Casettes and Chain Rings (Road Bike)
Discussion
Thinking of 'upgrading' my Shimano 105 casette and front rings.
Currently on a 11-30t with a 50/34t with a R7000-GS, medium cage. Covers about 98% of what I need
I top the gears out on some descents at ~44mph (consistent reading from Wahoo, Strava puts me a little higher - Managed 46 a couple of times in Italy down a really steep hill) and would like a bit extra but at the same time I do rely on the 30/34, usually on stuff like White Down Lane in Surrey or if I am burned out at the end of a ride.
I've no idea what the increase to a 36/52 would be like but I am certain that it would cause me problems at my current level, so thinking a 11-32/34 would maybe compensate for the larger fronts? I believe my Derailleur will accept that configuration, although not sure how the front Derailleur would work with the extra teeth being fixed to the carbon frame?
Any thoughts from someone that's done this would be appreciated
Currently on a 11-30t with a 50/34t with a R7000-GS, medium cage. Covers about 98% of what I need
I top the gears out on some descents at ~44mph (consistent reading from Wahoo, Strava puts me a little higher - Managed 46 a couple of times in Italy down a really steep hill) and would like a bit extra but at the same time I do rely on the 30/34, usually on stuff like White Down Lane in Surrey or if I am burned out at the end of a ride.
I've no idea what the increase to a 36/52 would be like but I am certain that it would cause me problems at my current level, so thinking a 11-32/34 would maybe compensate for the larger fronts? I believe my Derailleur will accept that configuration, although not sure how the front Derailleur would work with the extra teeth being fixed to the carbon frame?
Any thoughts from someone that's done this would be appreciated
Sounds a reasonable step to enhance steep climbs. For ultimate downhill speed (which let's face it in these parts will be under a minute elapsed time typically) why not spend money on a decent bikefit to improve your aero position, if you haven't already? Or training/ practice to corner faster?
Or consider tri-bars to enhance aero on long flattish stretches?
Or consider tri-bars to enhance aero on long flattish stretches?
Edited by millen on Monday 18th January 10:03
I wouldn’t bother, for the same cadence you will add less than two miles an hour to your speed.
You might be better considering your position, mainly to get more aero, I don’t know what the hills are like where you are, but I can descend my local hills here in the South Pennines at over 50mph on a single speed mountain bike if I get tucked in enough.
You might be better considering your position, mainly to get more aero, I don’t know what the hills are like where you are, but I can descend my local hills here in the South Pennines at over 50mph on a single speed mountain bike if I get tucked in enough.
no idea why you want to go faster on a downhill, perhaps get stronger and go faster up them if your needing the 34/30.
thats 70kph, your going to probably die coming off at that speed.
or you can switch to a 52/36 or 53/39.
i have bikes with compact, semi and standard, my racebike has a 54t, I still have no desire to go faster than 70kph ever.
thats 70kph, your going to probably die coming off at that speed.
or you can switch to a 52/36 or 53/39.
i have bikes with compact, semi and standard, my racebike has a 54t, I still have no desire to go faster than 70kph ever.
z4RRSchris said:
no idea why you want to go faster on a downhill, perhaps get stronger and go faster up them if your needing the 34/30.
thats 70kph, your going to probably die coming off at that speed.
I hoped all that was obviousthats 70kph, your going to probably die coming off at that speed.
Because its fun, may as well go for it proper then? These speeds are on wide smooth roads I know well. I dont get anywhere near that if I dont have good visibility or the conditions dont suit. There are roads in the Surrey Hills I am sure I could best that speed but you just wouldn't.
I am getting better at climbing all the time, in fact I enjoy it. I try to do some sort of 'progressive overload' using a higher gear to make it more difficult plus I'm chucking weight about in the gym. Its just certain sections of certain roads I need the granny gear in. For example the top of Coombe Lane at 20%, or White Down Lane at 18%
Bike Fits, Aero etc, will look into. Just enjoy putting the power down on certain sections of road, its a good feeling.Topping out isnt
I think there's a bit more to it than just top end speed. My old best bike had a semi-compact 52/36 with 11/32 cassette (lowest gear 34/30 equlivalent), and my current best bike has a 50/34 with 30/34.
I find with the compact I'm constantly swapping from the big ring to the small ring as well, much more often than on the semi-compact, where the small ring was good for up to about 17mph without cross chaining, so really suited me personally (I do a lot of rides which have undulating gradients).
I find the jumps between gears on the 50/34 with 30/30 too big, and DI2 prevents small ring / small cog combinations, so I'm left without that big a range of usable gears.
That said, one of my mates who spins a lot faster than me prefers his compact. It's probably worth trying them out to see if it's for you (if possible).
I find with the compact I'm constantly swapping from the big ring to the small ring as well, much more often than on the semi-compact, where the small ring was good for up to about 17mph without cross chaining, so really suited me personally (I do a lot of rides which have undulating gradients).
I find the jumps between gears on the 50/34 with 30/30 too big, and DI2 prevents small ring / small cog combinations, so I'm left without that big a range of usable gears.
That said, one of my mates who spins a lot faster than me prefers his compact. It's probably worth trying them out to see if it's for you (if possible).
I think the reason to change chainrings is more so you're not continuously swapping between chainrings (bigger small chainring will mean more time spent in the little ring before you have the change up) or to get a better chainline in commonly used ratios (rather than ultimate top end speed).
I prefer a compact chainset but I've got a relatively high natural cadence and it means I can keep in in the big ring most of the time.
I prefer a compact chainset but I've got a relatively high natural cadence and it means I can keep in in the big ring most of the time.
Hi,
Can maybe offer some insight. My old bike (now my winter) has a compact and 11-32 cassette. It’s good for climbing. When I bought my ‘best’ bike it has semi compact and 11-30 and I thought I’d struggle and have to change the cassette and possibly the rear cage.
18 months on and I haven’t changed it. Maybe I’m fitter (think I am) but I’ve managed just fine and I’ve got some juicy Cotswold hills to contend with. It took me on an Ironman in the Atlas Mountains and recently around Mull.
It’s also ace downhill and although going faster is gonna hurt more, I can’t see that falling off at 44 is going to hurt less than at high 40’s!!
So, I’d say try it and see how you get on?
I may yet change mine if a COVID delayed Alps trip happens this year....
Varying views on whether an 11-32 would work with the medium cage on which I can sadly offer no opinion
Can maybe offer some insight. My old bike (now my winter) has a compact and 11-32 cassette. It’s good for climbing. When I bought my ‘best’ bike it has semi compact and 11-30 and I thought I’d struggle and have to change the cassette and possibly the rear cage.
18 months on and I haven’t changed it. Maybe I’m fitter (think I am) but I’ve managed just fine and I’ve got some juicy Cotswold hills to contend with. It took me on an Ironman in the Atlas Mountains and recently around Mull.
It’s also ace downhill and although going faster is gonna hurt more, I can’t see that falling off at 44 is going to hurt less than at high 40’s!!
So, I’d say try it and see how you get on?
I may yet change mine if a COVID delayed Alps trip happens this year....
Varying views on whether an 11-32 would work with the medium cage on which I can sadly offer no opinion
Harleyboy said:
Master Bean said:
Shimano R7000 SS Short Cage handles a cassette between 25 and 30 teeth. GS Medium Cage between 28 and 34 teeth. I'd personally stick with what you've got and perfect the Peter Sagan super tuck.
Think I must have the short version then. Thanks for clarifying I have a semi compact summer bike with 11-30, down from a compact before. Thinking of getting di2 and will go back to compact if I do.
I'm a bit less fit than you but in summer peak enjoy all the climbs you mention, and going stupidly fast.
The problem I encounter is combining a steepness with end of ride exhaustion. Particularly post covid at the start of summer last year, it was a real bugger getting to (or thinking about) a 15%+ drag when I'd overcooked things, and never that bad topping out.
Don't tend to go that many places where the hill length / tarmac quality provide too much opportunity for those speeds though...
I'm a bit less fit than you but in summer peak enjoy all the climbs you mention, and going stupidly fast.
The problem I encounter is combining a steepness with end of ride exhaustion. Particularly post covid at the start of summer last year, it was a real bugger getting to (or thinking about) a 15%+ drag when I'd overcooked things, and never that bad topping out.
Don't tend to go that many places where the hill length / tarmac quality provide too much opportunity for those speeds though...
JPJPJP said:
Can you just change the big ring to a 52 - they are available individually
Not really. It's questionable that the front mech would handle the height difference between the two rings Officially definitely not. If it did, the shifting would be a bit sus. It would definitely be a 'suck it and see'. If I had spare hanging around, I'd give it a shot, but not have the confidence to shell out for a new big ring.
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