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Rims - Welded vs. Pinned

6K views 15 replies 6 participants last post by  tube_ee 
#1 ·
I'm shopping for a new set of rims/wheels, something similar to my Mavic CXP33s, and was wondering what people's thoughts are on the difference between welded versus pinned rims. It seems that most of the mainstream and newer stuff is pinned. Aside from the aesthetics (I much prefer the seamless look of welded), are there any durability or other issues you folks have experienced? Any specific recommendations for welded rims with a medium profile? Thanks.
 
#2 ·
What rims?

I thought most rims were welded these days. Velocity and MAVIC are welded, yes? What pinned rims are you looking at? In practice, welded are more popular due to the possibility of absolutely smooth sidewalls. No real advantage to one or the other that I can see.
 
#4 ·
Double check

I've got 3 Velocity Aerohead wheels I'm looking at, and if there's a pinned seam, I can't see it. I didn't pull the tires and rim strip to double check, but there certainly is no seam on the sidewall or rim surface. It could be that there is a pin along with the weld, but I would see these as welded rims, no question. Can't comment on the rest of the Velocity line as I don't have them in my hands. My memory of the Velocity DeepV is that there is no seam there either.
 
#5 ·
Kerry what year are yours from? i've got a set of velomax that use the aerohead rim and the are sleeved it's like pining but a little different no chanels for the pins just a sleeve that goes inside the rim and is a very common way of doing rims now. the same thing for my Deep-v's also.
 
#6 ·
Velocity

I think deluc is right about the Velocity rims. I didn't take the tire off to look, but the new Velocity wheels I've seen definitely have a visible, albeit small, gap where they are joined. I assumed they were pinned, but I guess the sleeve creates the same appearance from the visible side.

Kerry Irons said:
I've got 3 Velocity Aerohead wheels I'm looking at, and if there's a pinned seam, I can't see it. I didn't pull the tires and rim strip to double check, but there certainly is no seam on the sidewall or rim surface. It could be that there is a pin along with the weld, but I would see these as welded rims, no question. Can't comment on the rest of the Velocity line as I don't have them in my hands. My memory of the Velocity DeepV is that there is no seam there either.
 
#7 ·
Rim seams

My Velocity rims are all new this year. Upon closer inspection, I can see a seam, but that doesn't tell me that they are not welded. There is no visible seam on the side wall. These rims look the same (from the outside) as a MAVIC Open Pro or the last of the Reflex clincher rims. You can see a very fine seam, certainly with no daylight. The MAVIC rims are clearly welded. I assume that the Velocity's are too. If you have a non-welded rim I think you will have a sidewall seam. It is the welding that allows you to grind the sidewall smooth and have no seam. I have a Campy Electron, and you can see the seam in the side wall, which suggests to me that those rims are not welded. Likewise all the tubular rims I ever owned, IIRC.
 
#8 ·
Velocity Fusions

Kerry Irons said:
My Velocity rims are all new this year. Upon closer inspection, I can see a seam, but that doesn't tell me that they are not welded. There is no visible seam on the side wall. These rims look the same (from the outside) as a MAVIC Open Pro or the last of the Reflex clincher rims. You can see a very fine seam, certainly with no daylight. The MAVIC rims are clearly welded. I assume that the Velocity's are too. If you have a non-welded rim I think you will have a sidewall seam. It is the welding that allows you to grind the sidewall smooth and have no seam. I have a Campy Electron, and you can see the seam in the side wall, which suggests to me that those rims are not welded. Likewise all the tubular rims I ever owned, IIRC.
I have a set of 2003 Velocity Fusions that have a very definite seam. The rim is also quite a bit heavier at the seam location, suggesting a some kind of splice or pin. It may welded as well, but cetainly not on the outside of the rim.

Bryan
 
#9 ·
Machining over the seam...

When braking surfaces are machined, it usually obscures the portion of the seam that crosses the brake track, making it difficult to tell if the joint is welded or pinned/sleeved. Since some rims are powdercoated or have stickers applied over the joint, it may still be difficult to tell from other aspects of the joint. The most reliable way to find out is to contact the manufacturer or look up the rim's specs. Most manufacturers will specifically mention it if a certain rim has a welded joint, since it is considered a desireable feature.

Hope this helps.
 
#11 ·
No difference

The only difference is that, IME, pinned rims TEND to have a bit more of a braking pulsation. However, this is like frame material - a factor to consider but not a determinant in choosing rims. It has NO effect on durability. In practice, you could make rims without pins or welding (just a sleeve at the joint) because the forces of the spokes would hold everything together anyway. I have had rims with loose pins where you could physically separate the rim at the joint, but they built up into fine wheels.
 
#12 ·
Thanks

Thanks for your comments and help guys. I see that the Mavic web site says the CXP33s are welded. Web sites for some of the others don't mention welded vs. pinned either way, but I've e-mailed their customer service people and will post the results.
 
#13 ·
Velocity Pinned

I e-mailed Velocity asking if their Aerohead and Deep V rims were welded or pinned at the joint. Here's their response:

"All of our rims are pinned. Its not your ordinary process though, its a fairly elaborate process. We have an extra piece of extrusion that matches the inside of the rim that is joining the two pieces through a special heat activated epoxy. It works quite well. Let me know if you have any other questions."
 
#14 ·
MichaelC said:
Aesthetics aside, does it matter if they're welded or pinned/sleeved? from a durability standpoint?
Nope, not at all. If you figure that a well-built wheel will have an average spoke tension of 1200 - 1500 pounds, that means that the rim will be pulled inward with a total force of 38 - 48 thousand pounds. It doesn't matter what you do to the joint. Rims don't pull apart.

The method of joining has no real effect at all on the strength of the rim. It's all marketing. FWIW, brake pulsing is only an issue with new rims, and even then, it's pretty minor.

With the exception of carbon fiber rims, rim technology hasn't really changed since the late 1970s. They're still using the same alloys and the same manufacturing processes. The shpaes have changes, and some of the post-production working is different now, but really, rims is rims.

The spoked wheel is a very simple structure, whose properties are well known, and whose design has been the subject of over 100 years of continuous refinement. There really isn't much left to discover about it, and nobody has yet come up with a design that beats the balance of properties (strength, weight, repairability, failure tolerance, many others) of the 32 or 36 spoke, 3 or 4 cross, handbuilt wheel. Anyone who claims otherwise is focusing on one proerty at the expense of others.

--Shannon
 
#15 ·
Not so sure about this

tube_ee said:
Nope, not at all. If you figure that a well-built wheel will have an average spoke tension of 1200 - 1500 pounds, that means that the rim will be pulled inward with a total force of 38 - 48 thousand pounds. It doesn't matter what you do to the joint. Rims don't pull apart.
I'm not exactly a whiz this stuff, but aren't you off by an order of magnitude on the pounds? Can you take the total spoke tension and assume that it all goes to pulling the joint together (parallel to the rim) or is there some kind vectoring going on that distributes some of the load perpendicular to the rim (i.e. - adjusting for out of round). I really don't know the answer?

I generally agree with the principal of it all, but no so sure on the numbers.

Bryan
 
#16 ·
B2 said:
I'm not exactly a whiz this stuff, but aren't you off by an order of magnitude on the pounds? Can you take the total spoke tension and assume that it all goes to pulling the joint together (parallel to the rim) or is there some kind vectoring going on that distributes some of the load perpendicular to the rim (i.e. - adjusting for out of round). I really don't know the answer?

I generally agree with the principal of it all, but no so sure on the numbers.

Bryan
Yeah, I'm sure you're right. Those numbers are probably way off, I didn't bother to figure out the actual math, I just multiplied the spoke tension by the number of spokes. The point is, the spokes exert enough inward force on the rim joint to make separation not an issue.

--Shannon
 
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