2x8???? (?)

[Del Q]

The subject of 2x8 gearing came up in another thread and reminded me of some questions I have about it. I am about to order a new frame and am planning to build it as an 8 speed in hopes of ultimately benefitting from a beefier chain, greater tolerances, and better chainline. Currently I run 3x9 and have had no problems with it, but it seems like riding might be a little sweeter with 8 speed. Then again, maybe I should just start smoking crack, since someday it may be easier to find than 8 speed parts.

So I could go to 3x8, but awhile back I decided not to use the little ring anymore, so I figure why have it? So 2x8 would seem like the right thing to do on the next bike. I would hope that 2x8 might offer an even better chainline than 3x8, as TechniKal described in this thread (he was talking about 2x9, but the reasoning is the same)…

chainline thread (http://www.bikemojo.com/speak/showthread.php?threadid=5310)

Carlos, don’t you run 2x8? In the above thread, it was a little unclear to me how to make it result in a better chainline. I asked a mechanic at an LBS about it, and he thought using a 110mm BB might do the trick. Is that what Toonces was asking? And will it actually result in a better chainline?

What will be involved in setting up a bike for 2x8 (or 2xAnything)? Do you just remove the little ring, use a 110mm BB, and adjust the front shifter for 2 rings? Is it more trouble than it’s worth? Should I take up smoking crack?

Keep in mind that I don’t know much about bikes, so I have to ask stupid questions that may have been answered already.

[toonces]

Yeah, that's what I was asking. I was running a 113mm BB, so that would move my crank arm out effectively aligning the chainrings more with the small/high cogs. I used the 110mm to pull the chainrings closer to the BB and in effect try to get a better low gear chain line.

I now run a XT BB/crank combo so that's all out the door. I still do a 2x8 + bashring and so far have had no problems. I use the mid/granny rings tho. When I was running a 1x8, I felt that I didn't have a low enough gearing, but that was a 34 x 11-28 setup so I didn't have the 1:1 climbing gear.

[Del Q]

Toonces, thanks. Also your reply reminded me that I forgot to specify that what I am shooting for is a better chainline between the middle ring and the low/big cogs - although it was probably obvious anyway. I will keep a 1:1 or lower combo for climbing. Right now, my climbing combo is 32:30. I have 32:34 available as well, but it produces a noticable bend in the chain and that worries me... especially on steep climbs... especially as my chain gets older... especially since I am a masher/puller, not a smooth spinner... so I don't use it. Anyway, this is one the areas where I am trying to learn from my likes and dislikes about my current bike, so that the next one will be just right.

[carlos]

Del Q.....what? new frame? what you getting?

there are a lot of pros and cons to 8 and 9 speed. think about this though.....however great 8 speed is....at some point....it will be hard to find.

while there's lots of nine speed stuff out there, there are some flys in the ointment. tolerances are tight and because of that, you either have to keep it really clean fr it to shift well OR check the adjustments from time to time (just because someone says to you "i haven't had to touch my drivetrain, at all, for 4 months" is never a good sign. bikes need looking after. even bikes that cost $320 dollars need looking after. nothing in maintenance free. except for....maybe....peanut butter.) OR both.

it's not the checking of adjustments that's so important as catching some other types of damages or weirdness while you're checking adjustments. also, cleaning a bike reveals all sorts of stuff.

ok...now i'm way off....again.

crack IS nice.

i've never liked the little chainring...even when i did use it. a dramatic loss of momentum occurs. speed decreases. more effort is required for a longer period of time.

it always seemed when people were in the smallest chainring...they thought they were getting a break. in reality they spent more time climbing and more time on the side of the hill.

we're not even talking about weekend warriors here...we're talking about seasoned riders.

of course...we have to consider the bike, the riders style, and the current gearing. you can't really blame a guy who has a 11-28 8 speed cassette, for still having, and using the smallest chainring.

as for better chainlines....let's first look at what a chain line really is.

the chainline is the distance from teh center of the seatube to the center of the middle chainring. in the case of a double (2 X something), it's the smaller of the two.

to make matters a bit more complicated....there is a ideal chainline for cogsets as well. but you can typically count on hub manufacturers to provide pretty proper hub dimensions.

so why is chainline important? two reasons.

one, access to a handful of cogs for a given chainring. with 5, 6, and 7 speed drivetrains, that were properly set up.....you could cross gear all over ALF's green earth. but as 8 and 9 came along this became an issue. enough of an issue that Shimano is now including a small leaflet with their front der.s that basically says: "if you get chain rub in this gear combo on the front der. shift to the next smallest or largest cog, stupid!"

in some cases, some mechanics would pull their hair out trying to get zero chain rub when the chain was in the bigggest and smallest cogs and the middle ring. if the frame was nice and straight, and the hanger was of proper dimensions (angles and distances from the center of the rear axle), and the hub was of proper dimensions, and the parts were all installed correctly, cables and housing were done up right, and the right tunes were playing....they could get close. typically though, you could do it.

but some riders wanted a totally quiet ride. what can be done. some inventive front der. cage bending was usually the order of the day OR, my favorite fix...if possible to use....a '98-'02 top swing XTR front derailleur. the independent cage plates were so cool because they moved enough, in certain gearing combos to eliminate chain noise. it's an expensive fix...no doubt...but a nice one when you just want to install a front der. and have it work. not to glorify them too much, they do develop pivot slop and don't work very well with some chainring ratios. again...it's all in the install and set up.

two, the proper chainline allows the front der to move far enough, in the direction/toward, the center line of the frame, to derail the chain from the middle to smallest chainring. this can usually be a hassle if someone uses, say, a 107mm spindle and has a frame that has a seat tube with a 35mm OD.

when the front der. swings toward the center line of the frame, it might.....MIGHT (we have not listed a single variable so this is all just conjecture).......bottom out on the seatube before it can derail the chain from the middle to small ring. there are all sorts of fixes to this (slight bending of the cage, longer spindle**, BB cup spacers...).

**as for the longer spindle....it's a nice and easy answer to blurt out....lots of people, including myself did in the begining....but this also moves the biggest ring further out. shimano rapid fire shifters have a limited throw to move the chain from the middle to big ring...too far out, and now you can't get into the big ring. bummer.

i'm sure there are other reasons for a chainline.....but those seem to be some solid ones. every crank manufacturer has it's own ideal chainline. some are the same....some are kinda the same (not the same)....and some are not even close to the same (not the same). if they are kinda the same...then the shifting will kinda work. and sometimes...'kinda' is good enough. sometimes.

i use 2 X 8 because i like the simplicity of it. imagine this scenario.

you're rolling around at X trail. lots of different terrain. but for the most part you're keeping a nice skippy speed. you're using a 2 X 8. you're 44/28 combo. not fast but lively. you come up to a quarter mile climb with a few small lips and a few loose rocks here and there. but rather than hunker down for the shift to smallest chainring and a drop in speed.....you take hold of the LEFT shifter and fire off a shift. you're now 32/28. a perfect gear for this climb. you...with a heart pumping like an oil derek, begin a rather lively uphill roll. before you know it, you're at the top....you crest but continue to pedal since it took you less time, and possibly, effort to get up there.....and soon you feel the recovery coming on. and BAM-0!....back into the 44T and away you go.

City Park is a perfect place. 44/28 for everything but the climbs and 32/28 for the tech climbs...and 32/32 for the really techy steep stuff. the whole ride i'll have shifted between 3 gearing combos. that's it.

anyway....2 X 8 or 9 doesn't result in a better chain line....it simply places two rings in an ideal spot to cross gear a bit more.

the only way to know what chainline is ideal....the mechanic will first have to figure out the current chain line. sure we could guess 110mm BUT....what if it's still not close enough to ideal?

lets say you use a flangless BB....you could thread the BB more to one side to get the chain line.....but what if you have to thread it over 3/4ths of an inch? what about you knees? what about crank arm clearance and the frame? what about, how you will be pedaling?

numbers tell the tale and in this case....it's best to get the story straight.

i recently moved from a 110mm spindle....to a 107mm spindle.....and now to a tiny 103mm spindle. the bike was originally spec'd with a 113mm for a tripple. with the 110m i used a triple and double and a double with the 107mm.

take the Sugars.....most comes with 113mm spindles and lots of folks have problems that....when they are in their middle rings and largest cogs...the chain falls off the middle ring. assume they are using a square taper Bontrager Race Lite crankset. ideally they will need a 110mm. why? because 110mm is the next smallest size? nope. because 110mm will make the distance from the center of the seatube to the center of the middle ring, say, 49.8mm. and that's nice.

in that thread Toonces was talking about a single speed. you've got lots of room to play with on SS chainlines. some SS bikes have a rear hub that has spacers that allow you to move the single cog on the hub laterally. so you can set that chainline, to the chainring's chain line.

in his post he mentions he is going to use a 180mm XT crankset (splined we can assume) for the SS. but he couldn't get a 110mm BB because Shimano's shortest splined spindle for XT is 113mm. in reality the 113mm XT splined BB will work fine.

if Toonces has square taper....then a 110mm spindle will work well too. or a 107mm.

setting up a bike for 2 X anything involves finding out what the current chain line and the chainline you're shooting for.

there is some adjustment made to the front der and the shifter but other than that...it's pretty straight forward.

should you take up smoking crack? only if you can get it for cheap.

as for the asking of stupid questions...there are no stupid questions. but answering the same questions over and over allows me to revise my answers. and that's always good. and, of course...spreading info like STDs, is great fun!

[jrwjr_eng]

Carlos, Thanks for class today. I learned a lot except; How do you measure chainlines. You mentioned something about the center of the seat tube to the center of the middle chain ring. How does that have anything to do with spindle length? What would the new points of measurement be?

Or did I miss something?

[Del Q]

Carlos, thanks for all the advice and commentary. I had to read it a few times to digest it. Sounds like it will be pretty straightforward once the ideal chainline is determined. But you wrote:

"every crank manufacturer has it's own ideal chainline."

AND

"the only way to know what chainline is ideal....the mechanic will first have to figure out the current chain line. sure we could guess 110mm BUT....what if it's still not close enough to ideal?"

What about on a bare frame? Can you predict from a bare frame what the ideal chainline is and what size spindle to use for a given crankset, or do you have to take a guess, install, and check? Does my question even make sense?

Maybe a cottage industry will spring up around 8 speed once it's hard to find.

The new frame... ByStickel is going to build it, a steel HT. Once the frame is done, I will build it up at whatever pace my paycheck will allow over the next several months.

[carlos]

jrwjr_eng, no prob.

there are all sorts of ways to find out what the chainline is on a frame that already has the cranks and rings mounted to it.

one way requires basic algebra....another requires the use of a caliper. how has these things?

best way is to get your self a nice stainless steel and really narrow, ruller.....that is metric.

i like using the center of the water bottle bolts on the frame and measureing out from there. you CAN eyeball it and get really close. millimeters are a big enough a unit to see.

the longer the spindle....the further from the frame the cranks sit. and since the rings are mounted to the cranks...they are further away too.

does that answer the question about what the spindle length has to do with it?

========================

Del Q, no prob.

yeah...i try to give as much info as possible. even examples. i could have cut it down to:

2 X something is the best.

crack is cool.

yes i use 2 X 8.

110mm spindle sounds good.

just block out the front der and use the first two clicks on the shifter.

but that doesn't take into account lots of stuff.

------------

on a bare frame......

let's play pretend.

someone just bought a brand new frame...a custom Captain Sweaty frame with the sparkle fromnda cheese paint job.

first we'll measure the BB. looks like it's a 73mm BB shell. so we'll need to ask for a BB with a 73mm shell.

now for the spindle length.

this person wants to use Shimano XTR cranks. well...shortest spindle they make for XTR is 113mm. we can assume that it should be ok because there aren't many XC frames that require 116mm or 118mm spindles.

still haven't installed anything. the next day i call Sailor Rick at Captain Sweaty and ask what spindle they recommend. for a set of Shimano XTR cranks. he says "avast ye land luber! 113mm be yar length!!"

so the assumption was right.

but what if Captain Sweaty frames are built by people who LOVE big diameter and wide chainstays?

when in doubt....and you don't have the resources to try different lengths....call the manufacturer.

a ByStickle? BAD-O!

what color?

[Del Q]

Selecting a color will be the hardest part. There are so many. Maybe an earthy brown or green, or lime green, or pistacio, or burgundy, or charcoal grey, or...

[aLaN]

Originally posted by Del Q
Selecting a color will be the hardest part. There are so many. Maybe an earthy brown or green, or lime green, or pistacio, or burgundy, or charcoal grey, or...

:)


Colour selection is the hardest part. The nice thing with a custom frame is that you can order it and you still have some time to decide, as the painting is one of the last steps.

I changed the colour on my IF at least once during its frame construction.

I was unsure about the Black fade to Red but decided on it due to the Mojo Colours.

Anyway the frame came into Ride Away bicycles and it was awesome. While it was there being built a guy from San Angelo came in to order some custom road frame. He saw my bike and had his painted the same way....

A year ago I am riding in San Angelo State Park and this dude comes up to me and tells me that he has the matching road bike. Strange but true. I met the guy on the trail.

Owning a full custom bike with custom paint is the ultimate expression of you. And this is why it is the hardest part.

What/Who do you want people to see when they look at you and your bike?

I say go loud and proud!

[toonces]

Originally posted by aLaN

I say go loud and proud!

Rainbow fade kinda proud?

:eek: ;) :p :D

[Del Q]

carlos asked

what color?


midnight blue frame and fork


aLaN advised

What/Who do you want people to see when they look at you and your bike?


I chose the colour from those available on the old Shelby Mustangs, a car I've always lusted for. But on my lab tech salary... well, at least I can get a bike painted the same colour.



I'll post pics when it gets here.

[carlos]

is it here yet?

[Del Q]

Not yet. The frame and fork are done. Now he's ordering some parts for it.

[carlos]

have you put the parts you've purchased down your pants?

[Del Q]

If it's a performance-enhancement, I'll do it... when they get here!!!

[aLaN]

Originally posted by carlos
is it here yet?



hehehe

Carlos, when do you think that it will arrive?

[carlos]

oh.....Del Q is sure to wait and wait and wait and wait....at some point he'll see a movie....and wait and wait and wait.....and then.......when he least expects it...........it'll arrive.............right on time.

[aLaN]

Originally posted by carlos
oh.....Del Q is sure to wait and wait and wait and wait....at some point he'll see a movie....and wait and wait and wait.....and then.......when he least expects it...........it'll arrive.............right on time.

That's it...

It will come in, right on time....

[Del Q]

Some kind of inside joke...?

[aLaN]

Originally posted by Del Q
Some kind of inside joke...?


when you least expect it, it will arrive, right on time (http://www.bikemojo.com/speak/showthread.php?s=&postid=19988#post19988)

[Del Q]

Alan said
I 'patiently' waited 8 weeks for my frame to come in.



Ha! 8 weeks ain't no wait.

Look at when this thread was started.

The weird thing is, I'm going to a movie tomorrow. I never go to movies. Maybe it's a sign from ALF.

[carlos]

make sure the movie you see ins;t crap....cause then you'll come out and say "that sucked....who was given the go-ahead to film this shit??? hey! i'm supposed to be getting a frame soon! where the hell is my frame!!?!?!?"

at that point it'll fall apart and you'll shoot someone. don't ask me where the gun came from but you'll have one.

then you'll go to jail but the judge will see the pics of the frame and let you go....

then you'll get home and STILL not have a frame.

then you'll shoot your neighbor and the judge will stilll be reeling from the photos and let you go....

at some point the judge will stop reeling and throw you in the slammer where you'll become some bad man's boyfriend and spend your night sleeping on your stomach.

sooooo........choose wisely....for a good film with fill you with wonder and joy, while another will take it from you.....

[Del Q]

Alan, I didn't mean to diss on your wait and all. I'm sure it was tough... But at the 8 week point, I was just starting to settle in for a looooooooooong wait. Maybe ByStickel is some kind of artist or something.



(Actually he had to move his shop from Indiana to Virginia after I ordered the frame... some kind of trouble with the law, I think)

Carlos, I don't get to pick the movie, so I'm sure it will suck. So, see you in 5-10.

I kinda wish toonces and jrwwj_rjrj__jrjrr would chime in on this thread again... just for ol times' sake.

[carlos]

DelQ posted "(Actually he had to move his shop from Indiana to Virginia after I ordered the frame... some kind of trouble with the law, I think)"


if there is anything cooler than a custom ride, it's a outlawed custom ride!

http://roadsidephotos.com/sd/mu07.jpg

YEEEEEE!!!! HAAAAA!!!!!!!



bummer on the movie.....

[aLaN]

Originally posted by Del Q
Alan, I didn't mean to diss on your wait and all. I'm sure it was tough... But at the 8 week point, I was just starting to settle in for a looooooooooong wait. Maybe ByStickel is some kind of artist or something.




no worries,

Any ETA on it yet


Estimate?

[Del Q]

Probably next week. Just waiting on a couple of parts, then it all ships.

[carlos]

did the movie suck?

[Del Q]

yeah.

Waiting on the Phil. Stickel ordered the install tool. I think I'm gonna go ahead and try the install myself. Also, waiting on an XT 8 spd cassette... my 8 spd woes are starting already.

[carlos]

the BB install should be any easy one but you'll want to wait until you can mount the rear wheel and cassette with a chain so you can figure out the best chain line.

in some cases it's possible just to center the cups in the shell but sometimes there needs to be a bit of an adjustment either way.

although you could just install it dry and not tighten anything more than finger tight. mount the cranks up and only slightly tighten the crank bolts......then call into work and tell them you got SARS from Anna Nicole Smith and spend the day turning the cranks.

[aLaN]

Originally posted by carlos
then call into work and tell them you got SARS from Anna Nicole Smith and spend the day turning the cranks.


Speaking of SARS (http://www.canoe.ca/JamRollingStones/jul31_stones5-sun.html)...

http://www.canoe.ca/SarsStockGallery/23.jpg

http://www.canoe.ca/SarsStockGallery/24.jpg

http://www.canoe.ca/SarsStockGallery/25.jpg

[aLaN]

Trek's 2007 lineup to include 2X setup to alleviate the high Q factor with their current setups....

http://www.dirtragmag.com/web/article.php?ID=783&category=web_only


"And since Top Fuel is a race bike and many racers are reportedly not satisfied with the high Q-factor associated with the current trend of outboard bearing bottom brackets, Trek has designed the triangle for use with Bontrager still-in-the-works new 2-ring crankset. Think closely about that concept, and you'll realize that sliding a larger chainring closer to the bottom bracket demands tighter clearance at the chainstay--a significant design challenge indeed."

Should be interesting.

[Ormsbinator]

Hey buddy this is Steve O.

So you are talking bike crap....Well can't go here..Need to get into the mix of it all again.Looking forward hanging this fall at Ruston..is the crew going? We should have a extra one aboard Nikki and I are expecting a little one in March of next year....Keep us in your prayers you all...;) Good to be back in Texas....FEMA work is no fun but freakin pays great.
And man the people in LA.need the help big time.Take care you all riding and drink and drink and drink:D