Chainline/Drivetrain options and help.

[psyber_0ptix]

First and formost i've searched a bit, and have yet to find answers i need in reguards to measuring out chainline and or bottom bracket spindle lengths.

I have two frames for build. Monty 220 and a Norco Team Trials ryan leech blah blah

Monty Frame: nothing on it, no rear wheel, no cranks, no bottom bracket. when i get a rear wheel, how do i measure out the length of bottom bracket for whatever cranks i get if i were to use a WI freewheel in the rear, and some ring in the front? OR, if i used a FFW crank setup, and a fixed gear on the back, how do i measure proper bottom bracket spindle length(68 shell)? Are the locations of a freewheel pretty standard between manufacturers? so on any given hub, you thread on any freewheel, its in the same position? *i'm thinking about FFW and fixed rear for the monty*

the Norco i have together with a DMR hub/DX32 wheel. Spacers up the wazzoo with a 18t surly cog. front of the drivetrain is a 68x113 bb shimano xt hollowtech crank (temporary until replaced) and a 22t granny ring

DMR revolver has a weaksauce 18point engagement. i was also thinking of building a rear wheel for the norco. Surly SS hub and a DM24 rear wheel. [the dx32 is too wide for hs33's and makes the v-brake spread eagle to the point of knawing at my calf) Again, Freewheel in the rear? or fixed gear? in any case, what to do about bottom bracket spindle length. Granted, i'm going to need new cranks (front freewheel or not)



thanks for taking the time to read this, but i'm really stumped. I dont want to keep throwing around money to mix and match bottom brackets as they tend to be an expensive (to me) part to experiment with.

any links, or suggestions are greatly appreciated. flame away if you must, but if i get the answers i need, the purpose of this post would have been met.

[goose]

hey psyber,

Why not take chainline measurements to avoid the experimentation. If you measure the distance b/w the chainring and center line, you'll know what size bb you'd need to get a straight chainline with a thread on rear hub and bmx freewheel. I'm sure somebody on this board knows what the chainline is for a threadon hub and a bmx freewheel, say a surly hub and white industries freewheel. Chime in if you can:)

sheldon brown talking about singlespeed:
http://www.sheldonbrown.com/singlespeed.html#chainline

[psyber_0ptix]

i just wasnt sure where to measure from and what distances would be in relation to a freewheel (or front freewheel crank) setup to the actual spindle of a bottom bracket, but thanks for the link!

[bidaci]

I don't know exactly what year bike you have but bikesdetails.info list a 2003 220 Hydra as a 118mm BB. Can't vouch as to the accuracy of this site.

http://www.bikesdetails.info/Monty_220_Hydra_2003.html

[psyber_0ptix]

wow, actually, that is exactly as my frame looks...

will the bottom bracket spindle length change if i decide to go FFW?

[goose]

will the bottom bracket spindle length change if i decide to go FFW?

I believe that you'll need a longer bb spindle if you want to keep the tabs on your freewheel, unless you get a tensile freewheel. Some riders/manufacturers grind the mounting tabs off their freewheel once installed. I don't like this idea, as it makes removal of the freewheel very difficult. Tensile makes a freewheel that has small splines rather than large tabs. Search around.

I've never had FFW, but this is what I've read countless places. Most people running FFW use 128mm spindles to allow for the freewheel tab thickness, and to get clearance from the new fangled CNC chainstay yokes. I'm not sure which of those requires the 128mm spindle more, though.

I just thought of this now, but would the FW see less torque if it's in the rear, rather than the front? typical trials gearing uses a slight torque reduction (like 22/19, or 18/15), so the freewheel would see less torque in the rear, wouldn't it?

[nixon]

i'm about to go on the same adventure as you lol. i'm setting up a FW on the rear to a surly thread on hub and i didn't know what to use either. i'm not quite sure what people are saying by the tabs on the white industries FW but i got myself one of those try-all 108 engagement FWs and there's no tabs or anything on it from what i can see. the sides of the freewheel are completely flush. and there are 4 deep tabs for the freewheel to be installed/uninstalled with. i'm hoping my chainline will line up with a bb with 128mm spindle.

i was trying to ask around if anyone knew what i should do if it doesn't? some people told me that you can get spacers for the rear but i don't know hwo spacers would work with a thread on hub...anyways, my hub is in transit and i'll let you know how it works out in a few days.

[sputnik]

I have a Surly thread rear hub and a 128 mm BB, WI freewheel and it works great, straignt chainline. Get a SS chain to top it off (KMC 3/32).

I made an alloy floating axle (7075) for the Surly hub as well, the stock one is like, real heavy. Drilled and tapped so it's still a bolt-on.

Only potential problem is that your stuck with a 22-18 ratio if you use WI trials FW. You get 88 points of engagement however, and no grinding the FW/stripping FFW cranks.

[goose]

Only potential problem is that your stuck with a 22-18 ratio if you use WI trials FW. You get 88 points of engagement however, and no grinding the FW/stripping FFW cranks.


What about 20-18, 21-18, 23-18, 24-18? All possible, yet difficult to find:(

Thanks for chiming in on the chainline issue, though. If you use a ACS, you can get 16,17,18,20,22T

g

[spoke2570]

All are easy with rear fw, above 20 tooth front. Suntour XC pro or sport 165 cranks. (they are still out there). 22 tooth and up can be handled by any modern crank. With rear FW 72 engagements(FW) is 92 engagements at the crank for 23/18.

pete b

[psyber_0ptix]

...anyways, my hub is in transit and i'll let you know how it works out in a few days.

let me know!