2 different spoke calculators 2 different numbers ? ! ?

[ScooterMan101]

Trying to calculate my spokes for Q 100 cst hub and 700c/ 29 er wheel with a ERD of 600

Rim ERD is ... 600mm
Hub Flange Diameter is ... 109mm
Hub center to flange is , left side ... 30.5mm and on right side ... 11.5mm
Hub spoke hole diameter is ... 3mm
Number of spokes is ... 32
Cross pattern will be ... 1 cross
Flange Spacing is .. 42 mm or more like 42.5 mm

Grin technologies says I need spokes 249.6 mm long ( they will not let me put in the correct 600 ERD , even clicking on Custom Rim )
and
Grin does not say how to figure Dishing Offset or even let me change it .

SPOKE CALCULATOR
Quick Links:Hub SettingsRim SettingsLacing OptionsResultsWheel building


But

bikeschool.com ( united bicycle instute ) says that I need 291mm for left and 289.7 mm , rounded up to 290mm for the Right side spokes .



Spoke Length Calculator

Effective Rim Diameter (ERD): 600
Hub Flange Diameter: 109 mm
Hub Center to Flange Center: 30.5 ( left side )
Hub Spoke Hole Diameter: 3
Number of Spokes in the Wheel: 32
Cross Pattern : 1 cross
SPOKE LENGTH = 291.1

With Hub center to Flange Center 11.5 right side , Spoke Length is 289.7

Who is right ?

 

[d8veh]

Before anything, measure the inside diameter of your rim. I've known some stated ERDs to be quite a bit off. Add 5mm to the inside diameter and it should be close to the ERD.

The spoke flange diameter of a Q100C is 108mm, not 109. I never bother with the offset. The difference normally comes to + 0.5mm on one side and - 0.5mm on the other. On a double-walled rim, there's plenty of depth so it doesn't matter if your spokes are a bit longer. The chances are that you have to round up a couple of mm anyway because the spoke suppliers don't have every size.

When I do the calculation, for 32h 1-cross Q100C 600 ERD, I get 250.8mm, so anything from 250 mm to 253 will probably be OK.

Are you sure you have 32 holes?

 

[ScooterMan101]

d8veh,

The ERD seems to be 600, but I did calculations this 2nd time with both 600 and 602 ERD just to be sure.

The Q100 cst I got is in fact 109 , but really a 109.5 Hub Flange Diameter . ( I checked 3 times with the calipers , BMS also shows it as 109 on the diagram )

I did get a 32 hole motor , because the rim I got only came in 32 hole . ( I have seen with many rims that they only come with 32 holes )
I think I put into the notes that I wanted a 32 hole motor, and 201 rpm as well.

I just went back to both websites : ebikes.ca , and , bikeschool.com and recalculated again. ( perhaps I had left the standard 3 cross pattern on bikeschool calculator instead of 1 cross ? , I tried that and the numbers came very close to the first time I used their calculator so perhaps that was where the discrepancy was )

This time ebikes.ca said 249.3 both sides
and
bikeschool.com said 251 left and 249.2 right
However I also did calculations for 137 mm spacing since I might add a 1mm spacer on each side, to help with aligning the disc brake caliper and to allow a 10 speed cassette instead of a 9 speed cassette.

I also calculated for a ERD of 602mm , in both 135mm spacing and 137 spacing, so I will go with that number since it is only 2mm longer spoke length on the left side and 1mm more on the right side and my rim is plenty deep enough.

bikeschool.com came up with the same range of numbers as you, apx 250 to 253mm . Your calculator works good !

Before anything, measure the inside diameter of your rim. I've known some stated ERDs to be quite a bit off. Add 5mm to the inside diameter and it should be close to the ERD.

The spoke flange diameter of a Q100C is 108mm, not 109. I never bother with the offset. The difference normally comes to + 0.5mm on one side and - 0.5mm on the other. On a double-walled rim, there's plenty of depth so it doesn't matter if your spokes are a bit longer. The chances are that you have to round up a couple of mm anyway because the spoke suppliers don't have every size.

When I do the calculation, for 32h 1-cross Q100C 600 ERD, I get 250.8mm, so anything from 250 mm to 253 will probably be OK.

Are you sure you have 32 holes?

 

[spinningmagnets]

Are you measuring the outside diameter of the spoke flange? I believe the spoke Pitch Circle Diameter (PCD) is measured from the center of one spoke hole, to the center of the spoke hole on the opposite side. The PCD would be several mm less than the OD of the spoke flange.

 

[ScooterMan101]

spinningmagnets :
I am measuring the center of one spoke hole to the center of the spoke hole on the opposite side of the hub motor flange.
The Q100 cst is so small that my calipers fit around the center of the hub to do an accurate measurement. it is even .5mm more than the spec's
at 109.5 mm.

d8veh :
I have a different looking hub from what is on the bmsbattery.com website. so I am not sure if I got a newer version or what is happening there.
Now when I go back to their website , I do not even find a way to chose 36 or 32 hole. So not sure what is happening with them on that also ?

Are you measuring the outside diameter of the spoke flange? I believe the spoke Pitch Circle Diameter (PCD) is measured from the center of one spoke hole, to the center of the spoke hole on the opposite side. The PCD would be several mm less than the OD of the spoke flange.

 

[d8veh]

Is yours the new black one with a marking on it that starts with AKM......?

 

[ScooterMan101]

It is black, however, it has two numbers,

on top they start out with A15
and
under that a second set of numbers that start with CSV

What do I have compared to the one that the numbers start with AKM ?

Is there an youtube video on how to wire together the controller and how to set up Program the display ?
Throttle and no pas at this time.
There were no instructions that came with it,
and
with the 24-36 volt controller some of the connections do not match with other parts. even though I think I want to use the
other controller I bought the 48 volt one that I think will work on 36 volts should I decide to start off with 36volts.

Is yours the new black one with a marking on it that starts with AKM......?

 

[d8veh]

You need to show us what you've got before we can tell you how to wire it.

 

[ScooterMan101]

I have just ordered some spokes to build up the wheel, after I get that done and found a bike, I will post some pictures of the connectors on the controllers. Not sure which one to go with 24-36 volt one or the 48 volt one that interestingly looks the same on the outside, if the 48 volt one can work / sense that I have a 36 volt battery, then I will use that one since I have a 36 volt bottle battery can be used , I am thinking I might want to run it on 36 volts for a short while before going with 48 volts.

You need to show us what you've got before we can tell you how to wire it.

 

[wesnewell]

Using your data, this is what I got. I'd just get 250mm spokes all around. It's not that critical.
Spoke length left 250.9 mm
Spoke length right 249.3 mm
https://leonard.io/edd/