How to Measure Hubs and Rims for Perfect Spoke Lengths, Ebike Hub Motor Wheelbuilding
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- čas přidán 29. 10. 2021
- If you are lacing a hub motor that's not in our dropdown list, you'll need to input things like the rim ERD, the hub flange diameter etc. This video shows how you can measure those values for your particular parts without using any special calipers or shop tools, just a measuring tape and some flat surfaces.
See: ebikes.ca/tools/spoke-calc.html for our actual spoke calculator page.
Robert is our resident wheelbuilding pro here at Grin, and his last video showing how to lace a hub motor without all the special lacing tools shop proved to be quite popular. We're hoping this video further helps people do their own wheelbuilds by getting their spoke lengths right the first time. - Věda a technologie
Your single-cross lacing video was perfect, I laced your new motor to my old wheel and it was made easy by following the instructions. Grin is an impressive company.
Just when this old bike mechanic thinks he knows everything…it turns out he doesn’t 😊. THE BEST TUTORIAL I’ve ever seen. Incredible tips and info. Thank you.
Watching a real pro in action is oh so satisfying 😊
Don't give up on wheel building. It may seem intricate, but it REALLY is a matter of paper and pencil and about six measurements that you poke into a web site form (that has many cells, and you ignore half of them) and you will have your spoke lengths.
1. OLD (OUTER LOCKNUTS DIMENSION)
2. LFL-OLD (LEFT FLANGE)
3. RFL-OLD
4. FLD (DIAMETER, HOLE TO HOLE)
5. FL-FL (R-FL TO L-FL DISTANCE)
6. ERD (EFFECTIVE RIM DIAMETER - from where a spoke fastener head sits on the rim, to the opposite spoke fastener head)
7. SPOKE D (memorize standards)
8. SPOKE HOLE D (memorize standards)
9. XP (CROSS PATTERN) (not a measurement)
This simple list has taught many to build their first wheels in 3 hours, box-of-parts to on-the-road. As you build, the pattern becomes natural, and this (excellent) video shows more detail. There is a "wheel builder" book out there 250 pages long... that I boiled down to one page to help people start. Building wheels is the key to bike building freedom. You never have to wait for a set to become available from a vendor. Find your local bike co-op and bring your numbers.
Remember: The video was edited for quick viewing to hold your attention, so pause and draw pictures rather than trying to eat the whole elephant in one go.
Above all; Blind Bob eats, sleeps, and f.... breaths wheels to within 1/2 millimeter. You (all) can fudge 2 mm long or short and still build solid wheels.
Ssbpo
Thank you, Robert! You are the best.
Hey Robert! Nice seeing ya buddy!
Yeah, imma just gonna buy a new motor, rim and spokes from you folks. The lacing and truing I really enjoy but this is some next level alchemy. I’m glad I watched it though so, come a zombie apocalypse, I’ll have a clue as to becoming a wheel wizard.
I feel the same way. Robert is my world-wide e-bike wheel guru whether he knows it, or not.
What a huge help, thanks for the very informative video, and the laugh!
Super helpful and clear to follow ❤
Robert has a way better handwriting than I do!
Love the glasses dude!
Thank you! Thank you! Thank you!!!
Your A great help thanks
FYI. You can buy a set of callipers for like $10.
Thank you
The wheel boss 💪🏽😎💯
I found a ebike kit I like but want a wider rim. So probably just going to grab some spokes and attach to my original mountain bike rim.
is the offset (l-r)/2 =offset, backwards by chance? your smaller number 44 had 51 for the brake freewheel side seem interfered? or am i crazy? should it be (r-l)/2= offset, not (l-r)/2. i assume this is from the perspective of sitting on the bike and the left side is the brake side and right is freewheel side.
I hope this helps me, I got an e-scooter but I think I want to build a fatboy bike out of the guts. So I got to fit the hub to a different rim.
Thanks for this explanation... it means, then, that I cannot convert a rear hub wheel to a front wheel without actually changing the spokes ... damn... lost 4 hours trying to do it and failling because the spokes are too short on one end... damn
They do actually make extended length nipples that can in some cases help with situation of spokes that are too short. But the main reason you can't usually convert front to rear is that axle lengths of the hubs are totally different.
But the
ROBERT!! You saved my ass bro, then caused me to LMAO twice now! Please keep the vids and the cursing coming! Luh you man! Whooo! Grin tech!!
Does the calculator give proper spoked for wheel with more spokes that motor? Thanks
There are some tricks you can use if you are lacing wheels that have a large common divisor, like a 48 spoke rim can sortof be laced in a 36 hole motor, or more commonly you'll see like a 24 hole rim and 36 hole motor (where you skip every 3rd spoke hole in the flange). But if you've got like a 32 hole in one a 36 holes in the other you are out of luck.
Hi. Do you ever suggest using washers to seat the spoke head against the hub nicely?
We'd recommend this if you are using conventional straight 14g spokes as most ebike hub motors are drilled our for 13 gauge. But no need if you are using butted spokes that are 13g at the head and taper to 14g toward the nipple. That had the benefit of a stronger spoke too, and is what we recommend and sell.
@@GrinTechnologies much appreciated!
@@GrinTechnologies Hi do you measure up to the washer? Mine has a lock nut on both side with a washer/spacer @3:26 Thanks
Hey Grin Tech. When will you have the phase runner in stock and also, which one do I need for the bafang BBSHD 03?
Regards Paul.
Cheers Grin.
Accelerated Systems Inc was very helpful, yes it cost me more but the service they provided helped me buy from them.
@@paulspyker3749 You should ask yourself why it cost more to get the same thing Justin sells, from the manufacturer he buys from.
Couple mins in, as he's measuring the diameters, it was stated as 190 mm OD minus the 13 mm to get the diameter that the spoke holes are at. I got all that until he said that equals 187 mm. What am I missing? Was the motor OD actually 200 mm??
Nice catch! This was definitely a slip-up from doing math under video pressure. The correct result should have been 177mm not 187mm and all final results are off as well. Luckily no actual spokes were cut to incorrect length during the making of this video ;-)
I have a 1983 Fuji Espree. Front wheel is 27” using 1 1/8 inch width tire. Can I use a front hub motor without bending my fork? How skinny can the motor be? I can build the wheel if you supply parts.
All the front hub motors are meant for 100mm spaced dropouts with 10mm wide slots. If your slot is more like 9 or 9.5mm then you'll have to file it open to 10mm for the hub motor to fit in, but that's not a big deal. You don't have to bend the fork in any case. All the CAD drawings and dimensions for all the motors are on our website. Usually for a road bike the G311 or SX1 hubs would be recommended. See czcams.com/video/qHj3Qk5Whfo/video.html
@@GrinTechnologies good. I measured 4 1/8” or about 104mm between the front dropout forks. Good!
I always knew Roy Orbison would find a bright new career once he retired from singing.
Haha he loves the work but misses the fans.
hello Robert, thank you for the video. I have an issue rebuilding my friends wheel for a cargo bike. is a 24 inches and the ehub is small,flange diameter 115,5mm with 3mm spoke hole. I can put my hands on quadruple butted pillar spokes 2,5-2,3-1,8-2,0mm and thinking to lace it on 3 cross. Is difficult to get in scandinavia sapim strong spokes, or to buy them online on the desired length. Don´t know how to make the decition if to stick to 3 cross that is the one I am used to or just 2 cross. Whats your opinion on this combination of spokes and lacing pattern? thank you again for your time.
Hi question,i have snap my axle/spindle of my geard drived hub,and i was looking to find a new spind to replace it ,the rest of the up is great only the spindle has broken i have completely disassembled the hub down to the axle and have remove both axle halfs with a press,but cant not find any dealer to sell me a new spindle,its the "ez" type hub but not the exact brand ,i was wondering if you guys know of a seller or can sell me a new axle,im considering welding the axel back together but if you have axles for sale please let me know✌✌,its from a read lock nut type hub
It is not an easy thing to find a replacement axle for a random make and model of hub motor. None of them are interchangeable, and usually the axle itself is not considered a user replaceable component so it's not a part that is stocked by dealers. Your best bet would be to scavenge one from an identical motor that isn't working for other reasons.
Have you ever added a hud motor to a mongoose 3” fat tire bike. It’s an odd size hud and wheel thickness. There in the middle of a standard hud and wheel thickness and a 4” fat tire hud and wheel thickness.
Measure your spacing of the dropouts and the width and diameter of the rim and we can tell you if we have comparable sized hardware for that or not.
So this calculation method goes for all offset hub right? Both front and back?
Yes indeed, you can use this technique to measure front or rear hubs.
@@GrinTechnologies Thank you so much buddy. I wish you a great day!
I have a trike hollow hub with no axle. There’s no way I could measure the way you are. Is there a specific website or way to calculate spoke size for hollow hub?
It's really no different whether you have an axle present or not. The axle just comes into play if you have a dishing offset but for a trike you'd generally just lace it centered between the flanges with no dish.
@@GrinTechnologies Would you kindly give me a website that calculate hollow hubs to determined spoke size? All the websites I gone to are only targeting hubs with axle.
Can I use a Mechanical pencil to measure?
Anything with a writing point that is concentric with its body will do the trick.
2:02 minus the radius of the pencil !!! 2:52 OK it is here
I have a hub motor can I just send it to you to be laced
We're not quite in the "lace a random motor" business, we only do this on the motors we sell. But if you watch this video too
czcams.com/video/3OialWggZJo/video.html
No reason you can't do it yourself.
I just found out that even accurate calculation is not really accurate. I ended up with wrong spokes which I purchased online and went according to the online calculation which it was deemed accurate.
I think i screwed this up. My spokes came about 2 mm too short. It's very difficult to get an accurate measurement. I could not find a vernier caliper this large
You can still use spokes that are 2mm shorter than they should be. But if you mean that they are 2mm shy of even reaching the nipple, then yeah you really messed up in the measurements somewhere!
@@GrinTechnologies no you can see a lot of visible thread on half the spokes. The wheel is at full tension. Any more tension risks cracking the rim
WTF is this guy
WTF is this comment