Singlespeed & Fixed Gear - Goin cheap on new crank arms. What do you think?

So I'm at the point in my conversion that I need to replace my vintage stock crank arm that doesn't allow me to switch out the chain ring, with more suitable ones. I found these on ebay, http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180416657797&ssPageName=STRK:MEWAX:IT

That's pretty much what I want, and I figure I can use it with the existing vintage bottom bracket I have on the bike now. Would there be any reason why I shouldn't get these? Thanks!

Those cramk arms should do just fine. My only concern is you might have a horrible chain line with your current bottom bracket. I would suggest getting a shorter spindle shimano bottom bracket. You should be able to get one from your LBS for around $15.

I'm basically obsessed at this point with how my drivetrain and bottom bracket feels. I can't see how anything that would lead to flex/roughness would be a good thing. I say get something rad and be happy with it.

a little cheaper, but with a 42 tooth ring.
http://cgi.ebay.com/FSA-Vero-Track-Crankset-with-42T-Chainring-Square-Taper_W0QQitemZ360201916625QQcmdZViewItem?rvr_id=&itemid=360201916625

I'm basically obsessed at this point with how my drivetrain and bottom bracket feels. I can't see how anything that would lead to flex/roughness would be a good thing. I say get something rad and be happy with it.

Yeah, but not everyone can even sort out rough spots in their drivetrain. Therefore, something less than rad would still make them happy.

That's pretty much what I want, and I figure I can use it with the existing vintage bottom bracket I have on the bike now. Would there be any reason why I shouldn't get these? Thanks!

just to be clear, your "vintage bottom bracket" is also a square taper, right?

just to be clear, your "vintage bottom bracket" is also a square taper, right?

Yeah it is a square taper, I checked first :)


Those cramk arms should do just fine. My only concern is you might have a horrible chain line with your current bottom bracket. I would suggest getting a shorter spindle shimano bottom bracket. You should be able to get one from your LBS for around $15.

Hmmm, I was hoping the chainline would be pretty good once I just replaced the old chainring (right now it is running on the inner ring and slightly off). When you say, get a shorter spindle, do you mean just the center axel like bar that goes through the bottom bracket, or you mean a complete bottom bracket? Because I don't think I've seen a bottom bracket anywhere for 15 bucks. My LBS tried to sell me a freakin 270 crankset and when I said that was too much he offered their "cheapest" 150 dollar one.. I'm trying to build this "on the cheap", as Sheldon would say, lol.

The arms are probably fine. 165 would probably be ideal- is it a conversion or a "track" frame? The chainring is probably terrible. I'd buy cheap arms and spend some money on a quality chainring- that's going to make a big difference in the smoothness and consistency of the chain tension. A decent road ring is better than a cheap track ring, and of course a good track ring is rounder than a good road ring. You're talking ~20 for the ****ty track ring, ~40 for a good road ring (Sugino, Shimano), and ~80 for a nice track ring(Sugino messenger, Miche, etc.).

Well, I also found these vintage arms on ebay, http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=130345254446&ssPageName=STRK:MEWAX:IT and I noticed that the right arm sits really close to the bolt pattern, as apposed to the first one I showed you all, http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=360201916625&ssPageName=STRK:MEWAX:IT

Is there a reason why the second one sticks out so much further? Is this what effects the chainline?

Oh, and my conversion is of a road frame, not a track frame. http://www.flickr.com/photos/tronicscribe/sets/72157622691740590/

Hmmm, I was hoping the chainlinene would be pretty good once I just replaced the old chainring (right now it is running on the inner ring and slightly off). When you say, get a shorter spindle, do you mean just the center axel like bar that goes through the bottom bracket, or you mean a complete bottom bracket? Because I don't think I've seen a bottom bracket anywhere for 15 bucks. My LBS tried to sell me a freakin 270 crankset and when I said that was too much he offered their "cheapest" 150 dollar one.. I'm trying to build this "on the cheap", as Sheldon would say, lol.

The bottom bracket is the unit that goes through the frame and the crank arms attach to. Iv had good success using a Shimano UN-26 bb with a 110mm spindle with FSA Gossamer arms on a conversion before. Iv also used the same BB with older Sugino Custom arms on an old Miyata conversion. The chain line was not perfect but allowed the chainrings to stay on the outside of the arm and ligned up better than any other BB combo iv tried. and looked great. Just my 2 cents.

Your LBS is nuts if they try to sell you that BB for more than $15. I work in a shop and can tell you wholesale is a bit less than half that.

Shimano 105 road cranks look better and cost like 25 bucks. Depending on the rings youll get a nice 42t chainring too.

Shimano 105 road cranks look better and cost like 25 bucks. Depending on the rings youll get a nice 42t chainring too.

What's wrong with the cranks you have? Is it just that they're a double? Because you can just get some shorter spider bolts and lose the inside ring, no problem.

Don't just guess at the chainline. You need to find the centerline of the frame at the bottom bracket and at the dropouts, then extrapolate from that how far out to the right the chainline will be. This will determine what bottom bracket you need. A sealed bottom bracket cartridge is around $20. You want this to be right- it's silly to spend money on nice parts when the set up is the limiting factor on the smoothness of your drivetrain.

My wife just bought a set of FSA Veros from that same eBay seller for her 1x7. I don't have a problem with Veros or other RPM cranks. For the money, I feel they're just as good as anything else in that price range and in my opinion, look nice and clean. The 46t chainring that came with the arms is bunk, though.

What's wrong with the cranks you have? Is it just that they're a double? Because you can just get some shorter spider bolts and lose the inside ring, no problem.

Don't just guess at the chainline. You need to find the centerline of the frame at the bottom bracket and at the dropouts, then extrapolate from that how far out to the right the chainline will be. This will determine what bottom bracket you need. A sealed bottom bracket cartridge is around $20. You want this to be right- it's silly to spend money on nice parts when the set up is the limiting factor on the smoothness of your drivetrain.
I have done this in the past. My Bianchi Brava fixed conversion had 105 cranks, I filed down the tabs on the back, put a 41t chainring on the outside and picked up a 68x107mm bottom bracket and had almost perfect chainline.

I worry when I see brand names shipped directly from Taiwan. Are they real, or knock-offs?

The set my wife got from that seller are real. They got here pretty quick too for something shipped from Taiwan.

As I'm still looking, mostly on ebay, for either a new crank arm set or a vintage set (just cuz I like the style and it will go well with my conversion), I am wondering what the most common BCD is. The FSA set that I linked to says it is 110mm, while I have found a couple others, I think Campagnolos, that are 135mm. There is also a shimano set that I found that doesn't specify. So, what is a good common BCD that I can find chain rings for, whether I go for a vintage set or not?

don't mess around with 135mm bcd. The only rings you'll find will be road rings, either 50s or 42. 40 39 etc. If you want a "street gear" for a 135mm crankset you either have to get an origin8 ring or spring for a $100 miche. Just buy the veros, steel wool off the logos and move on

Those particular Veros are 130bcd. Steel wool won't even be necessary in removing the logos...they'll wear off on their own pretty quickly.

don't mess around with 135mm bcd.
The only rings you'll find will be road rings, either 50s or 42. 40 39 etc.
If you want a "street gear" for a 135mm crankset you either have to get an origin8 ring or spring for a $100 miche.

Gebhardt
Cycle Underground
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Rocket Ring

Copied from the eBay listing:

It's for a set of new never used and never installed FSA Vero track crankset.


Crank arm length: 170mm
Chain ring: 1/2" x 3/32", 46T
130mm BCD
Square taper
Weight: 643 grams including 2 crank bolts

BB is not included.

So 130bcd should be easy enough to find good chain rings if needed? Also, I mentioned before, but I will ask again, I see some spiders that looked to sit farther out than others. the FSA Veros look like this, as apposed to others that are more low profile and will sit closer to the bottom bracket. Is there a reason for this, and will it effect the chain line?

Oh, and I was also considering the Eighthinch crankset. How are those?

With the Veros, you'll need a 107mm bottom bracket to have your chainring on the outside of the spider and a 103 to run it on the inside. The EighthInch crankset is also actually pretty good for short money.

With the Veros, you'll need a 107mm bottom bracket to have your chainring on the outside of the spider and a 103 to run it on the inside.

you meant 107 inside and 103 outside.

Yes I did. Oops!

Uh, yeah, as mentioned above, 135mm BCD isn't exactly obscure. But still, if you're looking at some cheap 130mm BCD cranks, that's a pretty easy size for sourcing rings across a range of quality and price. Just avoid super obscure sizes -- I actually have *two* 118mm BCD cranksets off old bikes that I use with my conversions. I actually lucked into a source for chainrings and bought a couple of spares while they were still available, but if I ever burn through those or suddenly decide I want something higher end (they're admittedly very basic rings and a bit out of round), I'm out of luck.

Simple contact us and if need be we will add that size of bcd to our jig and specially cut that chainring for you......no extra charge.

http://cycleunderground.com.au/contact.htm

jig:

http://cycleunderground.com.au/oneatatime1.jpg

http://www.weeklyreader.com/readandwriting/content/binary/spam%20boy.jpg
hmmmm tasty

hmmmm tasty

Negative. No affiliation with said company, or Hormel Foods Corporation. Try again...

Sorry, I guess you copy-pasted the info from their site, it sounded like you were talking as if you were from the company.

"custom rings
Simple contact us and if need be we will add that size of bcd to our jig and specially cut that chainring for you......no extra charge."

http://www.makelovenotspam.com/mlns.gif

With the Veros, you'll need a 107mm bottom bracket to have your chainring on the outside of the spider and a 103 to run it on the inside. The EighthInch crankset is also actually pretty good for short money.

I'll have to measure my stock vintage bottom bracket to see how long it is. I'd like not to buy a new one, but it sounds like I might have to.

That company does interesting work. If the poster works for them, thanks for letting us know about the parts source. You need a US dealer. If not, thanks for letting us know about the parts source. Prices in AUD, you think?

If they're in Sydney, those prices should be in AU$, but they're practically equal to US$ these days.

http://cycleunderground.com.au/contact.htm

That's pretty slick. I always thought something like this should exist out there, but never saw it before your post.

I worry when I see brand names shipped directly from Taiwan. Are they real, or knock-offs?


So, where do you think they're made then? Taiwan is not in the fake game like China is, so relax. And these days, even many places in China are reliable too.

So, where do you think they're made then? Taiwan is not in the fake game like China is, so relax. And these days, even many places in China are reliable too.

When I see someone on eBay selling FSA, Shimano, and Fizik direct from Asia, I'm a bit wary. That's why I asked if they were real or knock-offs.

That makes about as much sense as seeing a Ford truck for sale here in the US and thinking it's fake.

That makes about as much sense as seeing a Ford truck for sale here in the US and thinking it's fake.

No. It's about the same as someone in Mexico selling new Ford parts on eBay.

What about an old double like this one, http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260508507111&ssPageName=STRK:MEWAX:IT

the inner ring is 42, would it be possible to get rid of the outer 52, and just use the inner ring? or will it not fit with because it is only meant to be inner?

as long as you're saving money, what if you brought in the spindle with the original BB by mounting the axle backwards? Seriously...seems like you could do that with a loose bearing BB....

as long as you're saving money, what if you brought in the spindle with the original BB by mounting the axle backwards? Seriously...seems like you could do that with a loose bearing BB....

I'm no expert, but that sounds possible, and I just might try that when I need to adjust the chain line.

One other question I have is, what is a good crank arm length? I see a lot of vintage ones at 175mm, newer and some vintage at 170mm, and just now I was looking at the Eighthinch cranks and they offer them all the way down to 160mm I think. I would like having more clearance when I turn, but will a shorter 160mm arm cause any problems I'd be better off avoiding by getting a 170mm?

Most folks go 165mm, which gets you pretty good clearance and a reasonably tight spinning radius. I would think 160 would be uncomfy for most riders -- I ride 170 with a freewheel, and 165 is as low as I prefer to go.

For the bb, also keep in mind that, if you're running an older, non-sealed bb, you can swap spindles. They're harder to source these days, but you might bring your cranks by a bike stop to see if they have the right size or can order it for you. I did this with my conversion and ended up paying $5 for a dead-on chainline.

Most folks go 165mm, which gets you pretty good clearance and a reasonably tight spinning radius. I would think 160 would be uncomfy for most riders -- I ride 170 with a freewheel, and 165 is as low as I prefer to go.

So I've decided on the Eighthinch cranks in white. Now I just need to decide what arm length to get. I'm hoping to hear from a few people if they prefer 165 or 170, and if there is much of a difference in how it feels or spins. This is just for my casual riding around town, and getting better at riding a fixed gear. I'm leaning towards 165, but a little worried it will be too short, although I have nothing to compare that feeling to. Any more advice would be great. thanks.

So I've decided on the Eighthinch cranks in white. Now I just need to decide what arm length to get. I'm hoping to hear from a few people if they prefer 165 or 170, and if there is much of a difference in how it feels or spins. This is just for my casual riding around town, and getting better at riding a fixed gear. I'm leaning towards 165, but a little worried it will be too short, although I have nothing to compare that feeling to. Any more advice would be great. thanks.

I got these Eighth Inch cranks (http://www.eighthinch.com/cranks.html) in 165, and I'm very happy with them. I think that the 165 length is better for spinning, but that's just my opinion.

is there much difference from 165 to 170? or, what is most common?

So I've decided on the Eighthinch cranks in white. Now I just need to decide what arm length to get. ...

I ride 175's on my Steamroller because of my long legs (in addition to a set back seatpost). No pedal strike so far but I don't ride as hard as some here would.

I finally made a decision and got the white 170mm Eighthinch crankset. I was plagued for quite a while about the arm length vs. torque vs. pedal scape. Now I realize I will have to deal with my bottom bracket. It is stock from an old 80's Motobecane road bike, and I'm pretty sure it is an ISO bb. The Eighthinch crank I'm waiting for is made for JIS. I read it will most likely fit fine, but I have a feeling I will need to replace my bb, or flip it around or something. We'll see. This never ends, lol.