Crankset / Gearing Question

adrianshanahan

Hey,

So I've decided to add a road bike to complement my MTB, for just a change of pace and some nice fitness training.

I have decided on a Trek 1.5



There is an option on the crank set, FSA Vero, 50/34 (double) or 50/39/30 (triple)

I like the idea of a triple as will make things easier for me on the climbs if I need the help.

Are there any pros / cons either way?

Cheers,


Adrian

dubes

A triple will be slightly heavier than a double.

Also consider the Giant Defy 2, ive heard they are better than the Trek for similar money.

Or if you can get your hands on a Felt F85, you could get a better bike - double butted frame and full Tiagra for similar money. Try Wheelworx . . .

funkyjebus

no need for a triple if you have a compact on the front (which it does). Just change the cassette if you feel you need a lighter gear. You'll just loose out some gears in the middle, which is normally fine for most. If you go with a triple chances are it will also have a long cage rear mech which isn't as smooth and quick in shifting imo. Obviously if your riding nothing buts steep hills all the time then a triple might be worth it, but in dublin or other flat (ish) ground, there is no need for a triple....imo.

jdt101

dubes wrote: »

A triple will be slightly heavier than a double.

Also consider the Giant Defy 2, ive heard they are better than the Trek for similar money.

Or if you can get your hands on a Felt F85, you could get a better bike - double butted frame and full Tiagra for similar money. Try Wheelworx . . .

The Edge shop in Cork have an F85 in stock.

Lumen

A broader range is better. Smaller gaps are better. Therefore, a triple is better. The weight disadvantage is insignificant. The difference in shifting performance is marginal.

OTOH, if you don't need the gears a compact or standard double is fine.

650Ginge

Lumen wrote: »

A broader range is better. Smaller gaps are better. Therefore, a triple is better. The weight disadvantage is insignificant. The difference in shifting performance is marginal.

OTOH, if you don't need the gears a compact or standard double is fine.

Work out the gear ratios for both and see just what you are getting on both and then decide if it is worth it, I have a triple 9 speed but in reality I have only 13 different ratios, so there is 14 in there that can be got by using a different combination. Use the gear calculator on the sheldonbrown site, it is shocking the way marketing makes you buy things you don't need and we just follow like sheep.

If you just want a lower gear for hills changing the rear spockets is easier and cheaper.

cdaly_

I'm running a triple and, as 650Ginge says you have a lot of overlap and the third ring gets you only one or maybe two extra lower gears.

However, (and this is what convinces me), what you do get is the ability to run closer ratios while still having the large range. I find closer ratios mean I can adjust my normal pedalling speed for slight changes in conditions rather than having to pedal too fast or too slow. For that reason I recommend the triple.

Also get them to swap the cassette for a 12-27t, you don't need the typical 11-xxt unless you're really fast downhill.

Lumen

650Ginge wrote: »

Work out the gear ratios for both and see just what you are getting on both and then decide if it is worth it, I have a triple 9 speed but in reality I have only 13 different ratios, so there is 14 in there that can be got by using a different combination. Use the gear calculator on the sheldonbrown site, it is shocking the way marketing makes you buy things you don't need and we just follow like sheep.

I am intimately familiar with that Sheldon gear calculator.

The fact is that comparing a triple with a 12-25 to a compact on a 12-27, you get 6% more top end, 4% more bottom end, and a maximum gap of 10.5% in the bottom 3 gears compared to 14.3% with the compact.

So, from every functional aspect other than front shifting (and narrower Q-factor, if you actually need it) a triple is better, assuming you need the range.

Of course, if you don't need the range i.e. you are happy running 23 at the back on a compact or standard double, then a triple makes no sense.

On the issue of front shifting performance, I have doubts that a well-adjusted triple will shift worse between the two larger rings than a compact, since the jump is smaller.

Real men run 54-42 and 11-21. Everyone else is just a different flavour of wimp.

Sionnach7

Lumen I completely agree with you there on every aspect! It's good to see people being scientific about this, because it is engineering after all. I have a similar problems, particularly in relation to compatibility, but as I'm only a new user on here (today!) I'm not sure if I'm allowed to redirect people to my thread. It would probably seem rude anyway...
I'm not sure what the correct protocol is, but I'd love such knowledgeable replies like I've seen here.