Visit our Twitter feed for more great content
CKC

CycleKart Tech Forum

Up Tight Tonight

AutoShrine Sponsor
AutoShrine Sponsor

Denny Graham Gold Member Dennis Graham
Sandwich, IL, USA   USA
1950 Chevrolet 3600 "Old Blue"
1954 Chevrolet 3600
Seems to be dragging around here again lately. So…..I’ll bore you with another of my
anally retentive activities.
Got my Tusk spoke torque wrench in the mail today, an early Christmas present. I’ve had
a set of VKCo. wheels for better than a year now. Straight out of the box, I mounted up the
rubber last spring and they’ve been sitting untouched since then.
This afternoon I just had to try out my new toy so I mounted up one of the front wheels in
the balance stand and commenced to tune up the spokes. I was curious as to where they
would be tensioned at from their source so I started out at the lowest torque setting, which
is 30 in.lb. I was surprised at how many times I had to make the circuit before I got my first
click, probably a good dozen or more times round. Once they were all clicking at 30 in.lb. I
upped the ante to 40. A dozen or so circuits of ¼ turn tension turns and I got to 40 in.lb. By
now it was supper time and I’d had enough of working in the semi-cold barn. I’ll finish it off
in the morning as my target it 48 in.lb. based on research the FAST did on motocross bikes
serviced with their Torque Wrenches. I could not find any factory torque specs for Honda
CT90 wheels
The thing that stands out the most is how loose these spokes were, as shipped. I had
assumed that they would have been properly tensioned from the factory. And I’ll bet
I’m not the first one to think this. And if guys are mounting up the VKCo. wheels without
properly tensioning them, I’m sure that is why some are encountering problems.
The other thing that surprised me is just how tight the spokes are at 40 in.lb. And I’ll put
my money on the bet that most guys that are not experienced bike builders are not aware
of this either.
Project for tomorrow at sunrise is to bring this wheel up to 48 in.lb. and do a little more
truing of the rim.
Denny Graham
Sandwich, IL

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Racie35 Avatar
Racie35 Bruce T
Terre Haute, IN, USA   USA
I wonder if the repops are lighter material and need less tension or cannot take more? Cuz if they were paper that would be so.

Denny Graham Gold Member Dennis Graham
Sandwich, IL, USA   USA
1950 Chevrolet 3600 "Old Blue"
1954 Chevrolet 3600
I don't think so Bruce, they are a pretty durn close copy of the original rim.
FAST recommends 48 in.lb. pretty much across the board. They've tried
less and more and neither gave good results.
I would be very surprised that the rims were strung up with much more
than just snugging the spokes up. I had the torque wrench set at it's
lowest as I said, which is 30 in.lb., and it took a dozen times around
to get a click at 30. I've got three more to check out, I'll post if I find
out any more.
dg

. Hide banner ads & support this website by becoming a > Gold Supporting Member <
Racie35 Avatar
Racie35 Bruce T
Terre Haute, IN, USA   USA
Yes...probably just lazy assembly over there

Woodysrods Avatar
Woodysrods Silver Member Brian Woods
Westbank B.C., Canada   CAN
We are watching with interest!
Brian

CmdBentaxle Avatar
CmdBentaxle Dave D
Federal Way, WA, USA   USA
1950 CycleKart Italian "1950 Ferrari 166 F2"
Denny!
I found an original Honda shop manual with spoke torque specs. I'm having a hard time putting the pages up here, but if you go to ct90-ct110.com they have manuals. In the '66 thru '70 edition, on page 125 you will find them. Front wheel: 21 kg.cm or only about 1.5 lbs !!! 25kg.cm for the rear.
Holy cow!

Denny Graham Gold Member Dennis Graham
Sandwich, IL, USA   USA
1950 Chevrolet 3600 "Old Blue"
1954 Chevrolet 3600
Well…..I just spent one ‘ell of a day in the barn. I’ll elaborate below.
Thanks Dave for that link, all I found yesterday at their site were the operating manuals,
and they didn’t give the torque specs.
I’m not sure just exactly what the spec is saying. Specifically the first numbers as shown
in the service manual: that is the 4 the 8 the 10.3 and the 10.5?
This copied from the manual:
“(Specified torque)
Front wheel: 4~21 kg.cm. 10.3~1.5 ft.lb
Rear wheel: 8~25 kh.cm. 10.5~1.8 ft.lb”
But…what it boils down to when converted to inch pounds is shown below.
Front:
21 kg.cm. = 1.5 ft.lb. (18 in.lb.)
Rear:
25 kg.cm. = 1.8 ft.lb. (21.6 in.lb.)
Now, 18 in.lb. or 21.6 in.lb will not even register on most torque wrenches. The TUSK only
goes down to 30 and even me old Craftsman inch pound beam torque wrench only shows
20 in.lb, and I can twist that with my hand if I gab holt of the end with a socket on it. There
is a world of difference between 0 to 20 and 0 to 30 and 0 to 40 is really a big difference.
So…..the way my day went. I come to the conclusion that tensioning or torquing the
spokes is a futile endeavor!!!! It’s much like the dog chasing his tail. I’m not working with
a pointer, rather I’m using a dial indicator since it’s much more precise and I’m used to
using precision measurement instruments. The factory tolerance for run out and
egocentricity is .020”. First step is getting the rim to run concentric to the axle. Damn near
impossible to hold .020” with a roll formed steel rim. You might get it with a good cast
aluminum rim. So you get it to run as true as possible then move to the run out. That
you can get with in .020” however once you get the edge of the rim running true, guess
what, now the egocentricity begins to go to ‘ell. Next you start to tension the spokes.
In theory, when all is running true you should be able to tension all the spokes to the
same tension and still not pull the rim out of true. Surprise…..not all the spokes will torque
the same. By the time you bring all the spokes up to….say….30 inch lbs., you’ve pulled the
rim out of true….so then you try to pull the rim back in so it runs true and now the tension is
all askew. In the end…..the whole deal is very much a compromise, and the best one can
hope for is to get the three to a point that is livable at 40 or 50 mph.
The tires…..well that’s another story. But the short story is…they taint round and they don’t
run true.
Denny Graham
Sandwich, IL

carChips Avatar
carChips Victor Harnish
Kelowna, BC, Canada   CAN
1933 MG Magnette
1973 Triumph Spitfire 1500 "Chip"
1989 GMC Sierra 1500 "Bush Truck"
I think being truly round with moderate tension on all the spokes would be the best case scenario. Did you try measuring the spokes from the hub to the rim?

Of course it all goes for not if you loose a wheel off into the rhubarb. BTDT!



S'all for now!

Denny Graham Gold Member Dennis Graham
Sandwich, IL, USA   USA
1950 Chevrolet 3600 "Old Blue"
1954 Chevrolet 3600
That would be a bit difficult when your shooting for .020" on 36 7" long spokes with no real
solid points to datum off of Vic. And as I posted, all three parameters work off of each other.
You change one and you've changed the other two. A big bike that's made to run at highway
speeds and pro-racing bikes rims are held to much higher tolerances and I would think
they would be a whole lot easier to true up. These rims are made for low speed entry
level bikes and I wouldn't expect them to be as high a quality.
A good example of what sort of performance is expected is what I posted from FASST's
web site. From years of research they have determined that the optimum tension on the
pro racing rims is 48 in.lb. Compare that to the recommended torque from the Honda
service manual. Quite a difference.
One other thing that I did tonight was balance the wheel after I got it as close to true
as I could. I was quite surprised that it took 1 1/4 oz. to balance.
Also, I was wondering how much of a difference it made to true the wheel with the tire
inflated or not. So I let all the air out and trued the wheel, then inflated it to 25 lbs and
it didn't seem to change any of the readings.
dg


Attachments:
Truing the first front 01.JPG    60.5 KB
Truing the first front 01.JPG

Denny Graham Gold Member Dennis Graham
Sandwich, IL, USA   USA
1950 Chevrolet 3600 "Old Blue"
1954 Chevrolet 3600
Burrrrrrrr! Coming in from the cold for a nice warm Sunday supper,
but before the feast....I'm gonna throw some thing out to those "real"
bikers out there. Need to put some balance into this project and of
course those steel stick on wheel weights won't work on a CT90 rim.
Looking at the brass spoke weights, the price 'bout knocked me off
my stool. Now I've got lots of .750" and .500" brass round stock on
the stock rack and milling a slot and tapping a set screw hole is a
breeze.
So.....I'm making up a big batch of brass spoke weights of various values.
Just out of curiosity I went out to the garage and took a look at my
little Suzuki 250 and found they used tapered pinch on weights on
the spokes.
Then I looked for the weights on my 2010 Triumph T-100 and.......
it had no weights neither front nor back! I know damn well that
those rims and tires could not be perfectly balanced. Yet...I do
run the bike up to 100 mph at times with no sense of vibration.
So what the heck is going on??? I've seen "balance beads" for
sale at some of the motorcycle suppliers, could it be...that's
what the Triumph came with??? I replaced the rear tire and
tube a couple of years back when I hit 10k, and the shop where
I took it didn't say anything about balance beads.
And as far as those "balance beads" go.....I've tried them in my
new Michelin radial tires on my '50 Chevy truck and they didn't do
a thing for it. The whole concept of those beads seems kind of
hokey to me anyway, I really think they're a close cousin
to "Snake Oil".
Denny Graham
Sandwich, IL

carChips Avatar
carChips Victor Harnish
Kelowna, BC, Canada   CAN
1933 MG Magnette
1973 Triumph Spitfire 1500 "Chip"
1989 GMC Sierra 1500 "Bush Truck"
Tire balance isn't a real issue with the speeds we get to in a cyclecart, have you thought about fishing weights?



S'all for now!

1908Rick Avatar
1908Rick Rick Eggers
Cape Coral, FL, USA   USA
I've seen spoke wheels balanced with a small coil of lead solder wrapped around a spoke.

Denny Graham Gold Member Dennis Graham
Sandwich, IL, USA   USA
1950 Chevrolet 3600 "Old Blue"
1954 Chevrolet 3600
Don't want to pinch any thing on to the spoke, that's to permanent and could be
a butch to get off. I'm goin' with the brass and set screw. Calling my order for some
4-40 set screws in he morning. I suppose you would know if balancing is a waste
of time Vic.
But, while I'm at it I might as well do it right. Then on the road at 50 or 55 I won't have
to worry about it shaking any screws loose.

Now that you mention it Rick, I've seen the same thing somewhere back in my dark past.
That's probably a pretty good solution when you first think about it. It would be simple to
Zero in on the exact value. As usual I can see the good in that idea......but......I can also
see the yang. I can't think of any way you could keep the coil from sliding on the spoke.
Clamping with a set screw still seems like the best solution.


Denny G



Edited 1 time(s). Last edit at 2018-12-09 08:22 PM by Denny Graham.

carChips Avatar
carChips Victor Harnish
Kelowna, BC, Canada   CAN
1933 MG Magnette
1973 Triumph Spitfire 1500 "Chip"
1989 GMC Sierra 1500 "Bush Truck"
smallboregarage Avatar
smallboregarage Chuck Kraeuter
Portland, OR, USA   USA
I'll second Rick's solution. Pictured is lead wire from a fishing supply store. It can slide around on the spoke but stays put when needed. I believe it still passes tech inspection at any motorcycle race; the stick on weights need to be secured with tape.


Attachments:
image.jpeg    47.5 KB
image.jpeg

. Hide banner ads & support this website by becoming a > Gold Supporting Member <

To add your reply, or post your own questions




Registration is FREE and takes less than a minute!


Having trouble posting or changing forum settings?
Read the Forum Help (FAQ) or contact the webmaster





Join The Club

Sign in to ask questions, share photos, and access all website features

Your Karts

1942 CycleKart American

Text Size

Larger Smaller
Reset Save

Sponsor Links