Spoke Length for a Retro Rim Mavic

[Big Bear Kona man]

Hi there,
Don't know if anyone can help me on this?, Ive just found my ultimate rims a set of 26" Mavic 217 SUP Sunset rims New Old Stock, and I need to purchase the correct length spokes for the hubs I'm planning on using.

Rear rim has 36 Holes and will use either a Shimano Deore XT 7 speed, Hub M730 or a Deore XTR M900
Front Rim has 32 Holes and will use either a Shimano Deore XT Hub M730 or a Deore XTR M900

was wondering if anyone can help me with what length spokes I would need?
Ive tried looking at the calculators, and the best one Ive seen hasn't got the details of the hubs I plan to use.

 

[rmwesley]

Hi,

You physically need the rims and hubs in your possession to calculate spoke length unfortunately. You need the following measurements:

1) effective rim diameter (ERD)
2) hub pitch circle diameter - left and right (PCD)
3) hub flange distance - left and right
4) hub spoke hole diameter

I would never trust the manufacturer's quoted ERD since it is actually dependent on where the wheel builder likes to leave the end of the spoke in relation to the nipple. For example, I'm building some H Plus Son SL42 rims at the moment and my calculated ERD was 4mm different to the spec quoted by H Plus Son.

I wouldn't normally trust the hub manufacturer's dimensions for 2) and 3) either since they are easy to determine yourself.

For 1) you need two spokes of equal known length, two nipples you wish to use in the wheel build, and a ruler (with 0.5mm markings).

For 2) and 3) you need a height gauge and a flat surface.

For 4) you can trust the hub manufacturer's dimensions since in reality it makes so little difference on the calculated spoke length.

So if you have two spokes, two nipples, a ruler and a height gauge let me know and I'll happily do another post on how to calculate the dimensions. If you haven't got them, I'd just ask the wheel builder to calculate it for you.

 

[Fourbikes]

I recently built some wheels with those rims and Shimano hubs and I used 262,264 and 265 mm spokes. My hubs are both 32 holes. I think most Shimano hubs have the same BCD (a bit bigger on the rear).

 

[Big Bear Kona man]

cool Thanks for the help

 

[FluffyChicken]

Yes, Shimano hubs are all the same. even the 6/7/8 speed doesn't really alter it enough at the rear to worry.

I think, but check . 259/260 for the 36 rear.
Probably get away with 260 for all, or better 258/260


Worth a check your ERD of the rim is 540mm though.

 

[nicgel]

Hi,

You physically need the rims and hubs in your possession to calculate spoke length unfortunately. You need the following measurements:

1) effective rim diameter (ERD)
2) hub pitch circle diameter - left and right (PCD)
3) hub flange distance - left and right
4) hub spoke hole diameter

I would never trust the manufacturer's quoted ERD since it is actually dependent on where the wheel builder likes to leave the end of the spoke in relation to the nipple. For example, I'm building some H Plus Son SL42 rims at the moment and my calculated ERD was 4mm different to the spec quoted by H Plus Son.

I wouldn't normally trust the hub manufacturer's dimensions for 2) and 3) either since they are easy to determine yourself.

For 1) you need two spokes of equal known length, two nipples you wish to use in the wheel build, and a ruler (with 0.5mm markings).

For 2) and 3) you need a height gauge and a flat surface.

For 4) you can trust the hub manufacturer's dimensions since in reality it makes so little difference on the calculated spoke length.

So if you have two spokes, two nipples, a ruler and a height gauge let me know and I'll happily do another post on how to calculate the dimensions. If you haven't got them, I'd just ask the wheel builder to calculate it for you.

Where do you like the ends of the spoke to end up? Flush with the top of the nipple when at the correct tension?

 

[nicgel]

At the same time I was wondering what people's experiences were with DT 535 rims for bicycle touring. I have a Shimano XT 737 hub and paired with a DT Swiss 535 with an ERD of 540 would give me 261 mm on the L and 259 on the R.

 

[rmwesley]

Where do you like the ends of the spoke to end up? Flush with the top of the nipple when at the correct tension?

In a perfect world, flush with the bottom of the slot rather than the top of the nipple.

In the real world, some will be spot on, some a bit short, some a bit long. That's just the way it is

 

[hamster]

Not tried the DT rims, but Rigida / Ryde Sputnik are generally the touring choice, they are a fair bit heavier, whic hfirstly makes a stronger rim but also gives a lot more metal to soak up braking energy without overheating.

Nice choice on 36 rear, 32 front.

 

[nicgel]

In a perfect world, flush with the bottom of the slot rather than the top of the nipple.

In the real world, some will be spot on, some a bit short, some a bit long. That's just the way it is

View attachment 624255

Perfect thank you. I thought that was the case.