To Single Speed.

Wayne Plunger
Wayne Plunger Posts: 444
edited February 2019 in Workshop
My old winter bike recently got taken out by a motorist and replacing all the rear end stuff basically is not worth it.

I am thinking of turning it into a "knocking around on / fun not serious cycling bike"

Is it feasible to make an 8 by 3 into a single speed at the back but keep the triple on the front?

Also would consider changing to flat bars at same time so appreciate I would need two new brake levers and some kind of shifter if the triple could be used.

Appreciate this may be "meat and drink" to some of you on here but not very experienced in bike stuff yet, hopefully learn more as I go along.

Thanks in advance.

Comments

  • whyamihere
    whyamihere Posts: 7,716
    Technically, yes. You'll still need a rear derailleur though, to apply tension to the chain - singlespeed tensioners don't have anything like the amount of movement you'd need. You would take off all the cogs other than the one you want and replace them with spacers, or preferably, use a 3/32 singlespeed specific cog because they have taller teeth and no shaping so will retain the chain better. You would then wind in the limit screws on the derailleur so that it runs directly beneath the final remaining cog.

    If the problem is that you don't want to buy a new derailleur or you can't attach one, then you're a bit stuffed.
  • whyamihere wrote:
    Technically, yes. You'll still need a rear derailleur though, to apply tension to the chain - singlespeed tensioners don't have anything like the amount of movement you'd need. You would take off all the cogs other than the one you want and replace them with spacers, or preferably, use a 3/32 singlespeed specific cog because they have taller teeth and no shaping so will retain the chain better. You would then wind in the limit screws on the derailleur so that it runs directly beneath the final remaining cog.

    If the problem is that you don't want to buy a new derailleur or you can't attach one, then you're a bit stuffed.

    This
    left the forum March 2023
  • Thank you both for rapid and informative reply. May have to go back to the drawing board and rethink what I shall do.
  • Taking it one stage further if I settled for a single front chain ring do I still need the dureilier for the rear.

    I feel sure the bike I had when a youngster just had the chain and nothing else or did they use a specific set up to achieve that.
  • whyamihere
    whyamihere Posts: 7,716
    Single ring at the front makes it simpler. You probably still need a way of tensioning the chain - The bike that you had as a youngster would probably have had some horizontal adjustment in the dropouts allowing you to pull the wheel back to put tension on the chain. If you have vertical dropouts, you will generally need a tensioner of some kind, but there's options which attach to the derailleur hanger, the chainstay or the BB. Alternatively, depending on your gear ratios, you might get lucky and be able to find an option which gives enough tension without the need for a tensioner.
  • keef66
    keef66 Posts: 13,123
    I've just winged it with an old 2x7 speed steel Peugeot with semi-horizontal dropouts. I've ditched the big ring and mounted the 39t one on the outside of the spider using shorter bolts, left the 7 sprocket freewheel as is and shortened the chain. It's sitting on the 3rd smallest sprocket and the chainline is pretty good, and the chain tension is taken care of by sliding the axle in the dropouts. Even though it's a QR is stays in place.
  • whyamihere wrote:
    Single ring at the front makes it simpler. You probably still need a way of tensioning the chain - The bike that you had as a youngster would probably have had some horizontal adjustment in the dropouts allowing you to pull the wheel back to put tension on the chain. If you have vertical dropouts, you will generally need a tensioner of some kind, but there's options which attach to the derailleur hanger, the chainstay or the BB. Alternatively, depending on your gear ratios, you might get lucky and be able to find an option which gives enough tension without the need for a tensioner.

    Thanks for that, they are vertical dropouts. I'll do a bit more "mulling it over"
  • craker
    craker Posts: 1,739
    You can get half link chains (no experience) or you may get lucky with the tension on a normal chain with vertical dropouts, or you could get a chain tensioner (or an old dererailleur).

    My experience with hacking together ss bikes is the more hacked they are the less good they are as bikes. You could do without chainline woes and tensioners and things like that. Could make a passable beater though.
  • Purely as an example, if you want to set up 3x8 again instead, it will cost you ~£30...
    https://www.halfords.com/cycling/bike-p ... leur-black (default on my Voodoo)
    https://www.halfords.com/cycling/bike-p ... tte-11-34t
    https://www.merlincycles.com/sram-pc850 ... 44531.html

    You might get 10% British Cycling membership discount at Halfords

    A few other cassette options https://www.merlincycles.com/cassettes- ... ed=8-speed , I keep looking at the 13-26 for my Voodoo for smaller jumps between sprockets in a practical range, but I'm not sure what the rear mech will make of the 26T largest sprocket (I've just replaced a ~2.5 year old Shimano HG41(?) 11-30 with another one while fitting a new PC830 chain, but then I fairly regularly go up ~20% inclines with 24/38 chainrings).
    ================
    2020 Voodoo Marasa
    2017 Cube Attain GTC Pro Disc 2016
    2016 Voodoo Wazoo
  • cougie
    cougie Posts: 22,512
    With all the stuff you need to buy it'll be dearer to have it single speed than it would replacing your bits ?
  • cougie wrote:
    With all the stuff you need to buy it'll be dearer to have it single speed than it would replacing your bits ?

    You are probably correct, I will have a think on it, it was the winter bike so have a while to think about it.
  • cougie wrote:
    With all the stuff you need to buy it'll be dearer to have it single speed than it would replacing your bits ?

    You are probably correct, I will have a think on it, it was the winter bike so have a while to think about it.

    What is that you need?
    I am retiring a single speed conversion... I've got nice Campagnolo brake only levers, Alfine chainset with a solid Thorn 42T chainset, chain tensioner, a range of SS sprockets... happy to flog it all at a bargain price
    left the forum March 2023