Home› General Training Discussions

Bike Gearing Adjustments

Gary LewisGary Lewis
in General Training Discussions
I've seen some previous threads regarding gearing changes.  Since I currently ride in Arizona (flat) and will be racing in Lake Placid next year, I decided to look into this a little.  The top picture represents my current setup 10 speed 53/39 and 12/21.  The bottom picture would represent the change to a 50/34 in the front.  It would definitely add some more spin for climbing, and I would only lose one gear at the top end.  

My questions to the bike geeks/gearheads are:  
What would be the negative to this?  
Should i also consider a change in the back? I adjusted a bunch of numbers, but this seemed to work out pretty good on paper.



Comments

  • DAVID RICHMONDDAVID RICHMOND
    been road racing at a decent level and racing tris for years... found no cons on switching from 53/39 to a 50/34 despite funny looks from snobby road racers.... but I also have all kind of rear cassette to go with terrain ... If it's a very hilly IM course, might consider a bigger gear in the back (I have a 12/32 for very steep hills around me)
  • Doug JohnsonDoug Johnson
    I don't know how to interpret your diagram so I can't comment on it.  I think you're going to want a smaller gear than a 21 on the back, I would say 28 at least.  The fact is even in 53/10 you will have to coast on the Keene descent and maybe a couple other places but having the right gearing for climbing on that course will more than make up for it.
  • Doug SutherlandDoug Sutherland
    Agree with above. No problem switching cranks, but definitely play with the rear cassette. I would say a 28 is a minimum for a hilly course, and depending on your W/kg, some folks here go as low as a 32 (which may require a change in the rear derailleur).
  • Jacklyn MooreJacklyn Moore
    I run a 12/32. I live in a world of nothing but climb. It really helps to be able to be able to sit up and manage your watts up those big grinding climbs. If changing up means an entire drive train change. Just try and go as low as you can. Even a 12/30 would come in handy. Then go find some mountains to climb!
  • Attila MatyasAttila Matyas
    Agree with all of the above.  I would definitely get a larger rear cassette like a 28 or larger.  You can always back out the B tension screw with standard Shimano and the 32 fits just fine.  If you run SRAM you get a Wifli derailleur and run up to a 36 in the rear and shimano also make a long cage version for the rear. 

    Coming from the 130 BCD 53/39 will take a couple of rides to get used to the 110BCD with smaller gearing.  It felt goofy to me forcing me to spin more and grind less when I first switched but I'm used to it now. 

    If you want to maintain some of what you are used to for riding around the flats then you can also get a set of 52/36 110BCD rings also sometimes called an alpine double.  This will be almost identical in gearing/feeling of what you have now with the 53/39.


  • Robert SaboRobert Sabo
    50/34 front and at least 28 in back.  I use 11-28 in LP and Quassy and switch back now to 11-25 for AC 70.3.  I need the extra in between gears when hammering on the flats and appreciate the smaller gear up at Placid.
  • KARL BONNERKARL BONNER
    I switched to a 50/34 & 11-28 a couple of years ago, with the intention of swaping back & forth for different terrains, the reality is that I will change the cassette very ocasionally (not often). I've never looked back since changing and climbing is much better plus it helps keep my cadence higher, yes I spin out somtimes going downhill, but Im doing 35+ mph so for my level of racing its not a problem, just get areo and enjoy the free speed :-).
  • Gary LewisGary Lewis
    Thanks everyone.  I think I will go with the 11-28 and try it out with the 50-34 from my road bike.
  • Scott AlexanderScott Alexander
    No downside for switching to the compact 50/34 in my experience. 

    I run a 50/34 on both of my road and tri bikes, with a 12-27 on the tri (10spd) and 11-28 (11spd).
    I'm a big dood at ~210lbs and 6'1".
  • Gordon CherwoniakGordon Cherwoniak
    @Gary Lewis  I can't argue with the 50/34 and having a larger cog in the back. If you ride power what are your watts/kg? If you are a really strong cyclist 3.8 w/kg+ you might be able to tighten up the back cog a little maybe getting an 11-27 for the descent.  As mentioned you will spin out on the Keene descent but it's always nice to have an additional bail out gear for the climbs keep the power output in check. 

    As an aside,you are running a 12/21 right now and have no gaps.  A 12-28 will have some spacing which will most likely require you to utilize a wide cadence band than you are used to. 

    Having done LP with a 50/34 and a 27, 28 and 30 on the back at 225-235lbs.  The 28 or maybe a 30 could be useful.  I know don't have enough gears even with at 30 to keep the watts low enough throughout the course.  See my race report as I give a breakdown of time spent .75 and above. 
Sign In or Register to comment.