Switching sprockets

Anonymous
Anonymous Posts: 79,667
edited May 2013 in Workshop
I have 2 Ultegra 12-25 cassettes on 2 wheelsets and now have a third set of wheels.

Was thinking of getting an 11-25 for the third set but am now thinking of getting an 11-27 as doing a big hilly sportive and want an insurance policy for the hills!

Would I be right in thinking I could just swap the 11 tooth sprocket on the 11-27 with the 12 on a 12-25?

What is the next biggest sprocket up from the 11 on the 11-27?

Thanks for any help. Am getting the 11-27 anyway just not sure how I will find the larger ratio changes and wondered if there was anything worth trying as I already have the 12-25's.

Comments

  • sungod
    sungod Posts: 16,873
    the sprocket after 11 will be 12

    on an 11-xx cassette, the sequence is usually n+1 with the first 'missing' sprocket at 16 or later

    afaik there's no ultegra 6700 11-27 or 12-27, but if you want 12-27 why not get a 105 5700 12-27? that goes 12-13-14-15-16-17-19-21-24-27
    my bike - faster than god's and twice as shiny
  • smoggysteve
    smoggysteve Posts: 2,909
    There isn't an 11-27 Ultegra cassette. 11-28 maybe? Are you sure you aint buying a 105 cassette with them ratios?

    Mmm. beaten to it I see.

    On the swapping thing, if the other cassette is 105 it will not be interchangeable with the Ultegra cogs.
  • Anonymous
    Anonymous Posts: 79,667
    Thanks guys :wink:

    Sorry, yes 11-28 (which is better for what I need anyway)
    I would have thought it was 28 but sure it said 11-27 when I looked last time :?
    Old age lol.

    If the next ring is a 12 then there would be no point in swapping.
    Could always just use the 11 on one of my 12-25's I guess.
    Can you just buy an Ultegra 11 sprocket? Think I did a search quickly once but found nothing.
  • Monty Dog
    Monty Dog Posts: 20,614
    If you can track down an 11 tooth Ultegra sprocket, you'll also need a 11t lock-ring as the 12t lockring is too big. TBH if you're not racing there's little need for such high gears - simply learn to pedal faster, particularly as you say you need an easier gear for the hills.
    Make mine an Italian, with Campagnolo on the side..
  • ugo.santalucia
    ugo.santalucia Posts: 28,301
    If you need an 11 T sprocket you are doing something wrong... I seem to recall Merckx was sprinting with a 13 T and with all due respect, I don't think you are in that league
    left the forum March 2023
  • Anonymous
    Anonymous Posts: 79,667
    If you need an 11 T sprocket you are doing something wrong... I seem to recall Merckx was sprinting with a 13 T and with all due respect, I don't think you are in that league

    I didn't know Eddie Merckx road a compact :shock:
  • Anonymous
    Anonymous Posts: 79,667
    Seriously though, thanks to everyone for your help :wink:
    Good tip about the lock ring. I do not think I will bother doing that.

    The 12-25 is fine for me. I don't particularly need an easier gear for the hills (at least none I have been up to date) I was just thinking of getting a bigger cassette for ridelondon100 in case my legs were tired and the Surrey hills were hard.

    I do sometimes feel I could do with a faster gear (on my compact) but its not a big deal.
    It was mainly just that I had this new set of wheels and I thought about trying something different.

    I plan to pop over to Surrey soon so will have a better idea of how tough the hills are and may not need the 28 at all.
    It seems to be either 11-28 or 12-30 so I figured the 11-28 would be the better to get.
    Maybe I need to check out what size all the sprockets in between are on both of those though.

    Should I be thinking of getting a bigger cassette for one ride?
    Which would be best out of 11-28 or 12-30 if I usually ride a 12-25?

    I can get up hills but thinking after riding a fast 60 miles do I want to hit tough hills with a 25.
  • sungod
    sungod Posts: 16,873
    tbh with a compact i'd think 25 would be ok, i don't think there're any steep climbs

    but depends on you, an xx-27 or xx-28 would give you the option to spin up easily if you were tiring

    if it's the same as the olympic route there's a profile someone posted here...

    http://www.mapmyride.com/routes/view/76212894

    ...the gradients are averages, maybe steepest bits will be 10% or so
    my bike - faster than god's and twice as shiny
  • Anonymous
    Anonymous Posts: 79,667
    Ditchling Beacon at the end of L2B is the toughest hill I have ever been up in terms of gradient, length of climb and miles in legs before hitting it (about 50 miles).

    I might just get the 11-28 to try out both the larger and smaller sprockets anyway.
  • ugo.santalucia
    ugo.santalucia Posts: 28,301
    Carbonator wrote:
    If you need an 11 T sprocket you are doing something wrong... I seem to recall Merckx was sprinting with a 13 T and with all due respect, I don't think you are in that league

    I didn't know Eddie Merckx road a compact :shock:

    Many people think they can push over 35 mph... where 11-12T sprockets might come handy... truth is hardly anyone can. The fastest I remember pedalling for more than 10 seconds was a chain gang down in Oxfordshire, bit of tail wind, we kept 52-55 Kmh for a good 5 minutes... it was probably the only time I used a 12T sprocket... wouldn't know what to do with an 11 T
    left the forum March 2023
  • Anonymous
    Anonymous Posts: 79,667
    Are you using a compact though ugo?

    I only have the option of 11-28 or 12-30 so it was more because I want the 28 and not the 30, than the 11 over the 12.
  • ugo.santalucia
    ugo.santalucia Posts: 28,301
    Carbonator wrote:
    Are you using a compact though ugo?

    I only have the option of 11-28 or 12-30 so it was more because I want the 28 and not the 30, than the 11 over the 12.

    I was at the time, I don't now... Now I have 53 x 13 on one set of wheels and 53 x 14 on the other as biggest gears... I also have a bike with a 53 x 12, but I have never used that sprocket... I don't think I have used the 13 T on that one either... I don't know how people manage to use those sprockets... I am no slouch...
    left the forum March 2023
  • Anonymous
    Anonymous Posts: 79,667
    I do not really use the 12 for that long and so I agree that I do not need an 11.
    Peddling faster or just using the energy elsewhere on the ride would probably be better.
    Sometimes I just think 'mmmm is that my highest gear.
    Much more favourable than when I think 'Huh, is that my lowest gear' though' :lol: