Road bike gearing questions

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  • Road bike gearing questions
  • bluebird
    Member

    Is (s)he struggling with their current set-up? 34T on the back is a pretty big sprocket. Obviously, it depends how much you ride, but most would be able to get up pretty much anything in the Alps with a compact x 28T.

    Personally I’d go for 105, not Tiagra, that’s quite a step down from Ultegra (even older versions).

    Premier Icon amedias
    Subscriber

    A) i have suggest may be upping the rear cassette to 11-27/28. what is maximum rear cog a 6600 can run?

    Depends on the hanger geometry and if its a short or long cage mech.
    Since he currently has 11-23 I’d be assuming he has a short cage mech

    The listed max sprocket for the 6600 is 27t but I have a short cage one reliably running with a 28t on one bike, but it won’t clear on another, the hanger geometry differs a bit between the frames.

    I also have a long cage 6600 mech running quite happily with a 32t sprocket with the B-tension screw wound in a fair bit, shifting is fine.

    B)This lead to my next point which was if you replace you mech for a medium instead of short you could then potential run up to a 34?

    Again, depends on the mech and hanger geo, longer cage mechs for road were basically to accommodate greater chain lengths of a triple, not necessarily to take a bigger sprocket as the top jockey wheel was normally in the exact same place, but as things moved to newer 10 speed and 11 speed and compact chainsets the sprocket sizes also increased, so 5700 and 6700 mechs will normally allow bigger than 5600/6600 etc. but 34 is above spec again but Shimano are normally conersvative on paper and can go bigger in most cases.

    So my advice would be grab a cassette with a 28t big sprocket and give it a go, it will likely work with a bit of B-tension adjustment, and if it doesn’t then a 105 5700, Ultegra 6700 or Tiagra 4600 WILL work with the 28t and the existing shifters.

    C)Last and final suggestion question was…if you are going to the effort of replacing chain cassette mech etc…surley be worth looking at a group set?
    Suggested the new tiagra group set how does this ride compare to the older shimano 6600?

    Chances are it’ll work with just a new chain and cassette so not worth looking at full groups really, even if you have to do a new rear mech as well you’re talking less than £70 (mech £30, cassette £20-25, chain £10-25), vs. hundreds for a group.

    But, if everything is worn out including shifters then a new group might be an idea, the current 4700 10speed Tiagra is a very good economical group if you have 10 speed wheels, but be aware that it is not in any way compatible with older 10 speed mechs as it uses the 11 speed pull ratio, of course that means it IS compatible with 11 speed 105 and Ultegra mechs though. 4700 shifts well, is easy to set up and feels pretty damn good for the amount it doesn’t cost, longevity is likely to be OK but it’s only been out a year or two so no real long term data yet. it uses the new shifter design so hoods will feel different, worth having a go to see which shape you prefer, personally I don’t get on with the newer hoods as well but most people do.

    Ultegra 6600 was actually a very good group, nicely reliable and decent weight, and last of the externally cable routed 10 speeds, some people prefer the under-bar for neatness, some people prefer the external for reliability and ease of maintenance.

    one thing to bear in mind if you do go down the group route is make sure its a FULL group including brakes, as the lever pull ratio on 6600 is ‘Super SLR’ and 4700 (and other newer groups) are ‘New Super SLR’ so if you mate the new shifters to the old 6600 brakes you’ll get a bit less power and a more wooden feel, they;re still acceptable but not ideal, just soemthign to be aware of in case you try an ‘almost full’ or ‘transmission only’ groupset bargain deal like some retailers are offering

    Bluebird – yea they are, struggles on some hills with current 11-23. Person falls into older casual bimbler category/ not frequent rider.

    I guess, it be a case of finding a seeing if the the 6600 short cage mech can cope with the 28t cassette.

    Also get what you saying about the 105….looks hell of alot nicer too.

    fifeandy
    Member

    Obviously, it depends how much you ride, but most would be able to get up pretty much anything in the Alps with a compact x 28T.

    Do you work for Shimano and just like making everyone overgeared for giggles?

    You need to be able to hold about 3.5W/kg for 30mins at a time to make 34/28 work on any steeper(7+%) alpine climbs, which is not ‘most’ at all, its actually very few.
    ‘Most’ would actually benefit from a new sub compact chainset and a 32T cassette for a 28/32 ratio. Then they could actually enjoy climbs rather exploding their knees doing 45rpm.

    jonba
    Member

    A) Probably be fine, pretty sure I ran that on my CX bike. With a new/reversed B tension screw I think I bodged a 32t in there for the 3 peaks. There is naff all difference between a 27 and a 28.

    B) Yes but see C

    C) Obviouly full Di2 is the way to go but if not total up the spend on new bits for the 6600 then see what you could get for your money. Ribble, Wiggle, Merlin et al. all have cheapish groupsets. You’d probably get some money back for the old stuff too like cranks, brifters, brakes mechs. I’d say you wouldn’t notice 105 as it is pretty damn good. Tiagra, maybe as some of the parts have been value engineered and things like brifters aren’t quite as nice.

    Hello All,

    Sorry lots of questions regarding gear asking on behalf of a friend…

    He has a full Shimano ultegrea 6600 grouped bike, has just purchased a another frame as his one has cracked.

    hes asked me nicely to swap it all over for him which is fine. his only issue is the 6600 he as is quite old/worn and he is also not happy with the gear ratios he has

    currently he is compact front 11-23 cassette.

    when swapping it onto the new frame i have recommended to him to replace his chain and cassette (obv cables too)

    A) i have suggest may be upping the rear cassette to 11-27/28. what is maximum rear cog a 6600 can run?

    B)This lead to my next point which was if you replace you mech for a medium instead of short you could then potential run up to a 34? i presume a 105 5701 (10 speed) medium would be compatible with the 6600 shifters?

    C)Last and final suggestion question was…if you are going to the effort of replacing chain cassette mech etc…surley be worth looking at a group set?
    Suggested the new tiagra group set how does this ride compare to the older shimano 6600?

    Thanks in advanced

    Liam

    Premier Icon njee20
    Subscriber

    6600 was a really nice groupset, 5700 is not. The STIs feel horrible. 5800 is much better, and only about £30 more than Tiagra 4700.

    As evidenced by many of the posts here gearing requirements are a personal choice. I’m taking a compact and 28t sprocket to the Alps, and fifeandy’s now got me mildly concerned that I’m going to die a horrible death.

    I wouldn’t want to use an 11-34 block on the road, far too gappy. TMMV.

    TiRed
    Member

    I’d go with a 12-28 for 10 speed unless really struggling with hills. You can go up to 32 without a new RD. Keep the 6600 shifters. Their shifting is every bit as good as modern 11 speed, if not a little nicer. And I have every flavour of Ultegra from 6600 to compare.

    Might be a little spinny on 50×12, but it’s not a huge concern. I raced my compact with your friend’s current gearing. Get a 28 on there and they’ll most likely be fine.

    fifeandy
    Member

    I’m taking a compact and 28t sprocket to the Alps, and fifeandy’s now got me mildly concerned that I’m going to die a horrible death.

    Roll the clock back 5-6 years, and that gearing was the best that was available, and no-one actually died, so you’ll be fine.
    But now more gears are available, most people that wouldn’t be bold enough to consider themselves a strong climber would probably be better served by a 32t, subcompact or both.
    Bear in mind the pros were running 36/28 for Mont du Chat the other day, and they were pushing 5W/kg.

    deepreddave
    Member

    @fifeandy – good to read. I’m new to road and aware I need to get fitter but here in the Lakes I’d say there’s plenty of scope for more casual riders to prefer to spin 34-32 (or even 32-32 as Spesh fitted on their 2017 Diverge). 34-28 is feeling quite challenging at the moment staring at one of the passes more than 2hrs/30 miles in 🙁

    amedias-thanks for your in-depth explanation just what i need.

    Jonba – like wise thankyou

    Thanks for all the information. I will push him to get the 11-28 route, see if hes is keen for this and see how it goes. It will just need a good clean and chain and cassette.
    If on the other hand hes keen for the 34 cassette will go down the longer mech route.

    As for the group as whats been said, ill recommend 105 as start of the ‘Good stuff’

    Ill suggest the following-

    105 medium mech silver

    Rear cassette 32

    KMC X10 chain

    and i think that would be sufficient for his needs, Presume all of what i have picks will work in glorious harmony?

    Many thanks

    liam

    bluebird
    Member

    You need to be able to hold about 3.5W/kg for 30mins at a time to make 34/28 work on any steeper(7+%) alpine climbs, which is not ‘most’ at all, its actually very few.

    Like I said, it depends how much you ride, but a 95kg bike and rider going up Alp D’Huez in 90 minutes needs to generate 190W, which equates to less than 2W/kg. That’s a pretty achievable number for anyone who rides. (Source: http://www.cyclingascents.com/alpedhuez.html#.WWYMgtPysUE)

    Your friend needs to be very honest with himself, about the terrain he expects to ride and whether what sprocket he needs to manage a cadence of ~80+ to get up the steepest hill gradient (yes, you can grind at lower revs using a smaller sprocket, but this will come back to bite you on a longer cat4+ climb).

    I’m very glad my Cube came with an 11-32, trying to tackle the top of Harvesting Lane in anything but my easiest gear (34/32) would be a whole heap of pain, not just my legs but also I suspect my knees (my average cadence on the flat is ~100-110rpm).

    simondbarnes
    Member

    6600 was a really nice groupset, 5700 is not. The STIs feel horrible

    I’ve seen this said a few times but I have 3 sets that all feel lovely and the hood shape is much nicer than 6600.

    fifeandy
    Member

    Like I said, it depends how much you ride, but a 95kg bike and rider going up Alp D’Huez in 90 minutes needs to generate 190W, which equates to less than 2W/kg. That’s a pretty achievable number for anyone who rides.

    Yes, but it will also give them an average cadence of 54rpm which for 90mins solid is beyond stupid

    Edit:
    I plugged some predicted numbers in for myself (225W, 59kg, 8kg bike (saddle bag, mini pump and water bottle))
    From your link, that would give me 60mins, and an average of ~86rpm, so still a fraction over-geared.

    Premier Icon ransos
    Subscriber

    I have two road bikes, one with 6600 stis and the other with 5800. I must say that the 5800 wins for ergonomics, but they both shift very well, especially with the newer low friction shimano cables. IIRC, 5700 was a bit unreliable as Shimano didn’t get the concealed cable routing quite right.

    ETA: I used a 12-30T cassette and compact chainset for the Alps, and did AdH in an hour. Lower ratios and a higher cadence definitely work best for me.

    Premier Icon amedias
    Subscriber

    RE: gearing choices in general… there’s also a big difference between the gear you can push while fresh at the beginning of a ride Vs. hours later with a lot of hills in your legs.

    Gear choice should always try to accommodate the worst case scenario if possible, unless you’re happy to get off and push when it gets too bad.

    My Audax bikes are geared totally differently* to my road/training bikes, there’s gears there that I’d never dream of using on a normal ride, but >8hrs in when another 15-20% climb hits means I’m glad they’re there when I need them…

    Don’t be afraid of the low gears!

    *sub-compacts and triples

    TiRED – You can go up to 32 without a new RD

    Really?do it work ‘well’ or is it a bit of a stretch?

    As a ‘compromise’ to keep the same mech…. i have found a 12:30 ultegra cassette think that could be the sweet spot?

    Premier Icon amedias
    Subscriber

    Try it with the existing mech first, there’s normally leeway but it’s dependant on many factors and the hanger geometry, you’ve got nothing to lose by trying!

    bluebird
    Member

    Yes, but it will also give them an average cadence of 54rpm which for 90mins solid is beyond stupid

    Except the roads aren’t perfect, even slopes, so there will be periods of higher and lower cadence / more and less power. A lot of people can’t maintain an average cadence of 85rpm, even on the flat, and when climbing many drop to lower cadences anyway. It’s very personal, one of my friends is in the 70s on rolling roads and he’s very happy there.

    Anyway, I didn’t mean to come across like some kind of mountain goat. I was trying to get across that you won’t die if you don’t have a wide range rear cassette. Yes, the climb may be a tad tougher on your legs, but if you need a compact and a 34T rear cassette I’d argue it’s going to be pretty tough for you anyway. Which is kind of the point, isn’t it? We ride up these things for the personal achievement, if it was easy we wouldn’t bother.

    simondbarnes
    Member

    We ride up these things for the personal achievement, if it was easy we wouldn’t bother.

    I ride up hills for the view. YMMV.

    bluebird
    Member

    I ride up hills for the view. YMMV.

    🙂 good point

    Premier Icon aracer
    Subscriber

    fifeandy wrote:

    From your link, that would give me 60mins, and an average of ~86rpm, so still a fraction over-geared.

    😯 very few riders are holding 86rpm on the climbs, let alone those requiring low gearing due to lower power/weight ratio. I reckon I’d be dropping to 80rpm at most on steeper/longer climbs and I’m far from a grinder; 70rpm isn’t at all unreasonable.

    Working backwards, your 3.5w/kg suggestion appears to be assuming 90rpm cadence which is even more unrealistic.

    simondbarnes
    Member

    Working backwards, your 3.5w/kg suggestion appears to be assuming 90rpm cadence which is even more unrealistic.

    Indeed.

    UPDATE:

    after chatting it through with him pros and cons of each arrangement, to my surprise he has gone with a new 105 11 speed group-set (sub compact)

    which is a masive win for him ( and me i dont have to try and fettle a part 10 year old groupset and ‘get it to work ‘)he ends up with really nice bike and means it will all shift nice and work really really well.

    Thanks for the help.

    wilburt
    Member

    I would still get a compact, wiggle have 105 with 11/28 for just over £300.

    A brief scan of the posts above suggests a bit of the man up stuff about gearing. In my experience you can never have too many!

    for what its worth…

    i’ve just gone to compact on my road bike (from 53/39 – 11/28, short cage rear mech), wasnt intending to but i bought a used ultegra for my cx and thought id try it on my road bike and find i quite like it.

    its very hilly where i live, i could get up everything on the regular gearing but i find i just prefer the 50/36 up front because i can spin a bit cleaner. 175mm cranks btw.

    i did have a 34 inner but that was a bit too spinny for me even with a 11/25 on the back. may yet try a 52 outer ring.

    at the risk of being shot down, i read a fair few posts on forums about this same question and more than a few folk said you can get away with a short cage with an 11/32 if needed even if its outside specification. but i havnt tried it and really i dont need a 32.

    only prob is that as ive decided i like it i’ve got to find a duraace one now and get that past the wife. ; )

    breatheeasy
    Member

    105 don’t do subcompact, unless it’s a different chainset. There’s not many true sub compact Road chainset out there that don’t cost the earth at the moment.

    epicsteve
    Member

    I was out on my new road bike yesterday and it has 50:34 & 11-28 whereas my old Roubaix also has a compact but an 11-32 cassette. While Essex isn’t that hilly we did do some of the steeper climbs available (e.g. Mott Street) which is 12% or more in places. On some of those climbs I noted that I needed 400W+ to maintain my preferred climbing cadence (90rpm or so) which meant I was dropping down to cadences of around 60 at times as I can’t maintain 400W+ for all that long and having the 11:32 instead would have helped as steep stuff at 60rpm isn’t fun.

    In the Alps I’m not sure even a compact and an 11:32 would be enough to get me up the longer climbs though!

    fifeandy
    Member

    Sorry, missed this thread for a few days.
    @aracer, what is unreasonable about climbing at 90rpm?

    You wouldn’t ride a flat time trial at 70rpm, so why would you do it on a climb? Long climbs at low cadence is either some wierd self harming fetish or over-geared.

    Edit: And 3.5W/kg was loosely based on 80rpm.

    atlaz
    Member

    I’ve got 11-32 with a compact. I don’t race and, frankly, I rarely need the 32 for every day riding. That said there are a lot of 16%+ gradient hills around here and the option to use a 32 is nice to have. I get up the same hills with my 11-28 but it’s a bit more painful and sapping.

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