Well, I’ve decided to pull the trigger on a new tri bike, and I think I’m gonna try to set up my P2K as a fixie…take off the aerobars, leave on the base bar, leave on the brakes, take off the ders, and put on a fixie cog in the back. My questions:
-Do I need a new crank, or can I take off the 53, and just go with a 39 tooth up front?
-What works best for a fixie, gearing-wise? 39x20? 42x20?
Spot
If you don’t have horizontal dropouts in the rear, your gear ratio may be determined by what your optimal chain tension can be (the so-called magic gear). They sell chain tensioners but it just doesn’t fit with the idea of a clean, simple fixie, IMO.
You should be able to run your current crank- just choose your chainring size and mount it on the inside of the crank (you will most likely need to get shorter chainring bolts to do this) to get a nice straight chainline.
Pushing the same number of gear inches is a tad easier on a fix as opposed to a freewheeled bike, I think. My commuter fixie has 42x17 since I live in a hilly area and don’t run brakes. This also makes skidding and other fun things like backwards circles a little bit easier. If you live in a flat area, I’d say something on the order of 49x17 or even a little larger will be fine.
My fixie bike porn (I have since put nitto track drops on and it makes it even better)- http://fixedgeargallery.com/2006/june/BrianLawney.htm
New crank not required, just need to get single chainring bolts - your current set won’t tighten properly with a ring missing.
Gearing will depend on your area - lower gears for hilly areas. Most guys seem to go for 42x18.
Your problem is that the rear dropouts on the P2K will be too wide for a fixie hub, although a singlespeed mountain bike hub may fit, but don’t quote me on that.
You can get an adapter from surly with will convert a cassette hub to a fixed hub, from Harris cyclery http://sheldonbrown.com/harris/index.html
or you pack out your current cassette hub with spacers in place of the cassette to only take one sproket and run a single speed freewheel, like the aforementioned mountain bike.
EDIT: edited for spelling
42x16
sheldon brown for the best fixed info
I would get a hub for vertical dropouts.
you can’t use a chain tenshioner on a fixed gear bike only on a single speed.
I just got back from a fixed ride
Nice weather in nothern NY today .
the ice is starting to stick around all day in puddles .
can snow be far off ??
should be a very, very nice fixed gear you are building.
do it right the first time with a good wheel and hub (rear) it is worth it
dirt
The P2k rear spacing should be 130mm so it is not a problem. Surley and others make a fixed hub that can adapt to that spacing, so just buy the right width of hub for the rear wheel you will build. The Surley cassette hub convertor thing costs $80 bucks and you still have to re-dish the wheel. A regular fixed hub has less parts to break. I agree that Harris Cyclery is a great place to buy fixed gear stuff, and they offer a build service also. I had my wheel built locally, so I let local guy source the parts and paid him for the finished wheel (not cheap, but good quality parts and work).
Gearing? Here in Austin I’ll run 46/16 (700c wheels) for hills and good acceleration, or 48/16 for high speed on flats. The best thing that you can do for gearing is to find a local bike co-op or junkyard or local fixie riders who will sell/exchange your chainrings for $5-$8 each so you can try a range of gears. Buying chainrings is at retail prices expensive when you are experimenting.
Enjoy your fixed P2k. Try riding it fixed with both the aerobars and the bullhorns on, since the P2k has similar geometry to the P3 and I hate riding the bullhorns on my P3. I can ride aero for hours, but sitting up makes my bike too twitchy. I thought about doing the same thing since I bought one of those InsideOut bikes for $600, but too many friends are lined up to buy it so I guess not.
BNZ
I’m glad that Spot will be fine with riding his P2k as a fixie. I didn’t know for sure if there was a 130mm fixed hub available, that’s why I suggested the Surly converter. Never used it personally as I have a fixie already and run 50x15. See here
http://forum.slowtwitch.com/gforum.cgi?post=1076150;search_string=fixie%20position;#1076150
Your advice is good and I’m sure will stand Spot in good stead. I too hope he converts to the world of fixie.
Niel_lang,
You got right in that running fixed is what matters. Everything else is just minor details.
BNZ
I was hoping to do this as cheaply as possible at first…do I need to have my rear wheel rebuilt with a special hub, or can I go with the cassette hub convertor thingy without doing anything else? Will not having my rear wheel redished cause issues while I figure things out? And do you know where one can find those short chain ring bolts? Thanks to you and the others for advice on this…
Spot
go to the shop for the shorter bolts. alternatively you can just put spacers in there. Your shop may have those for free/cheap.
You can get the surly fixer. You can also order an inexpensive fixed wheel through QBP.
ain’t you got a loco bike shop ??
the boys their would know about the short bolts the rear wheel they maby got used stuff.
talk to them
If you got a old 5 speed wheel they can remove the freewheel and spin on a cog and bb lock nut and redish the wheel. then you are set if you can find the right gear combo for a tight chain line.
dirt
ps my first fixed cost $35. with spray paint
pss http://www.excelsports.com/new.asp?page=8&description=Fixxer+Cassette+Hub+Converter+Kit&vendorCode=Surly&major=8&minor=3
Don’t be a sissy! Go with the 53 up front and slap on a 17, 18, 19, or even a 20 on the rear.
That’s pretty cool…might have to get me one of those. Thanks for showing me this…they didn’t show it in the catalog. I think what I’m gonna do is convert it first to a single-speed, and then go the full fixie route after I have paid down the new bike.
Spot