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Old 09-16-05, 08:40 PM   #1
genericbikedude
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This can't be right...

So I just got a new Soma track frame (rush). While pirating movies off the internet and waiting for them to download, I Screwed an old 113 JIS BB into my frame, and put the hub (suzue promax NJS) into the track ends. I then slipped the crank onto the taper to check the chainline, and the spider almost touches the chainstay, but the crank is still slightly too far out to make a straight chainline. What gives? If I tighten the crank onto the spindle, the spider will rub the chainstay, and if I use a smaller BB to get a straight chainline, the spider will rub the chainstay even worse. If I use a bigger BB, the chainline will be off even worse.

What gives? Shouldn't a track frame work with a track crank? I even emailed suginio, and they recommended a 113 bb with their crank.

Even if ISO tapers are bigger (aren't they smaller than JIS?), I still have the chainline problem! Any insight is more than welcome. Thanks!
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Old 09-16-05, 08:56 PM   #2
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Originally Posted by genericbikedude
So I just got a new Soma track frame (rush). While pirating movies off the internet and waiting for them to download, I Screwed an old 113 JIS BB into my frame, and put the hub (suzue promax NJS) into the track ends. I then slipped the crank onto the taper to check the chainline, and the spider almost touches the chainstay, but the crank is still slightly too far out to make a straight chainline. What gives? If I tighten the crank onto the spindle, the spider will rub the chainstay, and if I use a smaller BB to get a straight chainline, the spider will rub the chainstay even worse. If I use a bigger BB, the chainline will be off even worse.

What gives? Shouldn't a track frame work with a track crank? I even emailed suginio, and they recommended a 113 bb with their crank.

Even if ISO tapers are bigger (aren't they smaller than JIS?), I still have the chainline problem! Any insight is more than welcome. Thanks!
What is the measured chainine? Should normally be about 42 mm.

See: http://sheldonbrown.com/chainline

You haven't said what kind of crank you have, but if the spider is in danger of hitting, I suspect it's a double type crank. True track cranks lack the shelf on the inside of the spider arms.

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Old 09-16-05, 09:04 PM   #3
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You've got the same problem as I do with my Steamroller. I only have a 1mm clearance between the ends of my 170mm Campy Record track arms and the chainstays, and yet my trackring is still about 44mm out of center. 111mm Campy spindle is the shortest I can use with this setup.

EDIT......never mind.....you're talking about the spider hitting the chainstay. I don't have that problem, I have a problem with the ends of my track crank arms hitting the chainstays when trying to achieve proper chainline.

Last edited by roadfix; 09-16-05 at 09:11 PM.
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Old 09-16-05, 09:04 PM   #4
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What crank is it??
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Old 09-16-05, 09:51 PM   #5
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Originally Posted by The Fixer
You've got the same problem as I do with my Steamroller. I only have a 1mm clearance between the ends of my 170mm Campy Record track arms and the chainstays, and yet my trackring is still about 44mm out of center. 111mm Campy spindle is the shortest I can use with this setup.

EDIT......never mind.....you're talking about the spider hitting the chainstay. I don't have that problem, I have a problem with the ends of my track crank arms hitting the chainstays when trying to achieve proper chainline.
That was a known issue with the first generation (brown) Steamrollers. They supposedly fixed it with the gray batch.

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Old 09-16-05, 10:59 PM   #6
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Hi--Thanks for the interest--I don't have a metric ruler here, but I got this email from a Mr Kaz Yoshida at Sugino:

>Mr. Drew hello.
>
>If it is 113mm that the BB length, the chain lin becomes about 43mm when the GS crank is used by the >track racing.
>It is possible to use it also with the thing of which manufacturer in case of being interchangeable BB >SHIMANO it.
>
>Please examine it.
>kaz Yoshida
>SUGINO CYCLE INDUSTRIES,LTD.
>DEVELOPMENT SEC
>yoshida@suginoltd.co.jp

The crank is a Suginio GS (looks like 65 too..), and YES, it does look like a double, but it has 144 mm bcd, and a very low Q factor. I just figured that it was a track crank where I could put the ring on the inside or the outside. And ANYWAY, the part that is about to hit the chainstays is the back of the chainring bolt, not the spider itself, or the lip where an inner chainring would be anchored. I have about 1.5mm clearance there, untightened.

The hub is a rough 42 or 43 from the quick measurement before I bought it (promax NJS), and I'm assuming that I got the right quote from Suginio. Maybe this frame has intolerant chainstays?
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Old 09-16-05, 11:49 PM   #7
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Originally Posted by genericbikedude
ANYWAY, the part that is about to hit the chainstays is the back of the chainring bolt, not the spider itself
I once added a small ding on the chainstay on another frame to add more clearance there.
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