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-   -   Bicycle thread (http://www.advrider.com/forums/showthread.php?t=150964)

kbasa 05-21-2010 09:27 AM

Out for 80 miles tomorrow. :wings

trailer Rails 05-21-2010 04:05 PM

Quote:

Originally Posted by Askel
My main beef with disc brakes on road bikes is that it's tough to find a good deal on wheels with 130mm disc hubs. So very few CX bikes actually spec a 135mm rear hub.

Yup, I just have a 135mm hub shoehorned in the back of my cannondale.

Gummee! 05-21-2010 06:33 PM

Quote:

Originally Posted by trailer Rails
Yup, I just have a 135mm hub shoehorned in the back of my cannondale.

You can get away with that on a steel bike. You may wanna take out a few spacers and get that spacing back down to where the bike wants it.

AL don't like being stretched...

M

slackmeyer 05-21-2010 09:00 PM

Quote:

Originally Posted by Gummee!
You can get away with that on a steel bike. You may wanna take out a few spacers and get that spacing back down to where the bike wants it.

AL don't like being stretched...

M

I may be sitting on a ticking time bomb, but my klein road bike (built for 126mm hubs) is now using 130mm hubs, with no apparent problems. It does add a couple seconds to rear tire changes.

pierce 05-21-2010 09:20 PM

I gotta stretch the back of my cruiser about 1cm. haven't measured it yet, but it used to fit a 70s vintage 5-speed freewheel mtn bike hub, and now it has a late 90s 7 speed cassette hub which is about 1cm wider. was reading on sheldon brown's site about using a 2x4 ;)

went for a good ride around town this afternoon, took the levies, checked out the bike routes around the harbor.

trailer Rails 05-22-2010 05:15 AM

Quote:

Originally Posted by Gummee!
You can get away with that on a steel bike. You may wanna take out a few spacers and get that spacing back down to where the bike wants it.

AL don't like being stretched...

M

I am not worried, it is a 5mm difference, 2.5mm on each side. The bottom bracket shell flexes more than that back and forth when I crank up a big hill.

Gummee! 05-22-2010 09:58 AM

Just keep an eye on yer chainstays. They crack in this situation. I'm sayin this as a mechanic, not just some wanker on the 'web.

M

pierce 05-22-2010 11:37 AM

Quote:

Originally Posted by trailer Rails
I am not worried, it is a 5mm difference, 2.5mm on each side. The bottom bracket shell flexes more than that back and forth when I crank up a big hill.

another consideration is if when spread, the dropouts are still parallel. if they aren't, it puts a nasty torque load on your axle and can lead to either bearing failure or broken axles.

http://www.parktool.com/images_inc/r...help/FFG19.jpg http://www.parktool.com/images_inc/r...help/FFG09.jpg

trailer Rails 05-22-2010 12:12 PM

Thanks guys,

I have been a bike mechanic for the last 18 years, I know a thing or two about these things.

I am not sure how to figure this out but I think my chainstays are somewhere around 15", I moved them 2.5mm. :eek1 OMG, that has to at at least a quarter of a degree out of alignment. It is amazing my my axle did not break or my bearings did not fail already!:lol3

pierce 05-22-2010 12:25 PM

Quote:

Originally Posted by trailer Rails
Thanks guys,

I have been a bike mechanic for the last 18 years, I know a thing or two about these things.

I am not sure how to figure this out but I think my chainstays are somewhere around 15", I moved them 2.5mm. :eek1 OMG, that has to at at least a quarter of a degree out of alignment. It is amazing my my axle did not break or my bearings did not fail already!:lol3

15" is 380mm. atan(2.5/380) in degrees == about 0.4 degree.

yeah, thats not a lot, but when you clamp down that quickrelease, you'll be applying torque on the dropout as well as the axle... if there's any carbon fiber in your stays, i"d be watching the joint where the dropout joins the stay. stressed carbon is unhappy carbon.

Gummee! 05-22-2010 02:18 PM

Quote:

Originally Posted by pierce
15" is 380mm. atan(2.5/380) in degrees == about 0.4 degree.

yeah, thats not a lot, but when you clamp down that quickrelease, you'll be applying torque on the dropout as well as the axle... if there's any carbon fiber in your stays, i"d be watching the joint where the dropout joins the stay. stressed AL is unhappy AL.

fixt

M

pierce 05-22-2010 06:05 PM

heh. resurrected another pile of junk from my driveway. my boy's old GT Rebound, something we'd bought used when he was 5' tall, that he long ago outgrew... this is the bike that donated its wheels to repair my cruiser as overly documented above....

so, I took the wheels of my other kids even tinier Hardrock, cleaned up the GT, readjusted everything, a bit of triflow on important bits, soaked the chain in WD40 and wiped down several times, then airdried and dribbled a bit of triflow on it, and took the uber-phat gel seat I'd just gotten for my wife's ancient heavy stumpjumper, and removed the lame bar end extenders (never liked those things, the balance is just wrong with them). I hope my wife likes it, its trigger brifters instead of friction thumbshifters like her old bike, and the pedals are funkier (but I could probably swap those), but its 10 lbs lighter, and rides great, and the old Rock Shox still has some boing to it. I think this is one of the old rockshox that used a polymer spring-shock thing, but its got some adjustments, and on stiff and hard, its not bad at all.

I wonder if she'll like it? (she's gone til tomorrow, then we leave Wednesday for the spring strawberry music festival, where I expect she'll be riding it). I still have to figure out how to mount the fenders on it as its likely to be a wet and muddy strawberry. I'm thinking I can use some kind of clamps on the springer forks, and hang the fender from the brake bridge. the back of the bike has fender lugs already. the fenders are off -my- old stumpjumper, which is now my son's college ratbike. loved riding those old things but they are -so- heavy. strongest bike frame ever made, I do think.

http://lh6.ggpht.com/_JS1yca5KB-0/S_...G_6337.CR2.jpg

trailer Rails 05-23-2010 02:49 PM

Quote:

Originally Posted by Gummee!
fixt

M

Thanks guys, but do you have any idea how much your frame flexes when you climb a hill?

Even Al and carbon frames move quite a bit on every pedal stroke.

Gummee! 05-23-2010 03:08 PM

Quote:

Originally Posted by trailer Rails
Thanks guys, but do you have any idea how much your frame flexes when you climb a hill?

Even Al and carbon frames move quite a bit on every pedal stroke.

Yup. I know how much it flexes. I also know that you're pulling it out of its 'happy spot' and bad things happen when you do that.

M

trailer Rails 05-23-2010 03:16 PM

Quote:

Originally Posted by Gummee!
Yup. I know how much it flexes. I also know that you're pulling it out of its 'happy spot' and bad things happen when you do that.

M

We will see, I have been riding it that way for over 2 years now. I'll let you know when it breaks.


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