A Much improved ebike spoke calculator,

[justin_le]

Wavecrest did paired radial for both wheels starting in 2003 but perhaps no one paid it much attention!

BTW Voicecoils, if you have a TidalForce hub around and can measure the spoke spacing and flange diameter, this would be a fun one to get on the list as well.

 

[Dark Knight]

Great updates to an already useful tool - subscribed

 

[Tench]

Would it be possible to add the ProWheel rims in 17 18 and 19" or is this just being kept to bicycle rims?

I could supply info for the 17" one.

 

[arkmundi]

We're in the midst of making a better online spoke length calculator tool to address the needs of people lacing up hub motors in to rims, and before going live would like to get a bit of feedback.
The test URL is here:
http://www.ebikes.ca/spokecalculator/index.html...

Looking pretty awesome! Thanks.

 

[justin_le]

OK, we've added the back side spokes to the drawing model as well:

They are shown in a much lighter shade of grey but I'm worried that the result is still too busy. What do you think, should we leave it or go back to only drawing the facing side spokes?

 

[justin_le]

Would it be possible to add the ProWheel rims in 17 18 and 19" or is this just being kept to bicycle rims?
I could supply info for the 17" one.

Could do, although I'm not sure that they would match any of the ETRTO sizes that we have in the drop-down for the bicycle rims, so the OD of the rim drawing may not be very accurate. Do you have the data on the actual bead seat diameter?

 

[amberwolf]

OK, we've added the back side spokes to the drawing model as well:

They are shown in a much lighter shade of grey but I'm worried that the result is still too busy. What do you think, should we leave it or go back to only drawing the facing side spokes?

I definitely prefer seeing the backside spokes too, but I can see how some people might not want to.

I know how "optionitis" affects both the programs itself and the GUI, but you could put a checkbox to optionally display the backside in gray like that, perhaps, bu tby default only show front.

 

[voicecoils]

Wavecrest did paired radial for both wheels starting in 2003 but perhaps no one paid it much attention!

BTW Voicecoils, if you have a TidalForce hub around and can measure the spoke spacing and flange diameter, this would be a fun one to get on the list as well.

I wish, but I don't think any made it to Australia. It was probably the first production electric bike I ever tried (in early 2000s).

There are some very loyal owners on E-S we might be able to get measurements from however.

 

[Obiwan007]

I'd be worried about adding a number of extra fields in the default view because that just complicates things for most people who don't need it, but we could have an "advanced" tab that opens up for those wanting dish control.

Ya, I agree. I would have been confused if I had to figure it out at first too. Sure would be nice, as you say, in an advanced tab though. The ability to "see" the dish that you have calculated, however, may be a good addition to the basic tab because, at least in my case, it prevented me from doing something silly. Thanks for the math help on dishing and offsets...I'll have to re-read it a couple times to internalize it. If only there was a place to make these golden nuggets of wisdom permenantly available to anyone who is interested....oh yeah, that's right, you have generously provided just that for all of us. Thanks again Obiwan

 

[Drunkskunk]

OK, we've added the back side spokes to the drawing model as well:

They are shown in a much lighter shade of grey but I'm worried that the result is still too busy. What do you think, should we leave it or go back to only drawing the facing side spokes?

I like it much better with the background spokes, but perhaps make it something that could be toggled? You had mentioned an Advanced tab, maybe they should default off but be something that could be turned on in an Advanced tab?
Or maybe they could only appear when you hover the mouse over them or something?

 

[justin_le]

I like it much better with the background spokes,

OK thanks. It seems that the concensus is to keep the backside spokes and have the drawing stay more complete and realistic. So unless others pipe-up that it's too busy/distracting then we'll leave it as is.

 

[pendragon8000]

I like it much better with the background spokes,

OK thanks. It seems that the concensus is to keep the backside spokes and have the drawing stay more complete and realistic. So unless others pipe-up that it's too busy/distracting then we'll leave it as is.

It was when I saw the back side spokes in the tightly paired zero cross pattern , iI realized the wheel as a whole would be quite strong.

 

[wingsuit]

this is super useful, thanks. only thing I noticed straight away was the fixed size for nominal wheel size. makes it so I cant option my 19" prowheel rims. Custom rim sounds like it should allow me to pick my own nominal wheel size, instead of being fixed to the current list? seem more like a visual thing anyway I guess as spoke measurements are calculated from the erd, so no big deal.

 

[John Bozi]

this is super useful, thanks. only thing I noticed straight away was the fixed size for nominal wheel size. makes it so I cant option my 19" prowheel rims. Custom rim sounds like it should allow me to pick my own nominal wheel size, instead of being fixed to the current list? seem more like a visual thing anyway I guess as spoke measurements are calculated from the erd, so no big deal.

Just what I was going to say and ask. Also, does the light grey and dark grey 2 circles that colour the rim mean anything?

Does it matter if I can't use the 19" nominal? I chose 20" and then the erd looks right but I need to be sure before getting spokes...

 

[John Bozi]

Thanks Justin, noticed you added the 19",
Just an idea..
it may help people, especially less experienced builders to realise that eyelets make a difference as well. The 371 ERD for the dx32 19" I calculated based on the Alex website is for without eyelets. Without exact measurement tools I still thought something was wrong, measured again and researched more that with eyelets it's 374.

Maybe a drop down menu for depth of eyelet?

Anyway thanks.

 

[justin_le]

Thanks Justin, noticed you added the 19",
Just an idea..
it may help people, especially less experienced builders to realise that eyelets make a difference as well. The 371 ERD for the dx32 19" I calculated based on the Alex website is for without eyelets. Without exact measurement tools I still thought something was wrong, measured again and researched more that with eyelets it's 374.

Maybe a drop down menu for depth of eyelet?

Anyway thanks.

Yeah, we've totally run into this issues as too, especially since we often have the same nominal rim with and without eyelets. Like when we order spare rims from Crysatlyte they include an eyelet, but if free up a rim from unlacing a pre-built motor from them it's been drilled out for 12g nipples and has no eyelet, and the difference in effective ERD is over 4mm in that case.

Our plan was just to include it in the rim description, so if a rim was available with eyelets and without eyelets then you could choose the appropriate one from the drop down. Is it normal that a company lists the ERD on their website as a non-eyelet value and then expect people to add this? I would have thought that if the rim comes with eyelets that they'd include an ERD value appropriate for that. If that is the case then your suggestion of having an additional field to add an eyelet depth wouldn't be a bad idea.

-Justin

 

[justin_le]

Just what I was going to say and ask. Also, does the light grey and dark grey 2 circles that colour the rim mean anything?

That's just to illustrate the typical machined flat area for the rim brakes vs. the curved section.

Does it matter if I can't use the 19" nominal? I chose 20" and then the erd looks right but I need to be sure before getting spokes...

The "nominal" wheel size only affects the drawing, it won't change the spoke length calculation at all. So no problem doing that. It is a bit annoying having to set both the nominal value and the ERD when doing a custom rim though. We were considering having this so that the nominal OD is chosen automatically whenever a custom ERD is selected based on the nearest appropriate value, but there are cases with really deep aero rims where it would choose the wrong size. So a 26" aero rim can easily have a smaller ERD than a 24" normal profile rim.

-Justin

 

[John Bozi]

Not even distributors know what they are selling half the time. Not talking about you.

researching my erd I had 3 common choices 371 374 378 all saying its from the manufacturers specs! None of them were clear about eyelets or not. They all use pictures with or without eyelets they didn't take and often the pictures were with eyelets when they were selling without!

eg.

Hi John Bozi,

Thanks again for your question about the Alex DX32 19". The reply to your question can be found below:

--------------------

Question:

On the alex site its listed as 371 erd, are you sure about your 374?



Answer:

Hi John - thanks for your question, and thanks for pointing this out. To double check, I went and measured one in the warehouse, and they came in at 371mm. The 374mm came from the older version of the rim that featured eyelets, slightly increasing the ERD. This did not get updated when the un-eyeletted version arrived. I will update the site so that it shows the correct ERD of 371mm now. Thanks again! Flipp.

 

[justin_le]

Hey guys, we've pretty much completed "phase 2" of the ebike spoke calculator that might be worth having a look at.
http://www.ebikes.ca/tools/spoke-calc.html
(you may need to hit refresh on your browser to show the new fields if you've recently used the calculator)


Here's a list of the main additions

• Edge Drawing View now included to see sideways spoke angles
• Ability to shift the motor left and right for different dishing
• Ability to select spoke elbows to face either inside or outside the flange
• Ability to set the left and right spoke hole offsets in the rim (especially important with fatbike rims)
• Ability to swap spokes from the right flange to the left rim hole and visa versa for extra triangulation (also useful for fatbike builds)
• Breakdown of the tension ratio between left and right side spokes
• In context dimensioning of the critical wheel building measurements

There are a few more tweaks that we are looking to add, such as tooltips when the mouse hovers over a field, and a more realistic drawing of the edge view of the hub. But I'm hoping in general that this now provides everything people would need for custom lacing hub motors into rims with confidence. Let me know if you think there are any critical or just nice-to-have features that may have been overlooked.

Also if people also have specific motors and rims that they'd like to see in the database, and they have independent or confirmed measurements of the critical parameters, then we'd welcome any of those too to put in the list.

-Justin
Oh right, I should mention that we're still in the midst of collecting all the dishing information for the rear motors currently listed, at present in the database they all draw centered which isn't correct.

 

[madin88]

fantastic

 

[ebikedelight]

I have a quick question.

I want to try my 1st wheel build using a 26 " fat bike rim - 36 spokes and a 1000 watt rear brushless hub motor with a single cross.

Id like to keep this build as simple as possible and make all 36 spokes the same length , instead of having different sized spokes for the freewheel side . I dont even care if I lose the ability to use all the gears on my rear freewheel since this is a ebike and I wont be using the gears or pedalling much anyways .

Heres the ehub im using :

http://www.ebay.com/itm/291119531800?_trksid=p2059210.m2749.l2649&var=590270751129&ssPageName=STRK%3AMEBIDX%3AIT

Will I be able to build this wheel using these 5 simple stats to get proper spoke length :

1. ERD

2. measurement from center of ehub spoke hole to opposite center of ehub spoke hole

3. 36 spokes

4. 26" rim

5. 1 cross pattern

Or do I need to also measure ehub width or other things ?

I actually purchased a spoke threader , this way I can make my own spokes since I have 100s of donor spokes laying around and if I make a mistake on spoke length, I can just cut new spokes myself.

This ehub was made for 12-13 gauge spokes , but my donor spokes are all 14 gauge . Will 14 gauge be strong enough and where do I purchase the spoke washers to slip over the head of the 14 gauge spoke to seat it properly in the 12 gauge ehub hole ?

 

[justin_le]

I have a quick question.

Quick answer is that the 5 data stats you referenced are insufficient. You will also want to get the flange spacing of the hub (distance between the left and right spoke flanges, super easy to measure) as well as the left and right spoke hole offsets in your rim (also pretty easy to measure). If on the spoke calculator the spokes wind up going straight up and down rather than angled into each other with triangulation, then you will want to use the "Swap Spokes" option if simply putting the spoke elbows on the outside does not result in sufficient triangulation. This diagram illustrates the issue with a narrow flange hub motor like you have going into a typical fat bike rim, and the effect of the different lacing options in the spoke calculator:

Id like to keep this build as simple as possible and make all 36 spokes the same length , instead of having different sized spokes for the freewheel side . I dont even care if I lose the ability to use all the gears on my rear freewheel since this is a ebike and I wont be using the gears or pedalling much anyways .

Dishing actually has less to do with enabling the use of gears as it does with having the tire sit centered in the bike without it rubbing against the left or right stays.

This ehub was made for 12-13 gauge spokes , but my donor spokes are all 14 gauge . Will 14 gauge be strong enough

14 gauge is more than strong enough, and your rim will have spokes holes meant for 14g nipples as well.

and where do I purchase the spoke washers to slip over the head of the 14 gauge spoke to seat it properly in the 12 gauge ehub hole ?

Same place you would purchase any washers, from a hardware store or fastener supply shop.

 

[ebikedelight]

Thanks justin.

so you recomeend that with a 1 cross pattern, 36 spokes using a fat bike rim and ehub motor , it should be laced with all spoke heads on the outside of the hub
{ selecting " in option" for left and right elbows } , which makes the wheel much stronger ?

 

[ebikedelight]

Justin...fast forward this video to the 9:00 minute mark.

https://www.youtube.com/watch?v=CKrzp39XPVE


You dont advise lacing a fatbike rim with ehub using this method and think its better to insert all spokes thru hub spoke holes so the spoke heads are on the outside of ehub ?

 

[amberwolf]

You want it to be in whatever pattern gives it as much side-to-side triangulation as possible.

Without that, sideloading can cause wheel problems.