Re: [RBW] Re: Broken Crank (Quickbeam)

thanks Bob, I was curious. While that is a high stress area, seems like there has to be something in the surface or microstructure producing a stress riser to get such a well-defined and straight crack origin. On Wednesday, May 6, 2015 at 11:26:16 AM UTC-5, Statrixbob wrote: > > > On Thu, Apr

Re: [RBW] Re: Broken Crank (Quickbeam)

On Thu, Apr 30, 2015 at 6:41 AM, Ron Mc wrote: > Was the crack coincident with a stamped marking in the crank arm? I checked and no, there's no stamped marking on that part of the crank. Just one of those things. :-) Aloha, Bob -- Robert Harrison Honolulu, HI rfharri...@gmail.com statrix.

Re: [RBW] Re: Broken Crank (Quickbeam)

On Thu, Apr 30, 2015 at 7:48 AM, Minh wrote: > if you want to treat yourself i recently put on a White Industries crank > that looks awesome. Which of their cranks did you use? What size BB? And, since you say it looks awesome, got an image? :-) Aloha, Bob -- Robert Harrison Honolulu, HI rf

Re: [RBW] Re: Broken Crank (Quickbeam)

I ran a Campy square taper crank with one 39t ring on the outer side of the crank with single ring bolts for a long time. The Campy 110 BB set up a perfect chainline. Recently switched to the VO with 44t ring and 115 BB which is a little inward. Michael -- You received this message because

[RBW] Re: Broken Crank (Quickbeam)

Bob, I am glad you didn't get hurt! Let the folks at RBW know, as I think at least Grant Petersen would want to see the crank. Seems like he has a great love for Sugino cranks and I think he would be interested. I need to remember to check my cranks from time to time. Congrats on the metric ce

[RBW] Re: Broken Crank (Quickbeam)

fwiw, the highest load you ever (always) put on a crank is when you stand on one side to take off. I know a lot of people lead with their right foot, but I do the left thing, too. In the taper area, right-side crank arms are usually stronger because there's more medal there. But that doesn't

[RBW] Re: Broken Crank (Quickbeam)

Yikes! That's disconcerting! I'm certainly glad you weren't hurt! On Thursday, April 30, 2015 at 9:56:15 AM UTC-5, Statrixbob wrote: > > Oops, I just made the photos public. > > https://www.flickr.com/photos/mgps-bob/sets/72157652254822642/ > > Mea culpa and aloha! > > Bob > On Apr 29, 2015 5:51 P

Re: [RBW] Re: Broken Crank (Quickbeam)

I have older Shimano 600s with 39/42 rings on my Quickbeam. Philip www.biketinker.com On Thursday, April 30, 2015 at 9:10:10 AM UTC-7, Statrixbob wrote: > > > On Thu, Apr 30, 2015 at 5:23 AM, Minh > > wrote: > >> well count yourself lucky that it happened at a pretty innocuous time, >> imagin

Re: [RBW] Re: Broken Crank (Quickbeam)

I don't have access to the bike (rode my Hunq to work) so I can't take a look till tonight. I do not remember it being near a stamping, but I also don't remember what I had for lunch yesterday. :-) I'll check tonight. Bob On Thu, Apr 30, 2015 at 6:41 AM, Ron Mc wrote: > BUT > > >

Re: [RBW] Re: Broken Crank (Quickbeam)

I'm constantly struggling between treating myself or using something good enough. so i'm using the same model crank that you just broke! if you want to treat yourself i recently put on a White Industries crank that looks awesome. second hand i'm a big fan of the older suntour superbe pro cr

Re: [RBW] Re: Broken Crank (Quickbeam)

BUT Was the crack coincident with a stamped marking in the crank arm? On Thursday, April 30, 2015 at 11:10:10 AM UTC-5, Statrixbob wrote: > > > On Thu, Apr 30, 2015 at 5:23 AM, Minh >

Re: [RBW] Re: Broken Crank (Quickbeam)

On Thu, Apr 30, 2015 at 5:23 AM, Minh wrote: > well count yourself lucky that it happened at a pretty innocuous time, > imagine if this had happened while bombing down a hill!! and now consider > replacement options > As far as replacement options go I haven't had time to really take a look

Re: [RBW] Re: Broken Crank (Quickbeam)

As far as I know it's never been dropped onto the pedals. And as far as I recall, the only time I've ever fallen over on that bike it was on the left side, not the right, and it was (embarrassingly) while I was stopped and tried to turn to talk with someone and got tangled and, well, never mind. :-

[RBW] Re: Broken Crank (Quickbeam)

hmm agree with Ron, not the place i would've guessed for a break before seeing the pictures. for a break like that, maybe it was it from the side and started to crack, crack, crack. it's a pretty straight/clean break! well count yourself lucky that it happened at a pretty innocuous time, ima

[RBW] Re: Broken Crank (Quickbeam)

I wonder if the crank had been subjected to a side force, like being dropped onto the pedal? On Thursday, April 30, 2015 at 8:04:23 AM UTC-7, Ron Mc wrote: > > that's a really strange place to break. It cracked gradually from the > inside. Was there any kind of stamped marking at the crack or

[RBW] Re: Broken Crank (Quickbeam)

that's a really strange place to break. It cracked gradually from the inside. Was there any kind of stamped marking at the crack origin on the inside edge? On Thursday, April 30, 2015 at 9:56:15 AM UTC-5, Statrixbob wrote: > > Oops, I just made the photos public. > > https://www.flickr.com/

[RBW] Re: Broken Crank (Quickbeam)

Oops, I just made the photos public. https://www.flickr.com/photos/mgps-bob/sets/72157652254822642/ Mea culpa and aloha! Bob On Apr 29, 2015 5:51 PM, "Robert F. Harrison" wrote: > First let me say...no injuries, no accident, didn't even fall over. Having > said that, it was a bit unexpected an

[RBW] Re: Broken Crank (Quickbeam)

the worst part is there is really no sensible way to ride after that - luckily when mine happened, we were on our way downtown to the Frankenbike meet. Walked the bike 20 blocks and bought a $5 crank arm to get home. On Thursday, April 30, 2015 at 8:24:03 AM UTC-5, WETH wrote: > > Bob, > I am

[RBW] Re: Broken Crank (Quickbeam)

Bob, I am glad it was not a more catastrophic experience for you. All the best, Erl On Wednesday, April 29, 2015 at 11:52:15 PM UTC-4, Statrixbob wrote: > > First let me say...no injuries, no accident, didn't even fall over. Having > said that, it was a bit unexpected and I'm terribly grateful it

[RBW] Re: Broken Crank (Quickbeam)

I'm glad you're OK, Bob! That was very good timing of it to break given some of the alternatives. I can't see your photos on Flickr as they are private. With abandon, Patrick -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe

[RBW] Re: Broken Crank (Quickbeam)

can't see your photos without a yahoo account. I think we're dealing with the biggest limitation of a square taper crank. The torque is going to gradually relax, and stresses become really high on the inside corner - the one that's loaded when you step on the crank. I had the same thing happe