i just recieved my new renn disc, and while i am very excited, i couldnt help but notice that it was slightly out of true. about 1/16 inch out of true and about the same out of dish.
is this normal? or should i be worried about it and call frank?
Thanks,
-kevin
A friend of mine bought one back in March and had the same problem. He sent it back and got his $$$ back. A new disc should be dead nuts true and dished.
I wasnt aware discs had to be dished…
1/16 of an inch is .0625. our wheels have a lateral rollout tolerence of .029 “roundness” to .039 (1 mm). most fall in between .015 and .025. if the wheel is the same one i am thinking (the only kevin in canada we’ve sent) it is .014 out and nothing has left even close to over .039 out of round.
the dish of the wheel can not be changed. our wheel dish is off less then one millimeter. this happened because the original thickness of the composite was to be .705. it is .685 now because of rim changes. we could not trash over 500 hubs for less then perfect dish.
our wheels compare very wheel to any other composite wheel regardless of price. do i wish they could be better…of course and they could be. do we want to manufacture a $360 wheel or a $500 wheel? pressures are taking us to the later.
frank rehnelt
Frank does a great job with his wheels. I have seen more expensive wheels that were not as true as his. It is hard to find a disc dead true.
I was looking at another disc on a pro’s bike from a different maker and I was very surprised how out of true it was. I think that this is the way it is, not something specific to any one manufacturer.
If you look at the design of a flat disc, the strength required to make them rideable, and the weight requirements we put on them as consumers, I’m absolutely amazed that discs are as laterally stiff and true as they are. (I imagine the forces exerted at the disc/hub junction during cornering are pretty huge and different from the forces exerted on a traditional spoked hub.) Obviously one can’t true a disc like a std spoked wheel, so the body must be manufactured to be completely flat and strong enough to stay that way. This would be very easy if weight weren’t a consideration.
Frank,
thanks for the reply. i am once again pleased with the excellet customer service. I actually was not the one who noted it, and did not measure it. My lbs guy was the one who mentioned it, and i took his word for it. He may have been off. I am not worried about it, and am very excited to have it.
Thanks again,
-kevin gregg
First, want to commend Frank for his reply and service – perfect response.
Second, not all outfits are this responsible. Bought a Zipp 3 years back which came from the factory so badly out of true (easily 3mm side to side) that I had to back off the rear brake significantly just to keep it from rubbing. Not what you expect after laying out close to a grand to go faster.
When my LBS shipped it back to them, they simply replied that it was “within (their) tolerances”. Very tolerant folks, apparently.
Don’t mean to trash them here, but facts are facts. That disk is now the LBS “loaner”.
Again, main point is to commend Frank for his response, and how his outfit handled this.
“A new disc should be dead nuts true and dished.”
Guess what? They can’t be. YOU CAN NOT TRUE COMPOSITE WHEELS.
IF they were perfect (or dead nuts true and dished) from all of the companies concerned, the asking price would either double or triple (more rejects), and there would be less available for the general public for consumption.
If anyone wants to do an experiment, here is one for you to try: Go to a bike shop where they have a large selection of composite wheels. Have a mechanic who KNOWS HOW TO USE THE CALIPERS and measure all of these things. Measure the tolerances between different models, even amongst the same model (if there are more than one of each wheel), and you will see what the side-to-side tolerance can be. Then put it in the truing stand. I guarantee NO wheel is out even 1/16 of an inch. It may just look like it.
As far as Renn is concerned: What do you expect for a $350 wheel? I have had the $1400 Zipp 3000 and it was out a LOT (.0035") and it looked bad, but it was well within their spec’d tolerances. I think the Renn is one HELL of a wheel for the $350 you dish out, and I think it is the BEST value out there. You can get a lot less wheel by spending a lot more, in my opinion.
You wrote 0.0035", but do you mean 0.035"? The only reason I ask is because a the thickness of a sheet of paper is about 0.004"…
wilson
Sorry about the typo. My head was a bit cloudy after my wreck…
A co-worker and fellow bike lunatic bought a set of Specialized (now Hed) 3 spokes and the rear is out by a bunch (3-4mm). I guess that’s why he managed to get the pair so cheap. He set the rear brakes very loose and lived with it for a while.
The front is perfect by comparison.
He got a disk (Hed) instead of a gold watch for his 15 year present from our company and the 3 spoke now graces the furthest reaches of his garage, behind the lawn mower.
TriDork
He got a disk (Hed) instead of a gold watch for his 15 year present from our company…
**DAMN **- what company is that? I wanna work there!
Then put it in the truing stand. I guarantee NO wheel is out even 1/16 of an inch. It may just look like it.
Straight from the factory, my 2000 Zipp was measured in a truing stand by one of the best wheel builders in the country – a guy who’s built wheels for world champions – as >3mm out of true. That’s not only 1/16th", it’s 1/8th.
Since the folks in Indy essentially said “tough nuggies”, I really appreciate your own guarantee on this.
When can I expect the $950 check?
Ooops – forgot the “just kidding” 
at the end to smooth the punchline’s tone. Sorry, b’man.
I do stand corrected. What year Zipp was this? I have seen them (composite wheels, not Zipp in particular) out quite a bit many years ago, as much as 1/16". So, if it came out even seven years ago, I don’t doubt your claim.
The point I was trying to make is that what is .025-.040" is no 1/4 of an inch- it just looks that way.
.050" is what many companies determine as their “reject threshold”. I think Renn’s is a lot toghter than .040". My first one was .015", damned near perfect.
.050" looks pretty bad, like it hit a few potholes.
My $950 cheque to you will arrive on 30 February 2004.
What do you mean by “out of dish” never heard of that.
Hi, b’man – appreciate your prompt claim processing
FWIW: I think I bought it in either late Dec '98 or very early Jan '99. As I said earlier, really wasn’t my intent to trash them specifically (probably caught someone there on a bad day, or in an uncharitable mood), but rather to commend Frank for they way *he *handled that issue.
Nor did that experience stop me from buying their new lighter disk in '02, which is what I race on now (just checked it carefully the day it arrived, not several months later when race season started as with disk #1).
“off center”
from my understanding of the term, it means that the disc is thicker on one side of the circle than the other, ie use the hub as the center and on that plane, there is more material to the left than the right, making it not perfectly round.
thats what i got from the lbs guy.