Single source for rim ERDs?

[Samuel D]

I’m thinking of building up a pair of wheels with wider rims to fit tyres up to 35 mm, preferably with my existing spokes as used for Mavic Open Elite and Open Pro C rims. How would I go about finding my options?

I realise ERD varies a little with manufacturing and silent design variations, but it would be useful to have a centralised list of rims and approximate ERDs as a starting point. Does such a list exist?

[NetworkMan]

Wish I did. I searched for one myself recently but the best I could find was last updated in 2004. Although it listed my Alesa Endeavour (as Rigida) the list is incomplete wiithout ERD. I think a re-rim might be a good first wheelbuilding project for me.

http://www.fa-technik.adfc.de/Komponent ... ge622.html

BTW does anyone know the ERD for the heavy old Alesa Endeavour in 622 36 hole?

[alexnharvey]

https://www.kstoerz.com/freespoke/rims

[NetworkMan]

https://www.kstoerz.com/freespoke/rims

Thanks that's good. My rim is just too old though

[Samuel D]

If you have the rim in a wheel you could measure it by peeling the rim tape back just one spoke hole and measuring the drop from the outer diameter of the rim to the top of the nipple, for example with the depth probe of a Vernier calliper from a ruler held flat across the rim walls as a bridge (then subtract the ruler thickness). Then measure the rim diameter with a metre rule and subtract twice the drop you measured to get ERD. You may know all this very well and have some other difficulty getting a measurement.

Thanks for the list suggestions. Neither covers Exal rims and some others I checked, but better than nothing!

[Brucey]

Wish I did. I searched for one myself recently but the best I could find was last updated in 2004. Although it listed my Alesa Endeavour (as Rigida) the list is incomplete wiithout ERD. I think a re-rim might be a good first wheelbuilding project for me.

http://www.fa-technik.adfc.de/Komponent ... ge622.html

BTW does anyone know the ERD for the heavy old Alesa Endeavour in 622 36 hole?

the rim looks very similar to a sputnik. If you have got some can you not measure them?

I’m thinking of building up a pair of wheels with wider rims to fit tyres up to 35 mm, preferably with my existing spokes as used for Mavic Open Elite and Open Pro C rims. How would I go about finding my options?

I realise ERD varies a little with manufacturing and silent design variations, but it would be useful to have a centralised list of rims and approximate ERDs as a starting point. Does such a list exist?

I'd use different lengths for Open Pro C and Open Elite, so its not entirely clear to me what ERD you really want. If you are intending to re-use them, I would make a note of the exact spoke lengths you have, and then work back to a target ERD value from that.

I have had various lists over the years but

- the numbers are not always accurate
- the numbers are often systematically wrong ( often NSD is listed as ERD, for example)
- the rims often exist in different versions, which have different ERD values, eg single eyelet, double eyelet, no eyelet; all different
- rims can vary in ERD with production batch anyway.


In reality the single biggest limitation is normally what rims you can buy. You can make a shortlist of rims that way and check those ERD values.

https://leonard.io/edd/

has a pretty good database but it isn't searchable by ERD.

FWIW if you built SF 36x3 before, a rim that is ~12mm smaller ERD will build x4 using very similar length spokes. This ought to open up some more options for you.

cheers

[alexnharvey]

I use Leonard's calculator most of the time. The open rims and hub database of freespoke makes searching by ERD much simple.

[Samuel D]

I'd use different lengths for Open Pro C and Open Elite, so its not entirely clear to me what ERD you really want.

I’ve got spokes of both lengths, at least for the front wheel. The spokes in my recently crashed wheel were first in an Exal XR2 wheel built by Spa Cycles that I re-rimmed with a Mavic Open Elite when the time came. Separately I have spokes for the Mavic Open Pro C.

I only have one rear hub but two front ones: a dynamo hub and a regular one. Unfortunately it was the regular one that I wrecked whereas I’d prefer to put the wider rim on the dynamo hub in case I keep two sets of wheels in the future, one fat and one skinny. I’ll have to sit down and sort all this out before buying anything.

Between those sets of spokes and:

FWIW if you built SF 36x3 before, a rim that is ~12mm smaller ERD will build x4 using very similar length spokes.

… I reckon I could use a few ERD values.

The idea is to try fat tyres while recovering from injury this winter. My fitness (and bravado, probably) will be shot to pieces, so fast group rides won’t be viable. And I have a phobia of crashing again while the metal plate is in my shoulder – which it will be for at least a year – so I may skip mudguards this winter to eliminate the minor risk they present. It all seems like a good opportunity to try fat tyres and save the skinny ones for next summer or beyond.

[slowster]

One option might be to delay building a new wheel with the regular hub, and try a good quality 32mm tyre on your dynamo wheel and rear wheel, and then decide what to do based on trying the 32mm tyre on your current narrow rims (I would happily fit 32mm to Mavic Open Elite/Pro C rims, even though the maximum width advised by Mavic is 28mm). After a trial you might want to take it further and build the new wheel with a rim which will take an even wider tyre, or you might feel that 32mm was as wide as you needed/wanted, or you might even decide that you do not like wider tyres and revert back to just using narrow high pressures.

[amediasatex]

I’ve also happily run 32mm (and 35) on open pros but there’s no denying they feel a lot better on a wider rim, especially at lower pressures.

Do you have any rims in mind Samuel? I wouldn’t let your existing spokes dictate too much unless there’s a happy accident of ERDs I’d just assume you might need new spokes and get the rims you want, and measure them upon arrival.

In the “classic looks but wide(r)” category my current favourite is H Plus Son TB14, followed by Kinlin ADHN if you want cheaper and a smidge wider again. Halo are also now doing a nice and reasonably priced option but I have my suspicions that it’s just a rebadged ADHN or a very minor tweak of it for them.

FWIW I re-rimmed a pair of Open Pro wheels with a pair of ADHNs and I did reuse the spokes despite there being a slight difference in ERD, but it was close enough and they built up just fine.

[Samuel D]

One option might be to delay building a new wheel with the regular hub, and try a good quality 32mm tyre on your dynamo wheel and rear wheel, and then decide what to do based on trying the 32mm tyre on your current narrow rims

Yes, not a bad idea. I’m attracted to 35 mm since that’s the frame’s limit and the greatest contrast to what I normally use, but 32 mm would get most of the way there.

Do you have any rims in mind Samuel?

The only one I thought of was the Exal LX17 until I saw its ERD (601 mm according to Spa’s website). That rim is non-committal because it also works with a narrow tyre.

I’d prefer the classic looks you mention and like the look of the rims you suggest. The ADHN additionally seems to be a close fit for the ERD of an Open Pro C.

[slowster]

I think the danger is that you get a heavier rim than you need and a tyre which might be relatively fast as touring tyres go, but which would be too slow and heavy for a rider like you who enjoys riding a light bike without much luggage (if any).

I suspect the LX17 is significantly heavier than you need - Spa say 575g. The H Plus Son TB14 suggested by amediasatex is 510g according to The Cycleclinic. Another possibility might be the Kinlin XM-250, which Spa say is 500g. (I've got a pair of wheels with XM-250 rims - I have not yet put them on my bike, but I measured the braking thickness to be 1.3mm at the thinnest on one rim and 1.4mm on the other, with the other measurements typically being 1.5mm.)

There's also not much choice of good quality fast 35mm tyres, and you might find that a fast supple 32mm tyre is either less expensive, more readily available and a wider choice of them, or simply better than available 35mm options.

[Samuel D]

This whole reassessment comes from my crash that will have torpedoed my fitness by the time I get back on the bicycle. Additionally, I want to take steps to reduce the risk of another bad crash over the next 18 months. I envisage more solo and gentle small-group riding and less big-group hammering where accidents are common and serious because of the high speeds. Maybe even some off-road trails while I’m at it.

All that to say the LX17 rim weight doesn’t really bother me. The price of the TB14 bothers me more. I have enough expenses as it is.

Your point about tyres is good. Looking around, it seems the road options have got as wide as 30 mm or 32 mm but not yet 35 mm, René Herse excepted.

[Mick F]

I’m thinking of building up a pair of wheels with wider rims to fit tyres up to 35 mm, preferably with my existing spokes as used for Mavic Open Elite and Open Pro C rims. How would I go about finding my options?

I realise ERD varies a little with manufacturing and silent design variations, but it would be useful to have a centralised list of rims and approximate ERDs as a starting point. Does such a list exist?

Even if it did, I wouldn't believe it.

Buy your rims and measure the ERD for yourself.
Buy your hubs, and measure them yourself as well.
Get online and check out a few spoke-length calculator websites, and come to a consensus of the lengths you want.
Round up the results.

[Brucey]

I agree anything much over 500g in a rim is probably overkill for you . I also think that you can try 32mm tyres on a rim with 15mm internal width and see how you get on, before taking the plunge and buying different rims.

My take on it is that you can't so easily run lower pressures on the narrower rim, not without the front tyre flopping about, but other than that it is likely to be OK; good enough to tell you that you are on the right track or not going to wider tyres, anyway.

cheers