Front Derailluer problem

supergunn
supergunn Posts: 59
edited June 2011 in The workshop
Hi Guys ,
Hope you can help,
I bought a Raleigh Pioneer Classic hybrid 15 speed bike for the commute to work to save my Kona MBT from taking a beating.
I paid £30.00 for it and it is in excellent condition with not a mark in the paintwork.
The crank and chain looked a bit rusty so I decided to replace them starting with the chain.
The new chain gave me a skipping problem on the rear cassette so after a bit of research I changed the rear cassette and this solved the problem.
I then decided to change the crankset which was a 48T with steel plastic coated cranks.
I replaced it with a Shimano tourney FC M191 also a 48T only with alloy cranks.
This gave me a new problem where the chain would not shift to the large chainring.
After repositioning the front derailleur ( Had to take it down the seat tube a bit ) and a bit of tweaking I can now just about get the derailluer to shift to the large chainring but this takes a fair bit of effort on the twist grip and I'm still getting a very slight rubbing.
It's as if the derailluer has reached it's maximum swing , the adjustment screw is unscrewed to the max.
The front derailluer is a TY-15 6s
The Shimano tech website states that the FD-301 Nexave derailluer is compatible.
Are there any other derailluers that would be compatible with this crankset.
I changed the brakes for deore V brakes and levers that I had in the toolbox and serviced the bottom bracket and hubs with new bearings and also replaced the tyres.
Apart from the shifting problem the bike is like new and takes me to work and back so much better than the Kona MTB ever did.
It's quicker and the ride is not as harsh.
I know it's not the best of commuting bikes but I'm really liking it.
Kind Regards
supergunn

Comments

  • neilvx
    neilvx Posts: 137
    does the twist grip take the derailleur upto the shift stop screw, is the cable tight enough to give it the full movement it requires?
    Cube Reaction GTC Pro 27.5 2017 Grey / Yellow Flash
    Ribble R872 Ultegra
    Skyway BMX
  • supergunn
    supergunn Posts: 59
    Hi Neilvx,

    Yep the cable is really tight
  • neilvx
    neilvx Posts: 137
    Does it stop screw?
    Cube Reaction GTC Pro 27.5 2017 Grey / Yellow Flash
    Ribble R872 Ultegra
    Skyway BMX
  • supergunn
    supergunn Posts: 59
    If I unscrew any further it will come out of the derailluer body .
    It's unscrewed to the max.
  • neilvx
    neilvx Posts: 137
    But can you see if the arm is hitting the stop screw or not?
    Cube Reaction GTC Pro 27.5 2017 Grey / Yellow Flash
    Ribble R872 Ultegra
    Skyway BMX
  • desweller
    desweller Posts: 5,175
    Try adding a bit more tension to the cable. The limit screws are only there to prevent you from accidentally derailling the chain off the chainring altogether.
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  • Vegeeta
    Vegeeta Posts: 6,411
    It is likely that if you have fitted a Shimano chainset to the bike you will require a shorter bottom bracket spindle by 2-4mm as is often the case when moving from something cheaper.

    The best way to check is to shift into the smallest ring at the front and remove the cable. Then unwind the lower limit screw as far as it will go.

    If you find the derailleur will move in by say 5mm, then you could probably get away with a 3-4mm shorter bottom bracket and so on. Just be sure to measure the gap between any chainrings and the frame.
    Rule 64:

    Cornering confidence generally increases with time and experience. This pattern continues until it falls sharply and suddenly.

    http://www.velominati.com/blog/the-rules/
  • supergunn
    supergunn Posts: 59
    Hi Guys,

    Thanks for all your help.

    Ok so this is where I am.

    I bought a new gear cable and and pulled the outer part of the cage to make it slightly wider.
    I can change from small ring to middle ring but won't go to large ring.
    or I can change from middle ring to large ring but it wont go to small ring.

    I still think the derailluer does not have a large enough swing span if you know what I mean.

    I think the derailluer is not compatible with this crankset and I will need to change it.

    What do you think
  • optimisticbiker
    optimisticbiker Posts: 1,657
    Assuming its hitting the stop screws at each end of travel then you've answered your own question... if not wind them out more... of course then it could be that the front shifter can't take up enough pull in the cable to move it far enough over...
    Invacare Spectra Plus electric wheelchair, max speed 4mph :cry:
  • supergunn
    supergunn Posts: 59
    Hi,

    The limit screws are properly set and the rotation is correct.

    Iv'e now managed to get it to shift to all three chainrings.

    It will shift most of the time depending what gear you are in.
    With some of the gears it wont shift to the lower ring but a change of gear on the rear derailluer makes it shift.
    Once it's on the small ring the gears all change ok

    I will persevere with this for the time being until I get a new front mech the one shimano recommends.
    It's ok in the middle and large rings which I use most often and all gears are changing on these rings .

    Kind Regards
    supergunn.

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