Showing posts with label wheel build. Show all posts
Showing posts with label wheel build. Show all posts

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!

Wednesday, February 6, 2008

Dynohub Wheelbuild!

Last night I built my first wheel from scratch! And it just so happens to be a light-generating dynohub, so the outcome is extra-fun. It was basically two projects in one sitting:

1) build a 32-spoke, triple-crossed wheel on a Mavic OpenPro rim & the dynohub
2) mount & wire a Schmidt E6 lamp to the dynohub

Here's what I started with: 32 spokes/nipples, a rim, and a hub! Using Schraner's wheel-building book, and some advice from the LBS, I sat down on the living room floor and went to work. (A real workspace would be nice, but our apartment just doesn't have the room..)


A few minutes later, and the wheel is starting to take shape. This is an awkward part of the build, because the hub wants to flop all over the place, but you don't want to bend or stress the spokes. A vice-grip would have helped, but I managed.


After probably another 30 minutes, it'd definitely looks like a wheel, and even feels like one! It felt great to pick it up and have it feel sturdy, like a real wheel. Hell, it is a real wheel! This pic is with the right side done, just starting on the left side:


Ta da! Using a truing-stand that the LBS let me borrow, the 2nd part of the wheel-build commenced: truing. This part is actually harder than putting the wheel together, and I probably spent at least another 30 minutes fine-tuning it.


So once it was more or less true (still some radial "untrueness," e.g. the wheel isn't perfectly round, but it was about as good as I could get it), I just had to try it out! Previously I'd planned on taking it back to the LBS for a check-up, since I didn't totally trust my newly-found wheel building skills. But fuck it, all this work, you bet I'm gonna take it for a spin!

The finished product - A Schmidt E6 lamp attached to my shiny new wheel/hub!

When everything was all finished, it was 2 AM. So what do you do with a new dynohub/light setup at 2AM? Test it out! Once I started rolling I was so excited to see the dynohub in action, I didn't even realize it was the wheel I'd built that I was rolling on! It didn't explode or crumple, so I guess I did it decently well. I think I'll still take it into the LBS for some fine-tuning, just to be sure. Last thing I need is to be on a 200k Brevet and have a wheel blow up!

And the light, you ask? How's the actual lighting? Holy shit, the Schmidt E6 lamp is insane! I almost felt embarrassed rolling down Broadway with what probably looks like a scooter headlight strapped to my bike! It certainly lights up the road no problem. And the drag is minimal, you don't even feel it when rolling.

From a product description:

"The E6 has the most focused and brightest light pattern available. It's rectangular window keeps all the light on the road in front of the rider. There is no extraneous light. It is the only light that can cut through on-coming auto headlights to light the road."
For night-commutes and overnight Brevets, this thing will be perfect! No longer will I be squinting into the darkness to try to make out my weak LED's light on the ground. No longer will cars in the distance be wondering if they see a fire-fly up ahead. They'll know that this is some kind of moving vehicle - even from up to 1/4 mile away, from what I hear!

But at the same time, I don't want to turn into one of those people (you know who you are!) that ride with ultra-bright lights on the Burke-Gilman/I-90 trails and blind everyone! Point that shit down! I usually say something ("too bright!") when attacked by someone's lamp, so I'll be sure to not blind anyone myself.

Bring on the night!