Change of ratio on front chainrings

bill_gates

Ive had a look at some of the online gearing tables but really wanted real-life feedback on whether I would notice if I changed my front chainrings from the current 50/34 to 52/36?

My LBS are saying that 52/36 is becoming the most popular setup nowadays as its Inbetween standard and compact.

I'd still likely keep an 11-28 at the rear as this suits my terrain and I'm also more of a spinner when the road goes up rather than grinding up an incline.

ForumNewbie

Bill Gates wrote:

Ive had a look at some of the online gearing tables but really wanted real-life feedback on whether I would notice if I changed my front chainrings from the current 50/34 to 52/36?

My LBS are saying that 52/36 is becoming the most popular setup nowadays as its Inbetween standard and compact.

I'd still likely keep an 11-28 at the rear as this suits my terrain and I'm also more of a spinner when the road goes up rather than grinding up an incline.

It depends how fit you are, but it will make it a bit harder to climb steep hills. I don't really see the point in making the change.

StillGoing

It'll be fine. As a spinner rather than a grinder, I often find I can happily use the 36 with a high cadence and the high gears of the cassette to carry a decent speed on the flat (for me) with less changing on the front if the terrain is rolling. Going up a steep ramp, I might take an extra lower gear at the back, but have yet to go to the "bail out" gear.

http://www.bikecalc.com/gear_ratios

imposter2.0

Bill Gates wrote:

Ive had a look at some of the online gearing tables but really wanted real-life feedback on whether I would notice if I changed my front chainrings from the current 50/34 to 52/36?

My LBS are saying that 52/36 is becoming the most popular setup nowadays as its Inbetween standard and compact.

I'd still likely keep an 11-28 at the rear as this suits my terrain and I'm also more of a spinner when the road goes up rather than grinding up an incline.

So you want to change to 52/36 because your LBS says it's more popular? Look at it another way, if you hadn't ever heard of 52/36, would you still be wanting to change?

kajjal

Most riders are not light weight and very fit. Due this they prefer 50/34 and 11-32 cassettes as it means they can go fast downhill and get up pretty much any hill easily enough. Once you get into road bikes you may find a different setup suits you as you frequently use different gear ratios.

The bike shop is giving strange advice but the main thing is choose the gearing that suits you and where you ride.

sloppyschleckonds

Bill Gates wrote:

I'd still likely keep an 11-28 at the rear as this suits my terrain and I'm also more of a spinner when the road goes up rather than grinding up an incline.

Imagine having a 11-26 on your current set up

bill_gates

I'm changing the groupset and chainset on my existing frame and there is a chance that the 52/36 is what most people go for as standard nowadays. This might be a story from them, I'm not sure, but I'd not think the shop would try to mis-sell as I'd simply keep at them again to put it right afterwards. It's maybe that they have that in stock and want to sell it, it's maybe genuine advice as they know my size, weight, abilities, etc.

In terms of currently using an 11-28 on the rear with my existing front ring setup, I'd miss not having the smallest gear on that for some of the gradients I do so maybe I should stick with what I am used to. I don't think I'm going to get that much fitter in coming seasons but really wanted to know if the difference would be so marginal that it's not a concern?

imposter2.0

It's not really something anyone else can answer unfortunately. You are in the best position to know what kind of effect different gearing would have on you.

cougie

If you're happy with what you have now don't change.

I'm a pretty decent climber but I always appreciate a low gear.

kajjal

To give an example today I went out for a ride much too soon after breakfast and the route I take is hilly with some very steep climbs. Normally I have to work up the hills but it is no problem. This morning it was desperate for the first hour of the ride, I was struggling at the end of every long hill. Luckily I had really easy gears to bail me out. After an hour back up to normal speed.

ForumNewbie

If you look at the gear tables below, you will see that to get a similar low gear as a 34/28 with a 36 chain ring on the front, you will need a 30 sprocket on the back, so I think you will notice the difference, so I would say stick with a 50/34.
http://www.bikecalc.com/gear_inches

dennisn

I'm an old geezer who lives in the flatland's. I use a 50-36 with a 12-23 on back. I'm not a racer and have never "ran out" of gears, even on the occasional steep bump in the road. As for the high end, well, at 67 I don't find myself pushing a 50-12 all that much. If I do hit the Rockies for riding I switch to a 50-33 up front and a 12-30 aft. I do OK.

cougie

Well if you live in the flatlands it's no surprise you don't run out of gears...

Google Bwlch pen Barass climb and you'll be reaching for the small chainring.

super_davo

But where you live is very relevant to your choice of gears. I live in Essex where (contrary to popular belief) there are hills just not mega long or steep. But my parents live in the peaks where they most definitely are. I've always changed ratios when going from one to the other. Now I've fitted 52-36 11-28 theoretically I don't need to. I've had mixed results doing so. When in the peaks the difference between the 34 I was using and the 36 I am now wasn't major; there was nothing I couldn't get up - but I did find that I was slower on some of the steepest stuff because my cadence dropped.
If on the steepest gradients you ever go up you're noodling around at 90 rpm in your bottom gear, you'll probably be fine. If you're already struggling, stick with your compact.
It's not a major difference either end and not a huge amount of point in changing unless you're changing groupset like I was.

StillGoing

On the hills that you do, are you going to the lowest gear most of the time? If you are, stick with a 34. If you don't and on the few times when you do, you can keep a decent cadence going, then why not if you're changing things anyway. I have a 34 on my lighter bike and a 36 on the heavier one, I can barely tell the difference unless it is getting into double figure gradients when I know I will use the 28 on the cassette at some point.

bill_gates

Most of my climbs on a usual route can average 6-7% but some routes i do can have a max of 20% and I find those difficult as I'm not a light chap.

964cup

Worth searching - there's several long threads on this point. I think the summary as I see it is that 52/36 makes good sense if you've "grown up" on 53/39 and now want an easier life. I don't see that it adds much value if you normally ride a compact, unless you really prefer to grind out a low (60 and below) cadence. As has been said elsewhere, often, 50/11 is a massive gear, spinning out well into the 60kph range if you have reasonable leg speed. Remember that traditional freewheels usually had a 13 (or occasionally a 12) as their smallest cog, hence the need for a larger chainring.

kajjal

Bill Gates wrote:

Most of my climbs on a usual route can average 6-7% but some routes i do can have a max of 20% and I find those difficult as I'm not a light chap.

I know your pain I am 2 metres tall and 100KG.

Pross

The only logical reason for changing is if you are spinning out regularly on the 50 x 11 which I seriously doubt.

germcevoy

Stay put. I rude 52/36 - 11/28 s that's what came with the bike. I can get up anything but lack that bail out gear for when I'm struggling on a bad day or burn out half way up a hill. Ideally I would like a 30t at the rear but have to go to a 32 on 11spd Shimano. 52/11 is a wasted gear for me so I think I'll go back to compact and keep the 28. Best of both worlds.

webboo

I recently changed to 52 X 36 from 50 X 34 when I put on a new group set. It came with a 11 to 28 cassette. I find I'm using the little ring a lot more and I find I seem to be pedalling more efficiently rather than staying in the 50 and grinding it out.
I would have preferred a 12 to 28 cassette as I used a 11 to 25 most of the time with the compact. However Shimano only seem to do the 12 to 28 in Tiagra. I did notice Miche do a 12 to 29 though.

StillGoing

Pross wrote:

The only logical reason for changing is if you are spinning out regularly on the 50 x 11 which I seriously doubt.

That doesn't equate though does it. It might make the intermediate gears better being on a 52.

Pross

http://www.bikecalc.com/gear_meters_of_development

Don't see a huge amount of variance there to be honest.

ForumNewbie

super_davo wrote:

If on the steepest gradients you ever go up you're noodling around at 90 rpm in your bottom gear, you'll probably be fine. If you're already struggling, stick with your compact.

If the OP can spin at 90rpm in his lowest gear, 34/28, on the steepest gradients, i.e. say 15/20%, I would say he is doing more than all right as that would mean a speed of over 8.5mph. I don't think it would be easy to spin up very steep gradients on a 34/28, so I don't see the point in going up to a 36 smallest ring.

StillGoing

For a cadence of 90-100rpm, a 52 gives a better overall speed using the intermediate gears rather than a 50. Using the 52/16 combination they'll achieve 23-25.6 mph rather than 22-24.6 mph.

http://www.bikecalc.com/speed_at_cadence

Same goes with the 36. A 34 might be useful if you only ever ride in the Peaks, Lake District etc, but for rolling terrain, how often does the OP need the 34/28 combination. Can they get up a hill using a 36/28 combination albeit a tad slower and a little more effort and gain the benefits of the 36 with the intermediate gears. It might be they regularly find themselves near the point of cross chaining for their best gear where a bigger ring on the front would bring them towards the middle of the cassette.

http://www.bikecalc.com/speed_at_cadence

ForumNewbie

philthy3 wrote:

For a cadence of 90-100rpm, a 52 gives a better overall speed using the intermediate gears rather than a 50. Using the 52/16 combination they'll achieve 23-25.6 mph rather than 22-24.6 mph.

http://www.bikecalc.com/speed_at_cadence

I'm not sure that will make much difference as a 50/15 could be used, which is a slightly higher gear than your 52/16, and is still around the middle of the cassette.

Anyway, not everyone is strong and fit enough to go for any sort of distance on the flat at 90 to 100 rpm on a 52/16 or 50/16 gear. I think the 52/36 cassettes with an 11/28 at the back is probably better if you are a fit and fast cyclist that can regularly travel at the speeds you are talking about.

The only thing I don't like about my 50/34 compact is that it is a big drop from the 50 to the 34, so you sometimes have to change up a gear or two at the back. However I imagine that is the same with dropping from the 52 to the 36 chainring as it's also a 16 tooth difference.

I actually prefer the gearing on my steel touring bike - a triple 50/39/30 - as the drops between chainrings are less and it is therefore easier to keep a consistent cadence. It also allows you to get a reasonable speed in the middle ring as with a standard double, but with the added benefit of the small ring when it gets steep. Unfortunately not many light carbon bikes here in the UK come with triple chainsets.

super_davo

ForumNewbie wrote:

super_davo wrote:

If on the steepest gradients you ever go up you're noodling around at 90 rpm in your bottom gear, you'll probably be fine. If you're already struggling, stick with your compact.

If the OP can spin at 90rpm in his lowest gear, 34/28, on the steepest gradients, i.e. say 15/20%, I would say he is doing more than all right as that would mean a speed of over 8.5mph. I don't think it would be easy to spin up very steep gradients on a 34/28, so I don't see the point in going up to a 36 smallest ring.

Hence my comments about "the steepest gradients you ever go up". Where I live in Essex there are no 15-20% gradients. I can get up biggest hill we have in a 21 sprocket! There are lots of other places round the country that are similar. But when I do proper hills, as a comparison my time up Holme Moss was slower on 36/28 vs 34/28; as my cadence dropped from an average of 80 to 70 which was a bigger drop than the gearing increase. OK lots of other factors at play, not least wind, but the most important thing was that the small gearing increase made me feel less comfortable. If I was going to the Lakes I'd be looking at 30 tooth cassette.

If you can easily get up the biggest hills you need to get up with a 34 then you won't notice the change to 36 much, your cadence or position in the cassette will compensate. If you're close to your limit then you will notice.

dhungerf

You dont necessarilly need to change out the entire package. I had the mid-compact set up (52-36) but needed more climbing gearing so I just swapped out the 36 for a 34. No problems at all, no other changes needed.

StillGoing

ForumNewbie wrote:

philthy3 wrote:

For a cadence of 90-100rpm, a 52 gives a better overall speed using the intermediate gears rather than a 50. Using the 52/16 combination they'll achieve 23-25.6 mph rather than 22-24.6 mph.

http://www.bikecalc.com/speed_at_cadence

I'm not sure that will make much difference as a 50/15 could be used, which is a slightly higher gear than your 52/16, and is still around the middle of the cassette.

Anyway, not everyone is strong and fit enough to go for any sort of distance on the flat at 90 to 100 rpm on a 52/16 or 50/16 gear. I think the 52/36 cassettes with an 11/28 at the back is probably better if you are a fit and fast cyclist that can regularly travel at the speeds you are talking about.

The ideal is to keep the chain line as straight as possible for the least resistance. The OP has informed us he/she is a spinner rather than a grinder. We're all different in our abilities and in what works for us. I have gone from a grinder as a newbie to someone with a high cadence of around 94-105rpm over the "flat". But, for some, a high cadence doesn't work for them or they have the ability to use the leg muscles without tiring.

germcevoy

philthy3 wrote:

Same goes with the 36. A 34 might be useful if you only ever ride in the Peaks, Lake District etc, but for rolling terrain, how often does the OP need the 34/28 combination.

http://www.bikecalc.com/speed_at_cadence

This is a great point. The 36 at the front means you aren't constantly flicking between this big ring and the wee ring over rolling terrain. Just leave it in the 36 and go up and down the gears at the back. I find myself using the 36 a lot more than I ever used a 34 and not just on the hills. I still want one more gear than the 36/28 offers but don't necessarily want to go all the way to a 32.

Either stay at 28 and go back to compact or stay on the 36 and go up to a 32 at the rear. I may study the gear charts.

bill_gates

This is good thinking but there are times where I really need that 'get out of trouble' gear and I'm unsure if the 36/28 combo would provide that as well as the 34/28 combo. Every little helps?