Login required to started new threads

Login required to post replies

Prev Next
Re: Princeton CarbonWorks "white paper" [hajamac] [ In reply to ]
Quote | Reply
I meant the stress that the rim experiences due to that load.
Quote Reply
Re: Princeton CarbonWorks "white paper" [rruff] [ In reply to ]
Quote | Reply
rruff wrote:
... On a shallow rim the lower few spokes contribute nearly all of the upward force. ...

What keeps those spokes from buckling under compression?

Mark E
Quote Reply
Re: Princeton CarbonWorks "white paper" [mark.ewers] [ In reply to ]
Quote | Reply
They are still in tension just less than before.

For example, a spoke directly down from the hub with 50kg tension and a spoke up from the hub with 100kg tension, have a resulting vertical force of +50kg acting on the hub.
Quote Reply
Re: Princeton CarbonWorks "white paper" [rruff] [ In reply to ]
Quote | Reply
rruff wrote:
They are still in tension just less than before.

For example, a spoke directly down from the hub with 50kg tension and a spoke up from the hub with 100kg tension, have a resulting vertical force of +50kg acting on the hub.

The beauty of pre-stressed structures :-)

It's the same concept, but in the opposite loading, of how pre-stressed concrete can be designed to handle tensile loading that concrete structures normally can't handle.

http://bikeblather.blogspot.com/
Quote Reply
Re: Princeton CarbonWorks "white paper" [hajamac] [ In reply to ]
Quote | Reply
I'm apparently pretty late to this party but looks like Hajamac is a/the Princeton guy?

Hajamac, I highly suggest you change your username to something more easily identifiable as an industry guy and also add a signature line indicating that you are industry. Everybody is always thrilled to have the industry represent in these forums, but I sure was confused for the last 15 minutes looking at this thread and I'm sure there are others far more confused than I. It's just good practice to be as clear as possible as far as I'm concerned.

http://www.SILCA.cc
Check out my podcast, inside stories from more than 20 years of product and tech innovation from inside the Pro Peloton and Pro Triathlon worlds!
http://www.marginalgainspodcast.cc
Quote Reply
Re: Princeton CarbonWorks "white paper" [joshatsilca] [ In reply to ]
Quote | Reply
joshatsilca wrote:
I'm apparently pretty late to this party but looks like Hajamac is a/the Princeton guy?

Hajamac, I highly suggest you change your username to something more easily identifiable as an industry guy and also add a signature line indicating that you are industry. Everybody is always thrilled to have the industry represent in these forums, but I sure was confused for the last 15 minutes looking at this thread and I'm sure there are others far more confused than I. It's just good practice to be as clear as possible as far as I'm concerned.

Elevelo may also be affiliated. Or perhaps involved in testing. Not completely clear...
Quote Reply
Re: Princeton CarbonWorks "white paper" [joshatsilca] [ In reply to ]
Quote | Reply
Princeton CarbonWorks Team (http://www.princetoncarbon.com) is comprised of 4 principal members:

Myself, (Harrison Macris, BS, MS, Mechanical Engineer, Entrepreneur, all around good guy, solid 8/10 in the looks department, former rower and terrible cyclist)
Paul Daniels (@elevelo, cats out of the bag, also former rower [USA national team world champion], serious engine, great cyclist, solid 7/10 in the looks department)
Marty Crotty (cats out of the bag some more, Princeton rower now coach, serious engine, also very decent cyclist, brainchild of PCW, also all around good guy)
Brad Werntz (BS Aerospace, former rower, trying to be a decent cyclist, the other half of the technology trust driving PCW)

It's good advice Josh, I will update credentials. Keeping username because I like it.

Please ask more questions. I prefer to think of the bike as hanging from the upper half of the wheel from the hub, rather than sitting on the lower half. Again, pushing on rope doesn't work great.
Quote Reply
Re: Princeton CarbonWorks "white paper" [hajamac] [ In reply to ]
Quote | Reply
Any thoughts of eventually building rowing shells or oars? The last interesting shell was the Resolute, and that's been a while. And I've always been suspect of some of the Concept II blade designs.
Quote Reply
Re: Princeton CarbonWorks "white paper" [hajamac] [ In reply to ]
Quote | Reply
hajamac wrote:
I prefer to think of the bike as hanging from the upper half of the wheel from the hub, rather than sitting on the lower half. Again, pushing on rope doesn't work great.

Come on... your a ME! Surely you've dealt with pre-stressed structures at least in school?

Fuller really liked this stuff:

Quote Reply
Re: Princeton CarbonWorks "white paper" [MTM] [ In reply to ]
Quote | Reply
Now a button on homepage

Paul Daniels
paul@princetoncarbon.com
http://www.princetoncarbon.com
Quote Reply
Re: Princeton CarbonWorks "white paper" [Paul at PCW] [ In reply to ]
Quote | Reply
Paul at PCW wrote:
Now a button on homepage

Great! I guess you mean the button on the start page? I would also thinking about putting it as a headline on the top bar ("Technology" or something like that?) as that would probably be where I would look for it.
Quote Reply
Re: Princeton CarbonWorks "white paper" [hajamac] [ In reply to ]
Quote | Reply
You could perhaps put a short credential (and link to your home page if you'd like that - I guess that's within forum rules) in your signatures for fast/easy recognition.

Also, why no rating of Marty and Brad in the looks department?!
Quote Reply
Re: Princeton CarbonWorks "white paper" [Paul at PCW] [ In reply to ]
Quote | Reply
I am not sure about all of this spoke tension stuff. I picked up a pair of these because I have older (2011ish) Cervelos that needed a face lift. I cannot find it in me to part with my S1 or my R3sl but still wanted to freshen them up a bit. All I can say is that these wheels just ā€œseemā€ to want to go straight. The wheels themselves are not overly flashy with decals but start conversations when they are not spinning. Now when I am asked about them, I can add spoke attachment design to the list that includes new company trying to give more options.
Quote Reply
Re: Princeton CarbonWorks "white paper" [Riccardio] [ In reply to ]
Quote | Reply
Of course Paul would change his tag to "Paul at PCW..."

The overwhelming response so far, from those who have ridden the wheels, is that they are just plain faster than what they had prior to using PCWs. Enve, Zipp, et al. We're splitting hairs on the aero thing at this point because we're in a land of diminishing returns. So we have to master aero and then find gains other places (weight, stiffness, etc etc).

End of day, the wheels perform better than we could have ever hoped, and we are actively working on getting more demo sets in the hands of discerning riders (EMAIL PAUL to set this up: paul@princetoncarbon.com) so you all can experience what current users are telling us.

Really appreciate the feedback; we listen to every bit of it and work every day to improve.

Cheers,
HJM
Quote Reply
Re: Princeton CarbonWorks "white paper" [Riccardio] [ In reply to ]
Quote | Reply
Riccardio wrote:
I can add spoke attachment design to the list that includes new company trying to give more options.

Really? I thought that it is still a nippled spoke, which has been around a while. If you are talking about the convex attachment point of the spokes, that has been around the block before as well. Im not saying that they are good or bad (I don't know, because Im terribly cheap and would not pay retail for them or anyone else's wheels) just wondering how their claims make sense based on what is being said (because it just does not add up to my feeble mind)...and they were the ones who came here looking for feedback...or maybe I got it wrong, and they were looking for pats on the back with an 'attaboy'.

Stephen J

I believe my local reality has been violated.
____________________________________________
Happiness = Results / (Expectations)^2
Quote Reply
Re: Princeton CarbonWorks "white paper" [stephenj] [ In reply to ]
Quote | Reply
Quote:
just wondering how their claims make sense based on what is being said (because it just does not add up to my feeble mind)

Which parts don't add up to you?

To be honest, we didn't come looking for anything, but rather will take valid and pointed feedback to heart in regards to almost anything; however, when it comes to engineering, we obviously trust ours above forum fanboys.
Quote Reply
Re: Princeton CarbonWorks "white paper" [hajamac] [ In reply to ]
Quote | Reply
princeton guys,

just out of curiosity what other products do you see for future development? you mentioned it in earlier posts, just curios where you guys anticapite going with the future.

80/20 Endurance Ambassador
Quote Reply
Re: Princeton CarbonWorks "white paper" [damon.lebeouf] [ In reply to ]
Quote | Reply
Hi Damon -

Shallower / Wider

And like the WAKE 6560, Lighter - Faster - Stronger - than depth category peers, tubeless ready, sold direct to consumers.

#betterspeed

Paul Daniels
paul@princetoncarbon.com
http://www.princetoncarbon.com
Quote Reply
Re: Princeton CarbonWorks "white paper" [hajamac] [ In reply to ]
Quote | Reply
hajamac wrote:
https://www.youtube.com/watch?v=b1TqsoxWhQY

it's not hate it is frustration... You are taking about 1W advantage, I need more that that, to be even top 100 in our local races. Take my money, but 1W is not enough... got to do better than that. ;)
Quote Reply
Re: Princeton CarbonWorks "white paper" [hajamac] [ In reply to ]
Quote | Reply
hajamac wrote:
Quote:
just wondering how their claims make sense based on what is being said (because it just does not add up to my feeble mind)


Which parts don't add up to you?

To be honest, we didn't come looking for anything, but rather will take valid and pointed feedback to heart in regards to almost anything; however, when it comes to engineering, we obviously trust ours above forum fanboys.



So by your own statement you did not come looking for anything, yet you posted to this forumā€¦thus indicating that you are looking for somethingā€¦at the very least, you are looking for someone to read what you posted. Next, you state that you are open to ā€˜validā€™ feedback which when placed in a reply to my post indicates the perceived lack of validity seems to be dismissing any point that I was questioningā€¦combine that with the derogatory implication of a ā€˜forum fanboyā€™ (typically used to shut someone up), I think that you may be either missing something important (you have already stated that your group is young) or not explaining it in a way that is understandable for someone with a somewhat-functional grasp of engineering, but not currently well versed in FEA of metastructures (such as bicycle wheels). So, to address the question you asked about what part does not add up, it is the following statement made in an earlier post by you:


ā€œBecause our nipple bed is convex, it is more efficient at handling the tensile force from the spoke.ā€


What do you mean by more efficient? That word does not work by itself in that context unless it is used solely as marketing BSā€¦and if that is the case, it leads one to wonder what else is off.


Stephen J



I believe my local reality has been violated.
____________________________________________
Happiness = Results / (Expectations)^2
Quote Reply
Re: Princeton CarbonWorks "white paper" [stephenj] [ In reply to ]
Quote | Reply
 

Paul Daniels
paul@princetoncarbon.com
http://www.princetoncarbon.com
Quote Reply
Re: Princeton CarbonWorks "white paper" [stephenj] [ In reply to ]
Quote | Reply
this board is willing to break out the torches and pitchforks faster than any other iā€™ve read.

80/20 Endurance Ambassador
Quote Reply
Re: Princeton CarbonWorks "white paper" [stephenj] [ In reply to ]
Quote | Reply
stephenj wrote:
ā€œBecause our nipple bed is convex, it is more efficient at handling the tensile force from the spoke.ā€
What do you mean by more efficient? That word does not work by itself in that context unless it is used solely as marketing BSā€¦and if that is the case, it leads one to wonder what else is off.

It's a better interface shape for reducing peak stress in the rim.
Quote Reply
Re: Princeton CarbonWorks "white paper" [Paul at PCW] [ In reply to ]
Quote | Reply
Paul at PCW wrote:



Thank you. That is useful. So to summarize, the convex shape allows you to spread the force around the spoke hole over a larger area allowing you to take away material (which gets you to the lighter rim). So is that difference in force distribution solely due to geometry, or geometry and layup?


Stephen J



I believe my local reality has been violated.
____________________________________________
Happiness = Results / (Expectations)^2
Quote Reply
Re: Princeton CarbonWorks "white paper" [stephenj] [ In reply to ]
Quote | Reply
The geometry is what allows a more sophisticated layup;

My use of the term efficient was to try and wrangle the concepts of weight, material use, etc all in to one term. Probably not the most precise word choice, i'll eat that for sure.

H
Quote Reply

Prev Next