Confirmed ERD of Zac 2000 559 rims - anyone know?

[sarniacycle]

I'm trying to build my first wheels with help from Roger Musson's book where he says to wait and measure up the actual rims as manufacturer's details are often wrong. But, I'm keen to get going and also want to get rims, spokes and a few other bits altogether as cheaper/easier.

Ryde website says ERD = 532mm
SJS website says ERD = 533mm (with a note at bottom that they disagree with supplied info)

I'd be interested to know if anyone here can confirm ERD of these rims and also if I'm being silly and should do what Musson says i.e. wait and measure the actual real-in-hand rims.

Many thanks.

[alexnharvey]

I wonder, given it's only 1mm difference between the two quoted ERDs and therefore ~0.5mm per spoke, have you checked if it will make any difference to the length of spokes you would want to order?

I quite often find that spokes are so much cheaper from one of the mail order specialists that I end up getting them from a different supplier than the hubs and rims anyway though.

I recently dis- and reassembled a wheel with slightly too short spokes for a similar reason (not checking hub flange diameters and spacing carefully between two very similar Shimano hubs).
I now have a set of 'built but not used' spokes which I will probably struggle to sell. (Araya, black, stainless, PG 182mm!).

[Mick F]

Buy your rims and your hubs.
Measure them yourself. Do not rely on anything you read.

When you're happy .................... remember to measure at least twice to make sure ..................... then buy the spokes.
Use a few on-line spoke calculator websites to get a consensus. Don't rely on one single one.

I find it difficult to get the lacing correct first time. It's so easy to get the valve hole in the wrong place.
Found this YouTube video some time back when I made my new wheels for Moulton, and it makes it oh so simple, and it works for 28h and 32h too.

https://www.youtube.com/watch?v=mIU6mi0K4Y4

[Brucey]

Ryde usually quote NSD (Nipple Seat Diameter) as if it is ERD, and it ain't. You normally need to add 3-4mm or so onto the NSD figure.

ZAC 2000 measured ERD values are normally around

BSD - 22mm = ERD

where BSD is the ETRTO rim size, so

for 700C; 622-22 = 600mm ERD

for MTB 26"; 559 -22 = 537mm ERD

However note that rims can be made with size variations (due to manufacturing tolerances) and in addition that Ryde often make the same rim with no eyelets, single eyelets or double eyelets, all of which have slightly different ERD values. So yes, you are well advised to measure your rims and see what size they really are; that will be the only 'confirmed ERD' which matters.

cheers

[sarniacycle]

Ok, so the lesson is patience, then! I'll do that i.e. get rims first and then measure. Thank you all. And for the video (she's extremely clear, v helpful) and other pointers too. All the best.

[peetee]

You are referring to 26” rims but if it’s any help I have just built up a pair of these in 700c and going by their listed ERD and using Sapim’s spoke calculator I used spokes 2mm longer and they were spot on.

[Brucey]

peetee's observation tallies with Ryde's quoted value being NSD and ~4mm shy of a proper wheelbuilding ERD.

cheers

[peetee]

peetee's observation tallies with Ryde's quoted value being NSD and ~4mm shy of a proper wheelbuilding ERD.

cheers

It was purely based on a hunch that I chose that length. I saw Sapims calculations, looked at the rim cross section and thought, that seems a bit short. Either way, the nipple does sit quite deep in the rim in comparison to other rims I have built with.
Incidentally I was initially quite disappointed in these rims. The quoted weight on the site they were bought from (a reputable west-country retailer) was way below the actual weight.
With the build underway there was a pronounced edge at the joint that caught on the radius gauge on the jig. This persisted right to the point where I stress-relieved the wheel the first time. Another quarter turn, a stress relief and final tiny tweek and all was well.

[TheBomber]

I have a couple of 559 Ryde Zac 2000 SEs (both with eyelets) and looking back at my notes I have the ERD recorded as 535mm for the rear and 536 for the front. They were bought at different times - initially the rear to re-rim a wheel where the brakes had worn through and later the front to build a hub dynamo wheel. I suspect the 535mm value came from a spec sheet somewhere as I was attempting to replace the split rim using existing spokes. The 536 is more likely to be the value I measured myself.

As both of these values differ from what you have read it looks like you will have to wait and see though, annoying though that is. If it's any consolation I've found them to be great rims.

Edit: having read the other comments on this topic maybe my numbers do fit in - as long as we assume that Ryde are actually quoting a NSD value. I measure with a couple of old spokes which have the nipples glued onto the threads exactly where I’d like the spoke to end up once the wheel is built.

[sarniacycle]

Thanks peetee TheBomber and Brucey - I'm learning lots from this.

I've ordered the rims and will measure, then post findings here.

All the best.

[Brucey]

I stumbled across a 559 type ZAC 2000 rim in a wheel and I thought it might add to this puddle of knowledge if I measured it.

Now, ZAC 2000 rims can appear with Rigida, Weinmann, or Ryde branding on them. One would expect that the rigida and ryde versions are the same but they have moved factories more than once, so who knows? This one was eyeletless and weinmann branded. From the spokes used (which were too short) I calculate the actual ERD (for spokes that would finish flush with the nipple tops) is 539mm. If built to ERD of 537mm the spokes would come flush with the nipple slot bottom. Whoever had chosen the spokes in this wheel had presumably assumed it was 535mm and all the spokes were at least 1mm too short (i.e. shy of the nipple slot bottom by at least this amount).

cheers

[zenitb]

FWIW I tried to work out the reationship between the new chinese Weinneman and Ryde a while ago. It looked to me as if the Weinneman brand was spun off to a chinese company with some residual rights to some classic designs, including the ZAC 19 and 2000 rims.

https://www.weinmanntek.com/product/8/15

As you can see though the current Weinneman ZAC 2000 appears to have a wear indicator..which doesnt appear on either of my Ryde branded ones so maybe they have "forked" the design and started to make their own mods now. Its unclear whether Weinemann supply Ryde with these rims for rebranding or whether Ryde versions are made somewhere else.

You can see the ERD quoted is shorter ~=533mm.
Its also single eyelet (unlike yours) wheras their ZAC 19 is more budget..no eyelets.

[Brucey]

...You can see the ERD quoted is shorter ~=533mm...

very similar to what Ryde (wrongly) quote for their ZAC 2000.



the weinmann zac 2000 has external wear indicator grooves (which can be added to any rim during machining) and the Ryde version has internal (breakthrough type) wear indicators. The extrusions are very similar to one another but not quite identical.

cheers

[sarniacycle]

Ok, Zac 2000 rims arrived today and.... 537 ERD was what came out! Very consistent with above.

I'd ordered 4 rims following Brucey's earlier advice and measured 3 diameters in different places on each but they were remarkably consistent/round.

So thanks all, this was an interesting exercise.

Out of interest and in case anyone else is buying these, the rims did come out quite a bit heavier than listed on manufacturer's and retailers' sites, just over 570grams each rather than the 530 I saw. These will be my first go at building wheels and after I'll try and do a lighter pair for unladen/round town - Spa cycles look to do KINLIN XM-250's that would work out 100gms or so lighter a rim. Maybe this is getting silly but I'm quite enjoying this.

Now to order spokes. Double butted 2-1.8-2 unless anyone has strong opinions about something else?

Many thanks.