Topic: How true is SOHC4 wheel

[70CB750]

Trying to figure out how true is spoked wheel. I looked at K7 that's sitting in my shop and there is some wobble for sure.

[BenelliSEI]

I’ve often measured 1/8” (3.18 mm) on stock wheels. Remembering they are usually about 50 years old, who knows what they started at? When I rebuild them, I stop when 1 get to that number. For the riding I do, that seems to be just fine.

[newday777]

Following...

John
That's a funky centerstand stop you have...

[rotortiller]

I measure spoked wheel run-out where the tire seats on the inside the rim for both up/down and side to side. External surfaces may not be the best area to measure. There is quite an allowance in the manual and in my experience 0.050" is pretty easy to acquire with a decent rim.

[MauiK3]

I get them a little closer than 1/8" but these steel wheels usually have a tough spot at the weld. It's not easy.

[Ozzybud]

I use the same method truing wheels as I do when doing bodywork. You can never say "that's good enough" you can get the OEM rims or replacement DID units practically perfect. Not sure why you would want to run it with 1/8 runout? You are going to feel that at highway speeds. You might have a little blip where the weld is but not that much.

[BenelliSEI]

I’ve never felt any runout and it takes me 10 minutes to true a wheel to 1/8”…..

[bryanj]

Honda specs are up to 3mm

[BenelliSEI]

Following...

John
That's a funky centerstand stop you have...

Ha! Keeps it off the brake arms when there are no pipes…..

[Ozzybud]

If you are set up and "Truing" the wheel why would you stop at 1/8?
Why not get it True as possible?

[Ozzybud]

Every place online and in past forum discussions says less than 1mm is acceptable.
Not sure why anyone would want their wheel to wobble. 3mm

[BenelliSEI]

Every place online and in past forum discussions says less than 1mm is acceptable.
Not sure why anyone would want their wheel to wobble. 3mm

That’s because there is no wobble at less than 3mm.

[Ozzybud]

Every place online and in past forum discussions says less than 1mm is acceptable.
Not sure why anyone would want their wheel to wobble. 3mm

That’s because there is no wobble at less than 3mm.

3mm or 1/8 is a wobble.  Not my definition of "True"

You can see it wobble with a naked eye.

[Ozzybud]

When Truing you should be shooting for the Standard value 0.5mm or 0.020 inch

This  table is from the CB750 Service manual

[HondaMan]

Honda's 1970s spec for the 750 and CB500-4 was 3mm in their shop notices, but the rims themselves could be +/- 2mm all by themselves! Made "truing" tricky at best. Most of the time the wheels weren't all that high quality, with especially the weld bumps where they were assembled. Hurriedly welded and ground, then sent to the chroming station: the weld bumps on the front of my K2 are more than 1mm high. I finally went to truing them up by measuring just at the bend toward the tire's bead. This seemed to be a tiny bit less deviant?

[Ozzybud]

This is the Documented specifications for the CB 500 and 550.
I can guarantee Mr Honda did not want to ship these bikes all over the world with wobbly rims.

The reputation of the company was resounding  Quality!. If guys like me bought a Honda in the 70's and took it home put it on the center stand and  The wheel wobbled 1/8;of an inch I would loose respect of Honda and go buy a British bike. The last thing Mr Honda wanted.
Truing wheels is an art. Not all shops had someone to dial it in to the standard spec. So maybe your shops laxed on the tolerance.
I believe all these bikes left the factory at or below the "Standard" of 0.5mm. The group doing it were professionals
Please show me this 3mm in documentation.

[seanbarney41]

Ozzybud, the real problem is it ain't gonna stay put anyway.  Basically, true a wheel perfect (or really the closer to perfect possible) and it has no where to move to other than much less perfect.  I often wonder how much of the mushy wishy washy handling of 70's jap bikes is from these very flexible steel wheels.  I answer my own question every time I ride one of my bikes with Lesters, Morris, Hayashi, etc...Comstars are even quite good as are the high quality wheels Honda used on early GL1000/Hondamatic

[MauiK3]

Yes, my 75 Wing rims were pretty nice stuff.

[70CB750]

Ozzybud, the real problem is it ain't gonna stay put anyway.  Basically, true a wheel perfect (or really the closer to perfect possible) and it has no where to move to other than much less perfect.  I often wonder how much of the mushy wishy washy handling of 70's jap bikes is from these very flexible steel wheels.  I answer my own question every time I ride one of my bikes with Lesters, Morris, Hayashi, etc...Comstars are even quite good as are the high quality wheels Honda used on early GL1000/Hondamatic

Amen.  I checked the original rear wheel from Dorothy - it aint pretty. 

[70CB750]

How about torque for spokes?

Buchanan, on the note with spokes talks about torque 80 inch pounds or more.

[Ozzybud]

How about torque for spokes?

Buchanan, on the note with spokes talks about torque 80 inch pounds or more.

I do it by feel and the sound of the spokes. They should have a ring or a ding sound never a thud.

After truing do them in sets of 2 or 4 180 degrees apart. turn equally. I usually mark the rim with a felt marker A,B,C.... Then on the other side A1,B1,C1....
Repeat until they all make a nice ding!

[HondaMan]

BMW sent our shop a special release for truing their wheels (after they discovered we also sold Honda and Suzuki) to 'ensure' their bikes were well-trued. Their spec was at 0.4mm, and if their bike came out of a crate with more than that we were to 'retrue' them. I never saw one come out of their (magnificent) crates beyond that, but the few I measured were right at it, when measured by raising the front wheel and measuring it right on the bike(s).

The Honda 'specs' we had weren't in the manuals, but via their traveling Honda Rep who visited each shop in his area. These were often mimeographed (remember that stuff?) typewritten instructions, no pictures, no Honda logos, but with an issue date and a rep's name. Those were the majority of the 'clues' we got from Honda about the 750's changes, and the specs for things that weren't in the shop manuals (or were wrong in them) that we had formally requested. Since we had some racing in our area and a Honda-sponsored dirt racer, we got at least SOME attention for this kind of stuff: today I'd bet lunch that it would fall on deaf ears. ;(

[PeWe]

Hard fork (spring  pretension, oil and amount) plus hard shocks and high tire pressure will cause jumpy feel, to blame the wheels.

My K2 front end was like that. I remember I measured the wheels.
Have it on video too.
Rim is within 1mm total before tire. Not much more measure on tire.

[simon#42]

How about torque for spokes?

Buchanan, on the note with spokes talks about torque 80 inch pounds or more.

thats high i torque mine to 48 .

[Mark1976]

How about torque for spokes?

Buchanan, on the note with spokes talks about torque 80 inch pounds or more.

thats high i torque mine to 48 .

   Even 48 is on the high end (imho), it depends on the spoke gauge, nipple and rim type. But these are traditional rim spoke arrangements, between 3-4 ft lbs is more than enough.