Spokes.

[Leedspete]

I am going through spokes at an alarming rate. They keep breaking at the motor. Been told I may need a rebuild but what would best solution for rear hub motor. I.e spokes and rims.

 

[Nealh]

I use 14g s/s sapim strongs and generic rims from practical cycles , typically 20 quid a pair. I build my own wheels and apart from the first one or two many years ago have no issues with broken spokes.
If you get your rim and motor to ryanbuilds wheels he will do the job for you.

 

[Bikes4two]

I use 14g s/s sapim strongs and generic rims from practical cycles , typically 20 quid a pair. I build my own wheels and apart from the first one or two many years ago have no issues with broken spokes.
If you get your rim and motor to ryanbuilds wheels he will do the job for you.

What size rims Neil and what spoke pattern - 1x, 2x 3x?

Cheers.

@Leedspete -what wheel size and spoke pattern and who built/supplied the wheel you're having problems with?

 

[Leedspete]

I think its a 32 spoke 29 inch rim but not sure and its 3x on my bike. The wheel came fitted

 

[Nealh]

I use 36h 700c x 19mm rims and go only with 2x lacing otherwise the nipple angle entry is too great . Ryde z2000 blue rims from Bankrupt Bike parts not Practical cycles.
If using a large hub motor like BPM or CST then a 1x lacing may be better, it all depends on the nipple entry angle. It needs to be 6 degrees or less.

 

[Bikes4two]

If using a large hub motor like BPM or CST then a 1x lacing may be better, it all depends on the nipple entry angle. It needs to be 6 degrees or less [\quote]

+1 for that

 

[Leedspete]

I am really fed up with this bike now. Been told I need a rebuild and maybe a new rim as this could be causing my spokes to break. What rim would I need for a 700c ebike.

 

[Nealh]

Once spokes start breaking then yes it needs a rebuild and best to start from scratch, I have already posted on the rims I use that I am happy with and don't have issues.
One has to buy a rim with the same spoke hole count as the motor , so if your motor is 32h then you need a 32h rim , if 36h motor then you need a36h rim.

Simply start at the valve and count the spokes C/W .
Tell us the motor diameter or show us a pic of the motor but tbh I wouldn't go more then 2X lacing and use sapim strongs.
A spoke calc will tell you the spoke angle once the ERD of the rim and the motor details are in put , then one can see whether a 1x, 2x or 3x will be best.

 

[Leedspete]

ok gimme a sec.

Once spokes start breaking then yes it needs a rebild and best to start from scratch, I have already posted on the rims I use that I am happy with and don't have issues.
One has to buy a rime with the same spoke hole count as the motor , so if your motor is 32h then you need a 32h rim , if 36h motor then you need a36h rim.

Simply start at the valve and count the spokes C/W .
Tell us the motor diameter or show us a pic of the motor but tbh I wouldn't go more then 2X lacing and use sapim strongs.
A spoke calc will tell you the spoke angle once the ERD of the rim and the motor details are in put , then one can see whether a 1x, 2x or 3x will be best.

 

[Nealh]

The rim is likely ok if true, not buckled or cracked, look at each eyelet and check for any hair line cracks. If it looks ok then opt for new spokes to rebuild the rim with.
Who is going to build the wheel up ?

Usually one can remove good spokes and measure them carefully from the centre of the J bend to the tip to get the length in MM , though I also prefer to use a spoke calc to see that they are right .

For a spoke calc the two important measurements needed are the ERD and hub spoke hole diameter.
One can measure ERD carefully int two or three places to make sure one gets a similar measurement once the motor is out , measure the rim inside side to side from opposing holes and then add 5mm allowing for the rims material thickness.
Or one can simply apply a wrap of tape a round apair of spokes near the J bend , insert the other end in the rim and add a nipple so it is flush with end and pull the two spokes tight so the nipple sits correctly .
Then add three measurements together for the ERD, two measuerments are the spoke length form the nipple end to the end of each tape line on the spoke and the third measurement is the gap between end of the tape on the spokes when pulled together.


The rIm hole diameter should be fairly easy to measure using a compass or caliper tool in an opposing hole to get the spread width.

If the rim ERD measures differently form a few opposing holes then it may be out of shape and slightly eliptical so would be best to replace.

 

[Leedspete]

Thanks. Am getting local mobile mechanic to come pick the bike up on Tuesday and he will sort it. Hopefully once and for all. I did mention it to the place I brought it from but they weren’t interested and blamed me for the problems. Hmmm.
To tell the story I have nearly gone through a wheel full of spokes and its been doing my head in.

The rim is likely ok if true, not buckled or cracked, look at each eyelet and check for any hair line cracks. If it looks ok then opt for new spokes to rebuild the rim with.
Who is going to build the wheel up ?

Usually one can remove good spokes and measure them carefully from the centre of the J bend to the tip to get the length in MM , though I also prefer to use a spoke calc to see that they are right .
For a spoke calc the two important measurements needed are the ERD and hub spoke hole diameter.
One can measure ERD carefully int two or three places to make sure one gets a similar measurement once the motor is out , measure the rim inside side to side from opposing holes and then add 5mm allowing for the rims material thickness.
Or one can simply apply a wrap of tape a round apair of spokes near the J bend , insert the other end in the rim and add a nipple so it is flush with end and pull the two spokes tight so the nipple sits correctly .
Then add three measurements together for the ERD, two measuerments are the spoke length form the nipple end to the end of each tape line on the spoke and the third measurement is the gap between end of the tape on the spokes when pulled together.


The rIm hole diameter should be fairly easy to measure using a compass or caliper tool in an opposing hole to get the spread width.

If the rim ERD measures differently form a few opposing holes then it may be out of shape and slightly eliptical so would be best to replace.

 

[Nealh]

A badly built wheel no matter what you do will keep having issues , if the rim is fine then simply have all brand new spokes laced up . 14g sapim strongs in a 2x lacing as it is already.

 

[Leedspete]

A badly built wheel no matter what you do will keep having issues , if the rim is fine then simply have all brand new spokes laced up . 14g sapim strongs in a 2x lacing as it is already.

Gonna have to ride with one broken spoke for now. Just until I can get it fixed.