New Groupset

[Tint1n]

Good Afternoon all,

I currently ride an 8 speed Cannondale Caad8 road bike. I am looking at upgrading the groupset to the Shimano 105 5800 11speed.

I am very unsure though which gearing to go for. I mainly ride out in the countryside which have a mix of long steep uphill's and steep descents.

Which gearing would I benefit from the most. The options are as follows:

Shimano 105 5800 11 Speed Double Chainset

1. 50-34t
2. 52-36t
3. 53-39t

Shimano 105 5800 11 Speed Road Cassette

1. 11-28t
2. 11-32t
3. 12-25t

Any help would be much appreciated

I will also be upgrading my wheels to Shimano RS21's at the same time.

thanks in advance

Matt

 

[Tenacious Sloth]

I don't know how strong a rider you are so it's difficult to make a recommendation.

However, when has that ever stopped anyone on this forum?

Unless you're a powerhouse, I would go for 50-34 with 11-32. This was fitted to my Merida when I first got into cycling and enabled me to get up any hill but still had enough legs on the flats and descents. I'm still using it now and although I'm a lot stronger/faster still find the gearing fine.

Graham

 

[Pale Rider]

Given it's a personal choice, you need to think about what you like and dislike about your current gears.

Pay particular attention to the highest and lowest, is it high enough and low enough for you?

The answer to that question will point you in a direction as regards range.

As a general observation, the 12-25t rear looks like a close ratio 'racing' cassette to me.

I doubt most recreational riders need gears that close together, and it might even annoy you having to change more often.

@Tenacious Sloth makes good points - I would also go for the widest range with the lowest bottom gear.

 

[Tint1n]

I don't know how strong a rider you are so it's difficult to make a recommendation.

However, when has that ever stopped anyone on this forum?

Unless you're a powerhouse, I would go for 50-34 with 11-32. This was fitted to my Merida when I first got into cycling and enabled me to get up any hill but still had enough legs on the flats and descents. I'm still using it now and although I'm a lot stronger/faster still find the gearing fine.

Graham

Thanks for your reply,

I have pretty strong legs, I am finding I am spinning out with the current 8 speed I am using, I want something that I wont be able to spin out when flat out riding.

thanks

Matt

 

[goody]

Whats your current gearing? If you're spinning out on 50-11 then maybe go up to the 52-36 chainset and if you're strong and never struggle with hills the 11-28 cassette may be OK or the 11-32 if you want some easier options for steep climbs.

 

[cyberknight]

Thanks for your reply,

I have pretty strong legs, I am finding I am spinning out with the current 8 speed I am using, I want something that I wont be able to spin out when flat out riding.

thanks

Matt

Are you riding at more than 30 mph on the flat ?
My current commuter is set up with a 12-25 8speed and a 50 front , at 90 rpm i need to be hitting 30 + to use the top gear and 90 rpm is hardly spinning out by a long shot ,
If you can then mea culpa but you really shouldnt be spinning out even flat out , dont use it as a reason not to buy shiny stuff if you can affordit though
My other bike has a 10 speed 11-28 that gives me a good spread , a bit low imho but gives me bail out gears if i ever bonk.

 

[Globalti]

More to the point; where do you live? If it's flat go for the semi-compact 52/36 with 11-28. If it's hilly go for the compact 50/34 and 11-28 or even 11-32, depending on your age and strength. My Mum's family is from Salisbury and I know the area is characterised by flat valley bottom rides with steep climbs up onto the downs, so unless you're a racing snake aged 24, I'd go for the compact and 11-28 combination.

Compact gearing and wide-range cassettes have done more to bring new riders into road cycling than even SIS and carbon frames.

 

[Citius]

Which gearing would I benefit from the most.

Your fitness will dictate which gearing you will benefit from. Unlikely that you are genuinely spinning out on your current gearing.

 

[busdennis]

Hi Tint1n, after reading your question I haven't ready any replys to be influenced . forget about the 53 39 unless you are racing. A strong club rider could use a 52 36 for hill climbing and general riding but a 50 34 I would suggest would be the most useful chainrings for most people. on the rear cassette again the close rations of 12 to 25 would best be suited to racing. use your current 8 speed groupset to workout if you need a 32 rear or if you can climb your local hills on the 28. best of luck in your choice

 

[Ajax Bay]

Whats your current gearing?

In order for better advice to be given @Tint1n , it would be most useful if you say what you've got now assume 2x8 eg 52-39 and 12-25.

Also say whether the lowest gear (say 39/25) is a short enough (gear length) or whether you want a lower gear to get up the local hills, and how much lower - 10%, 20%? Do you get up the hill going south over Knapp Hill south of Fovant, for example? Comfortably? If so your lowest gear is fine and can be replicated.

Finally say what gear you are 'spinning out' in (say 52/12) - this gives you 117 inches which at 90 rpm cadence would give you 50+ kph: impressive if sustained on the flat. And 'spinning out' implies at least 110 rpm so as @Citius says "Unlikely that you are genuinely spinning out on your current gearing." = 61kph.

You might find this link useful too (and it has a drop down list of all manufactured cassettes and a variety of chainsets) to inform your choice:

Here is 34-50, 12-25, where the jump is expressed as 'Gear Step %'.
http://www.gear-calculator.com/?GR=...16,17,19,21,23,25&UF=2125&TF=90&SL=2.6&UN=KMH

 

[Tint1n]

Thanks everyone for your replies. Today I had five minutes spare so have had a look at my current set up. It is as follows:

25-12 rear cassette
50-34 front

the steepest hill I ride is snakey hill which I think is a 12degree incline. I find I can climb this using small gear and front and second cog from top on rear cassette.

The type of riding I do currently is a variety of steep up hills, long down hill sections aswell as a good amount of flat or small inclines. When on the flats and declines I find my 8 speed on back is not enough to. I find my legs are turning over too easily and I cannot put anymore power down to increase my speed due to legs spinning to fast.

I find climbing fairly easy with my current set up.

I need to find a set up that will continue to help me climb but give me the extra bit I need when on the downhill sections etc.

I am 30 years old and am generally very fit. I have good strong leg mussels aswell.

Hope this helps and thanks again for any assistance

Regards

Matt

 

[cyberknight]

Yup , but what speed are you doing in those gears ?
I dont think anyone is disagreeing with you , we are just trying to define what leg speed you feel like your running out of gears when it might be a question of learning to pedal faster with the gears you have got as even the pros will not generally be running more than a 53 x 11 max and they are cracking along at a fair old lick and even they use compact sets when the terrain demands it

 

[Ajax Bay]

Which gearing would I benefit from the most. The options are as follows:
Shimano 105 5800 11 Speed Double Chainset

1. 50-34t
2. 52-36t
3. 53-39t

Shimano 105 5800 11 Speed Road Cassette

1. 11-28t
2. 11-32t
3. 12-25t

My recommendation, based on the info above and making the assumption you're set on 11 speed, is 52-36 and an 11-28.
You're currently 'spinning out' (some disagree - just up your cadence to 130) even on the flat with 50/12. And you're content with 34/22 up steep hills with the 25 in case. Your current top and low gear ratios are: 4.17 and 1.36. The 52-36 and 11-28 combo will give you 4.72 - 13% more for those fast downhills (66kph @ 110 cadence) and the lowest ratio would be 1.29, 5% 'better' than your current set up, for those demon hills when you've already done 50km.

This is in line with some of the advice above eg @goody and @Globalti but takes advantage of the extra info provided. Hope that helps. For assurance, open and use the calculator in my last post.

 

[cyberknight]

The above is mph for each gear at 90 rpm according to sheldon brown. His 12 % hill gearing would be 16 mph at 90 rpm , of course the OP might be doing this ?

 

[Ajax Bay]

[On] his 12 % hill, gearing would be 16 mph at 90 rpm , of course the OP might be doing this

My maths/units differ (I lie; I'm using the calculator (see above)) but with 34/22 (he's comfortable going up in the second largest sprocket in a 12-25 8sp cassette) at 90rpm gets you 16 kilometres per hour. Think if you're out of the saddle cadence could easily drop to 45 and that would mean he's climbing it at 5mph: entirely reasonable.