# Would someone perhaps help this noobie out?



## pavena (Nov 12, 2012)

*Would someone perhaps help this noobie out? BB Problem*

Forewarning: I'm *completely new* to bikes.

I found a really old geared Free Spirit on the street. It was completely useless. Part of the rims were eaten by rust, the grips literally cracked off by touch, flat tires, etc etc. My friend told me it'd be cheap to convert it into a fixie, and I did as much research a noob could do, and I'm almost positive I still don't know the half of it - call me ignorant for diving into this project without completely knowing the know.

I took apart the bike entirely, sanded and repainted the frame, determined what I needed and didn't need, as well as ordering myself some new parts while trying to keep within a reasonable budget. I ordered rims that came with hubs and a 16 T cog + tubes, a crankset (160mm as I am not that tall), a bottom bracket, and 1/8 chains. My tires, grips, and pedals didn't come in yet, and I'll get a brake system for the front later. I'm pretty sure I'm missing something? I've watched some videos on installing the bottom bracket, and I've noticed most frames had threads where they install their bottom bracket, and mine, well, it isn't the same (at least I don't think so). Can someone fill me in on as to what I'm needing to install the bottom bracket? Pardon my lack of knowledge 

I just finished putting spokes on one rim I'll do the other and attempt to true it a little later, so don't mind those 











I also kept a somewhat photo journey on "Instagram" if anyone wants to pointlessly view it, but feel free to ignore, or point out any misdoings..










Note that I'm too cheap for powder coating.


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## axlenut (Sep 28, 2010)

Hi, that's awesome! While you did not know much about working on a bike before you started on your project you will after you get done 

Regarding the BB, that looks like it was used with the old one piece cranks. I think there may be an adaptor available that will allow the use of a threaded BB. Will post follow up if I can find it.

Later, Axlenut


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## axlenut (Sep 28, 2010)

Looks like this might do the trick: 
http://www.treefortbikes.com/produc...to-Euro.html?gclid=CIC5ve-lybMCFQGFnQodrg4AOQ

If the link does not work try google "BMX bottom bracket adaptor"

Also, double check the threads on the new BB, make sure they are the same as the adaptor.

Hope this helps, Axlenut


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## pavena (Nov 12, 2012)

axlenut said:


> Looks like this might do the trick:
> TruVativ American to Euro BMX Bottom Bracket Adapter in Tree Fort Bikes Bottom Bracket Parts (Mtn) (cat481)
> 
> If the link does not work try google "BMX bottom bracket adaptor"
> ...



Hi! Thank you so much for the reply, but I forgot to update this thread;

I did discover that the crankset that was used previously was a one piece, and that I would need an adapter -










I took off the bearing cups which I didn't notice I didn't take off in the first place, and then tried to fit the BB in to see if it'd fit through, but the protruding tube pieces are in the way, which is now the main problem because I concluded that if my BB doesn't fit now, it wouldn't fit even with the kit..










My debate now is wondering if grinding/filing/cutting the tubes off will allow the conversion kit to fit. My question now is if the BB shell's diameter, I think. I'm scared if I get the kit, it won't fit? Or are all shells pretty much the same in diameter, and the BB the only different component? :cryin:


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## pavena (Nov 12, 2012)

Oh, and I've already impulsively ordered the conversion kit earlier. I'm just hoping it'll fit into the shell D:


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## UrbanPrimitive (Jun 14, 2009)

Someone may correct me if I'm wrong, but here's what little I think I know about the "American" (a.k.a. "one-piece crank) bottom bracket shells Schwinn used.

I have never encountered different diameters of shells among the Schwinns that use one-piece cranks. Similarly I haven't encountered any different specs for those shells among parts that are still being manufactured. The "euro" (a.k.a. "three piece crank") bottom bracket shells (found on most contemporary road bikes) are where things get tricky. Threading is the major issue. Italians used just about the same thread count and pitch as the English manufacturers. However the English (current standard among most manufacturers) threads one side normally (right=tight, left=loose) and the other side with _reverse_ threads (right=loose, left=tight). I suspect the converter you ordered is most likely using English threads.

As for the tubes protruding into the bottom bracket shell, that's pretty common among that configuration. Because only the crank spindle went through the entire length of the shell there was room for the tubes to be cut long and left in place. A dremel tool with a grinding bur or a file and some swearing could take care of it. The areas to be most careful of are where the bottom bracket adapter may contact the bottom bracket shell. The outside portions of the chainstays come to mind as likely culprits. Go slow and easy with it. If you're using a file, be very careful not to reshape the outer edges and lips of the bb (bottom bracket) shell. Depending on how you go at it you may need to take it slow to avoid heat build up and possible paint damage. If the tubes as they come out of the shell feel warm it's fine. If they feel hot you may need to cool them off or move to another area with your die grinder.

Other things worth thinking about:

It appears you've removed your headset (the bearing linkage between the fork and frame). You definitely need one. Whether you use the old one (if it's functional) or get a new one is your choice. If you have a local bike shop you might want to take the old headset in and have them confirm it can be replaced. Schwinn used a proprietary size on some of their bikes, but not all of them. If it can be replaced be sure to get a threaded headset. Threaded plays with threaded and threadless with threadless. Without funky adapter ne'er the twain shall meet.

Chain line - this is determined by the spacing on your rear hub (usually 42mm for new flip/flop hubs) That means the center of the cog is 42mm off center from the center line of the bike. Your cranks should get very close to matching that to avoid chain rub (which results in noise, premature wear, and potentially thrown chains). This determines what length of bottom bracket spindle you need. Figuring this out isn't hard, but requires a little research. You crank manufacturer will likely provide some information on chain line. It's usually in the technical specifications or installation instructions (example: when installed with a 113mm bottom bracket the chain line is 47.5mm). That gives you the numbers you need to achieve your desired chain line. Also remember that ISO and JIS designations are important. They refer to the length and shape of taper on a square taper bottom bracket, as well as headset designations. There's a lot of history, but the gist is ISO only works with ISO and JIS only works with JIS.

Great resources for keeping this going are all over the place. Sheldon Brown's website is a wealth of information. Just poke around, use the glossary and the search function. You'll be able to answer a lot of your questions just looking through those pages. Also check out Park Tool's repair help section. It's basically (if not actually) their "Big Blue Book of Bicycle Repair" for free online.

Other than that all I have to say is kudos for taking on the project, the Rosy the Riveter pic, and remember to grease everything with threads.


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## axlenut (Sep 28, 2010)

There might be another way to go that would be worth looking into. YST makes an interesting square spindle BB for use with the American BB frame. What I'm not sure about is what taper is used and what the chain line would work out to but you can take a look at:

http://www.huskybicycles.com/Mercha..._Code=304-115&Category_Code=bb&Store_Code=hbs

Or google "bmx bottom bracket conversion kit"

A few more things to think about, if the outer shells of the new BB adaptor you already ordered fit the frame and the only remaining problem is the new BB cassette not clearing the end of the frame tubes you might be able to find an old school ball, cup and spindle BB that would fit without cutting the frame.

If you decide to cut I think I would use a 32 tooth hack saw blade and some oil. Insert the blade into the frame and then attach it to the bow so the blade is inside and the bow outside. A good bow with also allow the blade to be mounted at an angle to clear the down or seat tube.

Hope this helps, Axlenut


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## pavena (Nov 12, 2012)

UrbanPrimitive:

Wow, that is a GREAT deal of information I definitely need to know!! Thanks so much for taking the time to type that out. I think the threads are English, as it read "American to Euro adapter"? I had no idea the threads were different. 

I had taken off the headset to clean it, I'm sure I can still use it, but I'll definitely check on it!

I looked and it's an "EIGHTINCH 68x107mm JIS BB". I didn't see my brand on the site so I don't know.. if.. I just don't know.. >___< 


And AH! I'm excited! You're the only person who realized I was trying to imitate Rosy!

Will definitely keep the greasing of threads in mind. Thank you thank you times a million times infinity!








Axlenut:

I'm super determined and set on using what I already have, I'm pretty stubborn on that behalf :/ But thanks for the input, if all else fails, I'll probably come back to this! 

BB.. "cassette"  more terms I need to learn. *sigh

My brother's friend's lending me his dremel, I'll see how this goes!


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## FatTireFred (Jan 31, 2005)

are you a riveter? unfortunately I think you're on that slippery slope of a frugal conversion/upgrade turning into a whole new bike


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## pavena (Nov 12, 2012)

FatTireFred said:


> are you a riveter? unfortunately I think you're on that slippery slope of a frugal conversion/upgrade turning into a whole new bike



Heh, I wouldn't label myself as a professional one, but I sure have been riveting! 

Yeah, I obviously had NO IDEA what I was getting myself into! WHO KNEW THERE'S SO MUCH TO KNOW ABOUT A BIKE?! To think that they're a simple mechanical machine.. Now I'm really angry that someone stole my bike as a kid. Bikes are special stuff, man!


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## markaitch (Nov 3, 2010)

yes, this is indeed riveting...

several years ago i went through exactly what you are experiencing now with your old 1-piece crank/bb dilemma & it turned me off from ever converting another old bike boom roadie.

@pavena...considering you are still in the midst of that problem, are you ready for a warning about another one that might be looming? i'm not gonna research what is the the old on a bike like yours so maybe you oughta measure the spacing on your rear end :wink: & compare it with your track wheel to see if you need to add spacers on the axle or if the dropouts need to be reset a bit closer together.

keep up the good work...


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## UrbanPrimitive (Jun 14, 2009)

markaitch said:


> @pavena...considering you are still in the midst of that problem, are you ready for a warning about another one that might be looming? i'm not gonna research what is the the old on a bike like yours so maybe you oughta measure the spacing on your rear end :wink: & compare it with your track wheel to see if you need to add spacers on the axle or if the dropouts need to be reset a bit closer together.


Excellent point. For some reason I had convinced myself the OP was converting a Schwinn Collegiate. I have no idea how that happened. Apparently it's been a long day.

Pavena - The rear drop out spacing could be an issue to contend with. However there are several unknown factors which could make it difficult or falling off a log easy. I'm going out on a limb and guessing, based on the "before" photos, that this bike has a rear drop out spacing of 126mm (the reason for this guess can be found here). The next question is what hubs you bought. You mentioned that you're lacing your own wheels, so I'm assuming there's some kind of branding on the hubs (Formula, Quando, Sun Race, et cetera). Most of the decent flip/flop hubs currently available have long enough axles to allow spacers to be added. Their native spacing is usually 120mm, which is the current standard among factory build fixies and dedicated single speed road bikes (not so for single speed mountain bikes). In order to do this you would use a couple cone wrenches (narrow wrenches made from plate steel) to loosen the locknut on the axle. You would then replace the current spacer or add a 6mm spacer, then put the locknut back on. Boom. Proper spacing. This is also possible for bikes with 130mm rear spacing., but I don't think it can be pushed to 135mm without needing a longer axle (which is possible, just more work).

The other obvious solution is "cold setting" the frame. In layman's terms you're bending the stays to move the drop outs closer together. Some people have had great luck cold setting steel frames (don't try it with aluminum, it tends to break). Some people bork their drop out alignment and end up with a bike that pulls to one direction or another. If you decide to cold set, do it carefully and evenly. The link above has information about cold setting and frame alignment as well. If it's between cold setting or adding a spacer, it's a lot easier to add a spacer. 

If anything I've said here or above is muddy, feel free to PM me for clarification.


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## pavena (Nov 12, 2012)

markaitch said:


> yes, this is indeed riveting...
> 
> several years ago i went through exactly what you are experiencing now with your old 1-piece crank/bb dilemma & it turned me off from ever converting another old bike boom roadie.
> 
> ...



Kill me now. You didn't tell me if you finished or not. Have you successfully converted it that old bike? PLEASE SAY YES. I NEED TO KNOW I HAVE HOPE. I refuse to throw this out and start all over. I better be able to use every single product I already bought! 

I'll get back to you about the spacing thing if I get done with this problem, thanks!


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## pavena (Nov 12, 2012)

UrbanPrimitive said:


> Excellent point. For some reason I had convinced myself the OP was converting a Schwinn Collegiate. I have no idea how that happened. Apparently it's been a long day.
> 
> Pavena - The rear drop out spacing could be an issue to contend with. However there are several unknown factors which could make it difficult or falling off a log easy. I'm going out on a limb and guessing, based on the "before" photos, that this bike has a rear drop out spacing of 126mm (the reason for this guess can be found here). The next question is what hubs you bought. You mentioned that you're lacing your own wheels, so I'm assuming there's some kind of branding on the hubs (Formula, Quando, Sun Race, et cetera). Most of the decent flip/flop hubs currently available have long enough axles to allow spacers to be added. Their native spacing is usually 120mm, which is the current standard among factory build fixies and dedicated single speed road bikes (not so for single speed mountain bikes). In order to do this you would use a couple cone wrenches (narrow wrenches made from plate steel) to loosen the locknut on the axle. You would then replace the current spacer or add a 6mm spacer, then put the locknut back on. Boom. Proper spacing. This is also possible for bikes with 130mm rear spacing., but I don't think it can be pushed to 135mm without needing a longer axle (which is possible, just more work).
> 
> ...


Hm, the hubs are Quando.










That was a lot to take in, so after I solve this BB problem, I'll return for that other problem  I appreciate you a lot, my friend!


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## JCavilia (Sep 12, 2005)

pavena said:


> Hm, the hubs are Quando.
> 
> That was a lot to take in, so after I solve this BB problem, I'll return for that other problem  I appreciate you a lot, my friend!


If the spacing doesn't match up, adding some spacers to that axle is a piece of cake. Nothing to worry about. You can tackle your BB issues without unnecessary worry about the hub.


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## UrbanPrimitive (Jun 14, 2009)

I'm with JCavilia in that it looks easy to add/change a spacer on those hubs. As much as this is a lot to take in, it's actually simpler than it sounds. There's a lot of jargon to learn and that always complicates things. You're also learning what to worry about, so there may be a sense of doom that for every problem you fix there are two more waiting. That really isn't the case here. The things you actually need to think about are:

1) Cutting off/grinding out those tubes from the bottom bracket shell.
2) Install the bottom bracket and adapter.
3) Install drive side crank arm - check for chainstay and crank arm clearance! The last thing you want is to bash or saw through your chainstay.

That's pretty much it for now.

Things to think about _later_:

A) Measure chain line (remember we're looking for 42mm. It can still work if it _isn't_ 42mm. That just requires more adjustment later. More info on measuring chain line is available later if you need it)
B) Measure drop out spacing (likely 126mm +/- a few millimeters)
C) Adding/changing spacer on rear hub. This process is actually pretty easy. It also teaches you how to adjust bearing preload (tension applied to bearings) which is a useful maintenance skill.

It can be pretty overwhelming. There were several times I worried my first build was doomed. It wasn't. Neither are you. If you can tighten a bolt you can install a square taper crank. As a parting note, nice Vibrams.


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## pavena (Nov 12, 2012)

JCavilia said:


> If the spacing doesn't match up, adding some spacers to that axle is a piece of cake. Nothing to worry about. You can tackle your BB issues without unnecessary worry about the hub.


:thumbsup:


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## pavena (Nov 12, 2012)

UrbanPrimitive said:


> I'm with JCavilia in that it looks easy to add/change a spacer on those hubs. As a parting note, nice Vibrams.



Whoa I didn't think people pay attention to little details in a photo! Thanks! Are those yours?! 

If so, I think we should be best friends already 

Also, why are you wearing socks with them? 




Alright, so spacing shouldn't be THAT big of a deal? I mean, it's easily solved, right?


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## pavena (Nov 12, 2012)

So far, 












Now, who's down for some wheel talk?! Pretty please! 











I'm just wondering, because I'm trying all kinds of different patterns.. I know that crossing the spokes together makes the wheel stronger, BUT.. is it MANDATORY that the spokes touch? Or is it just a plus sort of thing? What happens if I don't interlace them together?


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## pavena (Nov 12, 2012)

I mean, is it okay if I do it like this? I did one crossed (the back one), and I'm not diggin' it. I'm having a tough time centering that one.


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## AndrwSwitch (May 28, 2009)

For a rear wheel, the semi-tangent spoke pattern is a necessity on at least one side. That's how the torque you put into the hub gets transferred to the rim. If you didn't do that type of spoke pattern, the hub would twist a little relative to the rim until the spokes were tangent enough to transfer force. That'd probably put a pretty insane load on them. So, do the rear wheel conservatively. For a 32-spoke wheel, that's usually 3-cross, which is also the most common spoke pattern and the one you'll find the most write-ups talking about.

For the front, you get a lot more flexibility. However, changing the spoking pattern also changes the length of spoke you need for the wheel. If you don't mind spending more on replacing all the spokes for the front wheel with some shorter ones or getting them rethreaded in a shorter size (if any shops near you can do that!) there's nothing wrong with doing the front wheel radial or with a different number of crosses. It puts more stress on the hub flange, so it wouldn't hurt to see if the hub is rated for radial spoking. People do tear chunks out of their hub flanges in real life.


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## pavena (Nov 12, 2012)

AndrwSwitch said:


> For a rear wheel, the semi-tangent spoke pattern is a necessity on at least one side. That's how the torque you put into the hub gets transferred to the rim. If you didn't do that type of spoke pattern, the hub would twist a little relative to the rim until the spokes were tangent enough to transfer force. That'd probably put a pretty insane load on them. So, do the rear wheel conservatively. For a 32-spoke wheel, that's usually 3-cross, which is also the most common spoke pattern and the one you'll find the most write-ups talking about.
> 
> For the front, you get a lot more flexibility. However, changing the spoking pattern also changes the length of spoke you need for the wheel. If you don't mind spending more on replacing all the spokes for the front wheel with some shorter ones or getting them rethreaded in a shorter size (if any shops near you can do that!) there's nothing wrong with doing the front wheel radial or with a different number of crosses. It puts more stress on the hub flange, so it wouldn't hurt to see if the hub is rated for radial spoking. People do tear chunks out of their hub flanges in real life.


Ah, I see. So it's semi-mandatory and mostly recommended. Yeah, I think I did the "3-cross" one for one. 

What do you mean by "tear chunks out of their hub flanges"? I'm imagining tearing paper here.


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## UrbanPrimitive (Jun 14, 2009)

Spokes can put a large enough load on the hub to shatter the hub flange. Not pretty. It's one of the worst case scenarios for wheel failure. AndrwSwitch nailed it. For more advice on wheel building, I recommend checking out the tips written up by Ric Hjertburg (co-founder of Wheelsmith and Madfiber):

Wheel Building Tip #1- TurningNipples
Wheel Building Tip #2 - Lubricating Nipples
Wheel Building Tip #3 - Stop Spoke Wind Up
Wheel Building Tip #4 - How To Pre-stress Your Wheel
Wheel Building Tip #5 - Be A Wheel Whisperer
Wheel Building Tip #6 - Build Rears From Right To Left
Wheel Building Tip #7 - Replace Spokes One At A Time
Wheel Building Tip #8 - Know Your Spoke Elbows
Wheel Building Tip #9 - Succeed With Alu Nipples
Wheel Building Tip #10 - Using A Dishing Tool
Wheel Building Tip #11 - Stuck Cogs
Wheel Building Tip #12 - Tuning The Ride
Wheel Building Tip #13 - Feeling Lucky
Wheel Building Tip #14 - Set The Spoke Path
Wheel Building Tip #15 - Spin Those Nipples
Wheel Building Tip #16 - Clinchers & Tubulars

That's all Ric has posted so far. There are quite a few there that you don't need to worry about now. But you might want to read them at some point. Go ahead and skip around to the ones that look the most interesting.

As for socks in the Vibs, it's a good idea in Michigan during November. Trust me.


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## AndrwSwitch (May 28, 2009)

pavena said:


> What do you mean by "tear chunks out of their hub flanges"? I'm imagining tearing paper here.












Found it on
Broken Bicycle Wheel and Stranded in the Snow – FelixWong.com

You can see that this wheel was laced radially. Looks like a low spoke count too. I guess I'd still trust a hub manufacturer to rate their hubs appropriately, but I wouldn't build a radial wheel on a hub that wasn't rated for it.


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## pavena (Nov 12, 2012)

AndrwSwitch said:


> Found it on
> Broken Bicycle Wheel and Stranded in the Snow – FelixWong.com
> 
> You can see that this wheel was laced radially. Looks like a low spoke count too. I guess I'd still trust a hub manufacturer to rate their hubs appropriately, but I wouldn't build a radial wheel on a hub that wasn't rated for it.




OH MY GLOB. That isn't pretty at all...... And I would've never imagined that being a problem as I've never heard of it ever.


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## pavena (Nov 12, 2012)

UrbanPrimitive said:


> Spokes can put a large enough load on the hub to shatter the hub flange. Not pretty. It's one of the worst case scenarios for wheel failure. AndrwSwitch nailed it. For more advice on wheel building, I recommend checking out the tips written up by Ric Hjertburg (co-founder of Wheelsmith and Madfiber):
> 
> Wheel Building Tip #1- TurningNipples
> Wheel Building Tip #2 - Lubricating Nipples
> ...



I'll be keeping this list! :thumbsup: Thanks a bunchies. 

Hahah socks and Vibrams are silly! It's already toe shoes! Are you wearing toe socks or.. untoe socks?


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## pavena (Nov 12, 2012)

To all, thanks! Although I wanted to just be whiny and go with the "radial" pattern because it was easy, I suppose I'll stick to the 3-cross. *sigh


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## markaitch (Nov 3, 2010)

there is nothing wrong with a radial spoked front wheel, in fact i have one myself that i like very much, but your spiral pattern looks like a recipe for disaster.

i'm guessing you had to do that pattern due to your spokes length. if you must use the spokes you have on hand & they were measured to use with 3x then for your own good...do that. if you really do want a radial front, get new spokes that are the right length to do it the right way.

keep up the good work...


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## pavena (Nov 12, 2012)

ALRIGHT! Time for some catching up. Sorry guys, I was out of town for an interview, and I don't wanna brag, but guess who got into med school?! 

Anyway.

So, I filed off those annoying tubes. My adapter came in, tried to fit it in, but it still stuck out. A lot of you said not to file down the second wall in the BB shell, but it was in the way, so I had to file that down as well. The tips for the Dremel my friend had sucked, so I had to resort to the yellow elephant. HOW ANNOYING TO KEEP WAITING FOR THE PSI GAUGE TO GO UP BEFORE GOING AT IT. My hands were literally numb! Anyway, hammered the betch in and after several silly attempts, I FINALLY GOT IT, DAMNIT! 

I fked up my paint job, but honestly, I don't even give a sht anymore, I was so frustrated! 










Now, someone made me aware of spacing issues?


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## UrbanPrimitive (Jun 14, 2009)

It's good to see more progress. I checked in with the folks at Eighth Inch about the crank you've got there. I'm going out on a limb and guessing that you followed their suggested bottom bracket and bought one with a 110mm spindle. Assuming nothing wanky happened you should now have a front chain line of 42mm. My understanding is the Quando hubs have the same chain line when the rear wheel is dished symmetrically (or as some would say, isn't dished). Next step is to check the rear spacing on your frame. A metric ruler is your best friend here.

If you don't have a metric ruler or measuring tape I suggest looking here for future reference.

If your rear spacing is 120mm it will be about 4 and 23/32 inches
If your rear spacing is 126mm it will be about 4 and 31/32 inches
If your rear spacing is 130mm it will be about 5 and 1/8 inches

Once you have that measurement you can figure out if you need to respace your hub. 

120mm - no adjustment needed. Build the wheel, true, tension, de-stress it, and have fun.
126mm or 130mm - hub needs spacers added to compensate.

Sock it to us with some math when you have the numbers. Congratulations on the interview!


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## pavena (Nov 12, 2012)

UrbanPrimitive said:


> It's good to see more progress. I checked in with the folks at Eighth Inch about the crank you've got there. I'm going out on a limb and guessing that you followed their suggested bottom bracket and bought one with a 110mm spindle. Assuming nothing wanky happened you should now have a front chain line of 42mm. My understanding is the Quando hubs have the same chain line when the rear wheel is dished symmetrically (or as some would say, isn't dished). Next step is to check the rear spacing on your frame. A metric ruler is your best friend here.
> 
> If you don't have a metric ruler or measuring tape I suggest looking here for future reference.
> 
> ...



My crank said it required the 107mm, so that's the one that I got. I don't THINK anything wacky happened. Dangit, now I'm paranoid. So I was supposed to have a 110?! What is this dish talk? I'm only familiar with dishes in the kitchen. Sexist joke. Anyway, what exactly am I measuring? 

Thanks, yo!


I bought my crank here:

EIGHTHINCH FIXIE FIXED GEAR TRACK CRANK CRANKSET 160MM WHITE | eBay

And followed the description and bought this

EIGHTHINCH 68x107 SQUARE TAPER JIS BOTTOM BRACKET 107MM | eBay


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## AndrwSwitch (May 28, 2009)

There are a few different sizes here that you need to keep separated.

The spacing people are talking about the most is the spacing of the rear triangle of your bike. That's 120, 126 or 130.

The next thing is the spindle width that goes with your crank. If your crank said it went with a 107 mm bottom bracket and you bought a 107 mm bottom bracket, you're probably fine.

The third thing is chainline. That's the distance from the centerline of the bike to the centerline of the cog or chainring. Ideally, those two distances should match each other.

To be honest, I'd just build the bike and eyeball it. While I won't pretend I can visually see what a chainline is, when they don't match, the chain makes a little bit of an angle as it comes off the cog and chainring if it's wrong.


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## UrbanPrimitive (Jun 14, 2009)

I had written a nice, thorough description of how to handle discrepancies in specs between the shop and the manufacturer. Then I noticed one important detail:

130 b.c.d. on your cranks.

144 b.c.d. on the Courier Crankset on the Eighth Inch website.

Unless the folks who sold you those cranks are truly boneheads (unlikely given their positive rep and number of sales) you have a different crankset than what is currently available through the manufacturer. My remark about needing a 110mm bottom bracket was based on an erroneous assumption. I believed that if it walked, talked, and looked like a duck it probably _was_ a duck. In this case it's a very peculiar pheasant.

Run with the 107mm bottom bracket that was suggested. Measure it to double check if you like. If you're interested in doing that, here's the breakdown:

Seat tube diameter = X
Distance from seat tube exterior to center of chainring = Y

(X/2) + Y = Chain Line

It's easiest to measure using a set of calipers. If you don't have access to calipers you can also measure the circumference of the tube, then divide by pi to find X. It's an extra step, but usually more accurate than eyeballing it.

So you're currently here:

Bottom bracket looks good. Therefore chainline looks good (unless proven otherwise by sawing through your chainstays). The hard part is done. Next is measuring drop out spacing (see my earlier post). Once that distance is known you can then add spacers (if needed) to your rear hub.

Here's the breakdown on dish:
Dish refers to how far off-center the rim is from the center of the hub. It is necessary to have the hub off center for road and mountain bikes to make room for their gear clusters (be they freewheels or cassettes). Because you're riding a single speed (fixed or free, it doesn't matter) you don't need that much room. On flip/flip hubs the rim is usually centered over the hub. That way the wheel can be flipped and the chain line is not altered. If necessary one can dish a single speed wheel to adjust the chain line. That can be necessary if you can't get the bottom bracket you need or if chainstay clearance is a problem and the chainline must be moved outward. It isn't a big deal. It just means that it isn't ideal to flip from fixed (where chain line is muy importante) to freewheel (which is a bit more forgiving. . . -ish).

Now that we've covered all of that stuff, has anyone brought up the issue of converting an old frame that likely used 27" wheels to 700c? The 700c wheel is slightly smaller. If you're using rim brakes they may not reach your new wheels. There are brakes available to solve such problems. They aren't hard to find, nor crazy expensive. Tuck that one in your back pocket as a something to think about "down the road". The stuff you're working on now won't affect it.


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## UrbanPrimitive (Jun 14, 2009)

Bump.

Updates?


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