compact or 52/39 for racing?

tom3

Morning all

I have only ever run a 50/34 chainset. I am buying a bike to race with next year so just wondered if I should consider a 52/39 and what are the pros and cons of both options.

thanks

iPete

Depends on the terrain. For flat circuits I moved from compact 50/34 to 53/39 on 11-23 (I had to buy new parts so went for it) but there is no reason you'll run out of gears with 50x11 unless you have the mother of all sprints.

@ 100 RPM you'll still be doing 35.6mph with a 50x11.

tom3

iPete wrote:

Depends on the terrain. For flat circuits I moved from compact 50/34 to 53/39 on 11-23 (I had to buy new parts so went for it) but there is no reason you'll run out of gears with 50x11 unless you have the mother of all sprints.

@ 100 RPM you'll still be doing 35.6mph with a 50x11.

thanks, there are closed circuits on race tracks and then the local road circuits have about 500ft of climbing per 10 miles, so would you say that is still reasonably flat?

Grill

In that case I'd run a 50/36 with a 12-23 for crits and maybe 12-25 for the road circuit. There's no way you'll spin out unless you're an amazing sprinter and the close ratios and small drop between rings will help a lot.

cycleclinic

It depends on your power output really. If you have ana average power put over 70 miles of 300W or more then a 53/39T could be fine with a 12-25T unless the gradients are 10% or more then that becomes hard pretty quickly. If your power output cannot average more than 250W then maybe a compact on hilly terrain would be better. Hills are where races can be lost and you need to climb at a pace that does not leave you burnt out at the top - that is something I have to work on.

If you buy a compact though rings can be changed with a 130 BCD you need to be sure what works for you. 500ft of climbing per 10 miles is not alot. 52/36T could be a good comprimise.

Monty Dog

I race with a compact chainset - generally stays in the 50 ring for the whole race, hills and all, my view being that if I can't turn the gear then I'm simply not strong/fit enough to race. Likewise, if you can't do the climbs on the big ring you're probably going to be dropped anyway. Most of my local races finish with a slight uphill, so 11 sprocket is rarely needs.

imposter2.0

As above - for regional road or circuit races there is practically no disadvantage in using a compact. And if you ever do decide you need to go bigger, just stick a 52 ring on your compact spider...

on-yer-bike

Monty Dog wrote:

I race with a compact chainset - generally stays in the 50 ring for the whole race, hills and all, my view being that if I can't turn the gear then I'm simply not strong/fit enough to race. Likewise, if you can't do the climbs on the big ring you're probably going to be dropped anyway. Most of my local races finish with a slight uphill, so 11 sprocket is rarely needs.

I agree with this and have done the same. In fact on a training/club run I only use the 34 occasionally on the long hills. Different story with a standard chaiset though.
Its funny how we've ended up only needing 9 gears (or 10 with an 11 speed cassette)

tom3

Thanks all. I think I will buy the bike with the compact option, then if I feel I need to go different I can.

I was most concerned that I would be at a greater disadvantage, over and above being new to racing, when in reality I shouldn't be judging by the responses.

buckles

Another vote for compact here. Worked fine for me on both flat and hilly circuits.

bigmat

I race on a compact. I could race on a double if I wanted to (I commute on a double and it has more climbing than the race mentioned above) but I have never felt the need. I do ride an 11 tooth smallest sprocket though, probably not entirely necessary but its nice to have for longish descents / bombing along in a breakaway with a tailwind.

The compact is fine for (rolling) time trials as well - never felt disadvantaged at all.