Shifter Question

[mtnbikinbryno]

I have a shifter question for a bike that I just bought used. It has LX rapidfires for both, but it's either mis-adjusted or broken. It's like this...... when I'm in the middle chainring trying to shift up into the big one, it's like there's nothing there when I push with my thumb until WAY deep into the push, then there's pressure again, but by that time I've run out of shifter and there's not enough room for it to shift. If I'm in the small ring, there's tension right away and it shifts perfectly into the middle. It's the same story on the rear one.... on the small gears it shifts perfectly until I try to shift into the big ones. Anyone know what's going on? I'd appreciate advice on if I need to get new ones.... otherwise, if someone knows how to fix it, please let me know... otherwise it's off to Freewheeler I go. Thanks!

Brian

[Ecruz]

it may just need lubed. i was having the same thing happen with my xt's. from what i understand, the lube in there either dries out or evaporates or or something and then things just don't work right. i just took the little screw out, shot some tri-flow in there and it's been perfect since.

good luck

[Iluvdirtandrox]

i have had that happen too. when i try to shift up from the middle ring to the big, you can push the shifter almost all the way in b4 having pressure... i just push it in all the way once and then a second push gets pressure almost right away. maybe my shifters are out of adjustment too, but i heard that is just what happens with rapid fires... you may have to push it twice. it doesn't matter so much to me now cuz i got SRAM XO grip shifters for Christmas! i hope you get used to the double push on that one gear, it always seems to do the trick for me!

[Justin 4.0]

Check the cable as well. I had a cable get a kink in it right before it went into the houseing and caused shifting delays and other misshift problems. Another thing is to check as see hose well the cable moves through your housing. I've seen a world of difference in shifting performance just from lubing the cable.

[LITW]

I’m not sure all of the Shimano rapid fires are the same because I haven’t worked on all of the different ones LX, XT, XTR etc. but my guess is that they are very similar. Inside the shifter there is a pawl and gear mechanism. When you push on the big paddle, the pawl rotates and contacts a gear, the gear is essentially attached to the cable and it pulls it. There is a little more to it than that, but these are the basics. The factory goops up the insides pretty good with grease. When it gets cold outside or the inside of the shifter just gets too dirty over time, the condition you are describing can occur. When this happens, the pawl has a hard time engaging the gear. They just need taken apart and cleaned. Just be careful, there are some small parts that may want to fall and hide somewhere on your floor.

From your description, this sounds like this may be your problem.

[Hippy]

I do not like the rapid fires for that reason and because it made my wrists constantly sprained from having them in an unnatural position on my handlebars when shifting on the fly. I switched to SRAM rocket shorty and will never go back!

[mtnbikinbryno]

Cool, thanks for the responses guys. I'll try to lube 'er up. Hippy's response gave me another question...... how many people use the SRAM grip shift shifters? If I can't get these rapidfires fixed I might consider a pair of them. What are the pros and cons of them? How does everyone like 'em? Thanks

Brian

PS... if switching from shimano to SRAM, do you have to change derailleurs, cassette, and chain to SRAM?

[Ecruz]

i had gripshifts and went back to rapidfire. i think the gripshifts put your wrists in akward positions. especially if you're changing two or three gears at a time, you have to wrench your hand halfway around the handlebar.

[Rod]

SOunds to me to be the classic to much cable slack. If they are brand new then most likely the cables have strecthed or whoever built the bike didn't tighten down the cap screws enough to hold the cable in place.

HOW TO FIX:

1. First start with the rear der.
2. untighten the socket head cap screw holding the cable (Ill just call it a bolt)
3. shift down to the smallest rear gear.
4. screw the phillips adjustment screw marked H until the top cog on the der is directly in line with the small cog in the rear cogs.
5. tighten the adjustment barrel at the rear shifter and the rear der. all the way back in and then screw it back out about two full turns.
6. pull the cable tight and tighten the cable bolt at the rear der so there is no slack in the cable.
7. now shift the rear der. all the way to the second biggest cog
8. use the adjuster barrel at the rear der to align the top cog of the der to the second biggest cog you just shifted to.
9. once that is in line shift to the biggest cog and adjust the phillips screw maked with a L until it is in line with the big cog on the stack. REAR IS ALL DONE.
10. Leaving the rear der. in the biggest cog, shift the front der. all the way down to the smallest cog.
11. loosen the bolt holding the cable
12. tighten the adjustment barrel at the front shifter all the way back in and then screw it back out about two full turns.
13. screw the phillips screw farthest away from the frame until the der is close to rubbing the chain (1/8" or so)
14. Tighten the bolt back down with the cable tight.
15. Shift to the middle ring and use the adjustment barrel on the shifter to get the der. within 1/8" of the chain with it still in the big cog
16. Shift into the big ring in the front and the smallest in the back, adjust the phillips screw closest to the frame until the der will shift quickly into the big ring but won't overshift off the big cog.

You should now have a near perfect drivertrain setup. I'm sure other people have other "simpler" ways to adjust the gears but after six years of solid bike assembly this makes for the quickest and easiest drive train set-up.

SRAM setup will work the same way.

I personally prefer SRAM XO for my cross country bike and XTR or XT trigger shift for freeride applications. (Bunny hopping, juping, push pull causes me to accidentally shift with SRAM). It happens a bit on my XC bike too but its very rare.

Rod Harper

[LITW]

I guess what I meant to say is that the factory puts a little too much grease in the mechanism. I would clean them up and use light grease sparingly. Some people think if a little lube is good more is better. When it comes to lubing things, this is not the case. Grease cuts down friction, but it also collects and holds dirt. If it is on the surface you want to reduce the friction on, fine, but just having a blob of it sitting in the housing doing nothing but attracting dirt doesn’t do any good.

I have used and worked on both Shimano rapid fires and SRAM grip shift. My experience with grip shift is with very old models. I’m sure the new stuff has changed quite a bit. I would say rapid fire versus grip shift is just a matter of preference. They both need maintenance now and then and you can get both to work well. It is all a matter of what feels best for you. I have heard, but don’t know this for a fact, that some models of the SRAM grip shifters do not work that well with a Shimano derailleur. The folks I talked to said that they had to go to a SRAM rear derailleur to get the best performance. I would ask a mechanic at a bike shop you trust to make sure before you spend any money.

[MiMtnBiker]

I have noting but SRAM on all of my bikes and love it. You can get SRAM shifters (Attacks) that will work with Shimano derailluers but if you want performance that beats shimano you really need to go to their ESP system. It shifts much cleaner and faster than shamino and eliminates the big cable loop that causes so much drag on shimano rear derailluers. The new XO is awsome and the shifter derailluer combo if lighter than XTR. It's also much cheaper than the new XTR.

[mtnbikinbryno]

Thanks to everyone who responded. Thanks to Rod especially, those instructions were easy and worked great!

Brian

[Rod]

Brian:

Glad to see it worked! If your racing at Yankee Springs TT, look for the guy with the black Giant NRS with a Red/White/Black Jack's Bicycle jersey and give me a hollar. Have a good one and enjoy the warm weather!

Rod