jk__74

I recently noticed that the 06 Bianchi Castro Valley frame has semi-horizontal, forward facing dropouts. I would assume that to convert one of these to a single speed (without buying a new rear wheel with a flip flop hub), you just need to:

- remove rear derailleur and cabling
- remove cassette and replace with a single speed spacer kit
- either shorten chain or replace with shorter chain
- remove right hand STI lever if so desired (still need a brake lever of some kind though)

At this point - you should end up with a 42T front chainring and whatever size cog you use with the ss spacer kit. Am I missing anything here? I have been shopping for a SS cross-type bike for winter commuting, but also recently saw a cross race and thought it might be fun to try one next year. Seems like a 06 Castro Valley could be modified to run through the sloppy weather as a SS and then reinstall the cassette and rear derailleur for cross season. Best of both worlds. Not a perfect cross bike - but something decent enough to give it a try on.

I'd imagine I would want to address the front generator hub if weight was an issue - but at this point a cross race is simply at a 'I'd like to try that' stage.

I'd also assume I could accomplish this with a Cross Check as well, although the complete Cross Check comes with a double up front, rather than the 1x9 setup of the Castro Valley. My LBS currently has an 06 Castro Valley in my size, thus the interest ....

M_S

Isn't the Castro Valley the same frame as the San Jose? That could potentially save you a lot of work

jk__74

They are very similar, except that the San Jose's dropouts are rear facing and the San Jose does not have a rear derailleur hanger. So - I believe the only way I could run a San Jose as geared would be using an internal hub - which from what I understand, cannot handle the stress of a cross race (except maybe a Rohloff).

M_S

Well, okay, but you said you want to run single speed, right? So why the need for the derailleur hanger?

jk__74

Sorry - I might not have laid this out very well.

I am pretty confident that I can handle my flat commute on a single speed.
A cross race - not so sure.
Thus, I'd like to run it geared for the potential cross season, and SS for the rest of the year (esp winter), for my commute.

modernjess

That seems like one way to do it. With that set up, I'd leave the brifters on and use a cable splitter for the rear derailleur cable, less of a hassle for the switching back and forth.

Also, you can get a decent a set of single speed wheels for not too much money. (used, ebay- CL etc..) This would then get you a front wheel with no dynamo hub as well. With 2 chains, a cable splitter, and the 2nd set of wheels, you could be swapping set ups in mere minutes. Not a bad idea for winter too.

vik 

Why not just leave the shifters and der on the bike. Leave it in whatever gear you want as your "SS". Then if you should feel the urge to shift you can and if not you can have a virtual single speed bike.

I can't see a lot of appeal to a SS bike when you already have the shifter/brake & der on it.

Percist

I've used an 06' Castro Valley as a commuter for the past year.

1. It's a heavy bike to race. I rode it on some training races when my Madone was in the shop and it really killed me on surges that are usually nothing. This was a flat couse, I'm thinking a cyclocross course would not be pleasant with such a heavy bike, although the top tube has a comfy flat spot for your shoulder.

2. You may have clearence issues with cyclocross tires. There's a lot of room down there for the 28's, but be sure to measure with your cyclocross tires in mind before you buy.

3. There's a lot of wiring associated with the generator hub. The light is hardwired so you will have to remove all the wiring down to the fork (which you will want to do if you race cyclocross).

I'd reccomend against it just for the hassle of changing out all those items above that make it a Castro Valley. Don't get me wrong, it's a great commuter though and an acceptable road bike in a pinch. I can't think of anything I'd want more in a commuter (short of an xtracycle. . .).

ceridwen

It's the Volpe frame (and dropouts). The San Jose shares the frame, but has different dropouts (actually track fork ends, not dropouts, apparently). I actually test rode a Castro Valley to decide on fit before having the LBS order my Volpe.

Clearance should be fine up to 32c tires and possibly higher. The Volpe comes with 32c knobbies (WTB All Terrainasaurus) and I was still able to fit fenders on mine (also the '06).

Sheldon Brown's page on singlespeed conversions should help point you in the right direction. Keeping in mind that I've never done a singlespeed conversion from the looks of it on that site, you should have no problems (the dropouts are the short horizontal type). You may need a chain tensioner depending on what size cog you want to use.

https://www.sheldonbrown.com/singlespeed.html

If the price is right I think it's a good option. It should not cost you much to change to single speed and it should work fine for you to get a feel for cyclocross. If you get really into cyclocross, you will want to upgrade but that could be said of pretty much ANY bike in the same price range.