Need spoke length calculation for 1000W E-bike build (135mm QR)

[mor9060]

1000W E-bike build (135mm QR)
"Hello everyone! This is my first e-bike build. I'm converting a Cannondale Trail 8 using a ECCRIDE X1 Pro motor (high torque).
Since the bike has a 135mm QR rear dropout, I'm building a very strong custom wheel to handle the power. Here is the setup I've plan to purchased (all 36 Holes):

• Hub: Shimano FH-UR600 (Center Lock, 135mm QR).
• Rim: DT Swiss 535 29" (The STD VI version, ERD is listed as 603mm).
• Spokes: DT Swiss Alpine III (J-bend, 2.34/1.8/2.0mm).
• Nipples: DT Swiss Brass 2.0x12mm.
• Brake adapter:SHIMANO SM-RTAD05 Center Lock to 6-Bolt Disc

I'm planning a 3-cross lacing pattern.
Could any experienced wheel builders help me calculate the exact spoke lengths needed for the Left and Right sides? I want to make sure I order the correct sizes for this high-torque application.
Thanks for the help!"

 

[E-HP]

You can easily calculate it yourself, using the same tools that an experienced builder would use, given the measurements that you can research online or that only you can provide/verify through direct measurements (the hardest and most critical part).

If you are lucky, you could find an online spoke calculator that has your hub and rim already included, which would help avoid doing the measurements, but I'd always double check them, since spokes cost a bunch, especially if you make a mistake.

https://www.prowheelbuilder.com/spokelengthcalculator/

The Grin spoke length calculator works well for lacing hub motors, but the page also includes some good instructional videos that include measuring the rim, hub, and offsets. It's one of 3 calculators that I used to triple check the spoke lengths, given that spokes are so expensive. I double checked the ERD, even though the manufacturer listed it.

Online Spoke Calculator for Hubmotors and Ebikes

Our handy spoke length calculator allows for easy calculation of spoke length for custom builds - and is the only one of its kind to include paired spoke holes in the flange as is common with many large diameter hub motors. It also creates an automatic side view drawing of the laced wheel and...

ebikes.ca

 

[mor9060]

You can easily calculate it yourself, using the same tools that an experienced builder would use, given the measurements that you can research online or that only you can provide/verify through direct measurements (the hardest and most critical part).

If you are lucky, you could find an online spoke calculator that has your hub and rim already included, which would help avoid doing the measurements, but I'd always double check them, since spokes cost a bunch, especially if you make a mistake.

https://www.prowheelbuilder.com/spokelengthcalculator/

The Grin spoke length calculator works well for lacing hub motors, but the page also includes some good instructional videos that include measuring the rim, hub, and offsets. It's one of 3 calculators that I used to triple check the spoke lengths, given that spokes are so expensive. I double checked the ERD, even though the manufacturer listed it.

Online Spoke Calculator for Hubmotors and Ebikes

Our handy spoke length calculator allows for easy calculation of spoke length for custom builds - and is the only one of its kind to include paired spoke holes in the flange as is common with many large diameter hub motors. It also creates an automatic side view drawing of the laced wheel and...

ebikes.ca

Thanks for your reply I really appreciate it
If that possible you can help calculating the size base on internet sizes I'm not good at this and I'm afraid make mistake
About the hub and rim they are good choices for qr135 ?

 

[E-HP]

Thanks for your reply I really appreciate it
If that possible you can help calculating the size base on internet sizes I'm not good at this and I'm afraid make mistake
About the hub and rim they are good choices for qr135 ?

If all of the required dimensions are available, then anyone could plug the values into a spoke calculator; no expertise needed to do that. I’ve only built one wheel, so I’m no expert. Just providing the things I learned along the way. Unfortunately, one of the members that had extensive knowledge on these bicycle matters, is no longer on the forum.

 

[RunForTheHills]

I don't think you need to over-engineer the rear wheel for a 1000W mid-drive motor. The chainring, chain, and rear cassette will take most of the abuse from too much power to the rear wheel, not the spokes, rim, and hub. That said, wheel building can be fun to do. The tools can be a bit pricey, there there ways to make do without the tools. Or if you are uncomfortable with it, you can pay a shop $50-$75 labor to build a custom wheel for you. The calculation should be something like this:

Flange distance (mm) 55.7
Offset (mm) 7.45
P.C.D. left / right (mm) 44.6/44.6
Flange diameter left / right (mm) 53.5/53.8

Left Offset 35.3
Right Offset 20.4

ERD 603mm

 

[dgc]

Even Spoke Calculator - SAPIM use it all the time

 

[OlderGiantFan]

1000W E-bike build (135mm QR)
"Hello everyone! This is my first e-bike build. I'm building a very strong custom wheel to handle the power. Here is the setup I've plan to purchased (all 36 Holes):

• Hub: Shimano FH-UR600 (Center Lock, 135mm QR).

Out of curiosity, why are you going with a quick release rear hub? Wouldn't a thru-axle give you more strength and stability? I mean if you're building from scratch anyway.

Shimano 105 FH-R7070 CL Disc rear hub, Silver | Bikeinn

Get Shimano 105 FH-R7070 CL Disc in Silver for 81.49 $. Ideal for bike with fast delivery. Buy Hubs at Bikeinn!

www.tradeinn.com

 

[dgc]

Thro' axle would be better, but then it's a new frame. Take the QR axle out and fit a solid threaded axle. I have used a double spoke overlap setup with Sapim Strong spokes but only go up to 500 watts. Built a lot of wheels, including the odd motor bike wheel.