I'm confused again. I was thinking that wide chainstays require high Q cranks. But if the drop out width is standard, is it just the way the chain stay splays out near the BB that determines Q? Can a frame builder make a bike with low Q yet still accept 50mm tires? If so, why does Rivendell make all their bikes with high Q?
Thanks. On Apr 30, 11:01 pm, CycloFiend <[email protected]> wrote: > on 4/30/10 8:08 AM, happyriding at [email protected] wrote: > > > I was thinking that as the chainstays got wider, the cassette moved > > outboard more, but that isn't true is it? The cassette must be in the > > same place no matter how wide the chainstays are? So that meas every > > crank has an ideal distance from the BB shell that perfectly lines up > > its chain rings with the cassette? So for bikes with wide chain > > stays, you need a crank where the crank arms are further away from the > > rings so that the crank arms clear the chainstays, but the rings still > > line up with the cassette? > > Yep. Pretty much. > > The idea is to design a bike which allows you to place the chainrings and > rear sprockets in similar relationship to the centerline of the bicycle. > > AASHTA -http://sheldonbrown.com/chainline.html > > It's not so much that the chainstays were widened - the rear spacing doesn't > really change as it's specific to the gearing. > > http://www.sheldonbrown.com/frame-spacing.html > > A few things have led to wider crank arm "splay" - shorter chainstays, which > move the wider part of the rear triangle closer to the bottom bracket; > larger diamter (i.e aluminum) and/or square tubing found on mtb designs; > suspension designs which favor oversized or square tubing. > > - J > > -- > Jim Edgar > [email protected] > > Cyclofiend Bicycle Photo Galleries -http://www.cyclofiend.com > Current Classics - Cross Bikes > Singlespeed - Working Bikes > > "You must be the change you want to see in the world." > Mahatma Gandhi > > -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group > athttp://groups.google.com/group/rbw-owners-bunch?hl=en. -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rbw-owners-bunch?hl=en.
