How can I put the derailleur on left side?

Discussion in 'Bicycle Mechanics and Repairs' started by stuee147, 11 May 2014.

  1. Archie_tect

    Archie_tect De Skieven Architek... aka Penfold

    That's a brilliant idea zack... it would remove the need for the inefficient long chain, reduce friction on the drive and simplify recumbent bikes in one fell swoop.:smile:

    Having thought about it a bit more.... front wheel drive would be better but would need a bit more technology to steer the driving wheels, which would then need to be bigger.... it's starting to unravel now...
    Last edited: 12 May 2014
    Illaveago likes this.
  2. I've seen the stuff you do in other threads, and am amazed by your skill and ingenuity, but I think the deal breaker in this would be the freehub/freewheel block. Put it on the left hand side and it'll only work in reverse! At least it does when I try to do this in my head. Maybe it's different in real life.

    If I've understood you properly, you want this is because last chain ring before the chain goes to the back will be on the left, and on the RH side of that BB will be a chain ring connected to the triple at the front. Surely it would be easier to flip the triple at the front to the other side, and flip the middle BB round, so that the last chain ring before the chain goes to the back is on the right as normal? I imagine wrong-sided front derailleurs would be much easier to make than wrong sided rears. Or have I misunderstood?
  3. Archie_tect

    Archie_tect De Skieven Architek... aka Penfold

    Could you just put tandem gear on it to avoid the crossover with another compact chain ring on the pedal set to get an extra set of gearing ...shouldn't have any worse drag or friction than a tandem set-up would?
    Last edited: 12 May 2014
    classic33 likes this.
  4. RecordAceFromNew

    RecordAceFromNew Swinging Member

    West London
    If I understand it correctly, the only thing as proposed that is unusual and on the left is the triple up front, driving a single on the left in the middle (presumably there is a tensioner), which drives directly another triple at the middle this time on the right, which in turn drives a conventional rear train again on the right as normal.

    The challenge of that is if the front mech for the front triple is mounted upside down (so that it is on the left) it will be facing backwards in terms of chain direction since it has to be rotated 120 degree to derail the driven/upper chain.

    If I were you what I would consider is to keep the triple in front on the right and let the chain drive the inner or outer ring of a triple/quad* chainset at the middle again on the right, leaving 2/3 rings driving the rear conventionally. You will having to play with bb/chainring spacers/bolts to ensure no clash between the two chains, but it is simple, cheap and should be efficient.

    * via a triplizer ring e.g. With a trike I would have thought you have quite a bit of freedom re chainline.
  5. OP

    stuee147 Senior Member

    north ayrshire
    iv thought of that but i think a delta trike with that method would work best as in my experience rear steering is a bit tricky on the roads, and best suited to a trike im thinking of doing just for off road with suspension front and rear and having rear steer for manoeuvring around trees and tight turns

    :blush: thanks but i think its more luck than skill lol you dont see the 20 attempts that failed loln

    i think i have confused most folk on here what im thinking is getting a standard rear section of bike with gears chain pedals ect then remove the pedal on the left and fit a single gear this would be driven by a second bottom bracket on the left at the front and i was thinking of using a old rear deraillier to provide tension on the chain so its just changing the gears on the front triple.
    i have been thinking of turning the derallier upside down and then maybe making new chain guide arms. it seems to work but im not sure how to make strong enough guide arms,

    iv never thought of a tandem gearing ill have to look at that iv no experience in tandems yet lol

    i did have an idea last night i thought maybe try and make up spacers and bolts to fix a 4th gear to the triple on the rear half of the trike that will still give me what im after with the normal, extra low and extra high gear sets but all the gearing and chains will be on the right it should make it easier i just need to work out where the chains will run and how far out it will be under the seat. its just another idea iv had but i always look forward to anyone else's input

  6. OP

    stuee147 Senior Member

    north ayrshire
    thats just the sort of idea i had last night lol and yea i do have a good area to play with for the chain run ^_^
  7. Duh. I see, sorry.
    stuee147 likes this.
  8. OP

    stuee147 Senior Member

    north ayrshire
    dont worry i get myself confused all the time as you can tell from some of my posts lol
    Illaveago and Dogtrousers like this.
  9. voyager

    voyager E- tadpole Triker

    Just read this thread
    There are other ways to get over the gear ratio problems without resorting to these measures that can be done at home .

    RX4ray on the AZ site and I have experimented with dual rear mechs and a Jackshaft this combination would allow if developed further could make an interesting low cost alternative . Quite happy to expand on the way it can be done ( more details on my 20/20 e-trike thread on AZ shows an easy to build jackshaft that drives all the way down on the right .and fits in the bottom bracket position on the MTB rear triangle .
    The reason I used a 21t take off cog was I was using ( like Ray ) 20" wheels and the maths are 26/20 = 21/16 for a standard final drive .
    I converted a 6 speed freewheel less pawls to a 4 speed with 21t take off ( to correct the gearing and be a totally free freewheel ) this requires disassembly of the freewheel and rearrangement of the sprockets . That gave me 12 speed with the triple on the front ( 16 withn a quad ), IF the 21 ( on 26" wheels was changed to 18 or 20 and drove a 7speed 11 to 32 freewheel on the rear whee from the take off cog l then 84 gears would be available from very low silly gears to super high of 140" plus ratios .
    There are other little opportunities to watch out for but if this is the way for you to progress then PM me
    regards emma
  10. Hey Brian,
    What Derailleur did you use for your left hand drive bicycle? Or did you have to build it? I'm building a reverse bicycle for a university project and this is one of the last components I need.

  11. Ian H

    Ian H Guru

    It might be possible to remove the side plates from a front derailleur and fabricate a pair of mirror-image ones. The mechanism itself should work adequately in reverse. You might need to change the angle at which it's mounted.
    Illaveago and ReverseBike like this.
  12. youngoldbloke

    youngoldbloke The older I get, the faster I used to be ...

    I think he's managed to fit LH brakes too ;)
    Illaveago likes this.
  13. winjim

    winjim A youth of interminable age

    He's even got a left handed bird bath.
  14. Ajax Bay

    Ajax Bay Veteran

    East Devon
    By using a longer chain you could set the chain up in a figure of 8 - with the tensioned section of the chain running from the top of the chain ring to the bottom of the cassette (rear flipped round obv) - and with a bit of fabrication mount a 'normal derailleur' upside down to allow rear sprocket changing and sufficient chain tension (cage axis might need a stronger spring). The freewheel/freehub pawls would work 'as normal'. Probability of some chain rub here and there but not project threatening. Maybe best with a 5 speed freewheel to minimise the chainline angles (more risk of chain coming off the chain ring without the benefit and with the detriment of gravity) or when proving it at the project demonstration, limit rear sprocket changing to the three middle sprockets. Would need a braze on cable stop on the left chainstay.

    This could allow the bike to operate as designed: in reverse (so maybe add some stabilisers onto the back dropouts).
    Edit: I think the presentation at the end of the OP's project could be highly entertaining.
    Last edited: 27 Feb 2018
  15. Why?
    Illaveago likes this.
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