1980 Honda CB 900 wheel alignment.

[Chris Turl]

Hi all!...

New to the forum and was wondering if anyone out there can help...
I'm currently in the middle of a build and have hit a snag. Long story short, I have deisgned my own rear wheel to take a spoked rim using the original wheel hub from a 1980 comstar wheel. Before removing the hub from the original wheel I had all the appropriate measurements taken from the original (Rim position etc) so that when I got the new rim spoked to my hub, it should align perfectly with the front wheel. Having had the wheels made i've checked the wheel alignment and have found it to be 11mm out. All the original spacers are used in the wheel (one of the reasons for using the original hub) and everything is as it should be from the wheel builders.
If I have the rear rim moved over 11mm to align the wheels it will foul on the brake caliper arm and will not be central in the swinging arm.
Unfortunately I never checked the wheel alignment on the original wheels so have no idea if they were way out in the first place.
Does anyone know of any CB wheel alignment troubles or have come across any similar problems on a build?

Thanks in advance, Chris.

[Chris Turl]

No its impossible to do that, cush drive, sprocket carrier etc would be on the wrong side.

Spent last night looking at it and the only thing I can think is maybe the frame is bent at the headstock.
Think my next course of action will be to buy/borrow a standard rear wheel, fit the standard front end back in and check the alignment between the two original wheels.
If this is out then it can only be the frame is bent.

If there is anyone in the Bristol/Glos area that could lend me a rear wheel to check this, would be very much appreciated!

Cheers.

[Laverda Dave]

Hi Chris, I can't help with the rear wheel but I would strongly recommend having the frame checked for alignment. I get every frame checked when I rebuild a bike due their age and unknown history. 3 of the last 4 frames I have checked have been out of alignment at the headstock (the Morini by 2.5 degrees).  Its relatively easy to straighten them. For the sake of £70 to check and maybe tweak it back to where it should be is a good investment.
The guy I use runs his own workshop called Hybrid Motorcycles, he's based in Sarratt, Rickmansworth in Middlesex. His number is 01923 776660. He builds specials and knows what he's doing.
Good luck, keep us posted.

[Chris Turl]

Hi mate, that's brilliant, thanks for the info!!....

Def going to get the frame checked, will let you know how it turns out.

Cheers guys!

[K2-K6]

As Laverda says, there's quite a few running around I see that are clearly out of alignment one way or another.

If anyone watches that Henry Cole program, shed and buried, he bought and kept a Kawasaki 400 rat bike. In the initial shots out riding it you can almost see between them wheels from head on its so skewed. You could probably ride it with a wheel either side of a white line at the same time it's so misaligned!

It'll give you a good datum if you get the frame checked, often these services are labelled "motoliner " after the jig manufacturer if you are looking locally for that facility.

Be interesting to see pictures of your Comstar hubs built up in the conversion if you've any available.

[SteveD CB500K0]

I did have an FZ but it was a few years ago now...

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[Chris Turl]

K2-K6 I was going to post a pic last night of the build just to make it easier to see what I was up to, but the 1000kb file size limit stopped me posting any. Will try and re-size some pics when I get time and post them up for you to see. They do look nice!

[Laverda Dave]

Lovely looking bike Steve, great looking engine.

[K2-K6]

It might be possible oddjob,  if you've got rear centred in swingarm and check alignment against front wheel then if you've offset the front you'll see a difference.