Converting rigid MTB to CX/road friendly

[redkow97]

This winter sucks.  I bought a fat tire bike to ride MTB trails through the snow, and all it's done since then is rain.  I literally have 70+ road miles on my fat bike, and about 12 trail miles.

It can't rain forever, but it's becoming increasingly apparent that I am going to have to ride on pavement more often than I anticipated.

My long-term solution is to purchase a cyclocross bike, and live with its shortcomings on the street.  My local CX series is an easy (close and cheap) 8-9 races, and it has a fat tire division, so I can do 2 classes if I want.

A new CX bike will run me $1200-$1600.  A good used model with older tech (i.e. rim brakes) will run me more like $600.  Having just spent more than that on my fat tire bike in December, I don't want to bring that up to the wife until after our tax return hits, if at all.

My goal is just to have fun and get better at cycling.  I would like to be competitive some day, but I don't think that's going to happen in my first year riding.  With that said, I am thinking I can spend $150 or less and make JB's Trek 850 more street/CX friendly.  The Fat bike is still my primary ride, and I hope to have it off pavement as much as possible, but the Trek will be my 'commuter' style trainer to grind away miles without destroying expensive fat tires.  I also want the Trek to be wife-friendly for when we take rides as a family.  My wife's super hot and in good shape, but she's not a cyclist.  My goal is for the Trek to be efficient (low rolling resistance) and comfortable (compared to a road bike) for her, and then I can tow both kids in the bike trailer on my fat bike (which should slow me down enough for her to keep up).

This is what I'm thinking:

- new tubes and tires.  Stock tire size on the Trek is 2.1" tires.  I'd like to definitely go with something narrower than 2", and as small as 1.4".   The real debate here is whether I buy a tire that is 90% road, or spend a little more on a purpose-made CX tire, and then ruin the tread by using it mostly on road...  Leaning toward road-biased tires.  $50 for a set, plus another $10 for tubes.

- new seat and post and seat.  JB has a pretty comfortable gel seat on the bike.  that will be great for Sara, but not efficient for me to grind out 20+ mile rides.  I'm currently putting in 20 miles on the fat bike.  With a more efficient tire setup, and lighter weight, I'm hoping 30+ miles will feel routine relatively quickly.  I have no perspective for what a base-quality seat post costs, but cheap seats are $15-$25 all day long.  What's really tempting though is to swap in the post from my fat bike, and buy a dropper post to replace it.  That's assuming they're the same diameter post...  But that takes my cost up to $200 for the dropper post, so that may be a birthday present to myself (in April).  I'll estimate $50 total for seat and (non dropper) post.

- Ergon GS1 grips have been a life saver on the fat bike.  $30 to put them on the Trek is a no-brainer.

 

That puts me right at $140 for my 'build,' and I should lose some weight by fitting the skinnier tires with less tread.   I'm going to have to do some general brake and derailleur tune-up stuff, but that's sweat equity ...or $40 at the LBS if i get lazy.

[motocat12]

find a park with some grass field elevations and ride the fattie some laps there.

[redkow97]

On 1/27/2017 at 4:38 AM, motocat12 said:

find a park with some grass field elevations and ride the fattie some laps there.

Yeah, lack of daylight has been a real drag... I have a decent location for that, but I have to drive to it, and by the time I'm home from work, it's pretty dark.