Singlespeed & Fixed Gear - Build Project Question: Rear Dropout/Hub/Fixed/Free Spacing & Compatibility of Parts

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Mr.Fixie
11-14-09, 05:59 PM
I'm building a fixed/free bike right now from a 1977 Schwinn Traveler frame. Soon I'll be done with the paint job, but I was wondering about how I should go about the spacing for the rear dropouts and everything else.

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First of all, what is the difference between these two products and which BB should I get if I'm using the Truvativ BB Conversion Kit (http://www.amazon.com/Bb-Conversion-Tv-American-To-Euro/dp/B000VT550K/ref=sr_1_16?ie=UTF8&s=sporting-goods&qid=1258246854&sr=8-16)?

Shimano BB-UN54 Bottom Bracket 122.5mm 68mm (http://www.amazon.com/Shimano-BB-UN54-Bottom-Bracket-122-5mm/dp/B000AL58RO/ref=reg_hu-wl_item-added)

&

Shimano UN54 Tapered Spindle Bicycle Bottom Bracket (http://www.amazon.com/Shimano-UN54-68x110mm-BB/dp/B0011ZEIVK/ref=sr_1_2?ie=UTF8&s=sporting-goods&qid=1258129708&sr=1-2)

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For one of them, Shimano lists several sizes, which should I get if my BB shell is 64-65mm (and then taking the Truvativ BB Adapter into account as well)?

For this, I was thinking about getting the Origin8 Single Speed Crankset (http://www.amazon.com/Origin8-Square-Single-Bicycle-Crankset/dp/B002I7MAIS/ref=sr_1_20?ie=UTF8&s=sporting-goods&qid=1257996784&sr=1-20) which is 165mm x 46T, which says it uses 107mm square taper BB...

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Then finally, I was curious about the rear dropout spacing for this, as the wheelset I'm getting is 700c x 23c, with a 16T fixed cog on one side and a 16T freewheel sprocket on the other, and the spacing is claimed as:

-Spacing: front 100mm, rear 120mm
-Axle Length: front 137mm, rear 163mm

How would this work with my other parts??? My rear dropout spacing as it stands is ~126mm, but the frame is steel so I can cold-set it to a different spacing if need be. Do I even need to cold-set it to a different spacing, do I need to use spacers, etc??? Please help!


bbattle
11-14-09, 06:55 PM
I assume the UN54 you want is the 107mm one. That's the one I'd get.

As for rear spacing, you can add washers to each side to cover the extra spacing or cold set the frame. I really wouldn't worry too much about it but here's a link on setting the rear dropouts:

http://www.sheldonbrown.com/frame-spacing.html

If your calculations show you to be off by a couple of millimeters I wouldn't sweat it. I've built a couple of fixed gears simply by winging it and the chainline is fine.

RoyIII
11-14-09, 07:10 PM
Sounds like you are well on the way to a really cool bike. I have had good luck just eyeballing the chainline.


xB_Nutt
11-14-09, 07:13 PM
2- 3 mm spacers, one on each side if you are really worried about it. You have to put them between the 2 lock nuts that keep your bearings adjusted properly. However, steel is pretty flexible, so it will tighten down just fine on the 120 mm hub without spacers.

Mr.Fixie
03-18-10, 11:18 PM
Hey everyone,

I know it's been a LONG time since I wrote on this thread, but I've been slowly working on taking the paint off the frame that I'm going to be using and redoing the paint job (it was already wearing off pretty bad, but it's been slow b/c of the winter weather and lack of access to a garage). Anyways, I am getting close to being done and have been thinking more and more about my bottom bracket/crankset combo, and I think I have decided on it. Remember that I said my BB shell is about 64-65mm wide!

Sugino Bottom Bracket 68 x 103mm (http://cgi.ebay.com/Sugino-Bottom-Bracket-68x103-Track-Fixed-Gear-Crankset_W0QQitemZ360243951393QQcmdZViewItemQQptZCycling_Parts_Accessories?hash=item53e0367721)
Origin8 Track Crankset 165mm 46t (http://cgi.ebay.com/Origin8-Track-Cranks-BLUE-165mm-46T-Fixed-Gear-Crankset_W0QQitemZ300408201068QQcmdZViewItemQQptZCycling_Parts_Accessories?hash=item45f1b95f6c)

**I opted for the Sugino BB instead of the Shimano one because it just seemed like a better fit for the Origin8 cranks, and the Shimano one with the measurements I wanted aren't for sale anymore.

The other crankset I was looking at was this: Sugino Single Speed 165mm 48t Track Crankset - 130mm (http://www.amazon.com/Sugino-Single-Speed-165mm-130mm/dp/B001F6VVYM/ref=reg_hu-wl_item-added) but I'm pretty fond of the origin8 one that I've chosen.

The main input I'm looking for is...
-Whether they'll all be compatible (BB shell, Truvativ adapter, Sugino BB, and Origin8 Cranks)
-If they're decent quality (for a singlespeed city bike)
-If they're not compatible (i.e. wrong size = sticks out of shell or whatever), what WOULD be the right sizes to get, etc.

I'm really trying to look for confirmation and last-minute things I should know, since I'm very close to purchasing these and wanted to make sure I'm making the right decision.