Synergy cracking already after 9 mos

[Jim Bronson]

I have a 32h rear Synergy that I broke a spoke on a recent brevet.  One of those "Handspun" deals.  When the shop called me back to tell me that they had replaced the spoke and the bike was ready, they also told me that the rim was starting to crack.

This setup is only 9 months old.  I'm a little disappointed.  Granted, I am a large person at 6'7" and 250+ but I don't think I've had a wheel start flaking on me this soon before.  And I've been running 38mm tires at 70 psi which should be easier on the rims and wheels in general.

I recently had a 36h wheel built up with a Soma Weymouth for my Grand Randonneur, looks like I will need it for my current brevet bike instead until the GR is ready. 

I was using Velocity Deep V when I was running 700c and having pretty good luck even using 32h.  I thought that I would be easier on 650b rims due to their smaller size.  What's a similar pretty tough rim for 650b that doesn't weigh a ton?  Say around 500 grams?  Maybe the Velocity A23, since the Dyad doesn't come in 650b?

Lastly, are these Weymouths going to hold up?

[Steve Chan]

   Out of curiosity, were the spokes single or double butted? If these rims are so prone to stress fracturing, maybe going to butted spokes to shift the deflection into the spokes are a reasonable mitigation.

   Steve

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[Jim Bronson]

DT Swiss double butted spokes were used in the build.

[Kieran Joyes]

The Dyad does come in 650b, but they are hard to find. I believe Longleaf Cycles has them, on and off. Might want to look into that?

KJ

[Jon Doyle]

I would talk to some pro wheel builders about quality 650b rim options; Anthony of Longleaf seems a good place to start. Maybe you can get a free rim from Velocity as well.

For randonneuring, I think weight should take a back seat to quality and strength. Personally, if I were 250#, I'd go with 36 spokes in the rear wheel. Just because I'd feel better about having 4 more spokes carrying the load. It's not going to be slower.

I haven't heard a peep about Soma rim durability; I think they're fairly new.

Jon

Watertown, MA

On Wednesday, May 28, 2014 12:50:49 PM UTC-4, Jim Bronson wrote:

[franklyn]

I believe I saw message on one of these list earlier that Riv got a batch of 650b Dyads and you can order them directly from Rivendell. But that needs to be verified.

best,

Franklyn

[Jim Bronson]

That would surprise me, the 650b dyads have been unobtainium for a while now.

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[Mike Schiller]

hmmm.. Riv suggests that Synergy's should be used by riders under 200 lbs.  

Anthony at Longleaf had some 36 hole 650B A23's last I looked.   If you can't find Dyads I would suggest those.

~mike

[Jim Bronson]

I take back what I said before, Rick Lesnik's shop has the 650b Dyads, but it looks like they won't sell them to you separately.  I suppose I could call and clarify.

[Allan Desmond]

yes with your size and weight along with the style of ridding your doing ..You should always go with the bigger better stronger heavier parts ...whom ever gave you cycling advice otherwise, stop listing to them ok. Cheer's, Allan 

Allan Desmond
Desmond Tactical
702.764.8656
desmond...@gmail.com

[Jim Bronson]

I've always gone on the heavy side when it comes to components.  The wheel in question is laced to a Deore LX hub, for example.  I've had several catastrophic hub failures so I stay away from the bling lightweight hubs.

I never had any problems running 32h on 700c and I thought that with the wider tires at lower pressures, the Synergy 650b would be ok.  Never heard about any weight limits on them either.  In retrospect, I guess I need something more heavy duty.  Live and learn.

[Nick Payne]

I had a Synergy 650b OCR rear rim crack at the eyelets - I only weigh just over 140, and the bike hadn't been used for fully loaded touring. However, that was after several years of use. As the shop I had bought the rim from was no longer in business, I emailed Velocity with photos of a couple of the cracks, and they sent me a new rim without quibbling. They also commented that they had beefed up the Velocity rim section some time after the rim was initially introduced.

[WMdeR]

Dear Jim,

The Synergy OC rims have commonly cracked. Winding them up to the recommended tension by Velocity will almost guarantee a cracking rim. Your weight and power output further militates against these rims. 

If Nick Bull is on-list, you may wish to inquire as to his preference on rims. I've ridden a cracked Velocity rear Synergy OC  for three years (the cracks didn't advance after forming in the first two months of ownership), mostly off-pavement, without issue, but I'm not a big/heavy rider. Velocity has stood behind their rims--they'll replace the broken one--but then you're riding another Synergy OC rear. I'd be more concerned about the build, honestly, given that you broke a spoke.

I did recently replace the rear wheel on my Allroad with an A-23 OC rims (I've had good luck with Aerohead OC (40,000mi+) and the substantially similar A-23 OC (8,000mi and counting) in 700C), and demoted the Synergy OC to my guest bike. It is still holding true, and the cracks aren't advancing.

Best Regards,

Will

William M. deRosset

Fort Collins, CO

[Anthony King -- Longleaf Bicycles]

On Wednesday, May 28, 2014 12:50:49 PM UTC-4, Jim Bronson wrote:

I have a 32h rear Synergy that I broke a spoke on a recent brevet.  One of those "Handspun" deals.  When the shop called me back to tell me that they had replaced the spoke and the bike was ready, they also told me that the rim was starting to crack

Since Velocity changed the Synergy extrusion and thickened up the spoke bed a few years ago I have had zero cracks. These are the rims with the columbia blue and orange stickers.

But I'd never put a 250+ pound rider on a 32h Synergy. Not the OC version and especially not the symmetrical version.

The Handspun wheels are built very well though the spoke tension last I checked one about 10kgf more than I would put into a Synergy. They do have uniform spoke tension, which is rare in wheels at that price point. It is unlikely that a material defect or wheelbuiding error was the problem here--the component choice was very poor for the intended rider and use. (I'm 210-ish pounds myself and I wouldn't use that rim for a rear wheel.) 

Unfortunately the Synergy is no longer being made in the OC version thought there are still some out there (I have a few). Since the A23's are available in 650B OC there's a superior replacement (which might be why the Synergy OC is no more). The A23 offset is actually .5mm great than the Synergy, so it better ameliorates the spoke tension disparity.

And of course there's the Dyad if you want something heavier.

Use the Dyad or a 40H OC Synergy.

Usual disclaimer: I sell and build wheels with all the rims in the above post.

[bikerbob]

I will never use another Velocity Synergy rim.  As Will already noted, they are prone to cracking at the eyelets, regardless of how much you weigh or how easy you are on wheels.  About the only thing the Synergy rims are good for is a show bike hanging on the wall that never gets ridden.  I got about 7000 miles out of my 700C before it developed cracks (wheel built by Peter White).

Bob Bingham
Graham NC

On Wednesday, May 28, 2014 11:21:44 PM UTC-4, WMdeR wrote:

Dear Jim,

The Synergy OC rims have commonly cracked. Winding them up to the recommended tension by Velocity will almost guarantee a cracking rim. Your weight and power output further militates against these rims. 

If Nick Bull is on-list, you may wish to inquire as to his preference on rims. I've ridden a cracked Velocity rear Synergy OC  for three years (the cracks didn't advance after forming in the first two months of ownership), mostly off-pavement, without issue, but I'm not a big/heavy rider. Velocity has stood behind their rims--they'll replace the broken one--but then you're riding another Synergy OC rear. I'd be more concerned about the build, honestly, given that you broke a spoke.

I did recently replace the rear wheel on my Allroad with an A-23 OC rims (I've had good luck with Aerohead OC (40,000mi+) and the substantially similar A-23 OC (8,000mi and counting) in 700C), and demoted the Synergy OC to my guest bike. It is still holding true, and the cracks aren't advancing.

Best Regards,

Will

William M. deRosset

Fort Collins, CO

On Wednesday, May 28, 2014 10:50:49 AM UTC-6, Jim Bronson wrote:

[Anthony King -- Longleaf Bicycles]

I was using Velocity Deep V when I was running 700c and having pretty good luck even using 32h.

One more note, you can easily put 130kgf into a Deep-V without the rim cracking, but I wouldn't put more than 110kgf in a Synergy, which is why you need more spokes on the Synergy, even when comparing 650B and 700C rims. 

[Brad]

I am curious about the eyelets.   Remember the collective problems with Mavic MA-40 rims where MA-2 rims rolled on for decades without issue?   My suspicion is that there is an interaction between the eyelet shape and material and the rim material that triggers stress fractures.  That being said, I have moved to heavier rims ( which are often less expensive) on expensive smooth running hubs and I am happy.  Unfortunately the Triple- V is out of production, at least in 650b.

[Nick Bull]

I am on-list but hardly qualify as a wheel expert, though I've built nine or ten wheels over the years.  I've had two Synergy rims crack and Velocity has been good about replacing them.  Both of the cracked ones were produced when Velocity was in Australia and the replacement ones are both Made in USA and have now lasted three years and one year, respectively.  I think.  Supposedly the US-built rims are better.  That said, if I were building a wheel now, it's unlikely I'd use Synergies.

Nick

[David Pertuz]

I have had four Synergies crack, though all of them (three rear, one front) cracked on the sidewall ( brake track), not at the spoke nipples. In two cases the rims had high mileage and I considered the failure acceptable; in the other two cases they failed at quite low mileage. At least one failure was of a newer rim. In both cases Velocity was very good about replacing the rim, exceptionally so in the second (recent) case. But like you, I'm not going to use Synergies any more.

David
Chicago

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[Brad]

There are enough anecdotes here for some serious research on cracks.   How do we set it up?   There have been other rims in the past that developed crack issues, the Mavic MA-40 being one. 
Have the cracked Synergy's been all in the  32 hole flavor?
Does Velocity do any heat treating on the Synergy?
Does something in the production process work harden the rim near the spoke holes?
Or my favorite theory- does the shape of the eyelet or its insertion process create a crack?
Would soaping the spoke nipples at the eyelet during wheel building  help prevent cracking?

[Nicholas Bull]

Supposedly they have solved the rim cracking problem and it was related to the alloy being used in Australian production.  That's what I heard, anyway.