I’m getting killed on the big climbs. I’ve got a tri specific bike with 650 wheels. On the back I’ve got a 11/23 cassette and on the front I’ve got 55/42 chain rings.
Some have told me to change the small front ring to a 39. Yet others say doing that will cause the derailer to rub on the chain.
A few guys suggested going to a 12/25 or 12/27 cassette. I have no clue which direction to go. If I switch the back to 12/25or27 which would be better? I live in a pretty hilly area.
I have 650 wheels and run a 39 on the front and 12-25 on the back with no problem. I’d probaby be better served with a 27 for some of the hills around here.
Wow, 55/11 biggest gear. Even if you are a strong rider do you think you might be able to go to a 54/39 or even a 53/39? I know it is a sacrifice on the descents (what goes up must eventually come down) but the benefit and time you might save using a 39/23 on the climb and learning to use a resonable, comfortable cadence that works for you might be a net gain over using your “afterburner” 55/11 on the descent. Using a 55/39 is probably not going to work correctly because of the difference in size of the two chainrings. Going to a 39 might make the entire climbing thing much more enjoyable and faster. Good luck!
Your current low gear is 42/23 which is 46.75 gear inches, your choice is between a 42/27 which is 39.82 and 39/25 which is 39.94.
You may get chain rub with a 55/39 but I didn’t on a softride. Going to a 53 means you will spin out quicker on the downhills. Going to a bigger spread on the back means you’ll have bigger gaps to bridge when changing up on the flat.
Personally I’d go to a 53/39 12-25 until you’re stronger.
Tom am I wrong or is a 650 wheel bike with a 55/42–12/23 almost the same gear ratio as a 700 wheel bike with a 53/39-----12/23 ??? . This is the set ups that I ride and it feels the same!
Highlighter, a 55/42 with 650 wheels gives a biggest gear of 130" and a smallest of 47.48". Compare this with a 52/39 with 700 wheels which gives 132.36" and 47.48". Basically exactly the same gear range. I assume you now ride 9sp with a cassette of 11/12/13/14/15/17/19/21/23. Do you really need an 11 sprocket? How often do you push that 130" gear, except on downhills? If you like to spin and need some help on hills, a 25 or 27 will be much more useful than the 11. Try changing to 12/25 or even 12/27. I always used to push a 39/21 standing on hills, but knee problems last year meant I changed to a 25 sprocket. I now ride my local climbs faster than any time in the last 10 years with a lower heart rate because I stay seated and spin.
Why don’t you get a triple setup… you can do the conversion for a couple of hundred bucks, and keep the same rear cassete… its unglamorous but you will never be at a loss for enough gearing.
If these ratios are correct why do we hear people saying put a 53/39 on a 650 bike but never hear put a 42 /29 on a 700 wheel bike? Also why did 650 bikes quit coming with 55/42 and go to 53/39 is it just that they can put the same cog set on all bikes that way(650/700)? I am being serious I’ve always wondered this but no one has ever explained it to me. Maybe Dan or Tom may know.
front ring teeth/rear cog teeth X wheel diameter (inches).
This formula is not really all that accurate, esp since he’s used the nominal wheel size (26") rather than the ERTO actual sizes. Its fine for this purpose, if you aren’t comparing gearing from 700c to 650c. But if comparing gearing between different bikes & wheel sizes, better to use the actual wheel diameter X pi in the formula. This will give the distance travelled per revolution of the cranks.
If you’re going to get a triple, buy an MTB and a paper bag to put over your head at races at the same time. As for ‘a couple hundred bucks’ for the conversion - new chainset, bottom bracket, shifters, front derailleur and rear derailleur? For $200? I don’t think so. This also assumes that your frame is designed to accept a triple (many aren’t). It will also mess up your chainline and give you less usable sprockets when in the big ring. Try changing the cassette to 12/27 first and if you still need a lower ratio, change your small front chainring to a 39. 39/27 gives a gear of 37.56", a 30/23 (triple - which I doubt your frame will accept) gives 33.91", a small enough difference as to make no difference unless you’re riding the Angliru. Sorry to disagree with you taku, but that’s my view of the easiest way to achieve what he wants to do.
Denewolf, they do put 42/29 on 700 bikes, or 52/40/30 in the form of triple chainrings. As for 53/39 on 650 bikes, this is probably high enough gearing for most mortals anyway.
here goes my rational for “a couple of hundred dollars”
Bar end shifters do not require changing to accomodate
Needs new bottom bracket
Needs new crank arms
needs small chain rings
new rear derailer
new chain…
now anyone who has ever shopped on ebay knows that ultegra cranksets retain their value very well ditto for the rear derailer… less so for the bottom bracket. so the crank arms would me a minimal cost and the bottom bracket a little more so if you shop around and sell all of the other stuff you are only looking at a capital investment of around 200.00
You may think that it is a bad idea but if he is really struggling on hills I think it is something to think about.
And yes there is a certain stigma about having a triple… but who cares what other people think as long as you can get up the hill also.
Also there is nothing about the biek that would make it non compatible with a triple crank set.
My point is that everyone I know and every double 700 bike I have seen has 53/39 or larger on it. 650 bikes with a 55/42 is very equal to that but just like you said 53/39 is big enought for mortals, why then do 99 percent of 700 wheel bikes have a 53/39? Using this reasoning wouldn’t that be to big for a 700 bike?
Sorry to disagree with you again taku, but many race bike frames are NOT designed to take triple chainsets. The longer BB axle required for a triple messes up the chainline and hence gear shifting and very often there is not enough clearance on the seat tube for the greater range of movement required by the front derailleur.
Thanks I actually assumed that this was possible for any bicycle… either way just out of curiosity I called cannondale and they said that the ironman 2000 which this person has is compatible with a triple setup…
This is not necessarily the right solution to his problem but it is another option
thanks for the info though…
for anyone who is interested Chain reaction a nice bike shop in california has a nice article talking about triple versus double cranks
It never ceases to amaze me that the people that believe that anyone who rides a triple is a loser are the same people that can’t wait to get the new DA 10-speed, or already ride the Campy 10. Do these same people play the latest Titleist Pro V1 golf ball with their old persimmon woods?
Gears are gears- a triple means 9 more gears (OK, maybe more like 7 more, since the cross-chained gears are unusabe). Even if the $200 is sketchy, it is guaranteed cheaper than the Campy 10 or DA 10. Why the hangup over a triple? I’ve got one on my Trek 5200, and laugh my ass off every time I see someone trashing their knees at 40 rpm on a double up a 12% grade. My advice- get the triple!