Losing speed when changing to the inner ring on hills

unixnerd

When I change from the big ring to the inner ring on a decent size hill I find the lose the best part of 2mph, say from 18 down to 16.5mph. I ride a compact and I find the best speed I can maintain when in 34x11 is a shade under 20mph (my cadence could be better), lower than my entry speed to most hills. If I can I'll change down to the inner ring before the hill to avoid losing momentum due to the small time spent not getting power down, but often I enter the hill too high a speed to do this. On short hills I'll stay in the big ring and just use lower and lower rear gears, but it's not ideal on the chain line.

If I try and put power down whilst changing at the front I know there's a decent chance I'll drop the chain, so I have to back off. My understanding is you can still keep the power on with electronic shifting but that's a step too far for me. So even on a fairly quick change I'm losing momentum. I'm a pretty good climber as I get lots of practice living in northern Scotland. Any advice?

imposter2.0

drop a couple of gears on the back first.

goonz

Pedal harder?

t4tomo

change on the front a bit earlier whilst you are spinning a decent cadence (so the change happens quickly and chain isn't under too much tension) and at same time drop to a smaller rear cog - so you can maintain similar cadence, then gradually ease back up the cassette as teh hill steepens - or get out of the saddle and honk up if its quite short!

Grill

1. Why the hell are you using the 34x11?
2. If those speeds are correct you are not riding any 'decent size hills'
3. Trim

unixnerd

1. Why the hell are you using the 34x11?

So that can I change down to the inner ring just before the hill gets steep.

2. If those speeds are correct you are not riding any 'decent size hills'

Cairngorm ski road big enough to qualify?

The problems I'm having isn't on big hills, it's where you're going along at a decent rate then you come to a hill big enough to warrant changing to the inner ring. My usual 30 mile training route has quite a few like that. The problem is having to back off the power when changing from the big ring to the inner ring whilst on the hill.

slowbike

I would've thought your bikes would have reasonable groupsets - I found a big difference in front shifting going from 2300 to 105 - the 105 being far better!

For you to get ~20mph in 34/11 you've got to be pedalling at 85-95rpm - but are you really preparing that far before the hill? I could see where it becomes a conundrum though - if you've got a fast flat going into a hill you could be north of 20mph in the big ring (say 50/13 - 85rpm = 26mph, 90rpm=27 and 95=29 ish) then you come to a hill and need to drop down - do you do it before you hit the ramp or when you're on it....
Personally, with my Tiagra and 105 stuff I can flip down a ring quite happily - it's going UP to the big ring that takes longer. As has been suggested above - do this when you're spinning and it doesn't take long at all.

Grill

You're not climbing Cairngorm ski road anywhere near 16.5mph much less 18mph (KOM is 13.3).

If you are indeed a good climber then you would know where you should sit for a for a comfortable cadence and rhythm, as well as be able to shift without scrubbing so much speed. I've never had an issue with drops in speed when going big to little as I know that I need to shift up on the rear to compensate for the change in ratio. The issue seems to be a combination of lack of shifting technique and low cadence (you seem to struggle to hit 80- 34x11 at 80 rpm is 19.4mph). Practice.

blinddrew

Depending on what the hills are like round your way you could get a larger front inner ring. A 38t rather than a 34t for example. I do know what you mean, when I got back into road biking a couple of years ago I went for a compact chainset and have regretted it ever since. The drop from 50-34 takes away any momentum so I end up either changing up at the back first or trying to change both ends at once. Quite happy with a 50t outer but I keep meaning to get a 38 (or 39 if I can find one) inner.

slowbike

Grill wrote:

<load of blurb>
The issue seems to be a combination of lack of shifting technique and low cadence (you seem to struggle to hit 80- 34x11 at 80 rpm is 19.4mph). Practice.

yes - but practice what ... thats what the OP is asking ..

if he's grinding away in 50/13 then having to change down on the ramp then it's going to graunch a bit .. so what should he do ...?

Well - one answer is to get his cadence up - approach in 50/16, once the cadence drops to say 80 flip it down to 34/14 then work your way up the cassette ... the key being changing down whilst having a reasonable cadence. Some might say 80 is too slow - try it and practice at various cadences till you find something that works for you & your bike.

unixnerd

You're not climbing Cairngorm ski road anywhere near 16.5mph much less 18mph (KOM is 13.3).

I wish! :-) Best time was slightly over 40 mins from the centre of Aviemore (just over ten miles).

You're exactly right, it's my technique when changing that's the problem. Tried a few different methods but always seem to lose speed if I change ring.

Grill

Up, Up, Down

diamonddog

Grill wrote:

Up, Up, Down

^^ This, top advice from Grill.

unixnerd

when I got back into road biking a couple of years ago I went for a compact chainset and have regretted it ever since.

It was the only option on my Roubaix. Been thinking of changing to a 52/36 as I miss 52x11 descending (my Cannondale is a triple and it has a 52x11). Lowest gear I have now is 34x28 I only need that on Cairngorm if it's windy.

Up, Up, Down

Yes, I think you're right. I've been trying to change down at the front and up at the back simultaneously and that's maybe my problem.

foggymike

You shouldn't do both at once - much greater chance of the chain coming off/jamming as it's floating at both ends at once so not under proper tension.

reformedfatty

Look at it this way, you may drop 2mph on that initial change, but thats because you are still scrubbing off speed you were carrying on the approach, if it were a pace you could actually sustain on the hill you would get it still whilst on the inner ring.

The magic trick is managing to time that change so that its at the point where you lose as little speed as possible, and don't get to the point where you are mashing pedals and trying to put too much power through the drivetrain as you shift.

Personally I just accept that for the first 2 -3 seconds of shifting in to the inner ring that my cadence will bounce up to 115 or so until I've lost the carried speed.

also up up down as stated

rolf_f

foggymike wrote:

- much greater chance of the chain coming off/jamming as it's floating at both ends at once so not under proper tension.

Theoretically or practically? I've never had any problem with double shifting. And the chain does remain in tension because the front mech is derailing the chain at the top of the chainring and the rear mech is derailing it on the underside of the sprockets - there is never actually a point where there is no proper tension (ie no actual effective drive assuming that the gears are set up well). And, of course, the rear will have completed the shift well before the front anyway. I can't see how the chain at the front end can mechanically have any knowledge of the chain being derailed at the back and vice-versa. To me this is one of those things that somehow feels like it ought to be wrong but in practice is absolutely fine - and quite fun!

As to the OPs issue - I think it is mostly about timing. There is a point when the bike is decelerating as the gradient cuts in when the shift into the smaller ring works effectively - but it is the point at which if you leave it any later you really do lose speed as you need to keep pedalling to maintain momentum but, if you shift too early, you lose speed due to ending up in too low a gear. Aside from the up up down thing, I think it is just a matter of feel to get it right.

Incidentally, a well indexed front mech makes a big difference - the shift needs to be immediate.

bernithebiker

Get DA 9000. Front shifting is quick and flawless.

And please don't grind up hills in 34-11, it makes my teeth itch just thinking about it......

davep1

I'm not sure I understand the problem - it's inevitable, as you're going uphill and changing gear?!

I have a 53/39 and 25/12; when I get near a hill I work up the rear cassette, and don't drop on to the small ring at the front until I have 3 or 4 cogs left. I'm not a great climber but won't give up; then again here in the south we don't have many properly long hills.

Initialised

diamonddog wrote:

Grill wrote:

Up, Up, Down

^^ This, top advice from Grill.

Usually works for me.

btw ended up grinding up Cairngorm in 28 - 34 at about 4mph when I rode it (but didn't stop!).

unixnerd

Cairngorm needs a big sign just after the middle car park saying, "don't worry, it's easier after this bit" :-)

blinddrew

DaveP1 wrote:

I'm not sure I understand the problem - it's inevitable, as you're going uphill and changing gear?!

Can't speak for the OP but for me it's only really a problem on climbs you don't know. Say you're halfway up a fairly steady climb and to break up the ride a bit (and rest your arse) you've decided that this looks like a good time to stand up for a bit and stretch off as you go up the climb. You get a nice gear on the big ring and a good pace and you're bouncing up the hill when you round a corner and there's a big old ramp in front of you - at this point you can either try and grind up it in the big ring or drop to the little ring and spin up it. Generally dropping straight down to the little ring means virtually coming to a halt, trying a two-up-one-down can help but if the ramp is steep going up the gears can slow you down just as much. Basically at this point I'd just want a smaller gap between the two front rings. Hence thinking about getting a 38 / 39t.

rolf_f

blinddrew wrote:

DaveP1 wrote:

I'm not sure I understand the problem - it's inevitable, as you're going uphill and changing gear?!

Can't speak for the OP but for me it's only really a problem on climbs you don't know. Say you're halfway up a fairly steady climb and to break up the ride a bit (and rest your ars*) you've decided that this looks like a good time to stand up for a bit and stretch off as you go up the climb. You get a nice gear on the big ring and a good pace and you're bouncing up the hill when you round a corner and there's a big old ramp in front of you - at this point you can either try and grind up it in the big ring or drop to the little ring and spin up it. Generally dropping straight down to the little ring means virtually coming to a halt, trying a two-up-one-down can help but if the ramp is steep going up the gears can slow you down just as much. Basically at this point I'd just want a smaller gap between the two front rings. Hence thinking about getting a 38 / 39t.

Naaah, no excuse there. Firstly, you shouldn't have been being so manly and staying in the big ring when you were climbing. You'd have been better off in the small ring on bigger sprockets so that you are ready for what might be round a blind corner - it's not as though you won't have had time to consider what might be round the corner.

And if you are going fast enough to justify being in the big ring in the first place, and you are standing, really as you see the ramp you have no excuse not to give a quick burst of power to the cranks and use that momentum to give you time to shift rings as you drop back into the saddle.

The only really tricky situation with this shift, IMO, is when you are blasting downhill (and therefore legitimately in the big ring) when you go round a corner and find a sudden ramp straight infront of you. The corner drops your speed far enough that you lose most of your momentum but catches you out as you still expect to be descending round the corner. Anyone who has climbed Park Rash and carried on down Coverdale will be only too familiar with this situation! You are left moving relatively slowly already heading up a low gear climb in big ring and small sprockets.

blinddrew

Rolf F wrote:

blinddrew wrote:

DaveP1 wrote:

I'm not sure I understand the problem - it's inevitable, as you're going uphill and changing gear?!

Naaah, no excuse there. Firstly, you shouldn't have been being so manly and staying in the big ring when you were climbing. You'd have been better off in the small ring on bigger sprockets so that you are ready for what might be round a blind corner - it's not as though you won't have had time to consider what might be round the corner.

And if you are going fast enough to justify being in the big ring in the first place, and you are standing, really as you see the ramp you have no excuse not to give a quick burst of power to the cranks and use that momentum to give you time to shift rings as you drop back into the saddle.

The only really tricky situation with this shift, IMO, is when you are blasting downhill (and therefore legitimately in the big ring) when you go round a corner and find a sudden ramp straight infront of you. The corner drops your speed far enough that you lose most of your momentum but catches you out as you still expect to be descending round the corner. Anyone who has climbed Park Rash and carried on down Coverdale will be only too familiar with this situation! You are left moving relatively slowly already heading up a low gear climb in big ring and small sprockets.

I fully accept my being distracted and not reading the road is the main cause of my problems here, but I'd still rather have a chainset that let me get out of it! :¬)

unixnerd

Tried the "up, up, down" idea on my last few rides and it works a treat, I lose far less momentum now :-)

alan_sherman

I couldn't get on with a34 inner ring for this reason, the front shift is always where you want to be on rolling terrain. I moved to a 36 inner, and am considering going to a 38 or 39. With 10 or 11 speed cassettes now widely available up to 28 teeth the ratios should work better.

rolf_f

blinddrew wrote:

I fully accept my being distracted and not reading the road is the main cause of my problems here, but I'd still rather have a chainset that let me get out of it! :¬)

My old Raleigh Record Ace has a real standard; 52-42. Every time I need to switch chainrings for a climb I end up thinking 'Was that it? Has that done anything at all?!"

I tend to think the chain should be on the cassette sprocket that you want it on now and the chainring that you want it on in the next few moments.....

blinddrew

Rolf F wrote:

I tend to think the chain should be on the cassette sprocket that you want it on now and the chainring that you want it on in the next few moments.....

Good theory, but helps if you know the roads! I'd actually quite like an old 42-52 you know. Or maybe a 50-40 in deference to my advancing years ;¬)

thatkidpercy

I keep a cadence of around 85-90 when climbing (spinning without much torque), and my tried and tested technique in this situation is to upshift 3 cogs at the back IMMEDIATELY after downshifting to the smaller chainring on the front, while maintaining cadence. I've got this little move down and can complete it within one full rotation of the pedals, meaning there's no noticable difference in speed or feel as the whole thing's over in about half a second.

I try not to use the 2 largest cogs on the cassette when I'm in the big chainring, and so usually switch to the small chainring when I reach the 3rd largest cog (23 tooth on my 12-27 cassette). Looking at the chart below, you can see that changing to the small chainring and upshifting 3 at the back (the technique I describe above, red to blue) gives me the same gear as shifting to the 2nd largest cog while staying in the big chainring (red to green).

Nailing this technique allows you to maintain cadence and keeps the bike moving forward steadily, which is nice for the guy who might be following your wheel behind!

LC: 50 / 34
12: 8.0 / 5.4
13: 7.4 / 5.0
14: 6.8 / 4.6
15: 6.4 / 4.3
16: 6.0 / 4.1
17: 5.6 / 3.8
19: 5.0 / 3.4
21: 4.6 / 3.1
23: 4.2 / 2.8
25: 3.8 / 2.6
27: 3.5 / 2.4

NITR8s

Why shift from a 50-11 to 34-11 when you have 9 further gears in the big ring? How about shifting down the cassette one by one to about the middle as you are on the climb to maintain a similar cadence and then shift to the 34 about half way through the cassette.

diamonddog

34/11 - cross chaining not a good idea.