50/34 on a TT bike?

Graeme Jones

I am looking for a TT bike for the back end of this year to train on ready for the new season next year.
I have noticed some have compact set ups and was wondering is this aimed more at the hilly courses or Triathalon athletes?

I'll be looking at 10 and 25 mile TT courses that are considered flat.

cougie

Compact is an unusual choice for a TT so I'd think they might be for long distance triathlons over hilly courses. Which is a fairly small market.

I'm sure they'd swap it for a more conventional set up if you asked ?

drlodge

Ditto, I would get a compact only if you need the lower gears that a 34T chainring provides. That said, I would rather have a 34/50 with a 11-21 cassette, than a 39/52 with a 11-27 as the ratios will be closer.

markos1963

Apart from the Little Mountain TT I have never used the inner ring on my TT rig this season even on a Spoco 100. My set up is a 55/39-12/23 and consider myself more of a spinner than a grinder.
I would ask them to either swap the chainset for a 53/39 or a set of larger rings with a 110 BCD. They would probably be happy to do it as they could sell the compact no problem and would have dozens of standards sitting out the back

nochekmate

Triathletes often use compacts on their TT set ups as it is preferable to 'spin' their bike section rather than push a big gear as they still have a run to complete and need to look after their legs.

cycleclinic

I think a 36T inner ring is a better option though tha a 34T. At TT speed a 34T inner will have you having to use the outer most of the time. A 39T:23T gearing is fine for me on 10% gradients so long as they do not go on for too long as that is alot of effort.

For TT's a 53/39T and 12-23T cassette should be enough for most course except the most evil. 39T:27T gearing is the sort of thing I would use to climb an Alp (a 39:29T might be more appropriate for some climbs though)! It does depend though on how fit you are and is unknown to us.

bigmat

I've done alright on hilly 10s riding a compact. Benefit of a 50 front is that you can basically ride the whole time trial in the big ring, 50/11 is a pretty big gear although might not be enough for fast dual carriageway stuff, but anything rolling its probably not a bad option. In fact, unless you have a lot of power 50/11 is going to be big enough for most stuff.

markos1963

It's not so much that a 50/11 isn't big enough it's more because of using a 53 or bigger gives a better chain line.