Singlespeed & Fixed Gear - Cheap bottom bracket?

I need to replace my bottom bracket to get my chainline all sorted out on my first conversion, and I'm wondering: what do I lose by buying a $30 cartridge instead of the ~$100 Sugino 75 part that matches my cranks? I'm a firm believer in you-get-what-you-pay-for, but then again...

you lose some quality and smoothness.
you get a virtually maintainance-free hunk of machinery with killer seals that you don't have to rebuild after every time you ride through a puddle.
ok, that's a bit of an exaggeration, but the 75 is atrack bb,which means it's seals aren't designed to withstand the abuse that street riding throw at it.

my $0.02

i'm digging my shimano LX. heavy, compared to other things, but smooth, quiet, CHEAP ($30), and i've had 2 LX's that have been swaped back and forth between all my bikes, nary a complaint. Seriously, the thing has lasted forever, despite me treating it like crap. (it's been submerged at least 3 times).

A 68 x 110mm Shimano bottom brackets (UN73 or 53) are a perfect match for the Sugino 75's top give you that elusive 42mm chainline. Probably a lot more durable in the crud too.

Me, I picked up a Phil Wood in anticipation of using some Sugino 75's on a fixed cyclocross build. Got the bracket, now all I need are the rest of the components.

A 68 x 110mm Shimano bottom brackets (UN73 or 53) are a perfect match for the Sugino 75's top give you that elusive 42mm chainline. Probably a lot more durable in the crud too.

Me, I picked up a Phil Wood in anticipation of using some Sugino 75's on a fixed cyclocross build. Got the bracket, now all I need are the rest of the components.


Actually a 110mm shimano bb will cause your non drive side crank arm to stick out much further from the bb shell than your drive side arm. You will have an ugly gap betw. bb shell and crankarm. You need a 68x107mm un72/3 or 53 to get them even. I installed two 107s with sugino 75s last week and both of them were dead on with a 107. Also, the only difference betw. the 107 and the 110 is the non drive side spindle length. Drive side is the same on both. Makes no sense I know, but hey they are shimano and do what they want.

how are you sure that the "only difference between the 107 and the 110 is the non-drive side spindle length"? you're right; this doesn't make any sense. i have an "ugly gap" between the shell and the crank on my non-drive side but the outside of the crank is still the same distance from the shell as on the drive side (because the thickness of each crank is different). maybe you're right, though. i just don't know.

A 68 x 110mm Shimano bottom brackets (UN73 or 53) are a perfect match for the Sugino 75's.

Sugino 75 BB (109mm standard) and Sugino 75 Cranks on a 04 Surly Steamroller
http://img99.exs.cx/img99/8646/chainline.jpg
http://img99.exs.cx/img99/5074/clr1.jpg
http://img99.exs.cx/img99/5941/clr2.jpg
Sugino recommends a 109mm spindle for their cranks. I am using a surly hub on the rear with a surly 17t cog. Chainline = near perfect. Distance between crankarms/chainstays = equal on both sides (drive side is taken from an angle).

As far as crud goes, I would agree since the Sugino is a caged bearing system. But it would still work. And have a better native chainline.

I got a UN53 (square taper) at Performance w/ a coupon (team perf coupon, not online) for less than $20 recently. Works great on my Il Pompino and running it w/ 105 cranks.

how are you sure that the "only difference between the 107 and the 110 is the non-drive side spindle length"? you're right; this doesn't make any sense. i have an "ugly gap" between the shell and the crank on my non-drive side but the outside of the crank is still the same distance from the shell as on the drive side (because the thickness of each crank is different). maybe you're right, though. i just don't know.

I have a UN72 107mm and a UN73 110mm that I don't have installed now. Here's a pic of the two showing the drive side and non-drive side spindle differences.

I'm running a UN73 and it's smooth as all heck. Great seals, cheap, I say it's a winner of a component.

Actually a 110mm shimano bb will cause your non drive side crank arm to stick out much further from the bb shell than your drive side arm. You will have an ugly gap betw. bb shell and crankarm. You need a 68x107mm un72/3 or 53 to get them even. I installed two 107s with sugino 75s last week and

Wow, never knew that difference existed between the 110 and the 107. But I'd have to ask, in reference to the followup Habitus, are the outside edges of the crank the same distance from centerline when using the 107s?

Poking around, I find the Sugino 75 bottom bracket is sys.. sym.. symet......equal length either side (Buisness Cycles (http://www.businesscycles.com/tbb-sug.htm).

how are you sure that the "only difference between the 107 and the 110 is the non-drive side spindle length"? you're right; this doesn't make any sense. i have an "ugly gap" between the shell and the crank on my non-drive side but the outside of the crank is still the same distance from the shell as on the drive side (because the thickness of each crank is different). maybe you're right, though. i just don't know.

I measured them. and since they are both UN72s I sincerely hope that the bearings are the same. measure the gap betw. the chainstays and the crankarm it should be equal on both sides. It won't be equal with a 110.

Poking around, I find the Sugino 75 bottom bracket is sys.. sym.. symet......equal length either side (Buisness Cycles (http://www.businesscycles.com/tbb-sug.htm).

and a UN72 110 is not symmetrical... Why would it be a good match?

The chainline depends on what cog and hub combo you are using. The whole 42mm chainline is arbitrary. If you use an Iro 120mm hub with an EAI 3/32 cog your chainline will be 43.13mm. If you use a surly cog 3/32 it is 41.28mm. - And now they are telling me that one specific bb will always guarantee perfect chainline with its matching cranks!?!??! Laugheable (unless it's a phil)! The hub and cog matter as mutch as your bb and crank.

Wow, never knew that difference existed between the 110 and the 107. But I'd have to ask, in reference to the followup Habitus, are the outside edges of the crank the same distance from centerline when using the 107s?

they are off by about 0.4mm.

and a UN72 110 is not symmetrical... Why would it be a good match?

The chainline depends on what cog and hub combo you are using. The whole 42mm chainline is arbitrary. If you use an Iro 120mm hub with an EAI 3/32 cog your chainline will be 43.13mm. If you use a surly cog 3/32 it is 41.28mm. - And now they are telling me that one specific bb will always guarantee perfect chainline with its matching cranks!?!??! Laugheable (unless it's a phil)! The hub and cog matter as mutch as your bb and crank.

thanks for your explanations of all this stuff. i wasn't aware of this shimano idiosyncracy.

however, 42mm is not arbitrary. it is probably not the chainline that you're going to get with your hub/cog or crank/bb combo, but it's probably about the average of all the combinations you can think of. something like 75mm would really be arbitrary.

Taking what 47x17 has stated, I found myself on a quest to determine what Shimano was actually up to with these bottom bracket spindle lengths and which ones have offsets.

Reading thru the Barnett manual I found this interesting page/table. Thought it might be of interest.

so a filwood bb is adjustable?

Nashbar makes a square taper cartridge BB for $10. Works fine, better than the $25 cheapest Shimano BB from the LBS.

thanks for your explanations of all this stuff. i wasn't aware of this shimano idiosyncracy.

however, 42mm is not arbitrary. it is probably not the chainline that you're going to get with your hub/cog or crank/bb combo, but it's probably about the average of all the combinations you can think of. something like 75mm would really be arbitrary.

Arbitrary might be exagerated, however the holy number 42mm is ballpark at best. Getting a perfect 42mm chainline in the rear and front is an exeption. Even a sugino 75 with a sugino 75 bb will have a 42.5 chainline.

so a filwood bb is adjustable?

Yes it is. Usually about 5mm side to side. Allthough, this still does not mean that you can get perfect chainline AND crank arm spacing by just ballparking the spindle. You can also spacer out any shimano UN bb on the drive side and if you machine the cup lip away it will be as adjusteable as a phil.

right. the best thing to do is not worry about the "42.00000" and worry about getting a straight line.

Yes indeed! thanks for summarizing!

right. the best thing to do is not worry about the "42.00000" and worry about getting a straight line.

I shoot for near 42 and not noisy.

I shoot for near 42 and not noisy.

Whatever works for you! If you want to be sure send me the names of your hub and cog and I can tell you EXACTLY what your chainline should be.

Whatever works for you! If you want to be sure send me the names of your hub and cog and I can tell you EXACTLY what your chainline should be.

Using Sheldons Table (http://www.sheldonbrown.com/chainline/) I get 52.3 with an IRO MTB hub (I used the Kogswell 135 # since I've been told the IRO, Formula, Kogswell are all the same) and a Dura Ace 1/8" cog.

I planned on using a BulletProof crank on this particular build. According to Sheldon, a 107 gives me an outer ring chainline position of 47.1. I need a 52.3. That's a +5.2 on the spindle. According to my prior post, the 118 gives me a chainline offset from the 107 of +5.

Blind luck was the key here.

Whatever works for you! If you want to be sure send me the names of your hub and cog and I can tell you EXACTLY what your chainline should be.

how are you able to do this? like dobber said, sheldon has a table, but i've noticed that it doesn't list all track hubs (e.g., formula).

how are you able to do this? like dobber said, sheldon has a table, but i've noticed that it doesn't list all track hubs (e.g., formula).
formula=iro=bensbike=NYC Bike hubs. I think sheldon's table has iro hubs.

formula=iro=bensbike=NYC Bike hubs. I think sheldon's table has iro hubs.

i'm well aware of that "equation"; i was just looking at the wrong table. there's a chainline entry in the glossary that has an older table that doesn't contain the iro hubs.