Yes, I remember reading that article, as ell as this from Peter White's web page:
The quickest shifting on triple chainring cranks with Shimano's STI shifters can be had only with matched sets of chainrings. For example, the nine speed Shimano Ultegra Triple crankset 6503 comes with three matched rings; 52 - 42 - 30 teeth, and the later ten speed Ultegra 6603 comes with 52 - 39 - 30. The alignment of the teeth and the positions of the steel pins that lift the chain from smaller to larger rings are carefully positioned to make up-shifts as quick and smooth as possible, even under considerable pedaling forces. With a few exceptions, TA chainrings are designed to be used with many different adjacent rings. The TA rings have pins for lifting the chain, but since you can choose from many chainring combinations, the three rings you end up with won't be matched for tooth position or pin position. That makes the shift a bit slower than if you use Shimano's matched chainring sets. But STI shifting still works. You just can't pedal as hard while shifting as you can with Shimano's rings and still get a smooth shift. Don't worry though, they still shift very well. This is only an issue with triple cranksets. Then there's experience. I have two cranks with ramps and pins. They both shift phenomenally well. The first one I ever bought was the White Ind. VBC. I run a 44/30 on my ram. The second one was for the tandem, which had a lot of shifting issues until I made a number of changes, including buying TA rings for the outer and middle position (48/38). Both of these shift very well. What I gather from Jan, Peter, & GP is that these ought to be a bit slower. Well they may be a bit slower than STI, I wouldn't know about that, but they are certainly no slower than unpinned rings. What I experience and appreciate is that neither of these ever struggle to connect and they never skid over the top. I can rely on them to be as easy as a rear shift. Of course, there is always the issue of teeth wear, which can be difficult to see. How many miles / years can you expect from a 7075 Al ring? I got out for 35 miles on the Ram today but plan a 15 mile ride on the Trek with it's questionable crank, so we shall soon know if it's toast or jam. Time to fire up the grill & open a bottle of wine. Michael On Thursday, June 19, 2014 10:55:34 AM UTC-4, Michael wrote: > > I think this is the interesting article I once read which explains having, > vs. not having, ramps and pins. > > http://janheine.wordpress.com/2013/04/23/chainring-choice-or-shifting-ramps/ -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/rbw-owners-bunch. For more options, visit https://groups.google.com/d/optout.
