I'm building a 1952 Schwinn Phantom into a clunker, and I'm wondering what I need to convert it from a one piece crank to a sealed three piece crank. Does anyone know a good deal on conversion kits??
Bottom Bracket Conversion
- Thread starter schwinn boy
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Check out Porkchop's for a conversion kit.. Or you can get a Profile crank set. There's quite a few cranks sets that you can use to convert your cruiser to a 3pcs..
I just got done converting my 51 Schwinn to a 3pcs.
I just got done converting my 51 Schwinn to a 3pcs.
I do this on nearly every build. I like using Felt bottom brackets and 3 piece cranks off of eBay. I try to keep it in the BMX side with American sized bottom brackets. Danscomp BMX is also another good place. If you can buy the cranks and bottom bracket as a kit go for it.
I am currently trying to fit FSA BB cranks onto a Felt Cruiser. A little removing of material must be done, I am talking millimeters, and I have to use the FSA bearings in the Felt Sealed bottom bracket cups. Don't do as I did and make more work for yourself. Avoid mountain bike cranks? [emoji61]
- by Gigmata
I am currently trying to fit FSA BB cranks onto a Felt Cruiser. A little removing of material must be done, I am talking millimeters, and I have to use the FSA bearings in the Felt Sealed bottom bracket cups. Don't do as I did and make more work for yourself. Avoid mountain bike cranks? [emoji61]
- by Gigmata
I've found that it's pretty easy to use the American-to-Euro adaptors (like this: http://www.niagaracycle.com/categories/truvativ-bottom-bracket-conversion-american-to-euro
And then just thread in whatever MTB/road/Track-type Euro BB to mount the cranks. The only reason I tend to avoid this is b/c it's a kludgey solution where, in the end, your crank set-up will be weaker. Even if you're running the most bomb-proof mtb/dh cranks, your BB interface is weakened via the use of the adaptor-- more parts, more bolts, more things to flex and wiggle.
OTOH, tubular chromo 3-piece cranks, like they use in bmx, you've got very sgtrong and stiff cranks that are designed to work in a BB set without a bolt-in adaptor. Even better, you have a lot of adjustability in the chainline with a BMX crank, which is weird b/c BMX set-ups tend to have standard chainline, but it's an awesome surprise advantage.
A lot of folks go 3-piece on their cruisers. I've got 3-piece cranks on a couple different bikes with american-sized shells, and RRB is littered with hundreds of posts about it. Going with the euro adaptor and a thread-in BB/crank is totally workable, and it ain't bad, and it's not even all that weak if properly installed. But, if you go with a square-taper type of crank/bb (and most RRB types do), then you're going to be wondering what length spindle to get, and you;re gonna be PO'd when you realize that these things aren't standardized.... you're going to have to research it, google it, do some math to make it all fit your application, and then it still might take some trial and error.
If you go with a more modern external bearing set-up, you'll find that chainline for the MTB-type cranks is far too outboar (and not adjustable). If you get an external-bearing road crank, it's pretty straightforward, but chainline is not adjustable plus you gotta run the sprocket on the inside of the spider which works fine, but it gives the bike a no-talent hack-job kinda look (and yeah, I've sported bikes like that...so i speak from experience).
Get yourself some of those Sunday Saker cranks; they're cheap and ppl seem to like'm. I just installed some Redline Flights on my Triple S, and while they're a bit pricey, they look awesome and they're stiff as can be....
And then just thread in whatever MTB/road/Track-type Euro BB to mount the cranks. The only reason I tend to avoid this is b/c it's a kludgey solution where, in the end, your crank set-up will be weaker. Even if you're running the most bomb-proof mtb/dh cranks, your BB interface is weakened via the use of the adaptor-- more parts, more bolts, more things to flex and wiggle.
OTOH, tubular chromo 3-piece cranks, like they use in bmx, you've got very sgtrong and stiff cranks that are designed to work in a BB set without a bolt-in adaptor. Even better, you have a lot of adjustability in the chainline with a BMX crank, which is weird b/c BMX set-ups tend to have standard chainline, but it's an awesome surprise advantage.
A lot of folks go 3-piece on their cruisers. I've got 3-piece cranks on a couple different bikes with american-sized shells, and RRB is littered with hundreds of posts about it. Going with the euro adaptor and a thread-in BB/crank is totally workable, and it ain't bad, and it's not even all that weak if properly installed. But, if you go with a square-taper type of crank/bb (and most RRB types do), then you're going to be wondering what length spindle to get, and you;re gonna be PO'd when you realize that these things aren't standardized.... you're going to have to research it, google it, do some math to make it all fit your application, and then it still might take some trial and error.
If you go with a more modern external bearing set-up, you'll find that chainline for the MTB-type cranks is far too outboar (and not adjustable). If you get an external-bearing road crank, it's pretty straightforward, but chainline is not adjustable plus you gotta run the sprocket on the inside of the spider which works fine, but it gives the bike a no-talent hack-job kinda look (and yeah, I've sported bikes like that...so i speak from experience).
Get yourself some of those Sunday Saker cranks; they're cheap and ppl seem to like'm. I just installed some Redline Flights on my Triple S, and while they're a bit pricey, they look awesome and they're stiff as can be....
I've found that it's pretty easy to use the American-to-Euro adaptors (like this: http://www.niagaracycle.com/categories/truvativ-bottom-bracket-conversion-american-to-euro
And then just thread in whatever MTB/road/Track-type Euro BB to mount the cranks. The only reason I tend to avoid this is b/c it's a kludgey solution where, in the end, your crank set-up will be weaker. Even if you're running the most bomb-proof mtb/dh cranks, your BB interface is weakened via the use of the adaptor-- more parts, more bolts, more things to flex and wiggle.
OTOH, tubular chromo 3-piece cranks, like they use in bmx, you've got very sgtrong and stiff cranks that are designed to work in a BB set without a bolt-in adaptor. Even better, you have a lot of adjustability in the chainline with a BMX crank, which is weird b/c BMX set-ups tend to have standard chainline, but it's an awesome surprise advantage.
A lot of folks go 3-piece on their cruisers. I've got 3-piece cranks on a couple different bikes with american-sized shells, and RRB is littered with hundreds of posts about it. Going with the euro adaptor and a thread-in BB/crank is totally workable, and it ain't bad, and it's not even all that weak if properly installed. But, if you go with a square-taper type of crank/bb (and most RRB types do), then you're going to be wondering what length spindle to get, and you;re gonna be PO'd when you realize that these things aren't standardized.... you're going to have to research it, google it, do some math to make it all fit your application, and then it still might take some trial and error.
If you go with a more modern external bearing set-up, you'll find that chainline for the MTB-type cranks is far too outboar (and not adjustable). If you get an external-bearing road crank, it's pretty straightforward, but chainline is not adjustable plus you gotta run the sprocket on the inside of the spider which works fine, but it gives the bike a no-talent hack-job kinda look (and yeah, I've sported bikes like that...so i speak from experience).
Get yourself some of those Sunday Saker cranks; they're cheap and ppl seem to like'm. I just installed some Redline Flights on my Triple S, and while they're a bit pricey, they look awesome and they're stiff as can be....
So is this BB set (pictured) good to use for a conversion?
Depending on what crank you use, probably not. Those have a looooooong spindle, at something like 127mm, which will throw your chainline out pretty wide with most cranks, especially modern ones. It'd be cheaper to use that than to use the threaded adaptor, plus a BB set, but it'd also be more of a headache, as far as set-up goes. I can really only recommend that if you're running some very old cranks. (Plus, most threaded square taper BB sets have cartridge bearings nowadays, which reduces maintenance. Not a deal breaker, but another factor.)So is this BB set (pictured) good to use for a conversion?
The Renaissance Man
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I've found that it's pretty easy to use the American-to-Euro adaptors (like this: http://www.niagaracycle.com/categories/truvativ-bottom-bracket-conversion-american-to-euro
I just got one of these type adapters today. I tried it out a few hours ago and it is too big to fit into the BB. (Very disappointing on the eve of the build off). I assumed that American BB's are all the same size. Did I order the wrong part? The one that I ordered looks like the one pictured above except that it has 4 bolts.
I just got one of these type adapters today. I tried it out a few hours ago and it is too big to fit into the BB. (Very disappointing on the eve of the build off). I assumed that American BB's are all the same size. Did I order the wrong part? The one that I ordered looks like the one pictured above except that it has 4 bolts.
Wow, that sucks. While I've only seen these with 3 bolts in the past, you are basically right that all American BB shells are s'posed to be the same ID (2.02" or 51.3mm), although I have found that tolerances can be pretty crude (some will be a little tight or a little loose) I've always been able to press them in. (American BB shells are also supposed to be 68mm aka 2.68" from left to right, but i've seen a lot of variation here, with shells off by a few mm, but this won't matter for most cranks.)
Which part, exactly, did you order?
My best advice at this point is to get some calipers and start measuring. The cups should be, theoretically, a little bit too big to get the friction needed for a nice press-fit. But, they ought to be like 2.03"/51.5mm. The shell's ID should, theoretically, be 2.02" but it wouldn't surprise me if it were 2.0 or 2.01, and you should be able to MacGyver-up a solution for that (like, file the cups down or something.)
My final thought, and it's from way out in space, is that maybe you got a frame with a Thompson-style BB shell (AKA "Thun")? These look like American shells, but smaller, with a few different "standards" out there. They typically came on older European bikes, and usually ran 2- or 3-piece cranks of unique design. Even the biggest Thompson shells are going to be 6mm too narrow for an American-sized cup, so I'm guessing it'd be super obvious that the parts were incompatible.... that's just my weird, outlying guess.
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FWIW often those conversions don't just 'screw in' with the supplied bolts. On my projects they've typically pressed in just as tight or tighter than the original OPC cups. Can make lining up the bolt holes a bit tricky- grease, patience, trial and error will usually do the trick... ;-)
( That and a bottom bracket press
)
( That and a bottom bracket press
)
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FWIW often those conversions don't just 'screw in' with the supplied bolts. On my projects they've typically pressed in just as tight or tighter than the original OPC cups. Can make lining up the bolt holes a bit tricky- grease, patience, trial and error will usually do the trick... ;-)
( That and a bottom bracket press
Yeah, definitely use a press! do one at a time, it's easier to line the bolts up once you got one pressed in.
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Sorry, I know this thread is a little old, but it's not clear if the OP ever got his answer, and I just went from never having done such a conversion to doing both a cottered-to-3 piece and one piece-to-three piece conversions in the last two weeks, so I think I can break it down at the level you may be at.
The main thing to keep in mind in this conversion is chainline. Chainline, Chainline, Chainline. That's what it's all about. Now, of course there are two chainlines - front and rear. Front is how far out your chain ring is from the center of the frame. Rear is how far out your cog is from the center of the frame. Ideally they should both be equal. Since the one thing that you won't (I presume) be changing is the rear wheel, let's start with the rear chainline.
1. It looks like you've got a coaster brake on there. Per Sheldon Brown, the average chainline for coaster brakes is around 42mm. This is good news, since 42mm is kind of an industry standard for single speeds (freewheels, fixed gear, etc.).
2. If you do a search on Amazon for single speed cranksets, check out the item description for one of them - most of them should list the spindle length necessary for a 42mm chainline (for example, if you bought an Origin8 crankset and a bottom bracket with a 103mm spindle, you would have a 42mm chainline). If you're planning on using an old crankset you have laying around, then you're just going to have to figure out the appropriate length spindle through trial and error. That said, you'll probably be somewhere around 110mm, plus or minus 5 or so mm. It depends on factors like whether the crankset had originally been a double or a triple.
Now that you know your spindle length, you have a few options for a bottom bracket:
3a. Get the Truvativ conversion kit and then buy a cartridge bottom bracket with the appropriate spindle length to give you a good chainline. Bicycle808 has outlined some disadvantages to this setup above - which have me a little worried as I just went that route myself. I'll be road testing the bike soon; we'll see how the set-up works. I'm liking it so far.
3b. Get the Sunlite conversion kit, which has the aforementioned problem of having much too long of a spindle. You could however try replacing the spindle with this one, and probably have a pretty good chainline with a 108mm spindle. But without being able to compare it's measurements with the spindle in the Sunlite kit, there's no way to say for sure that they are interchangeable.
3c. Get the aforementioned Truvativ conversion kit, and throw on any 24tpi cup-and-cone-style 3-piece bottom bracket you have lying around. This could potentially be a very cost-effective solution, but chances are the spindle will be too long for your chainline, and once again you'll probably have to replace the spindle.
Any of these methods will probably work for you, just do yourself a favor and approach it following this order: figure out your rear chainline first, then figure out what crankset you're going to use, and then pick a bottom bracket with the appropriate spindle length.
The main thing to keep in mind in this conversion is chainline. Chainline, Chainline, Chainline. That's what it's all about. Now, of course there are two chainlines - front and rear. Front is how far out your chain ring is from the center of the frame. Rear is how far out your cog is from the center of the frame. Ideally they should both be equal. Since the one thing that you won't (I presume) be changing is the rear wheel, let's start with the rear chainline.
1. It looks like you've got a coaster brake on there. Per Sheldon Brown, the average chainline for coaster brakes is around 42mm. This is good news, since 42mm is kind of an industry standard for single speeds (freewheels, fixed gear, etc.).
2. If you do a search on Amazon for single speed cranksets, check out the item description for one of them - most of them should list the spindle length necessary for a 42mm chainline (for example, if you bought an Origin8 crankset and a bottom bracket with a 103mm spindle, you would have a 42mm chainline). If you're planning on using an old crankset you have laying around, then you're just going to have to figure out the appropriate length spindle through trial and error. That said, you'll probably be somewhere around 110mm, plus or minus 5 or so mm. It depends on factors like whether the crankset had originally been a double or a triple.
Now that you know your spindle length, you have a few options for a bottom bracket:
3a. Get the Truvativ conversion kit and then buy a cartridge bottom bracket with the appropriate spindle length to give you a good chainline. Bicycle808 has outlined some disadvantages to this setup above - which have me a little worried as I just went that route myself. I'll be road testing the bike soon; we'll see how the set-up works. I'm liking it so far.
3b. Get the Sunlite conversion kit, which has the aforementioned problem of having much too long of a spindle. You could however try replacing the spindle with this one, and probably have a pretty good chainline with a 108mm spindle. But without being able to compare it's measurements with the spindle in the Sunlite kit, there's no way to say for sure that they are interchangeable.
3c. Get the aforementioned Truvativ conversion kit, and throw on any 24tpi cup-and-cone-style 3-piece bottom bracket you have lying around. This could potentially be a very cost-effective solution, but chances are the spindle will be too long for your chainline, and once again you'll probably have to replace the spindle.
Any of these methods will probably work for you, just do yourself a favor and approach it following this order: figure out your rear chainline first, then figure out what crankset you're going to use, and then pick a bottom bracket with the appropriate spindle length.
@mornview excellent advice there, especially in the summary re: the chainline order of operations. I have found, however, that many ads won't list spindle recommendations for a given chainline. Some do (like the Origin8 example you mentioned), and there seems to be more of that info out there than there was in the past, but you definitely cannot count on it... and don't count on an accurate response if you ask the seller via email.. I'd also like to add that if you're running a vintage crank, you can usually find it on velobase.com, see what the oem spindle was, and then extrapolate what you should run based on the original chainline and what position you're going to hang the sprocket on.
What some folks do is, though, is they pm me and ask me and I think I usually point'm in the right direction.
One thing I feel like I gotta point out is that the advice offered in "3B" is potentially misleading, b/c the 108mm spindle won't work in that conversion kit. If you look at the conversion kit's spindle, it's threaded to accept the BB's cones, and the other spindle you linked to is for a conventional looseball euro BB set... it doesn't have male threads to accept the adjustable cones b/c a conventional euro BB will have an adjustable cup instead of adjustable cones.
(See those threads on that spindle?)
(No threads there....)
All the threads on the longer spindle does mean that you can adjust chainline somewhat, but that will result in a skewed/uneven q-factor, plus IME there's not quite enough adjustment to bring the sprocket in to a 41 or 42mm chainline like most SS coaster hubs take....
But thanks, Mornview, for breaking that down step-by-step. I know I'm guilty of tossing around a lot of bizarre jargon, and assuming that folks know what i mean by chainline and q-factor and stuff like that...
What some folks do is, though, is they pm me and ask me and I think I usually point'm in the right direction.
One thing I feel like I gotta point out is that the advice offered in "3B" is potentially misleading, b/c the 108mm spindle won't work in that conversion kit. If you look at the conversion kit's spindle, it's threaded to accept the BB's cones, and the other spindle you linked to is for a conventional looseball euro BB set... it doesn't have male threads to accept the adjustable cones b/c a conventional euro BB will have an adjustable cup instead of adjustable cones.
(See those threads on that spindle?)
(No threads there....)
All the threads on the longer spindle does mean that you can adjust chainline somewhat, but that will result in a skewed/uneven q-factor, plus IME there's not quite enough adjustment to bring the sprocket in to a 41 or 42mm chainline like most SS coaster hubs take....
But thanks, Mornview, for breaking that down step-by-step. I know I'm guilty of tossing around a lot of bizarre jargon, and assuming that folks know what i mean by chainline and q-factor and stuff like that...
This would be my recommendation too, those BMX 3 piece cranks are simply awesome, I buy every bike I can that has them, just to get enough for future builds... I am even using one for a single sided rear hub on my "OutLaw" build, that is how strong I think they are!
Luke.
Yeah, I hope I didn't imply that your (or anyone else's) input was not helpful; it's just that he seems to be going into this for the first time (much like I just did), and everybody is trying to suggest bottom brackets. That's what I got hung up on, thinking that the bottom bracket was the place to start. It took me a while to realize that was actually the last piece of my equation .
And thanks for catching that bit about the Sunlite kit. I really like the idea of that kit, because I just prefer the idea of cone and cup bottom brackets (I like the idea of something I can maintain, not something I need to throw out). But I avoided that route because of the spindle length. I guess I never thought through the spindle being threaded, but now that I think about it, it should be obvoius - how else would it work? Good catch.
Edit: I should note that some of the suggestions you (and others) were throwing out are still foreign to me. Could you post any examples of these 3 piece bmx cranks you guys are talking about? I'd have to imagine the setup I have is going to be strong enough for me, but I'm always open to an even stronger set-up.
.And thanks for catching that bit about the Sunlite kit. I really like the idea of that kit, because I just prefer the idea of cone and cup bottom brackets (I like the idea of something I can maintain, not something I need to throw out). But I avoided that route because of the spindle length. I guess I never thought through the spindle being threaded, but now that I think about it, it should be obvoius - how else would it work
? Good catch.Edit: I should note that some of the suggestions you (and others) were throwing out are still foreign to me. Could you post any examples of these 3 piece bmx cranks you guys are talking about? I'd have to imagine the setup I have is going to be strong enough for me, but I'm always open to an even stronger set-up.
Oh, I wasn't thinking that you were implying anything like that; i'm thinking it's awesome for you to give the advice as someone who went thru all this recently, whereas I tend to assume that folks have more experience/specialized knowledge than neophytes often would.....
I understand the appeal of loose bearings versus cartridge bearings in terms of DIY ethos and (arguably) less waste, but I gotta say, those square-taper cartridge units from reputable manufactures, they last a VERY long time, and require dang-near zero maintenance. Considering that you'll go through a ton of grease and a couple sets of balls in the time it takes to kill one cartridge set, waste isn't really a factor, but the cartridges do cut down on the DIY aspect a bit-- mostly b/c there's less to do.
As for bmx-type 3 pieces, most of these will have sealed cartridge bearings, and they'll be replaceable, meaning you can pull the cartridge out and snap a fresh one (most all are standard sized) into the cups. I like examples with pinch bolts, but other popular manufacturers make some where they're simply held on by the crank bolt. These things tend to be steel, they tend to have splined axles (aka spindles), they tend to be overbuilt for casual riders/commuters/cruisers, but they're stiff and tough for klunkin duty or any other kind of 2-wheeled mayhem. Here's a pic of a Redline Flight crank on my Worksman INB: (scroll down) http://www.ratrodbikes.com/forum/index.php?threads/3-piece-crankset-on-cruiser-frame.86047/ Probably overkill for most folks' riding, but they handle my 250lbs ont rails without a hiccup, and (IMHO) they look pretty BtotheA
I understand the appeal of loose bearings versus cartridge bearings in terms of DIY ethos and (arguably) less waste, but I gotta say, those square-taper cartridge units from reputable manufactures, they last a VERY long time, and require dang-near zero maintenance. Considering that you'll go through a ton of grease and a couple sets of balls in the time it takes to kill one cartridge set, waste isn't really a factor, but the cartridges do cut down on the DIY aspect a bit-- mostly b/c there's less to do.
As for bmx-type 3 pieces, most of these will have sealed cartridge bearings, and they'll be replaceable, meaning you can pull the cartridge out and snap a fresh one (most all are standard sized) into the cups. I like examples with pinch bolts, but other popular manufacturers make some where they're simply held on by the crank bolt. These things tend to be steel, they tend to have splined axles (aka spindles), they tend to be overbuilt for casual riders/commuters/cruisers, but they're stiff and tough for klunkin duty or any other kind of 2-wheeled mayhem. Here's a pic of a Redline Flight crank on my Worksman INB: (scroll down) http://www.ratrodbikes.com/forum/index.php?threads/3-piece-crankset-on-cruiser-frame.86047/ Probably overkill for most folks' riding, but they handle my 250lbs ont rails without a hiccup, and (IMHO) they look pretty BtotheA
And here's a pic of a Profile, complete with arms, axle, bearings, spacers, bolts, and American-sized cups. Basically, everything but the pedals and sprocket:
And here's the current Redline Flight, same list of stuff:
Profile has the advantage of more splines; the Redline has the advantage of pinch bolts. I think the pinch bolts are more important by a mile, but I'll probably recant that if I ever strip the splines on my Flights...
And here's the current Redline Flight, same list of stuff:
Profile has the advantage of more splines; the Redline has the advantage of pinch bolts. I think the pinch bolts are more important by a mile, but I'll probably recant that if I ever strip the splines on my Flights...
I'm a fan of the pinch bolts too, and also a fan of the slightly coarser splines, seems like it would take significantly more to strip them... But that is just me!And here's a pic of a Profile, complete with arms, axle, bearings, spacers, bolts, and American-sized cups. Basically, everything but the pedals and sprocket:
And here's the current Redline Flight, same list of stuff:
Profile has the advantage of more splines; the Redline has the advantage of pinch bolts. I think the pinch bolts are more important by a mile, but I'll probably recant that if I ever strip the splines on my Flights...
Luke.
I "feel" the same way about the bigger (6, 8, 10, or 16)spline set-ups, but everything I read suggests otherwise, as do discussions with my engineering and mechanic buddies. Apparently, the finer 48 spline set-ups are stiffer, and less prone to stripping b/c the load is spread out among many more splines. I guess it makes sense, and the same is basically true for fasteners, at least as far as strength of the bolt but I do find that the finer threads strip easier....
At any rate, something like a Redline Flight, with 6 splines and double pinch bolts, is just so easy to set-up, and it's definitely as stiff as I'm gonna need. Yeah, I flex it a little when I'm riding hard, but I'm a fat guy on a hi-ten frame doing things that the equipment was never intended to do. When I ride a bike with a euro conversion and a square taper crank, I flex it just riding around. Not b/c i'm some sort of beast-mode powerhouse, but b/c I weigh a cool 245lbs...
