Rear wheel conversion

[Land_Shark]

I'm now in the process of fitting a wider rear rim & tire to my frame. I'm hoping someone else has gone through this and can fill me in on how they ensured a straight line from the counter-shaft sprocket to the drive sprocket. My swingarm is not an issue as it is a Panther Racing (specialty) application and has more than enough room for everything. Any feedback whatsoever would be appreciated :)

[EMS]

You are in a litttle bit of a predicament. You need to make sure, that your front and rear wheel are properly aligned. Ideally the tire centers should be on the same line, although a slight offset may be acceptable. On the other hand, you don't want too much offset between sprockets. If the rear wheel is too wide, you may have to machine your sprocket flange on the wheel hub to get the chain closer to the tire, if that is possible. The other option is to move the front sprocket outwards. This can cause higher loads on the final drive shaft bearings and may be a problem.
Not an easy task. Just shows how challenging it is to mess with the work of the original creator. Ask the guys who are trying to clone human beings...

[Guest]

As far as I can tell I shouldn't have a problem aligning the front and rear wheel; but definitely the cush drive and sprocket is a problem. I do believe I'll be able to machine the cush drive down to sit deeper into the wheel, hopefully enough to bring the sprockets in-line but I won't be sure until I come up with a way to line it all up. I'm considering taking the whole thing to a frame straightener and seeing if they can line it up and tell me how much to take off the cush drive to bring the sprockets inline while keeping the rear wheel centred on the swingarm.

[Land_Shark]

The above post was me, by the way

[EMS]

Land-Shark: You seem to have a plan! That's half the trip there!

[Land_Shark]

Thanks! I'm definitely trying to be as 'professional' about it as I can. Having started this project (basketcase '79) 2 years ago now it's nice to finally be getting into the 'meat and potatoes' of it all. Of course I'm running into issues I haven't even considered but that's all part of the fun. The USD front-fork conversion seems to be going smoother than I had originally thought, the steering stem from the CBX is exactly the same width as that of the Hayabusa (where it joins the lower triple) so I'm having the old stem pressed into the new triple and it will bolt right up using the original CBX bearings. My only concern now besides the rear wheel alignment is ground-clearance. I'm hoping that by fitting taller, narrower tires than what the Hayabusa came with will give me more clearance, and I'm also considering installing longer rear shocks. Any thoughts on this matter?

[EMS]

You are performing major surgery and I am not sure, whether the patient will be able to walk afterwards! Changing the fork to a non-CBX product, even a Prolink part, will change the trail and thus alter your steering response - maybe significantly. Look at some earlier posts about that. The same applies to raising or lowering the rear swingarm pivot which will actually alter the rake of the fork which in turn will change your steering response. You could potentially open a can of worms. I don't want to spoil your fun and curb your enthusiasm, but that stuff is not just a matter of bolting components together that look good. We have a PC-based chassis
program we use for my racing Ducs to play with adjustable rake and different fork lengths in order to find the best set-up for different race tracks. I can plug in some numbers for your fork, if you are interested and then we could check what the rear end needs to do to compensate. Please ! I do not want to be negative, but I don't think it is wise to just change chassis parts. Remember, these "cool looking" Harley customs just need to pose. They don't have to make many turns. Just around the block into the trailer!

[Land_Shark]

Not to worry about curbing my enthusiasm! I appreciate any and all feedback regarding modifications to my bike. This particular upgrade seems to be quite popular as many have converted over to USD fork setups from GSXR100's with good results. My intent is purely from an 'improvement' point of view; rather than from an aesthetic one. I do, however appreciate your offer to plug some numbers through your program - and very well may take you up on that What kind of information is required?

[Dave Hansen]

I put a swingarm and wheel off an F2 on the back of my 79. I had to do quite a bit of messing around with shimming the swingarm in the frame and the wheel spacers to get it aligned with the front. Lucky for me the sprockets lined up perfectly. I think I had to turn the countershaft sprocket over(its offset.) I did raise the back a bit to compensate for the smaller tires ( I also have a modern front fork and wheel). I didn't encounter any handling problems from it, and the bike is waaay better than stock. I took a shot at it and got lucky, so if you can get your setup checked on that guys computer program, do it. Then you will know it will be OK. Good luck, Dave

[Land_Shark]

Thanks for the input, Dave. In my case, I'm lucky that the aftermarket swingarm which came with the bike seems to be identical in all respects to stock except for the fact that it's box-section and therefore square along the inside edge. It does however, bolt right up to the frame and was in fact used on the bike for several years before it was taken off the road. The 6-inch rim fits inside it quite easily with room to spare; of course my concern now is the sprocket alignment as I mentioned previously. EMS has been kind enough to let me know what measurements to take and to process them once I've done so. Once I've got it all 'squared' away I'll certainly post the results for others who are considering the same.

[z1x]

Land_shark

Well I see that you are going to a custom swingarm so I can't really help to much there. But I have put the 1100F rear swingarm into my 79 and using a 82 rear wheel kept the alignment perfect and I'm running a 150 70 18 on the back and had to work only two (2) pieces. If anybody needs information about that set up I have it and pictures I took as I went thru and did mine.

[jt]

I would be interested in the info and any pics of your conversion. How is it to get up on the centerstand with the 70 series tire I have a set of the European CB1100F (3.00x18) rims and will probably have to use a 70 series also.

Thanks

Jerome Tarpey

jtarpey@swbell.net

[CBXzREG]

Land-shark, I am not qualified to give you expert advice, tho a number of members of the UK CBX Riders Club have added japanese front ends with upside down forks, single sided swinging arms etc.. The club also has technical experts to ask for advice.



Look at the website at: http://www.ukcbxclub.com and contact the head honcho Mel at CBX6MELUK@aol.com There are a few pictures of these transformations on the website.



Good luck.

[z1x]

JT

The picture that is with my profile is on the center stand, I don't have any problem getting it up onto or off of the center stand and still have the same amount of clearance from the bottom of the tire to the ground.

[CBXzREG]

Z1X, would be most grateful to see an account of the CB1100F rear end conversion. Please email me per my profile. Many thanks in advance.