Thursday, December 18, 2008

New Shimano 3N80 Dynohub & Another (Partial) Wheelbuild

Word of Shimano's new 3N80 dynohub has been out for a few months, and I finally found it online, so I just had to put in an order. It was supposedly lighter than both the Schmidt & older Shimano dynohubs, and cost just $50 more than the 3N71 that I already have. Plus I wanted to do another wheelbuild, and this was the perfect opportunity.

(Unofficial) Dynohub weights*, prices

Shimano 3N71: 735 grams (Peter White says 680 g) ($90)
Schmidt SON: 575 grams ($200+ for the SON28)
Shimnao 3N80: 490 grams (~$145)

The weights & prices were googled, so I'm not sure of their accuracy. But if those weights are correct, I'm dropping a half-pound off my current front wheel (Open Pro with 3N71), and thus off the bike! Of course it would be cheaper to lose, say, 5 lbs (2,267 grams) off the engine.. but of course that takes time and dedication.

I'm not sure of the efficiency of this new 3N80 yet, but I'm eagerly awaiting trying it out! And no matter the exact weights, it's not like 100 grams is really all that much..

The Wheelbuild

This was my second attempt at putting together an Open Pro rim, a Dynohub, 32 spokes/nipples together, in the "triple-cross" lacing format. (Using this book as a guide)

For some reason I thought that since I put one together back in March, that this time around would be a one-hour affair in which everything worked out.

And due to my overconfidence, I put about four spokes incorrectly (I did every 3rd rim hole instead of every 4th), which meant I had to undo them and start that part over.. Well, at least I can file those extra minutes under "Experience."

Eventually I got it put together, but it was two+ hours by that time, way over how long I'd expected.

Then I proceeded to get to the hard part of wheelbuilding, truing/etc. (I don't have a dishing tool, so I knew I'd be taking it into the LBS anyway at the end). Even with my truing stand it was a task, but I got the rim to go from a wobbly mess to a clean looking rim.. Except for that radial tension wasn't set correctly, so when looking at the wheel from the side it looked really wobbly.

And as much as I tried to get it all the way true, I just couldn't do it. After taking it into the LBS, Lloyd the owner informed me that they keep the rim true raidially while building the wheel, and then true laterally.. so I was doing it backwards. Thanks Lloyd!

* As a point of reference, a Ritter Sport chocolate bar is 100 grams:

Those Ritter Sport bars are really good fuel, by the way!


Mars Girl said...

Ritter Sport bars rock. I love the chocolate covered butter cookie and the marzipan ones the best...

Robert H said...

100g is 100g though. It all adds up. I've been starting to notice where I can cut corners here and there for these rides. Do I need to lose 20 pounds off the engine? Sure...

Damn it, now I'm depressed.

Narayan said...

Open Pro's huh? You remember my wheel from the Windy as hell 600 don't you? That was an Open Pro.

Anonymous said...

I do remember that poor wheel of yours... that was awesome you still finished on it!

But if we avoided every wheel that had somehow broken in the past, would we have anything left to roll on?

I think the Open Pro has been popular for a reason (decent price), and while Mavic isn't as great as I used to think, my Ksyrium SLs are still "bombproof," and pretty damn light (maybe a little overpriced, I'll give you that).

New England Bicyclist said...

What's with the Open Pro hadte from Narayan? I have 12,000 miles on two sets of Open Pros (one 32 hole, one 36 hole) and love them. I just built up a wheel like your's and am excited to get it on the road once the mess of the blizzard dries up some. I'm wondering how your build stood up over time. Is the wheel still in use?