What spec MTB wheel for my ebike to prevent spokes breaking

[callagga]

Hi

my current back wheel must not be solid enough for my 4-5kg battery at the back as I get spokes breaking.

What spec MTB rear wheel for my ebike should i go for to prevent spokes breaking?

Thanks

 

[voicecoils]

Easy, good quality spokes and a strong rim.

Here's one option:

Spokes:
Cut to length 13ga/14ga single butted Phil Wood spokes from ebike.ca:
SPCust13

Disk specific downhill rim:
Mavic Ex 729 Disc Rim

Once you've got it all together, find a good wheelbuilder to lace it up, prestress and correctly tension. Ride a few hundred kilometers and bring it back to the wheelbuilder once everything's settled and seated and have them true and tension again. Then you'll have a very strong wheel.

 

[317537]

Sometimes spoke are too tight. I tune my down. Yes tune them by sound. Flick your spokes with you finger and listen, listen to the ones that are higher in pitch and lowest in pitch make a balance between them so they are all close in pitch, as long as you keep the rim straight you only have advantages .


My spokes are pretty lose now compared to how they were. Thbey dont break anymore either. Oil them before adjusting.

 

[317537]

I think its more to look out for lose spokes and the tight spokes that make up for the lose spokes. When one spoke is lose another spoke or spokes needs to be tighter to bring the rim true. Just tightening some lose spokes or lossening others isnt the whole picture.

Even if an unchewed rim isnt true the spokes should all have very similar tone to them when chewed up onto the hub. Where you get one really low toned spoke you can bet you will find either one or two that are over tightend to compensate, here is where you going to get a failure.

On the other side of the field of things if you have one tight spoke you may find the opposite spoke just as tight to compensate, this egg shapes the rim unless the 45, 90, 180, 225 -deg angle opposite and adjacent spokes are tight too. So dont go around making them all tight. Try the opposite. Oil up your nipples and go around and losen the whole rim until the rim wobbles.

Spin the wheel and set the centre by tightening nipples and make it as true as you can. Check spoke tension by tone and compensate as little as possible. Take it for a hard ride and true the rim again.

 

[callagga]

Spokes: Cut to length 13ga/14ga single butted Phil Wood spokes

oh - I'm used to the spokes where they seem to have to be the right length to start with? i.e. with the thread at one end, and the curled/hooked end thing at the other

 

[callagga]

Once you've got it all together, find a good wheelbuilder to lace it up, prestress and correctly tension. Ride a few hundred kilometers and bring it back to the wheelbuilder once everything's settled and seated and have them true and tension again. Then you'll have a very strong wheel.

BTW voicecoils - so you think in general you can't really find an off-the-shelf wheel at a bike store that would have a reasonable rim and the spokes you're suggesting? (I've got no idea at the moment) In other words to carry the weight we're talking about for an ebike you do typically need to "roll-your-own" wheel? I was hoping to be able to drop into a typical bike store and say give me a wheel with a rim size of X and spokes of rating Y, but perhaps its not that simple?

 

[317537]

Spokes: Cut to length 13ga/14ga single butted Phil Wood spokes

oh - I'm used to the spokes where they seem to have to be the right length to start with? i.e. with the thread at one end, and the curled/hooked end thing at the other

Get your old spoke, measure it, and have them cut them for you is what he means.

I use 12ga on my current hub. Go for the 13ga as the lower the ga (gauge) the thicker.

But when you get these spokes how do you plan to install them? You coulkd make your problem worse.

 

[317537]

Once you've got it all together, find a good wheelbuilder to lace it up, prestress and correctly tension. Ride a few hundred kilometers and bring it back to the wheelbuilder once everything's settled and seated and have them true and tension again. Then you'll have a very strong wheel.

BTW voicecoils - so you think in general you can't really find an off-the-shelf wheel at a bike store that would have a reasonable rim and the spokes you're suggesting? (I've got no idea at the moment) In other words to carry the weight we're talking about for an ebike you do typically need to "roll-your-own" wheel? I was hoping to be able to drop into a typical bike store and say give me a wheel with a rim size of X and spokes of rating Y, but perhaps its not that simple?

It's simply not that simple.

To go to ebike.ca isnt a bad suggestion. Then maybe get a shop mechanic to rim your hub.

One shop was going to charge me over $200 and they had as much luck as me getting 12ga spokes. I prolly would of ended up with some 15ga kitten whiskers.

 

[callagga]

thanks

I just noted at http://www.ebikes.ca/store/store_motors.php they talk about the Crystalyte 12ga that they now use, but note there may be some issues with compatibility. What do you think? Sounds easier to stick with 13ga if it's going to be a lot better with the standard spokes I got on my inexpensive MTB?

BTW - Do you think it would be a reasonable approach to just trying the better spokes on my existing rim? i.e. avoid forking out for a rim as well if I'm not sure it's the issue? (again I've pretty much got an inexpensive older MTB)

thanks again

 

[317537]

thanks

I just noted at http://www.ebikes.ca/store/store_motors.php they talk about the Crystalyte 12ga that they now use, but note there may be some issues with compatibility. What do you think? Sounds easier to stick with 13ga if it's going to be a lot better with the standard spokes I got on my inexpensive MTB?

BTW - Do you think it would be a reasonable approach to just trying the better spokes on my existing rim? i.e. avoid forking out for a rim as well if I'm not sure it's the issue? (again I've pretty much got an inexpensive older MTB)

thanks again

Out of my expertise here I dont own Crystalyte but I will guess chewing a set of 12ga isnt easy on any hub or rim. They are pretty thick and you may need to bends them lots to get into the right position past the flanges. I know I had some very U shaped spokes putting them on my golden hub, worth the headache IMO.

 

[fifthmass]

My experience with a Chrystalyte wheel and the 12 guage spokes has been very good. I had the vendor (Electric Rider) rebuild my front wheel after it was trashed in a crash last May. 2,000 miles later it's still dead true and all spokes same 'tone'.

However when I first got the wheel a year ago the spokes had to be tightened after the first 100 miles. I don't know what the difference was between the original and the rebuilt wheel but the rebuilt is doing great.

Bill

 

[Drunkskunk]

thanks

I just noted at http://www.ebikes.ca/store/store_motors.php they talk about the Crystalyte 12ga that they now use, but note there may be some issues with compatibility. What do you think? Sounds easier to stick with 13ga if it's going to be a lot better with the standard spokes I got on my inexpensive MTB?

BTW - Do you think it would be a reasonable approach to just trying the better spokes on my existing rim? i.e. avoid forking out for a rim as well if I'm not sure it's the issue? (again I've pretty much got an inexpensive older MTB)

thanks again

the Clyte 12 guage is a weaker spoke than the 14 guage DT Swiss or Phil Wood, even though the 14 guage is thinner.

Having a wheel built is the best route. However, you can get an off the shelf wheel from a bikeshop.. maybe.. if they are a good shop. you will need a wheel built for a Touring Tandem. 36 spoke or more, with a name brand, not generic spoke. Expect to shell out $200 or more. Getting one built can be cheaper.

you can also try to reuse your rim, but if it's a generic department store type rim, then you're going to find having realy strong spokes in a weak rim is just as much of a problem.

 

[etard]

I have been struggling with this same question myself. I want a good strong, wide rim laced to a decent hub for less than $100. Just simply not gonna happen. After many hours at http://www.jensonusa.com, http://www.mtbr.com and eBay, I came to the conclusion that while there are rims better design for sturdiness, and some designed to be light, you will always find some rider that "tacoed" thier rim and blame weak design while ten other guys will ride on the same rim for years without issue. So I think it all comes down to a properly built and tensioned rim, no matter the spoke gauge ( to a point) will last a long time if regularly checked for loose spokes. Also, I came to the conclusion that it seems to be an art that only certain bike mechanics are born with and get paid well because of this.

Since it sounds like you have a cheaper bike, I assume you need rim brake specific wheels. I have found the Rhyno Lite rim by Sun Ringle to be the best bang for your buck, add those Phil Wood spokes and a half decent hub and you should have a wheel that will give you trouble free service for a long time, IF it is built right from the beginning.

I agree with Drunkskunk, thicker gauge doesn't necesarily mean stronger. I'm guessing you want a little bit of flex here and the 12 gauge would rather break than bend ?

 

[E-Ticket]

All,

(I had just composed this post offline and intended to start a new thread, but just saw this similar thread, so here goes...)

I've ridden about 1,500 miles over the past year, with commutes/joyrides typically of 30-50 miles RT over reasonably decent pavement. Riding and tinkering on my e-bike has brought me much satisfaction. Unfortunately, I'm also experiencing ongoing frustration with repeated spoke breakage. Unfortunately, every 50-100 miles, another spoke or two fails - always at the hub flange, typically on the freewheel side. I'd really like to get this issue resolved so I can fully enjoy e-riding!

Reading accounts of others running similar and much higher-powered rigs with 14ga spokes and never facing any breakage issues while launching off curbs, etc., has me a bit dumbfounded.

My e-bike is an aluminum hardtail 26" MTB with F/R disk brakes, a rear 26" 9C, and a triangle-mounted Ping 36V/20AH. Total weight, including rider, is about 230 lbs.

Using techniques gleaned from online postings and personal experience, I've rebuilt the wheel for strength using a Sun Rhynolite rim and 169mm Wheelsmith DH-13 spokes. Attempts have been made to minimize the rim offset by dishing the wheel somewhat, with all spoke elbows currently facing the freewheel side. I've carefully trued the wheel on a stand. The freewheel-side spokes produce a fairly even pitch when plucked, while the non-drive spokes have lower tension. Previously, I've also tried using small washers to shore up clearances at the large-ish hub flange spoke holes, with some apparent success. Might the left spokes need to be tighter to minimize spoke flex, fatigue, and failure? This tends to counteract the dishing.

Hoping to cushion the shock a bit, the rear tire was just switched from a Forte Gotham 26x1.75 @ 60psi to a Schwalbe Big Apple 26x2.15 @ 40psi. I still managed to break a spoke on its first 30 mile ride. Did encounter a couple nasty bumps while exploring a new path where tree roots had buckled the pavement, but I'm not sure if that was responsible for the break.

I've constructed new dual 48V/10AH Headway packs to mount to the sides of the rear rack, but I'm concerned the additional weight may only compound the spoke issues.

Comments, suggestions, advice, pity...?

Thanks!

 

[voicecoils]

Once you've got it all together, find a good wheelbuilder to lace it up, prestress and correctly tension. Ride a few hundred kilometers and bring it back to the wheelbuilder once everything's settled and seated and have them true and tension again. Then you'll have a very strong wheel.

BTW voicecoils - so you think in general you can't really find an off-the-shelf wheel at a bike store that would have a reasonable rim and the spokes you're suggesting? (I've got no idea at the moment) In other words to carry the weight we're talking about for an ebike you do typically need to "roll-your-own" wheel? I was hoping to be able to drop into a typical bike store and say give me a wheel with a rim size of X and spokes of rating Y, but perhaps its not that simple?

Bikeshops often have bike mechanics who are good wheelbuilders but some don't. In some ways wheelbuilding is a dying art because many manufacturers have machine built wheels that are actually very good.

I've found that many bike shops are not interested in going out of their way for ebike riders. Some just don't like to deal with anything they're not familiar with.

Many bikeshops will have tandem/touring or tough mountainbike rims that are going to be sufficient on an ebike. If you can find a bike shop that sells things like touring bikes, commuter bikes, cargo bikes, longtail bikes etc they have probably thought 'outside the box' before to help their customers and may be more likely to take on a new challenge.

Every time you hit a bump on the road, the extra weight in the hubmotor will create extra force smashing the wheel back to the ground like a hammer. That puts extra stress on the wheel. It's not a obstacle that can't be overcome though, just a design consideration.

 

[voicecoils]

Spokes: Cut to length 13ga/14ga single butted Phil Wood spokes

oh - I'm used to the spokes where they seem to have to be the right length to start with? i.e. with the thread at one end, and the curled/hooked end thing at the other

By custom cut I simply mean the spokes will arrive at a length you specify. Phil Wood make excellent quality spokes and since hubmotors often force you to use hard to find spoke lenghts, ebike.ca cuts the spokes to the length you specify and rolls the thread onto the end.

A single butted spoke means that the hooked end is thicker in diameter then the rest of the spoke. That gives it extra strength so that it does not snap off at the head or bend.

 

[voicecoils]

Comments, suggestions, advice, pity...?
Thanks!

You may need a set of longer spokes on one side and shorter on the other to achieve the dish you want for a centred wheel.

I'd suggest you build the wheel and take it to a bike shop and ask them to true it, tension it and pre-stress. The ride it 100-200miles and go back and get them to do it again. With a good wheel builder's experience, a good truing stand and a tension meter they'll get the best result.

I took my red bike's front hub wheel to a bike shop to have this done, it cost $15. Well worth it IMO.

 

[dequinox]

So I returned my sh!7y a$$ wheel to REI...and got myself a nice 36 hole touring rim with DT spokes and a nice deore hub. I got it for $150, so hopefully no more busted spokes for some time. I just had to show somebody :

I will let you all know if it starts messing up or if it lasts 'till Armageddon.