need, sale what I am replacing, buy some more....and on and on it goes until I am broke. haha

Here is a thread takling about some lengths (550 and 650)
http://forums.sohc4.net/index.php?topic=106843.msg1199473#msg1199473
and a link to different sizes cycle x sells
http://www.cyclexchange.net/Frame%20Page.htm