Best way to improve climbing -- change crankset?
07-20-21, 01:29 PM
#26
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It does WHAT to the chain??
07-20-21, 02:32 PM
#27
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07-20-21, 11:51 PM
#28
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48/34 x 12-14-16-18-21-24-28 gives 32 - 106 inch gears, with pretty even ~7% gaps in the midrange and two ~15.6% gaps on either end, and with no duplicate gears. And it meets most of the factory specs of your derailleurs. 28T max rear cog, 14T chainring difference. The chainwrap is 30T, so 2 teeth beyond spec, but set the chain so that the 48/28 is safe. You'll have a little bit of slack in the 34x12 that you'll probably never ride in anyway.
It's a 1.5 step, (a front shift is 1.5 times larger than the average rear shift,) so the shift pattern is easy to remember but not as easy to do. If you want the next gear in sequence, it's up or down two in the back for down or up one in the front. With indexed bar-end shifters it's not hard, and with STIs it's a no-brainer. Downtube levers are harder, especially in friction, but indexed downtubers aren't that bad. And, really, you're most likely to really want that 7% change on a long flat or slightly rolling road, especially in the wind. Most of the time, you'll shift the front or the rear, depending on how big of a change you want, and it'll be fine, and you won't have to double shift. But if you do need exactly the right gear, you've got it available.
Beware: there are two 7-speed 12-28s out there. 12-14-16-18-21-24-28 is the one you want. The 12-13-15-18-21-24-28 ones make really good 8 speeds... with two chainrings. Seriously, half your gears on the small ring are doubles of a gear two cogs away on the big ring. No normal chainring combo makes any sense with them.
--Shannon
Gear Phreaking's Not Dead!!!
It's a 1.5 step, (a front shift is 1.5 times larger than the average rear shift,) so the shift pattern is easy to remember but not as easy to do. If you want the next gear in sequence, it's up or down two in the back for down or up one in the front. With indexed bar-end shifters it's not hard, and with STIs it's a no-brainer. Downtube levers are harder, especially in friction, but indexed downtubers aren't that bad. And, really, you're most likely to really want that 7% change on a long flat or slightly rolling road, especially in the wind. Most of the time, you'll shift the front or the rear, depending on how big of a change you want, and it'll be fine, and you won't have to double shift. But if you do need exactly the right gear, you've got it available.
Beware: there are two 7-speed 12-28s out there. 12-14-16-18-21-24-28 is the one you want. The 12-13-15-18-21-24-28 ones make really good 8 speeds... with two chainrings. Seriously, half your gears on the small ring are doubles of a gear two cogs away on the big ring. No normal chainring combo makes any sense with them.
--Shannon
Gear Phreaking's Not Dead!!!
Last edited by ShannonM; 07-21-21 at 12:04 AM.
07-26-21, 02:43 PM
#29
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I fabricated a chainring adapter out of 7075 Zicral aluminum plate that allows me to run 110BCD 50T/34T compact chainrings on my 90's Campagnolo Record 135BCD crankset. I bought the aluminum plate on eBay for $35. I also had to run a 105mm bottom bracket in place of the 102mm bottom bracket that is normally used with Campagnolo double cranksets. I had no prior experience doing this type of project. I just signed up on Bike Forums so after I make the required ten posts I will be posting a thread on the Classic and Vintage sub-forum with photos and the details on how I made this happen. If you are using a Shimano 130BCD crankset then I can also show how you can use an aluminum BMX chainring off of eBay in place of fabricating an adapter.
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