7 to 9 speed mod
11-25-12, 12:57 PM
#26
Constant tinkerer
New parts list:
Crankset, Raceface Cadence 39/53T
Ultegra 3X9 bar end shifters, SL-BS77
Front derailleur, thinking FD-2300 (Should work even though it 8 speed right?)
Rear Derailleur, Deore M591-SGS
Cassette, CS-HG50-9 speed Tiagra (11-32T)
Freehub Body, Tiagra FH-4500
Chain, CN-HG73 LX
Crankset, Raceface Cadence 39/53T
Ultegra 3X9 bar end shifters, SL-BS77
Front derailleur, thinking FD-2300 (Should work even though it 8 speed right?)
Rear Derailleur, Deore M591-SGS
Cassette, CS-HG50-9 speed Tiagra (11-32T)
Freehub Body, Tiagra FH-4500
Chain, CN-HG73 LX
Keep whatever FD you have unless it's broken. It'll work fine with a 9S chain.
11-25-12, 01:28 PM
#27
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53/11 versus 50/11 will only get you more speed if you have the power in your legs to drive it. Most riders use gearing to get speed, but also use cadence (rpm of the crankset). The speed you pedal has something to do with knee health and avoidance of injury even for young riders. A healthy cadence is in the range of 80 to 95 rpm. If you can turn a 53/11 at 80 rpm, you'll be going 30 mph. How long can you do that, in your experience? 50/11 is not much easier, being 28 mph.
30 mph takes about 400 watts for a 160# rider. 20 mph takes about 175.
Granted, riding feel (I like to pedal slow sometimes, like downhill) is part of it, but in terms of pure speed a compact at 50/11, 50/12, or 48/12 is going to get you where you want to go as fast as you can pedal, over the term of a ride.
30 mph takes about 400 watts for a 160# rider. 20 mph takes about 175.
Granted, riding feel (I like to pedal slow sometimes, like downhill) is part of it, but in terms of pure speed a compact at 50/11, 50/12, or 48/12 is going to get you where you want to go as fast as you can pedal, over the term of a ride.
11-25-12, 01:48 PM
#28
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"My" shop is in my garage. I volunteer at the coop, RIBS, though.
volunteers get something like an employee rate?
11-25-12, 02:10 PM
#29
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They do have a QBP account. The whole place is pretty disorganized, so there isn't a markup. To anyone. I guess it's just a perk for being a part of the coop. Nothing is sold there, it's a 100% charitable organization. The closest there is to an cash income stream is the donation box, and the 501(c)(3) tax forms that record a donation.
It's all funded through grants under the umbrella of a larger community organization here in Ithaca.
It's all funded through grants under the umbrella of a larger community organization here in Ithaca.
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11-25-12, 02:14 PM
#30
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Thread Starter
Tiagra 50/34T and bottom bracket would run a little over $100. Would the 9 speed crank work OK with all the existing 7 speed stuff on the bike?
11-25-12, 02:33 PM
#31
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I agree that you are probably overgearing the bike. Here is a gear calculator I use with your proposed gearing and another with a 50/34 compact crank and a hypothetical 12/28 cassette compared. Unless you are an extremely strong rider gearing over 110 gear inches is wasted and your remaining gears are stretched thinner than is optimum as a result.
https://www.kstoerz.com/gearcalc/comp...50,34&ighid2=1
https://www.kstoerz.com/gearcalc/comp...50,34&ighid2=1
11-25-12, 02:42 PM
#32
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You won't loose any top end that mere mortals can use. A 53/11 is what Tour de France riders use for time trials. As Road Fan noted, a 50/11 combination gives you 30 mph at 80 rpm and 36 mph at 100 rpm. Almost no non-professional rider needs more than that, or even that. As for fast downhills, it's probably faster to tuck in out of the wind and let the bike run than to try to pedal at those speeds. A compact will give you more usable gears at no sacrifice.
11-25-12, 02:53 PM
#33
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7-speed and 9-speed bodies IME use different seal arrangements between the body and the axle.
For a road bike, (not seeing much dirt) it's not a big deal, but I've always preferred to go for a donor wheel to get the full set of pieces that'll line up as intended all in one go.
For a road bike, (not seeing much dirt) it's not a big deal, but I've always preferred to go for a donor wheel to get the full set of pieces that'll line up as intended all in one go.
11-25-12, 02:58 PM
#34
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If the OP wants both top end to be able to stay on power, even during serious descents, and crawler gears, consider a triple instead. That's the way to go for both range and user-friendly tight spacing.
11-25-12, 04:15 PM
#35
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I'm getting ready to mod my mid 90's road bike from 7 to 9 speeds. Here's my shopping list, please me know if I'm going horribly wrong anywhere.
Crankset, sticking with a double but upgrading to 9 speed compatible. Thinking Stronglight 53/40 square taper. Ultegra 3X9 bar end shifters, SL-BS77 Front derailleur, thinking FD-2300 (Should work even though it 8 speed right?) Rear Derailleur, RD-3400 Sora, or RD-4500 Tiagra (is there much difference between these two?) Cassette, CS-HG50-9 speed Tiagra (11-34T)Freehub Body, Tiagra FH-4500Chain, CN-HG73 LX. I guess the one the one real concern I have is the 34 tooth cog on the Cassette. Do I need to buy a long cage rear derailleur to avoid interference with the derailleur cage? Thanks
Crankset, sticking with a double but upgrading to 9 speed compatible. Thinking Stronglight 53/40 square taper. Ultegra 3X9 bar end shifters, SL-BS77 Front derailleur, thinking FD-2300 (Should work even though it 8 speed right?) Rear Derailleur, RD-3400 Sora, or RD-4500 Tiagra (is there much difference between these two?) Cassette, CS-HG50-9 speed Tiagra (11-34T)Freehub Body, Tiagra FH-4500Chain, CN-HG73 LX. I guess the one the one real concern I have is the 34 tooth cog on the Cassette. Do I need to buy a long cage rear derailleur to avoid interference with the derailleur cage? Thanks
11-25-12, 06:41 PM
#36
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Thread Starter
Well I was going to 9 speed primarily to get a few low gears on the rear. Lots of hill around here and thought some low gearing would make sense. But the consensus seems to be, skip the mod to 9 speed and just buy a compact crankset. Maybe that's what I'll do first and see how it rides before going further.
Thanks for the input everyone.
Thanks for the input everyone.
11-25-12, 06:56 PM
#37
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I had the same thought for a different reason: I want to eliminate the bar ends and install some brake lever/shifters. Not really concerned with the 7 speeds vs 8-9-10. Any thoughts from the collective wisdom?
11-25-12, 08:22 PM
#38
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Another option is to start with friction shift on the Dt and a 9speed wheel/cassette/chain. If you like the extra range, move it all around from there. IF you buy smart used, you'll be able to recoup most of the changeover if you don't like it.
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11-25-12, 09:45 PM
#39
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Google "Kelly Take-Offs" and "Retroshift" for a look at ways to mount downtube or barend shift levers on conventional brake levers. These are both lower cost options with nearly (but not quite) the convenience of brifters.
11-26-12, 12:10 PM
#40
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Certainly it can be done but it's an expensive change as brifters are generally the most expensive single item of any component group. Also, the rest of the components must be compatible with the brifter's indexing as there is no friction option.
Google "Kelly Take-Offs" and "Retroshift" for a look at ways to mount downtube or barend shift levers on conventional brake levers. These are both lower cost options with nearly (but not quite) the convenience of brifters.
Google "Kelly Take-Offs" and "Retroshift" for a look at ways to mount downtube or barend shift levers on conventional brake levers. These are both lower cost options with nearly (but not quite) the convenience of brifters.
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