Road Cycling - Would 28T Granny cause any problems

Hi all,

I'm looking to buy a road bike (after riding 2K miles on my Trek 7700FX hybrid), but I'm not happy with the gear range, even with triple-chainring bikes. The standard setup for the bikes I'm considering use 30/42/52 front chain rings (Ultegra stuff). I think that a 28 granny with 12-27 rear cogs would give me the range I'm after.

I'd asked the LBS (reputable place, BTW) about changing the granny to a 28 and the sales guy said they don't recommend this. I'd like your opinions on this.

Thanks much
- GOLDENEYE

the deralleur cant handle that well

I went from a hybrid to a road bike, too. The trek 7300 had a 28 tooth small ring and the road bike had a 30 tooth ring. The road bike was about 5 pounds lighter and so I didn't really notice the difference. I just go a little faster up the hills.

I went from a hybrid to a road bike, too. The trek 7300 had a 28 tooth small ring and the road bike had a 30 tooth ring. The road bike was about 5 pounds lighter and so I didn't really notice the difference. I just go a little faster up the hills.


ditto! Much eaisier and faster over my Trek 730 (I got the allez).

Although the difference between a 28 cog & a 30 cog is quite noticable in the rear, it is really not that noticable of a difference in a chainring/granny. You're only talking a few gear-inch difference at most!
Stick with the 30 if supplied as such.....otherwise, your front shifting would suffer, most likely..... these triples are designed to work together, as shifting ramps are strategically placed.

George

Although the difference between a 28 cog & a 30 cog is quite noticable in the rear, it is really not that noticable of a difference in a chainring/granny. You're only talking a few gear-inch difference at most!
Stick with the 30 if supplied as such.....otherwise, your front shifting would suffer, most likely..... these triples are designed to work together, as shifting ramps are strategically placed.

George

Yeah, I suppose the 28 vs 30 isnt much...my goal was to get a ~28 gear-inch smallest gear. (There are some pretty brutal hills around here, 17% and up!). My hybrid will go to 25 gear-inches (and even lower, but that's nearly useless!). Would 28T vs 30T make that much difference for the front derailleur?

FWIW, my 7700FX is a 25 lb. non-suspension model with 120psi slick road tires...the change to a road bike should make climbing a lot easier, but I wouldn't mind having the low, low gearing when facing the likes of Redwood Gulch!

-Goldeneye

My lowest gear is 42f x 28r & I can tackle the hills ok with this ratio (NZs very hilly :eek: ) though to be honest I would like a triple on the front some days :( (i'm 57) & some days are better than others!

Hi,
I have a 28t grany on my Ultegra crank.
It works, shifting does suffer a bit. I also
put on a rear cassette with 34t ; that would give you the same result without affecting the shifting. For me, I like my 28/34 on a steep hill. New England has a couple of those....

The 28-42 gap may strain the front mechs shifting ability a bit, but most mechs have some spare capacity. I use my Campy Mirage road triple with a Shimano LX 24/36/46 !!!
If you do swap, you may want to lower all your ratios, to say a 28/38/48 or 28/40/50.
I use the 28/38/48 and find it a useful size for commuting and touring. I have used it to haul heavy shopping loads up very steep hills.

Thanks all -- I think I'll stick with the stock 30/42/52 for now. Sounds like the loss of shifting performance isn't
worth the slightly lower gearing for two extra teeth.

Goldeneye