Viewing 40 posts - 1 through 40 (of 56 total)
  • How do suicide shifters work?
  • Duane…
    Free Member

    As title really.

    Do they work with “standard” modern mechs? If so, how do they hold against the force of the mechs spring, without anyway of locking (like a modern mech does)?
    Same goes for any unindexed mech I guess?

    Ta, Duane.

    JoB
    Free Member

    what the heck are ‘suicide shifters’?

    Duane…
    Free Member

    Steve-Austin
    Free Member

    They’re not suicide shifters

    warpcow
    Free Member

    Mechs aren’t indexed, shifters are (nowadays). It’s a just friction from what I remember of old thumbies.

    goldenwonder
    Free Member

    SO you mean downtube shifters?
    They’re a friction shifter, they rely on the friction of the mechanism in the shifter to hold it in gear.
    Mech’s are indexed anyway, only shifters are.

    nickjb
    Free Member

    They have internal friction to hold the mech. That little D ring on the side turns to tweak the friction. Too much and the mech won’t return, too little and it won’t hold.

    aracer
    Free Member

    You’re not very old, are you Duane?

    ton
    Full Member

    those campag shifter were awesome……only bettered by suntour.

    aracer
    Free Member

    Of course you can also get indexed downtube shifters.

    JoB
    Free Member

    ohhhhhhh, down-tube shifters

    that D-ring on the outside simply tightens up against the lever to provide enough friction against the spring of the derailleur whilst still allowing the lever to move, they were simpler times

    thisisnotaspoon
    Free Member

    The ‘D’ shaped clip on the outside controlls the friction in the shifter, you wind it in untill the friction ballances the spring in the mech.

    Newer ones were indexed so the friction could be less as the ‘clicks’ held it against the mech spring, they usualy still had a switch to turn the indexing on and off as well as friction controll.

    Only refered to a suicide shift on motorbikes IIRC though?

    [edit] beaten to it.

    Duane…
    Free Member

    Sorry, I meant unindexed shifters, not mechs.

    Duane…
    Free Member

    Oh, didn’t realise they weren’t called suicide shifters on bicycles, thought they were.

    And aracer, aye I guess, younger than you anyway, grandad 🙂

    aracer
    Free Member

    Too much and the mech won’t return, too little and it won’t hold.

    Not true – too much just makes it harder effort to shift – the mech doesn’t have to overcome friction at the shifter, just friction in the cables. Those Campag ones pictured I assume are also retrofriction, with a clutch which makes resistance one way much more than the other (to counterbalance mech spring tension).

    Steve-Austin
    Free Member

    Can still buy friction shifters for MTBs. Real simple to use. no maintenance, last forever.


    http://www.tritoncycles.co.uk/m13b331s108p9236/SUNRACE_R90_SLR-R9_Thumbie_Shifter/RS_GB/25036

    I_Ache
    Free Member

    Cant remember where I read it but I think that D ring is used to tighten the shifter and provide friction so they don’t return. 😉

    Duane…
    Free Member

    OK, cheers.

    Basically, I want to fit a shifter to the seattube for a front mech, but don’t have a cable stop, so thinking of bodging a friction shifter to the seattube…

    thisisnotaspoon
    Free Member

    The mechs used to have 2 springs as well, one on the mech like modern ones, and one on the bit where the cable pulled, so you could shift the whole cassette with the shifter, but the spring would just apply gentle tension to the mech only letting it shift up a gear when it engaged the teeth of the next one. Making it possile (in theory, if your brave) to shift down the entire cassette under full power.

    thisisnotaspoon
    Free Member

    Basically, I want to fit a shifter to the seattube for a front mech, but don’t have a cable stop, so thinking of bodging a friction shifter to the seattube…

    I did that, works fine as long as you can get the right size shifter for the seatube or seatpost (and never move the seat post up/down).

    warton
    Free Member

    little known fact. Lance Armstrong used a downtube front mech shifter for all of his 7 tours wins. (not sure if he contuinued with it on his comeback) so yeah, they’ll be compatible with newer mechs

    Big-Dave
    Free Member

    I’ve got one of those old Campag shift levers lurking in a drawer in the garage somewhere. Lovely looking thing.

    I still use downtube shifters on my Cross Check; ultra reliable and easy to set up.

    Steve-Austin
    Free Member

    Basically, I want to fit a shifter to the seattube for a front mech, but don’t have a cable stop, so thinking of bodging a friction shifter to the seattube…

    http://www.billys.co.uk/english/group.php?prod=bsqb-backstops

    Duane…
    Free Member

    Why can’t you move the seat up and down?

    aracer
    Free Member

    The mechs used to have 2 springs as well, one on the mech like modern ones, and one on the bit where the cable pulled

    Not as standard they didn’t – “modern” location of springs goes back a long way. You’re referring to something a bit special there.

    thisisnotaspoon
    Free Member

    Not as standard they didn’t – “modern” location of springs goes back a long way. You’re referring to something a bit special there.

    Will have to dig them out then, 80s shimano ones IIRC. You could pull the lever the whole way but it wouldnt shift untill you started pedaling.

    sam_underhill
    Full Member

    little known fact. Lance Armstrong used a downtube front mech shifter for all of his 7 tours wins. (not sure if he contuinued with it on his comeback) so yeah, they’ll be compatible with newer mechs

    Why?

    iDave
    Free Member

    some of his lightweight climbing bikes had them to save weight. he didn’t use them on all the bikes he used

    5lab
    Full Member

    guess it’s lighter?

    alexpalacefan
    Full Member

    All you need to know about suicide shifters, plus lots of other fascinating facts.

    Thanks Dave Moulton.

    APF

    IanMunro
    Free Member

    IIRC when indexed downtube shifters first came in, quite a few riders wouldn’t use em as the distinctive click meant you couldn’t do a stealth gear change.

    clubber
    Free Member

    little known fact. Lance Armstrong used a downtube front mech shifter for all of his 7 tours wins. (not sure if he contuinued with it on his comeback) so yeah, they’ll be compatible with newer mechs

    He used them because at the time there was no UCI minimum weight limit and they were lighter.

    ourmaninthenorth
    Full Member

    I love seeing the old boys in cross races with their downtube shifters.I have trouble riding and shifting the Ergos on my bars, and these old goats skip past me, one hand on the bars and one getting the shift just right..! 😀

    clubber
    Free Member

    Getting a shift just right on non-indexed downtube shifters was really satisfying. I’d still never change back, mind..

    njee20
    Free Member

    He used them because at the time there was no UCI minimum weight limit and they were lighter.

    Sort of… the 6.8 rule came in in 2000, but bikes weren’t really pushing the limit until a few years later. By 2005 he was on STIs the whole time.

    PaulD
    Free Member

    Lance ran the front shifter on the downtube for weight and cage trimming reasons.
    STI does not trim (DiD does tho’) so you can get cage rubbing at the extremes of the cassette use.
    Talking of which….a certain younger TdF runner-up knows all about chain crossing in the Pyrenees…

    njee20
    Free Member

    There is a trimming click in STIs (Dura Ace ones at least), but it’s obviously not automatic like Di2.

    thisisnotaspoon
    Free Member

    STI does not trim

    My Sora’s trimmed, they had loads of clicks on a ratchet so a big push shifted from one ring to the other, a small click trimmed it in the gear it was in.

    As Njee20 said, DA has 2 big clicks and a minor one for trimming. Both function the same DA just takes marginaly less thought as you can’t accidentlay trim and end up dropping the chain off the big ring as the next click after trimming is to shift into the little ring.

    Andy
    Full Member

    Those Campag ones pictured I assume are also retrofriction, with a clutch which makes resistance one way much more than the other

    Nope just some nylon washers inside to cause the friction.

    The mechs used to have 2 springs as well, one on the mech like modern ones, and one on the bit where the cable pulled

    Nope again – the Record, Nuovo Record and Gran Sport mechs used with these shifters just had a single, quite strong, spring.

Viewing 40 posts - 1 through 40 (of 56 total)

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