Saturday, 1 February 2020

Zipp firecrest 303 marriage with Chris King

Zipp's rims are the best in class (period). They are light, braking well, made with quality and, honestly, I've never seen them overheating. Whole wheels are a different story. Build quality varies and hubs are not that great and long-lasting as adverts are saying. 
In this build, my job was to replace the Zipp hubs with something more decent and robust. See what came up from that project!

Let's start with the number of spokes. Front 18 and rear 24h, straight pull. My initial idea was to replace those Zipp hubs with the latest DT Swiss 180 ones. What a surprise when I found out that 18 drilling is not an option anymore. 

Checking further the premium brands I had to scratch out even more from my list: Extralite, Carbon Ti, Acros Nineteen, Tune - none of those are available in 18h SP.

Chris King came to the rescue, although not SP, but legendary construction, lasting for years, and available in 18/24h!




Next were the spokes. Taking into account the rider's weight, hub geometry and rim's profile (both symmetric) I decided to go with Wing 21 on front and Wing 21/23 on the rear. On the rear, I used an old trick to put thicker spokes on the DR side to thinner on NDR to get better tension of left side spokes. As per whish of the owner I used brass, although alloy with washers would be just fine.


Few words about the build:
  1. Watch out on the ERD. The catalog's one says 520mm for this rims, but measuring it by myself I came up with 505mm. That's 1.5mm difference, which is significant for spoke length. If I'd go as per catalog, I wouldn't be able to tension up those wheels to 115kg as they should be.
  2. Second, the Zipp spokes washers. Absolute nightmare if you need to change them. I have my own way to deal with that, however, if washers are in the good shape, not corroded and you won't change the placement of each, you can keep existing ones.


In any case, keeping washers or replacing them, you will spend much more time on build/rebuild Zipp wheels than normal rims. Those washers are bigger than the spoke holes and installing them is real hassle. 

Having spoke's replaced the build went just fine. Zipp rims are very well made so obtaining equal spokes tension and true wheels wasn't difficult at all.


Very nice looking wheels. Zipp rims married with Chris King hubs. 

Now, having such components, those hoops will roll for the next few years.

Legendary Zipp Firecrest 303 rims:


Pillar Wing Aero spokes with reinforced J-bend section, measuring 2.2mm:


Chris King hubs, with patented ratchet and drive ring, solid construction, good geometry and bearings play adjustment system:


This is, how the good pair of wheels look like:


If you have such or similar challenging project to rebuild then feel free to contact me. Blackcat wheelbuilding will be happy to take an interesting project on the workbench!

Cheers
Tomasz
blog-wheelbuilding

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