Bicycle Mechanics - problem with shifter

sorry in advance but i just realized i should posted it in this thread and not in the road thread

ok i rebuilt my bike today on a new frame and everything by fluke was perfect. the headset fit.. my BB happened to be italian threads which is what i needed. i had to by a brazeon FD tho. o well 25bux CDN for Shimano 600EX. not bad.

The problem i am having is with the shifters. They are DT Shimano 600 shifters. They are downtube. The front one works fine but the back on now when I try to shift it up to the larger cogs it just springs right back and goes to the smallest cog. The shifter is dual mode (SIS and friction). When i try to shift the shifter just gets looser and looser and even when tightening the screw it just gets looser. I also cant recover my SIS shifting from turning the thing. The result is it will just come loose. Can someone please tell me what i did and how do i fix it as i kinda need to shift. When i transferred parts i was sure to keep them organized and put them back just as i took them off. Thanks. BTW its not the derailleur cuz i had the friction shifting working for 5 minutes and then it crapped out on me again. I cant get SIS to work or shifting to work now. Thanks

I wonder if the shifter is on in an incorrect orientation. Referring to the spacer that goes over the shifter mount before you put the shift lever on: it has one big "key" on it, and this should be on the headtube-side of the stud. Those old 600 shifters could go all the way around if I recall correctly, so it could be 180 degrees backwards. Take the shift lever off and see if that could be the case.

It could also be that the indexing insert which has the D-ring on it has lost its "teeth," that shift lever seemed prone to this problem. These "teeth" mesh with the aforementioned spacer, and if they break, the shifter is going to turn under the tension of the derailleur cable. If this is the case, you'd need to find a shifter to cannibalize for the insert.

that could actually be it cuz i saw 2 little pieces of metal fall outta the shifter.
i know the orientation is correct because on the first part that goes in the frame there is a little stop.. only if its backward will the shifter not work. since its the right way the shifter spins right it just doesnt shift

do i need to replace the whole shifter?

Yes, unless you can find an old shift lever you can cannibalize, or perhaps (by some bizzare chance) your shop has the replacement index chunk lying in a forgotten drawer somewhere. Or perhaps you have some spare 6sp downtube shifters of another model, like some old Exage ones?

grrrrrrrrr ok

my next question is if anyone here has a spare 6 speed Shimano 600 DT shifter that they could give or sell to me.

Bet you could get some action on that in the Wanted forum, someone's bound to have some (hopefully in Canada) :)

any shimano 7 speed dwontube shifter other Than DA will also work with your 600 read derailer.Shimano 6 and 7 speed index spacing is the same.

so ill just have an extra click.. i dont even care for indexed as i dont like it on DT shifters. even friction is fine

umm i can pick up 8 speed shifters tomorrow if they work.. if i set 8 speed RX100 shifters to friction mode will it work or not. does spacing count on friction or will 8 speed friction work.

Originally posted by pokey
any shimano 7 speed dwontube shifter other Than DA will also work with your 600 read derailer.Shimano 6 and 7 speed index spacing is the same.
You might want to double-check that. I've seen plenty of situations where a Shimano 6sp cluster got onto a bike with a Shimano 7sp shifter somehow, and they just don't sync. 7 and 8 are essentially spaced the same, however... I remember back in the day, we weight weenies would buy the new-fangled 8sp XTR cassette (woooo, aluminum core! :D) and take out the 13T cog so we could run it on our 7sp freehub bodies. :)

ill ask my boss tomorrow.. look i dont need SIS, only friction.. in that case will 6,7,8 speed make a difference?

Originally posted by mechBgon
Yes, unless you can find an old shift lever you can cannibalize, or perhaps (by some bizzare chance) your shop has the replacement index chunk lying in a forgotten drawer somewhere. Or perhaps you have some spare 6sp downtube shifters of another model, like some old Exage ones?

Sorry, I don't recognize the model of shifter you mention, but it sounds like you have friction shifters. The pars that fell out was probably the friction cup. It is round and has a round hole in the middle. It will be slightly convex (or concave depending on how you look at it).

If you can't find the friction cup, replace it. IF you can't find replacement friction cups, you're screwed and the easiest solution would be to replace the shifters.

Go to the local dump or thrift shop and see if you can find a bike with shifters that might have the friction cups you need. Since you have Shimano shifters, you might be lucky.

i got dual mode shifters. u turn the knob and it goes from friction to SIS. I lost the teeth as was mentioned before as i remember 3 little square pieces of metal falling into my hand. i didnt know what they were for and i threw them out. im gonna look for some shifter parts at the shop today as i gotta lot of old stuff there.

Originally posted by WorldIRC
my next question is if anyone here has a spare 6 speed Shimano 600 DT shifter that they could give or sell to me. I would try the good people at www.thethirdhand.com
They have a good inventory of small and hard to find parts, especially for older gear.

Originally posted by WorldIRC
i got dual mode shifters. u turn the knob and it goes from friction to SIS. I lost the teeth as was mentioned before as i remember 3 little square pieces of metal falling into my hand. i didnt know what they were for and i threw them out. im gonna look for some shifter parts at the shop today as i gotta lot of old stuff there.

Oh Man! Never throw away a part just because you don't know where it goes. That's almost funny.

That rule goes for anything, but especially so for bicycles. Every component has a very important function on a bicycle.

In the case of this 1985-era shifter, the little bits fall out because they've broken off. :(

yah hes right.. if the teeth fall out u cant fix it.

In all cases, i found a set of 8 speed Shimano 600 DT shifters. Ill set the rear one to friction mode and all should be good. I dont need the SIS anyways as i dont like it on DT shifters. If 8 speed friction wont work with my 6 speed someone please tell me b4 i waste my time.

Almost any friction shifter works with almost any derailleur, provided that it provides sufficient cable take-up over its range of motion. (I once adapted a Schwinn TwinStick to handle a 7-speed freewheel by filing a few mm off of the stop.) Never throw away a friction shifter -- you will need it the day you finally realize that most indexed systems are temperamental, short-lived, and unreliable.

its true.. oh yah it worked btw. i used a 8 speed on a 6 speed. i dont like DT SIS shifting feel anyways.. not like rapidfire at all. so ill be fine on SIS. but hey, now if i wanna upgrade to 8 speed, i dont need STI shifters. Ill use DT shifters since i got it.. Oh well.. 6 is enough for now

I actually got fairly good at shifting with (yes, I know this sounds crazy) my knee. Jumping out of the saddle, I could rev out the 14, *boink* 13, *boink* 12, thanks to the indexing landing it in gear for me. Or I could easily *boink* the left side from the big ring to small just as I prepared to sit down after a bit of out-of-the-saddle effort, like topping a hill. Poor man's STI... :) Of course, not everyone has the right leg length for this. ;)