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[Closed] Anyone understand 1980s tube-mounted gearing?

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Here's a dumb 'I don't get bike mechanics' question for you expert bike builders to scorn - and then give me some good advice:

The lever controlling my front mech suddenly won't remain in the large cog position; for the past two days it's started to flip back as soon as I've let go... So, why do tube-mounted gear levers slip? And what's the solution?

Cheers, all.


 
Posted : 14/03/2013 9:13 am
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there's normally a nut/screwhead/thumb lever to grab onto on the outside of the lever to adjust the friction level on the lever, try tightening that.

the big one in the middle of this, for example;

[img] [/img]

or the loop of wire on these that flips out to turn;

[img] [/img]


 
Posted : 14/03/2013 9:15 am
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Cheers wwaswas - there is such a screwhead. Can it really be that simple?

You're a star! 😀

It's more like the bottom one - there's a loop of metal, but there's a screw fixing too...


 
Posted : 14/03/2013 9:17 am
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Yep - purely by friction, and it seemed to work fine!

Although there were fancy ones with some new fangled ratchet system to help the friction out, and make a satisfying clicky noise...


 
Posted : 14/03/2013 9:19 am
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go gently - you need just enough friction to conteract the spring force from the mech, not so much you snap the lever trying to change gear 😉

use the loop of metal - the other one holds it all together.


 
Posted : 14/03/2013 9:19 am
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ahhhh nostalgia 🙂

wot they said too BTW


 
Posted : 14/03/2013 9:21 am
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Will do, wwaswas. A little turn at a time until there's enough friction?

Thanks a million!


 
Posted : 14/03/2013 9:22 am
 Solo
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Ah, the memories those pictures ^^^, bring back.

No idexing, just knowing by feel alone, where to pull or push the lever to for another gear.

Being able to flick another rider's lever and then jump away.

The good Ole days.
🙂


 
Posted : 14/03/2013 9:22 am
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ahhhh nostalgia

I'm proper retro, me. 😉

Stylistically, aesthetically and functionally, tube-mounted gear levers from the 1980s on a dark brown metallic Bianchi are definitely the way to go.


 
Posted : 14/03/2013 9:23 am
 ton
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those shifters in the top pic look like simplex...i had some on a puch tourer, they were superbe to use, never missed a shift.


 
Posted : 14/03/2013 9:23 am
 Solo
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[i]Stylistically, aesthetically and functionally, tube-mounted gear levers from the 1980s on a dark brown metallic Bianchi are definitely the way to go[/i]

Technically referred to as bike pron.... Pictures pleeeeeeease.


 
Posted : 14/03/2013 9:24 am
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No pics today, Solo, but I'll sort some out, including some super close-ups of my 1980s SunTours.

That's bike pron with extra cream!

Flipping an old-style gear lever is way more satisfying than flipping a bar-mounted switch. I also own a tape machine, BTW.

Not mine, but close enough:

[img] [/img]

Note the side pull brakes, too. None of your fancy disk brake muck for Camo. 😉


 
Posted : 14/03/2013 9:27 am
 Solo
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[i]SunTours[/i]

Squeal !.

I had Sun tour on my 80s Raleigh GT10 road bike, in Silver and blue.
I loved that bike, rode it even after the frame broke. But it had to be retired when the crank fell out on the way to school one morning.


 
Posted : 14/03/2013 9:35 am
 Solo
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[i]I also own a tape machine, BTW[/i]

Please elaborate.

I recently discovered some very nice leather bar tapes made by a chap, the name for whom I could only deduce as "[i]busy man[/i]".

[img] [/img]

[img] [/img]


 
Posted : 14/03/2013 9:37 am
 Solo
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[img] [/img]

😉


 
Posted : 14/03/2013 9:48 am
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Blimey those are some pimped up gear levers. It's metal polish for my babies tonight. 😉

I also own a tape machine, BTW

Please elaborate.

This one actually is mine - mankind's useful technological evolution ended with the Philips Pocket Memo. Every household should have one.

[img] https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcRTLLr4I_AJvK5sf9C9569IcD7TDsuTKdMByoOMKcQW76k04UQO [/img]


 
Posted : 14/03/2013 9:52 am
 sbob
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It's more like the bottom one - there's a loop of metal, but there's a screw fixing too

The loop of metal is for switching between indexed and friction gears, the centre fixing is for tension.

ETA: for the Shimano ones pictured.
Ah, front mech. They weren't indexed, were they?


 
Posted : 14/03/2013 12:01 pm
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The loop of metal is for switching between indexed and friction gears, the centre fixing is for tension.

Imagine you're talking to an idiot... does this mean I have to tighten the centre fixing, or meddle with the loop of metal? I don't think the gears are indexed...


 
Posted : 14/03/2013 12:07 pm
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If it's proper 80's they'll be for the friction - they hadn't invented indexing 😉

try the loop first and see how you get on would be my advice. Don't force it but turn it a bit and see if the lever feel changes.


 
Posted : 14/03/2013 12:10 pm
 sbob
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If they are Shimano, you should be able to twist the loop clockwise (at least on the right hand side for the rear mech) to enable indexed shifting.
To stop them slipping you tighten the screw in the middle.
I think.
It has been over twenty years...


 
Posted : 14/03/2013 12:11 pm
 sbob
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wwaswas - Member

If it's proper 80's they'll be for the friction - they hadn't invented indexing

1984


 
Posted : 14/03/2013 12:15 pm
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I had dura ace shifters on an old peugeot. Bike was too big, but the shift was lovely. I now have an old PA10 frame in the basement waiting for some love and attention...


 
Posted : 14/03/2013 12:16 pm
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Brilliant advice. Thanks all.

It's a Sun Tour from around 1984. I'll try the loop first and then tighten gradually.

Been riding all my life and I'm beginning to realise I know nothing about bikes... 😳


 
Posted : 14/03/2013 12:16 pm
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I love downtube and bar-mounted thumbshifters! OP In several models there is a split washer which is why you don't need a lot of tightening to increase the friction and hold the shifter in place against the force of the derailleur spring.

J


 
Posted : 14/03/2013 12:18 pm
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Okay, so tiny turns then it is. Ta!


 
Posted : 14/03/2013 12:18 pm
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Dopio posto.


 
Posted : 14/03/2013 12:19 pm
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Sheldon knows;

[i]
In 1985 Shimano introduced indexed SIS shifting. Sun Tour underestimated the need for a competing product and postponed development of an indexed system until 1986, at which point SIS had become quite popular. [/i]

so if it's 1984 Suntour it's friction only.


 
Posted : 14/03/2013 12:22 pm
 sbob
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camo16 - Member

Brilliant advice. Thanks all.

It's a Sun Tour from around 1984.

In that case I don't think they will be indexed as Suntour didn't release their Accushift indexed levers until 1987, so the centre screw is possibly just for mounting onto the frame, and the wire D-ring is for adjusting tension, as mentioned in the first reply. 😳

(Though in my defence, the D-ring pictured on the 105 shifters is for switching between indexed and friction, I have them on my Peugeot road bike from many, many moons ago.)


 
Posted : 14/03/2013 12:23 pm
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Another stupid question - if it's friction only (I'm not absolutely positively 100% sure the levers weren't upgraded after 1984, but they look contemporary with the bike), what are the metal loops for?

Cheers in advance wwaswas and sbob - I know you'll know the answer!

EDIT: Ah - so this 'd ring' is the adjustor!


 
Posted : 14/03/2013 12:24 pm
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[i]Ah - this 'd ring' is the adjustor! [/i]

yep. In theory you could do it whilst riding along. I nearly fell off whenever I tried.


 
Posted : 14/03/2013 12:27 pm
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wwaswas, thanks again. My faith in the power of STW has never been stronger!


 
Posted : 14/03/2013 12:28 pm
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Daydreaming question...........

Could SRAM doubletap TT shifters be downtube mounted?

I've an old steel frame away with the LBS for some more forcefull extraction of siezed BB/seatpost/headset than my home tools could manage. I'm thinking 10s doubletap for no good reason other than I (possibly) can.


 
Posted : 14/03/2013 12:32 pm
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I'll fret the whole lever will self destruct as soon as you touch the adjuster now...


 
Posted : 14/03/2013 12:32 pm
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Fret not!

The worst thing that's going to happen is the lever doesn't work. It doesn't work now. At least my terror of fiddling with the lever has diminished...

Care will be taken. 😉


 
Posted : 14/03/2013 12:34 pm
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Kudos must be paid to wwaswas and others ^^^^ Tightening the d ring did the trick and I have my big gear back! Huzzah!

Thanks all.


 
Posted : 15/03/2013 9:35 am
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phew

🙂


 
Posted : 15/03/2013 1:34 pm

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