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Help! SS chainline question.....

2K views 11 replies 7 participants last post by  Pedlin' Slow 
#1 · (Edited)
I am replacing my Truvativ FireX cranks with some new Truvativ Sylo cranks. The new cranks have a 50mm offset, but I cannot find the offset of my White Ind. Eno freewheel, even on their website.
Will I have problems with this?
I have a 68mm bottom bracket and a Mavic 819 rim with a WTB Speed Disc rear hub if that helps.
I bought these quickly without thinking about chainline, assuming that the Truvativ cranks would probably have the same offset. I will only have one night to work on this from the time I receive them to an out of town ride the next day.
This is for all you SS brainiacs out there.

Thanks
 
#3 ·
Measure from the inside of the dropout to the center of the rear cog. Subtract that number from 62.5 (i.e 1/2 of 135mm). That's the offset from center for the rear.

Does that correspond to the manfacturers printed offset for this crank on your frame....I have no idea.
 
#6 ·
Having a tough time with math here. The previous post had 1/2 of 135 at 62.5. It's actually 67.5. When I subtract that from 12 I end up with 55.5. That's a 5.5mm difference!
Singlespeeding is picking up steam, but damn, will there ever be some sort of industry standard here, or will we SS's be happy with the fact that we have 10,000 ways of setting up a crankset and freewheel hub and simply revel in the fact that we are nonconformists and can thumb our noses at those who only run SRAM or Shimano on their geared bikes.
I have been on Sheldon Brown's site and White Industries site and get different variations on calculating chainline and what the actual offset is.
When you have to put together a matrix of hubs, freewheels, dishing and such, you know you have entered the outer sanctum of mountainbiking and truly are living the dream, however expensive that may be.
Crap, I just wanted a set of cranks to run on my SS Jamis without using physics and a myriad of tables to see if a WTB hub would work with a White Ind.freewheel on a Jamis bike with Truvativ cranks and whatever BB or sprocket spacers a machinist from Butte, Montana could come up with.
 
#7 ·
Another option, not perfect though, is to run the chain ring in the big ring position. The chainline will still be out, but only by about 2mm (ish) which is better than 5.5mm! I have the same issue, but am doing this and it seems to work ok.

I agree with the whole standardising thing, I want to run a surly hub with a WI freehub mainly for a dishless (stronger) wheel, but the chainline numbers are hard to match up unless you go with Middleburn square taper cranks and fiddle with the spindle lenght. One of the (numerous) problems with ISIS is you can only get 113 or 118mm spindles, neither of which allows an exact chainline. Also 118mm also pushes out the Q-factor a bit more, which feels funny...

C
 
#11 ·
OK, the original post was edited or all of us are complete douchebags. Hopefully now he knows that he can not run a White Ind. freewheel and that he has to use a cog style sprocket with the right spacers or PVC or whatever. I actually think this is a better set up unless you go White Ind. drivetrain front and back. Changing the cassette style is easier to get on and off and you can try other size options more easily, it's also cheeper. Dishless wheels are overrated for the common man anyway. If the wheel is built properly there should be no problem.
R
 
#12 ·
I understand what people are responding to on using a spacer for the rear freewheel. Problem is, I need to bring the freewheel in towards the center of the frame, not away from it.
This simply substantiates my claim that singlespeeding is not about simplicity, going back to basics or eschewing technology; it has become, it certain aspects an extremely difficult task of mating unstandardized, or bastardized parts to complete a ride that is supposed to give us the freedom to ride freely that we had as kids.
Don't get me wrong. I don't wish or hope that Shimano or SRAM would set the standard for what we ride, or are supposed to ride. Without new ideas the industry would stagnate.
It's just that with wheel dishing, freewheel or cassette hubs, spindle length, bottom bracket width, sprocket offset, hub offsets, ISIS/square taper/Shimano and whatever variations there are, single speeding is not simple.
Will I continue to do it? Of course. But just as with politics, we have the right and duty to speak out about what we want and demand.
So the bike is together now and the chainline is within 3mm. Totally acceptable. I got LUCKY!
I appreciate all responses as they made me research further and gather info. for my next build or project.
 
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