Topic: 1978 CB550K rear rim offset spec?

[Flyin900]

I am getting the rims replaced and I measured the rear offset from the outer edge of the brake drum at 3/8 inch on the right side of the rim, before I relaced the new rims and spokes up. The fellow who is doing the truing work is having a hard time getting that spec to work.

Can anyone confirm the offset, as I don't see a spec in the FSM for the wheels offset? I believe my measurements are correct, yet a confirmation from someone who has done this work and kept the spec would help.

Is this spec listed somewhere in a service manual or on this site?

[bryanj]

All Honda 4 wheels i have worked on are central to the hub

[Kevnz]

Agree with Bryan. I replaced the rims and spokes on my 550 this year myself, plenty of Youtube videos and pretty straightforward. Just tension the spokes evenly and the hub ends up central.

[Flyin900]

Bryan, thanks for the reply, yet I did measure the offset on the original rims before I took them apart. With the brake plate off the brake drum and no tire installed I laid a 3 ft straight edge across the center area of the outer drum edge. When I measured down from the bottom of that straight edge to the top of the rim edge I measured 3/8" in space. So there was an offset there.

The front wheel also was showing 1/4" from the center rim surface to the rim edge using the same straight edge across to the rim. Once the wheel is mounted with the spacers etc then would that account for the centering as your describing?

[Flyin900]

Agree with Bryan. I replaced the rims and spokes on my 550 this year myself, plenty of Youtube videos and pretty straightforward. Just tension the spokes evenly and the hub ends up central.

So did you not check for an offset before taking it apart and just put the rim and spokes together and the sprockets and disc brake all lined up perfectly?

[HondaMan]

Sometimes I think the 'offset' discussions do forget about the various spacers on the axles on these bikes. With the exception fo the CB750 front wheel of the K1-K6 bikes, the rims are lined up with the center of the bikes, BUT that does not mean they are centered on their hubs! I just had a long discussion of this with Buchannon Spoke and Wheel, and after 2 tries they came up with a set of spokes for offsetting the 16" rear wheel on a custom 750 rear I am lacing up now. This all feels a little strange: back in 1971 when I did my first one of these, I learned about it by getting spokes from Rocky Cycle of Chicago for the 16" rear wheel of the CB750. They were (and are) 4 different spoke types, 10 of each, of 2 different lengths in each head type. I've assembled these wrong more than once because of this, but at least found them before I tightened up all the spokes!

[toma]

Offset or dish should be avoided in the design  stage if possible. Dish requires that the spokes on the side that the rim is pulled toward be at a greater angle to the axle . This means that they will have to be tighter  than the spokes on the other side.  Offset is measured  from the center of the horizontal line between the two rows of spokes  and the edge of the rim. The hub may be symmetrical or not.
Dish or offset value decreases as you go toward the rim from the center line of the axle.
Not a simple subject. Best to keep the angle of the spokes to the axle the same on both sides if possible and center the rim and tire with spacers.

[Kevnz]

Yes, following Y\T video, install one set of inner spokes first( all in one direction, every 4th spoke hole), flip rim install next set of inner spokes opposite direction. Ditto for outer spokes, tighten spokes checking runout both radially and laterally. Ended up lining up perfectly in swing arm. Standard rim and spacers. Time consuming first time, 2nd time you get the hang of it. Key is only minute adjustments to eliminate runout.

[bryanj]

Offset is measured from the centre of the hub, the rim of the drum sticks out so is not the correct measurement, any wheelbuider measures offset from centre of hubflanges to centre of wheel rim

[Flyin900]

Thanks for the responses and we have resolved the issue and trued the wheel.

BTW I did use YT for the initial directions on respoking the new wheels and the presenter suggested using the straight edge off the hub for the “offset” measurements.

[Kadett]

So, did you end up having an offset on your rear wheel in the end?

I am planning on doing a similar project to you and want to relace my wheels with new DID rims on a CB400F and I have read the wheels are central with no offset. All of the spokes in the spoke kit are the same length, so it is hard to see how the wheel would not be anything other than centered. Can anyone confirm there is no offset front and rear on a CB400F?

[robvangulik]

I can

[Kadett]

I can

Thanks   

[robvangulik]

You're welcome, and good luck with your resto