Singlespeed & Fixed Gear - First frame buildup: Crank/BB Questions
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12-25-04, 05:17 PM
OK this is the first time I've ever built a bike from a bare frame. I bought it with nothing more than a couple of brakes mounted, and the headset/fork installed. I will figure out how to route the brake cables, etc, that'll all be pretty simple.
What I don't get though is what kind of cranks and bottom bracket to buy. I'm using a Suzue basic fixed/free hub. On the old bike (bent frame!) that I had built up, the outer (larger) chainring lined up perfectly with the hub. Is this true on all road doubles?
From what I have read, I just have to find a crankset to use, and then the crankset will specify spindle length required for the correct chainline. Then just mount a 42 tooth (my personal choice) chainring in place of the 52 or 53 tooth ring, with appropriate bolts, and be done.
Do I have the right idea here?
I am also lost as to what to look for in a crankset. I see many new ones costing alot of money, and I am TRYING to be frugal here. Aren't we all though :rolleyes: . I assume that I just want to look for one with a 130BCD so that chainrings will be easy to get. Do I have that right?
Thanks for reading, sorry for the 'book' of a post.
12-25-04, 05:29 PM
Why can't you just use the BB and crank of you old bike?
12-25-04, 05:38 PM
Good question! The fixed BB cup was rust-welded to the frame for one, and secondly this new frame is too nice for the hack job I had done on the uber-cheap cranks. Plus, I ruined the extraction threads on one of them, in my inexperience. So, I decided to go all out and buy new parts. Simple as that :)
12-25-04, 05:51 PM
Gotcha. Those are excellent reasons not to use the old cranks, and then buy new ones.
If cheap is the operative word here, then I would go to the LBS, and rummage through the parts bin, or ask (nicely!) if they have any used cranks that they don't need. They might even give you an old set, or let one go for a few $$.
You will probably find soem this route.
The other option is the bulletproof/dimension arms. They're around $35/set, and have the 110 BCD, so they're pertty verstile. You can get 110 BCD chainrings form danscomp.com for around $10, availavble in many differnt sizes/colors/chain types. The cranks are available in many different lengths from 140mm to 175mm. These cranks paired with a UN53 or UN72 BB should give you years of trouble free service.
scroll down a bit...
12-25-04, 10:46 PM
Thanks, I'll explore those options. My budget is about $100, but that's got to include the bottom bracket tool. I'm sure I can find a solution in that range. I just didn't know where to look! Thanks again.
12-26-04, 04:18 PM
I did some searching, measuring, learning about chainlines and what works etc. Looks like I'll be going with those Bulletproof cranks, a 107mm bottom bracket that is suggested for it, and putting the chainring on the inside of the spider, and a bash-guard on the outside. Thanks BostonFixed for the help, I appreciate it much!
12-26-04, 07:17 PM
Here are some other cool tricks. If you have an old 110BCD cahinring lying around, or ask your LBS if they have any old worn onut ones, grind or file the teeth off and make a bashguard. It looks really slick, and its free...!!
Break off the teeth first with some slip joint pliers, a vice , or vice grip pliers. Then continue with your file or grinder. Yea it will cost you time, but its free if you already have the part and tools, it also looks really good. You also can use the standard double crank bolts then.
For a bb tool, nashbar sells their bb tool for $7. It will only work with a 1/2" drive ratchet though, so you need to have the ratchet.
A UN53 bb at nashbar is only $19. These bbs are really good. I have a similar model on a bike, and its been on there since I bought the bike used, which was 5 years ago. This bike was used for many commuter miles year round, including boston sand/salt/snow/rain/etc. It's still going fine! Who knows how long it was onther before I bought the bike!
EDIT: heres a pic of a homemade bashguard, with cool teeth machined in...
all of these things should come in well under your budget of $100! Time to splurge on other things!
12-26-04, 09:15 PM
You rock man! Thanks for the tips!
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