Moving from a triple to a compact or double

prhymeate

Hi,

I've been riding a Triban 3 (53 (was 50)/30/39 and 12-25)for the last 2 years and am looking to upgrade in the near future. I had a bike fit/purchase advice at Cadence Performance in Crystal Palace over the Easter weekend. The fitter recommended that I go for a 53/39 and 11-28 as I never use the 39 on my triple and he felt that with a lighter bike and improved position I would find myself spinning out on a compact.

I'm tempted to go for a 52/36 and 11-32 just to be one the safe side, as it gives me a higher and a lower gear than I currently have. I don't often find myself spinning out on my current setup, but it would be nice to have a higher gear and the last time I used the lowest gear on my triple was in the Alps, so I'd like to have that as an option, which the 11-32 will give me.

I was wondering what others who had moved from a triple to a double had found or if anyone has any other advice before I click buy. Thanks

ForumNewbie

I have both triples and a compact, and I honestly think I get smoother gear changes with the triples. A compact would be okay, but don't go for a standard double if you plan doing any hills.

simon_masterson

Most people should 'spin out' somewhere between 150 and 200 rpm. On 50x12 your speed at 150rpm will be nearly 50mph. If you're going much faster than that down hills, assuming an aero tuck will probably be more effective.

prhymeate

I imagine 'spinning out' to be a lot lower than 200rpm, I'm definitely not going 50mph downhill anyway.

With regards to riding the alps with a standard double, if I had an 53/39 and 11-32 then at according to bikecal I'd be going 8.6mph at 90rpm in my lowest gear, compared to the triple which would be 8.5mph at 90rpm in the lowest gear. I guess the transitions between gears wouldn't be as smooth, but the lowest gears would be pretty comparable unless I'm reading the table wrong?

simon_masterson

Prhymeate wrote:

I imagine 'spinning out' to be a lot lower than 200rpm, I'm definitely not going 50mph downhill anyway.

Depends on who you are. Seriously good spinners can reach much higher than 200. At maximum intensity I'd expect your cadence to be in that range; if it isn't, then fitness rather than gearing is the problem. At 120rpm on 50x12 you almost reach 40mph. The point is that you aren't going to spin out a compact.

prhymeate

Simon Masterson wrote:

Prhymeate wrote:

I imagine 'spinning out' to be a lot lower than 200rpm, I'm definitely not going 50mph downhill anyway.

Depends on who you are. Seriously good spinners can reach much higher than 200. At maximum intensity I'd expect your cadence to be in that range; if it isn't, then fitness rather than gearing is the problem. At 120rpm on 50x12 you almost reach 40mph. The point is that you aren't going to spin out a compact.

Ok, thanks for the advice.

iPete

Personally, I would go 52/36 with a 11/12-27/28.

slowbike

I wouldn't have such a wide range cassette - 32-11 will give some big jumps and it'll be harder to get the right cadence/speed combo.

30-25 = 32"
34-28 = 32"

Don't forget - you don't have to have just one cassette - you can have several - normal riding, hill climbing, touring, cruising, racing etc etc ... with different selections depending on what you'll be doing.

w00dster

totally agree with Slowbike.
Cassette's are reasonably cheap so no problem having different options for different needs.

I have an 11-28 for the hills (I don't really do overly challenging hills). But even this cassette has some jumps that aren't the smoothest. 11-23 is ideal for my every day and faster rides. I'm probably going to get a 12-25 and use the 11-28 for the odd real hilly ride.

I went from a triple straight to a compact with 11-23, you'd be surprised how you adapt to what you have.

prhymeate

Thanks for all the replies. I think I will probably go for the 52/36 and 11/28, assuming that the transitions wont be too big, as that will give me a higher gear than I currently use and the lowest gear won't be too far off the lowest on my triple which I haven't actually used since last summer in the alps.

simon_masterson

But do you need a higher gear?

Most people do not really need an 11t cog - they are mainly good for very fast descending (which we've covered) and sprints; and even then, plenty of amateur racers use 12. At just 90rpm you are well over 30mph. The same people that can make good regular use of an 11t cog are also likely to be strong enough to use bigger gears on hills. I'm not saying you shouldn't want one; it's simply that if you also want a 28t you will have bigger gaps to deal with.

If you were using a triple but not touching the 39t, I suspect that the issue is that you are not using your gears effectively, and/or your cadence is significantly too low. Or you're seriously powerful on the flat and not so good at hills/only climb alps.

prhymeate

I realise I don't need a higher gear, but I would like a 28 and the Ultegra doens't come in a 12-28. Most of my climbing is at 90rpm, I'm no expert at climbing or on the flats, but I'm not bad at either.

prhymeate

The more I think about this and the more I compare speeds at 90rpm on bikecal, the more I'm thinking about getting a regular compact with an 11-25. That way the highest gear is still higher than my current setup, and the lowest gear is lower than what I currently use (39-12) and the gaps between gears will be smaller. There are too many options!

markhewitt1978

Compact with 11-25 seems the best option. 50/11 is a plenty high gear plus you could put on 12-30 if you fancied.

rolf_f

markhewitt1978 wrote:

Compact with 11-25 seems the best option. 50/11 is a plenty high gear plus you could put on 12-30 if you fancied.

I'd have thought 12-25 would be better. I have both and both are fine but I'm not fussy about varying my cadence so I don't notice the gaps. Besides, 12-25 is often cheaper!

Anonymous

I've just recently switched back from a double (53-39) to a compact (50-34) both with a 28-12 8 speed on the back.

My findings are, hills are easier (lower gears), but I ride them better, higher cadence, longer in the saddle. The 39-28 was pretty horrible on the steeper stuff.

On the flat I have the same average speed (around 30-35 Kph), but instead of being in say 53-18 or 20, ill be in 50-16 or sometimes 14.

kajjal

I would first work out which gear combinations you normally use and make sure the new setup gives you those. Then think of the full range you use and try to get those included as well. The advice of having a more than one cassette to choose from is useful if you cycle very different terrain at times. Just choose what you are comfortable and able to use as there is no point struggling on steep hills or not having the gears you want.

johnnybike

What is bikecal please