stupid crankset question

[AngryScientist]

i havent owned, or looked closely at a modern shimano crankset. thinking of using on on a project wayyy down the pipeline.

anyway: where are the chainring bolts on this thing? can you use regular rings?

http://www.jensonusa.com/images/Default-Image/Zoom/695/CR283B00.jpg

[zandrrr]

The bolts thread into the chainrings. I think you can use regular chainrings if you get new bolts.

[thwart]

The bolts thread into the chainrings. I think you can use regular chainrings if you get new bolts.

But it sure looks cool.

Then again, so did the Datsun B210... ;)

http://nozama.typepad.com/.a/6a00e54ed05fc2883301156e51711d970c-400wi

Well, then again, that is a little harsh.

[oliver1850]

The Tiagra/R550/R700 cranks are a little better looking. I replaced the rings on this R700 just because I thought the Shimano ones were ugly.

[sc53]

Oliver are those TA rings? They look great!

[oliver1850]

They are Control Techs. I don't expect them to have the lifespan of TAs, but they look nice.

[Ti Designs]

It's still either a 130 or 110 bolt circle, if that's what you're asking. You can put "normal" chainrings on there, using "normal" stack bolts. That said, Shimano engineers don't know about the outside world, they don't know that other chainrings exist. Shimano produces groups where all of the parts are designed to work together. The chain for the 6700 group is designed to work with the new chainrings which offer a smooth ramp down to the smaller ring. Start using normal chainrings and you risk chain links coming apart (the 6703 uses the older chain for this reason). Shimano has it's reasons for going to the new chainring design. The large chainring has far more cross section to it, so it's laterally stiffer. This was needed because the servo motor on Di2 is no wimp struggling to gain leverage on a shifter. Specialized uses their own crank on their Tarmac and Roubaix Di2 bikes, the aluminum stack bolts have been known to fail under front shifting...

[oldpotatoe]

Yep, chainring bolts thread into the big ring. You can use a regular big ring for either , the standard and compact, just get regular CR nuts/bolts. Still 130 or 110mm BCD

Until DA 9000..4 arm, unique to the crank, bolt diameter, threading into the back of the big ring. One crank for standard and compact..CRs will be in the $450 for the big ring, range..yowser.

[AngryScientist]

thanks guys, that's kind of what i thought. cheers.

[zandrrr]

CRs will be in the $450 for the big ring, range..yowser.

Ouch! Is that a guess or a confirmed number? Thankfully it won't take long for aftermarket options to pop up.

Anyone want to over/under the likelihood of the 4-bolt design sticking around? Or will it be another Biopace/Rapid Rise/7800 rear hub situation?

[LO^OK]

It's still either a 130 or 110 bolt circle, ........ The chain for the 6700 group is designed to work with the new chainrings which offer a smooth ramp down to the smaller ring. Start using normal chainrings and you risk chain links coming apart (the 6703 uses the older chain for this reason). Shimano has it's reasons for going to the new chainring design. The large chainring has far more cross section to it, so it's laterally stiffer. This was needed because the servo motor on Di2 is no wimp struggling to gain leverage on a shifter. Specialized uses their own crank on their Tarmac and Roubaix Di2 bikes, the aluminum stack bolts have been known to fail under front shifting...

.... interesting, thanks for the hint.

[oldpotatoe]

Ouch! Is that a guess or a confirmed number? Thankfully it won't take long for aftermarket options to pop up.

Anyone want to over/under the likelihood of the 4-bolt design sticking around? Or will it be another Biopace/Rapid Rise/7800 rear hub situation?

Well, 7900 are about that, maybe a wee bit less. No aftermarket, sculpted type, bolt from the back, rings. BUT a standard ring does work, altho looks a little ghetto.

4 arm design here to stay. Bet you see it on next gen 6700(8500?).