Are e-bike wheels different?
It can be quite hard to tell the difference between different types of wheels. Bicycle wheels are incredibly nuanced and it can be nearly impossible to tell a difference between wheels just by looking at them. Two wheels can even be built with identical components but one will work much better than the other. We will do out best below to show you what to look for and things to consider when buying your next set of wheels for your e bike. As always, if you have any questions you are always welcome to comment below or email us and we will try to answer any questions you may have.
We will address these key points in selecting wheels below
Bike rims come in countless sizes, shapes, weights and prices so it can be hard to pin down what is the best option for your riding style. Most of these points apply to standard bike wheels as well but are especially true with the added demands of e-bike wheels.
E-bike rims live a much harder life than those found on traditional bikes. The additional weight and torque from an e-bike absolutely puts more stress on a rim but more than all of that, the thing that makes things the hardest on e-bike wheels over traditional bike wheels, specifically in mountain biking is the fact it is MUCH harder to move the bike around and unweight it while going over obstacles. Because of this, the wheels tend to smash through objects rather than the rider being able to unweight the wheel while going over obstacles. For this reason, rims are one place we really want to go stronger on e-bikes if we are able to.
This is one place where you should take advantage of that electric motor and not stress over adding a bit of extra weight here and look for a stronger rim, especially if you like technical mountain bike trails. Some manufacturers label their rims as e-bike specific but you don't need a rim that is specific to e-bikes, those are really just beefed up trail rims typically. I usually look to put a person on rims for their e-bike that are marketed to one category stronger than I would for a non electric bike. So for example, if the customer is just looking to ride standard cross country trails I look for a rim marketed towards "trail" riding, if they want to do more aggressive "trail" riding I usually will look towards rims marketed towards Enduro riders, if they want to do enduro style riding I look more towards DH rims. If you are riding the road, you can typically get away with the same rims you would use for road riding, just plan on a few extra spokes.
Carbon or aluminum?
Both can actually work quite well here. Typically the main reason people go carbon is to save weight which isn't as critical on an e-bike since you have a little extra help getting things moving. If you really want to drop some weight from your e-bike though, because lets face it, e-bikes can get very heavy... Carbon is still a good call here. I would stay away from the stuff marketed towards lightweight race wheels and if given the option for a stronger layup I would take the stronger version but other than that, carbon can still work great for e-bikes and is plenty durable and safe to ride these days. If you want to level up your ride a bit, "compliant" rims like the Zipp Moto are actually a phenomenal fit here since it's not so easy to unweight the bike over obstacles.
I believe picking hubs is thankfully a bit easier than navigating rim options for e-bikes. While there are many hubs being marketed towards e-bikes specifically, many of the traditional hub options actually work fantastic for e-bikes too. Despite the additional torque from e-bikes, they really do not seem to be that much harder on hubs. I believe this is because the power on an e-bike is typically applied relatively smoothly. When picking out hubs, your budget is going to likely be the primary deciding factor as hubs are typically the most expensive part of a build unless you are looking at carbon rims. The difference in performance between mid level hubs like Hope and higher end hubs like I9 thankfully isn't huge and typically you are just paying for faster freehub engagement more than durability improvements so you can just as easily get away with a mid level hub like a DT 350 rather than spending $650 on the Industry Nine Hydra.
One thing I do believe is a nice option that some hub makers offer is switching from an aluminum freehub body to a steel freehub. Hope, DT, I9 and King all offer this and the minimal additional weight is more than worth it to protect from having your cassette dig into your freehub body. If you are riding the road you can likely get away with any hub out there, for mountain bikes, electric bike or not I am not a fan of cheaper hubs if you are riding even remotely hard. I've just seen far too many failures from cheap hubs on mountain bikes. I'd define cheap hubs as most options from Stan's, Formula, Novatec, etc.
Researching spokes is really easy to go off into the weeds but thankfully it does not need to be a difficult choice. It gets confusing as some spoke makers list things like tensile strength as a way to show how strong their spokes are but in reality, tensile strength RARELY matters when it comes to wheel durability. Fatigue resistance and "elasticity" I believe are much more critical components to durable spokes.
Fatigue resistance generally is hard to find real data on but is mostly a factor of material quality used and manufacturing techniques. Experience is helpful here but in general you can trust Phil Wood, DT, Wheelsmith pretty consistently to make a great product. Sapim can also be good but I have seen some consistency issues from them but most of the time they work well. There are other spoke brands out there you can look at but my experience with those other brands is limited to wheels I don't expect to be ridden hard. They might work just fine but when I am building for paying customers I like to stick with what I know works great every time.
For spoke type, my favorite spoke for nearly anything outside of race wheels is your common 14/15/14 gauge double butted spoke. They are reasonably priced, not super heavy and they last forever if you build them right. Bladed spokes like DT Aerolites or Sapim CX-Ray also work quite well but you are paying a lot more money for mostly just weight savings. If you really want to go over the top durable you can also look at spokes such as the DT Alpine III, it is a 13/15/14 gauge spoke although it is overkill for most applications and not all hubs will fit it without drilling so I tend to only use it for very harsh conditions like multi year loaded touring. The main thing I do not like to build with is straight gauge spokes, they are both heavier and less durable although you could argue, they make a marginally stiffer wheel. I believe the slight bit of additional "elasticity" from butted spokes helps them absorb impacts and tension spikes better along with taking a little stress off the rim. The easing the life of the rim is prominent enough that there are a couple rim manufacturers that will void your warranty if you build with straight gauge spokes.
Why are my spokes breaking? It's a common question and I'm sure a lot of you are wondering if you need a heavier duty spoke if you are having spokes break. The overwhelming majority of the time you really don't need heavier spokes. Spokes shouldn't break under normal riding which is why we always offer a lifetime guarantee against spoke breakage on all our wheels. We have built thousands of wheels and it is still EXTREMELY rare that someone brings us a wheel with a broken spoke that we built. Rare enough that I can count them all on one hand and our specialty is building wheels for riders who are very hard on equipment. Most spoke breakage issues come back to three key problems.
When a wheel is rolling with a load on it, the hub is essentially "hanging" from the spokes. This leaves the spokes at the top of the wheel at a slightly higher tension and the spokes at the bottom of the wheel at a lower tension. When you start with wheels that are under tensioned, the spokes on the bottom of the wheel can drop to nearly zero load and then bounce back up in tension as the wheel rotates. This movement is a lot like taking a coat hanger and bending it back and forth, fatiguing the metal until it breaks. Naturally this is bad and why we strongly believe that building wheels to the high side of your rims rated tension is key to durability. This is especially true when wheels will see a large load like with e-bikes, tandems, heavier riders, cargo bikes, etc.
Stress relieving wheels is a very simple yet surprisingly key part in building to ensure long life and no spoke failures. The act of stress relieving a wheel is simply grabbing pairs of parallel spokes and squeezing. Not only does this help seat all the components together but it also relieves internal stresses in the metal that can lead to excessive fatigue. Most metals have a sort of "memory" built in where when you bend them, they naturally want to go back to their previous position slightly. You can see this if you take a piece of metal and bend it, if you bend it to exactly 90 degrees it will spring back slightly because of this "memory" so to get it to stay at 90 degrees you want to slightly overbend it so it can relax to the desired position. Honestly though, I can't explain this nearly as well as Rick from Wheel Fanatyk, he was co-founder of Wheelsmith Spokes so he REALLY knows his stuff. He wrote a great article on the subject that I fully recommend you read if you like geeking out on this stuff. You can see that article HERE.
Poor Spoke Quality
This one is as simple as sticking to trusted brands that have a long history of delivery a quality and consistent product. Phil Wood, DT and Wheelsmith are my favorites here and I would group them all as nearly identical in terms of quality. Sapim can sometimes be very good but I have had a few bad batches of spokes from them that had 4-5 spoke failures within months. I rebuilt those wheels with Wheelsmith and they have not broken a spoke in years since. Other brands of spokes can absolutely be sufficient for your needs, again we are doing this professionally and like to stick with what we know works every time. If you are building your own wheels and want to experiment on your own wheels, I absolutely support that.
Build quality and wheel building tips
You can take identical parts and build one wheel that lasts for tens of thousands of miles from those parts and another wheel that falls apart in a few hundred miles depending on how they are built. This one is much harder to see a difference on and you absolutely will have a hard time knowing quality just looking at an online catalog but there are some questions you can ask your wheel builder to get an idea on how methodical they are in building their wheels. We will list some tips for building durable e-bike wheels below so you can ask your builder and see if they do similar. Even if they don't do things exactly like us, you can generally tell how much attention they pay to details and if they are happy to answer "why" questions and give thought out answers, you likely have found a good wheel builder. One other sign you found a great wheel builder is if they offer a great warranty on their builds.
Great wheel builders know that a well built wheel will very rarely have any issues and are happy to offer a warranty that represents that. If your builder tells you they don't guarantee their work and they tell you that you MUST bring your wheels back to be re-tensioned you should be hesitant. It's absolutely fine if they tell you that you can bring them back to be double checked after some miles but if you build the wheel well, it should not need the tension adjusted after a few hundred miles. If that was necessary then there would be no way we could ship wheels to customers who immediately put them on their bike and start multi year tours with us never seeing their wheels again.
Wheel building tips for e-bikes (these really apply to most wheels but are even more critical on e-bikes)
I hope this article helps demystify bike wheels a bit! Like I mentioned above, wheels are incredibly nuanced but thankfully there are a lot of different combos that can work quite well for most riders so there are very few "wrong" answers. If you have any further questions at all be sure to reach out and we will do our best to try and answer any questions you may have, even if you are not buying the wheels from us. You can use the contact form on our Custom Wheel page or email us by CLICKING HERE.
Thanks for reading!
Obsession, or passion? Who am I to judge? Either way I simply love building wheels for those who appreciate quality!