[Closed] How do suicide shifters work?

what the heck are 'suicide shifters'?

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They're not suicide shifters

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

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.

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.

You're not very old, are you Duane?

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

Of course you can also get indexed downtube shifters.

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

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.

Sorry, I meant unindexed shifters, not mechs.

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 🙂

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

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

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

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. 😉

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...

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.

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).

You can get clamp on cable stops

http://www.google.co.uk/search?hl=en&q=clamp+on+cable+stop&meta=#q=clamp+on+cable+stop&hl=en&prmd=imvns&source=univ&tbm=shop&tbo=u&sa=X&ei=fHfTTtsPjOnRAZ6m4JIP&ved=0CF8QrQQ&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=22236548b89b58ae&biw=1202&bih=562

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

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.

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...

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

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.

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.

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?

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

guess it's lighter?

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

[url= http://davesbikeblog.blogspot.com/2007/06/suicide-shifters.html ]Thanks Dave Moulton.[/url]

APF

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.

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.

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..! 😀

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

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.

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...

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

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.

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

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

Cheers for the replies.

So I'm looking for a friction shifter with oversized (34.9mm I believe) clamp.

Would I be able to run a inner cable going straight from the shifter to the front mech (if top pull), or will there not be enough friction in the system (if they normally use guides etc too?)/cable angled wrong?

Also seen that you can get front mechs with friction shifters built right into them ( http://davesbikeblog.blogspot.com/2007/06/suicide-shifters.html , thanks APF), guessing they're no longer available?

Ta, Duane.

Oh, and if anyone has a suitable shifter for grabs/sale, please let me know 🙂

Lance ran the front shifter on the downtube for weight and cage trimming reasons.

I never knew what it was for, just thought it was some strange set up he liked. Now I know.

I've definately got a shifter in the shed somewhere, pop me an e-mail and I'll chuck it in the post.

For the band you'll need to bear in mind most seatubes are a different diameter for the mech and at the seat clamp. So pick where you want the shifter and measure it with some callipers. It might be easier on the seatpost (if you don't plan to raise or lower it) as 27.2 I think was also the diameter of downtubes on some steel bikes.

Cheers, will drop you an email. Guessing it will just be the normal 28 or 28.6mm though?

Unfortunately I raise and lower the saddle a lot, bike is used for jumping as well as XC (hence wanting this kind of shifter), so really needs to be on the seat tube. Maybe I can bodge something up involving a hose clip or similar?