How to determine spoke length?

[p3eps]

This isn't specifically an eMTB question, but hopefully someone can help?

My daughter will be 9 in about 6 weeks. She's currently on a 20" Specialized Hotrock 20", which she had outgrown at the end last year.

She's a "girly" girl, and loves pink / purple / turquoise etc... and all her bikes so far have been pink so far. Unfortunately, the bigger kids bikes are more "generic" colour wise, so my best bet is to get something silver or white and customise it a bit.

I've been to my LBS and she's tried a few "big kids" bikes and also some XS adults. It seems the best option for her is a Specalized Rockhopper in XS. She's just on the lower limit, but that will give her some time to grow into it. Getting it in silver would give me the option to "hand me down" to my 4 year old son as he grows too... which is not something I've been able to do with the pink bikes!

ANYWAY... I intend ordering purple grips, bottle cage and pedals for the bike. She loves my Industry Nine wheels and has asked if we could do 'that' ( coloured spokes) to her bike. I wondered if I could remove 4 spokes on each wheel and replace them with purple?

Rockhopper Expert 27.5

Excuse the brag, but we’ve really outdone ourselves here. Proving that true trail-taming capability doesn’t have to come at an intimidating price, the R...

www.specialized.com

This is the bike I'm buying... but how do I determine which size of spokes to buy?
Is it as straightforward as ordering some spokes for a 27.5" wheel, or are there different variations?

TIA

 

[ThierryGTLTS]

This isn't specifically an eMTB question, but hopefully someone can help?

My daughter will be 9 in about 6 weeks. She's currently on a 20" Specialized Hotrock 20", which she had outgrown at the end last year.

She's a "girly" girl, and loves pink / purple / turquoise etc... and all her bikes so far have been pink so far. Unfortunately, the bigger kids bikes are more "generic" colour wise, so my best bet is to get something silver or white and customise it a bit.

I've been to my LBS and she's tried a few "big kids" bikes and also some XS adults. It seems the best option for her is a Specalized Rockhopper in XS. She's just on the lower limit, but that will give her some time to grow into it. Getting it in silver would give me the option to "hand me down" to my 4 year old son as he grows too... which is not something I've been able to do with the pink bikes!

ANYWAY... I intend ordering purple grips, bottle cage and pedals for the bike. She loves my Industry Nine wheels and has asked if we could do 'that' ( coloured spokes) to her bike. I wondered if I could remove 4 spokes on each wheel and replace them with purple?

Rockhopper Expert 27.5

Excuse the brag, but we’ve really outdone ourselves here. Proving that true trail-taming capability doesn’t have to come at an intimidating price, the R...

www.specialized.com

This is the bike I'm buying... but how do I determine which size of spokes to buy?
Is it as straightforward as ordering some spokes for a 27.5" wheel, or are there different variations?

TIA

Spoke calculator | Sapim

www.sapim.be

Have a Nice Day.

Thierry

 

[VWsurfbum]

I use an app on my phone called ingeniously named, "Spoke Calculator" and it does what it says on the tin.

 

[VWsurfbum]

Or you could message me with the measurements and i'll do it for you.

 

[p3eps]

Thanks guys... seems a bit more complicated than I was expecting.
Looking at the Spesh website, and then the Formula website - it looks like I'm lacking some info... that I probably won't get until I have the bike!
Might be worth asking the LBS if they can get this info for me... so that I can have spokes ready?

 

[VWsurfbum]

yeah need the hub flange measurements, and the ERD of the rim mainly

 

[deksawyer]

Just get some pink spoke covers, for gods sake!

 

[Dave_B]

when you get the bike, use a piece of string to measure the spoke from the hub to the rim, then add on about 5 to 6mm. that should give you a good enough spoke length.

 

[Shjay]

Industry nine coloured spokes are usually straight pull, the bike in question uses J bend spokes don’t think they come in many colours

 

[p3eps]

Industry nine coloured spokes are usually straight pull, the bike in question uses J bend spokes don’t think they come in many colours

Mine are straight pull aluminium. My EN315 wheels came with 2 different sized spokes as spares, and my EN325/310 set came with 2 other sizes for spares.
I wasn't suggesting getting i9 spokes - purely that she likes mine and has commented various times that she'd like wheels like mine!

I've found plenty of J spokes in purple... I'm just not sure what size to get.

 

[p3eps]

when you get the bike, use a piece of string to measure the spoke from the hub to the rim, then add on about 5 to 6mm. that should give you a good enough spoke length.

The LBS have a wheel builder, so I'll maybe just ask him to sort it for me. Good tip though - thanks

 

[p3eps]

Just get some pink spoke covers, for gods sake!

Would be easier... I've seen some heat shrink type covers that can be fitted.

 

[VWsurfbum]

I used coloured spokes for my own wheels.

 

[p3eps]

I used coloured spokes for my own wheels.

Looking good! That's exactly what I was hoping to do - either 2 or 4 coloured spokes round the valve.
Hopefully that'll be enough to shut her up

 

[VWsurfbum]

Looking good! That's exactly what I was hoping to do - either 2 or 4 coloured spokes round the valve.
Hopefully that'll be enough to shut her up

I used to ride with American Classic wheels and they used to do it, I love the look and whenever i do a standard wheel build for someone, one of my trade marks is to change the nipple colour either side of the valves.

 

[Shjay]

I always liked American Classics although never built a pair, as tended to go for which I could get at trade at the time

 

[p3eps]

Going back to this now the bike is actually ordered... and I have a pile of purple DEITY bits sitting on my desk just now, and a couple of Supercaz purple bits in the post!

I've never built a wheel or adjusted a spoke in my life, so please bare with me if I'm being stupid.

IF I figure out the spoke length, or even just wanted to swap the nipples for purple ones...
Can I just buy a spoke tension gauge, check the tension of a specific spoke, remove it / swap it, and then tighten it to the same tension as it was - without having to re-true the wheel? Spoke tension gauges seem to be about £20, so it'd probably be cheaper for me to buy one and do that myself than pay my LBS to do it.

 

[Bones]

You can use the tension meter. I personally just squeeze a couple of spokes and you can easily tell if they are too tight or loose. Once the wheel is straight and not egg shaped the spokes will be pretty much all the same tension anyway.

 

[VWsurfbum]

Doing it by tesion would be massively inaccurate.
If you do it nipple by nipple, wheels in the fram/fork with a secured tie wrap (cut down to the edge of the rim) against the rim so you can tell if you need to get it tighter / loosen to the tie wrap edge. (set up prior to removing any nipples)

 

[Bones]

Doing it by tesion would be massively inaccurate.
If you do it nipple by nipple, wheels in the fram/fork with a secured tie wrap (cut down to the edge of the rim) against the rim so you can tell if you need to get it tighter / loosen to the tie wrap edge. (set up prior to removing any nipples)

I had to read that twice before it clicked what you meant.
I also use the frame to set up any dish that's needed.
I also stand on the rim and carefully move the other foot around the rim to de-stress the spokes and it seems to work quite well. Something I watched on YouTube.

 

[p3eps]

Doing it by tesion would be massively inaccurate.
If you do it nipple by nipple, wheels in the fram/fork with a secured tie wrap (cut down to the edge of the rim) against the rim so you can tell if you need to get it tighter / loosen to the tie wrap edge. (set up prior to removing any nipples)

OK - I think I'm following...
Use the bike as a wheel truing station - the zip tie should be cut to touch the rim (on either side I assume?) and as I rotate the wheel I can see if it touches the zip tie or not.

Just wondering - how swapping them 1 by 1 and setting them to the same tension as the previous one is inaccurate? I'll take your word for it... but I'm curious!!

 

[Bones]

I actually use a piece of wood for the back wheel. Sat on the chainstays and mark the centre and rim width.
It's quite easy to see how far out you are. Once it's fairly straight then sort out the egg shape then the dishing.
You soon get the hang of undoing one side half a turn and tightening the next one half a turn to keep it in line.
Or with the oval part, undo or tighten a few equally .
Dishing is similar, undo all one side half a turn and tighten the other side half a turn until your happy
Never used a tension meter.

 

[VWsurfbum]

Just wondering - how swapping them 1 by 1 and setting them to the same tension as the previous one is inaccurate? I'll take your word for it... but I'm curious!!

because the tensioning meters give you wildly inaccurate readings unless you have a mega-expensive digital one.

 

[scrufy]

Why not just get a couple cans of spray paint, a roll of masking tape, and a newspaper?