maandag 8 november 2010

Weight wining, price fighting.

I'm becoming more and more of a weight weenie, it's becoming a bit of an obsession.... That may be a bit strange for a flatlander, but I find the handling and ease of acceleration of a light velomobile so much superior, that I've decided to spend some time and money to find out how to make a lighter Quest (my Mango Sport already has lightweight components) without sacrificing any of the practical features. It's no use to have a lightweight velomobile when it's components are to weak, right? There are plenty of exceptions to the rule that lighter is weaker however. Take the KMC X10SL chain: it is tougher than most heavier chains and the Ti-N coating makes for less wear and better shifting. There are three typical racing-bike lengths lying on my kitchen scale here, that's about how much I need for a Quest. One length of 114 links is 742:3=247 grams. That includes a 'missing link".  I found a cheap webshop that doesn't sell the chain one length at a time in a nice package, but straight from the roll. It was 105 euro (shipping included) and that saved me 40 euros from the cheapest eBay seller!? Another nice thing: I don't have to link the three chains.
But what about the weight reduction? Well that depends what quality chain you compare with, but even when compared to other light 10-speed chains, this one gives me about 120gramms reduction.

 Chains run over a cassette and RECON makes the lightest of them all. 108 gramm for an 11-27 10-speed cassette is amazing. They usually don't come cheap and they are hard to find. A Taiwanese seller said to have some for less than 100euro but after ordering it appeared to be out of stock. I got a full refund, no problem but no cassette either. I even e-mailed the manufacturer in Taiwan and he replied very correctly that an Italian reseller had all possible cassettes from RECON. But I don't want all, I just want the cheapest 11-27! So I looked around again with google and finally found a shop at the other side of the ocean that had my size for 130 euro (incl. shipping). That's a lot of money for a cassette that wears and will have to be replaced. The enclosed drivetrain ensures a long life I reckon. Light cassettes from SRAM and Shimano are mostly twice the weight of this one and are pretty expensive nonetheless. That's why I chose this one, giving me the greatest bang for the buck.
The reason that these cassettes are so light is that they were CNC fraised out of a solid piece of aluminium. Everything unneccesary is simply "grinded" away, like Apple is doing with the aluminium frame of the MacBook, making it stiffer then when made of seperate small parts bolted together. Aluminium is not very wear-resistant, but the ceramic coating should help. I have had a RECON 12-23 cassette on my Mango Sport for about 2000km now and see no wear so far, so I'm pretty confident it won't wear before the chain does. (edit: I have paid way too much, you can find RECON cassettes on the blogspot of luckynino, tip from Jeroen Koeleman for 50euro excl. shipping)

The derailer I chose is the X0 SRAM with medium cage. They have a very good reputation and I have good experiences with the X5 that has the same construction. I could get a good deal on Marktplaats from a bicycle mechanic. It's brand new and he wanted 20euro below the normal price of about 160 euro, but looking at eBay I found one seller that was significantly cheaper at 117euro. I confronted the man with this fact and after some tough negotiating we agreed on 118,35euro (incl. shipping).

X5 would have costed me about 60euro and it weighs 300gramm. The X0 has significantly less play mounted to a derailer hanger. The X5 is good enough for 9-speed but I think I will need better quality for a 10-speed system. Together with a weight reducion of a third, I think I made a pretty good deal. A derailer can last very long in a velomobile and then you'd better have one that shifts reliably.

More components to follow.....

2 opmerkingen:

  1. Hi H@rry,

    I'm also a wheightweenie and bought almost the same parts for my, still to build, carbon velomobiel. I've chosen for a Dura-Ace RD-7900-SS rear deraileur which is 25g lighter than the Sram X0 deraileur.
    I know it's a bit to late but I've bought a lot of parts from for less money than you did. Maybe this website is usefull for other readers of your blog.

    Good luck with you modifications!

    With kind regards,
    Jeroen Koeleman

  2. Hello Jeroen,
    very low prices indeed. I will keep an eye on that site.
    Thanks, H@rry.