Mtn bike tune-up

Post by **Legacy777** » Fri Jun 09, 2006 2:52 am

I played hookie from work today. Ran some errands, and tuned-up the bike.

It has been neglected for a long while. I polished the aluminum, so it looks a little better. It wasn't a great job, but ok.

For some reason the front shifter won't go into the largest front sprocket. I think the mechanism on the handle bars is toast. But the brake & shifter mechanism is all in one....so I'm not overly eager to replace it. I need some new rear brake pads, but other then that....it's not in too bad of shape for a 10 year old bike

http://www.main.experiencetherave.com:8 ... /bike1.jpg
http://www.main.experiencetherave.com:8 ... /bike2.jpg
http://www.main.experiencetherave.com:8 ... /bike3.jpg
http://www.main.experiencetherave.com:8 ... /bike4.jpg

G-reg · Post by **G-reg** » Fri Jun 09, 2006 5:24 am

Some old school cool right there. If your shifting problem is really at the shifter, take the plastic off the bottom of the shifter and lube up the "Pawls" inside. On older Rapidfire shifters the grease gets old and cakes up and keeps the ratcheting mechanism from working.

scottzg · Post by **scottzg** » Fri Jun 09, 2006 6:57 am

you know you can adjust the outside limits of the deraileur with those two screws on top of the polygon, right?

All_talk · Post by **All_talk** » Fri Jun 09, 2006 3:37 pm

I've got a GT K2 of the same vintage (mine's a '90 or '91 I think), I havent had mine out in a few years, maybe I give it a tune-up and go for a ride (I could use the exercize).

Gary

BAC5.2 · Post by **BAC5.2** » Fri Jun 09, 2006 3:46 pm

Goodness, I was a bike tech for some 6 years.

Replace the shifter cable if you haven't done so in a few months (or year, if you don't ride often).

For derailluer adjustments, shift into the smallest chainring and the largest rear cog. This is the farthest towards the inside that the chain will go. Turn the limit screw in to push the cage away from the seatpost.

Which limit screw is it? It's usually the outermost screw for the LOW adjust. It should usually say what screw adjusts what.

Now, you've set the inner limit. There should be VERY little cable tension at this point. But it shouldn't be floppy.

You should have about 1 to 1.5mm between the cage and the chain.

Pedal the bike and put it in the smallest cog in the rear and the largest chainring up front.

Set the limit the same way. You want about the same amount of room, though a little less is OK.

If it WON'T shift up, you might just have far to great cable tension.

When you install the shifter cables, shoot some lube into the housings.

Despite what any random bike shop punk might tell you, there is an incredible benefit to using really high quality cables and housings. The absolute BEST cables I have used on my bikes were made by GORE (the company that produces Gore-Tex products). They were something like $17 for both derailluer cables, but they were amazing. The second best were Shimano XTR's, but I had to solder the tip and dip it in plasti-goo instead of using standard crimps. They are teflon coated, and surprisingly nice. They are like $8 each.

Another tip, use deraileur housing for brake cables. Your brake feel will increase an incredible amount, because the housing won't flex as much. Standard brake housing is like a big coil of flat wire. Deraileur housing is a lot of wire strands run laterally. Deraileur housing doesn't compress like brake housing does.

Post by **Legacy777** » Fri Jun 09, 2006 6:26 pm

G-reg wrote:Some old school cool right there. If your shifting problem is really at the shifter, take the plastic off the bottom of the shifter and lube up the "Pawls" inside. On older Rapidfire shifters the grease gets old and cakes up and keeps the ratcheting mechanism from working.

It is in the shifter. I tried taking the screw off, but appears to be stripped, and I'm not sure if I want to try and force it, and have a completely broke shifter. I may decide to play with it. We'll see.

Post by **Legacy777** » Fri Jun 09, 2006 6:31 pm

Thanks for the comments guys. I definitely know how to tune up a bike, and do all the adjustments. I've been messing with them since the mid 90's.

The cables probably could use to be replaced, but for how much I ride currently, it's not worth the money. I lubed everything up yesterday, and shifting is fine, other then the shifter mechanism on the handle bar being broken or gunked up.

If I move to some place where I can ride more often, I'll probably end up getting a new bike....or possibly outfitting this frame with new stuff....but it'd probably be better to just buy a new one.

I'd really like disc brakes.....I've always hated adjusting the brake pads.

206er · Post by **206er** » Fri Jun 09, 2006 9:00 pm

nice, onza bar ends and a mag 21. those were sweet back in the day. RE the shifter stickiness, you might spray the crap out of it with WD40 through the cable access hole while running it through the gears.
guess what, I run that exxact same LX groupe on my trailbike today. it was in my spare parts box, and after trashing a couple 9sp parts, I returned to the worn out old LX stuff and 8sp, and I actually prefer the shifting(with a near new cogset and chain). a friend of mine runs old 8sp xtr with a dura ace derailleur on his DH bike and it shifts awesome even with a full length cable housing.
replacing the cables and housings is definitely a good idea, but I bet you would see an improvement as well from just cleaining them out really well and re lubing with something like dumonde-tech or a good teflon lube.
BAC, I agree those gore cables are EXCELLENT especially in a muddy area. have you tried the new avid housing that is super stiff? my dad runs it on his titus and loves the shifting.
I just got my trailbike running again yesterday after I busted the derailleur hanger about 3 months ago on a climb. had to talk the bike shop into even trying to order one since they werent a giant dealer.

Post by **Legacy777** » Sat Jun 10, 2006 12:14 am

The cables are fine.....it's the shifter. I'll probably take a look at it again tomorrow.

G-reg · Post by **G-reg** » Sat Jun 10, 2006 3:11 pm

I've got to disagree with BAC regarding some of his cable advice. Gore cables were over priced and not much of an advantage in 1996, that's just an opinion though. Using derail housing as brake housing on the other hand is flat out wrong. Derail housing is not even kind of designed to take the forces from brakes. The Derail housing will blow out and leave you with nothing. Getting the most out of cables has more to do with the initial set up and install than anything else.

206er · Post by **206er** » Sat Jun 10, 2006 11:36 pm

yeah, derailleur housing for brakes? yuck. probably take about 2 rides for pieces of wire to be poking through your ferrules.
here's a good way to run the rearmost housing for the derailler that has the nasty curve: put a metal noodle from v-brakes on the derailler and run your housing from that.

Post by **Legacy777** » Sun Jun 11, 2006 1:42 am

Got things fixed.

The cog that ratchets and hooks the gear has a spring that keeps it against the gear. The spring was worn. I bent it so it keeps in contact with the gear.

Also the housing that the screw goes into was just spinning around....so things weren't tight.....which I think may have contributed to the issue.

Here's some pics
http://www.main.experiencetherave.com:8 ... avalanche/

Here's the cog
http://www.main.experiencetherave.com:8 ... P_6665.JPG

G-reg · Post by **G-reg** » Sun Jun 11, 2006 6:22 am

Yea, that's the stuff I was trying to explain.

Oh, and you have not fixed anything. This is fixed:

scottzg · Post by **scottzg** » Sun Jun 11, 2006 7:49 am

G-reg wrote: Oh, and you have not fixed anything. This is fixed:

hah. My road bike with no climbing gear kicks my ass. Single speeders are badass.

G-reg · Post by **G-reg** » Sun Jun 11, 2006 1:41 pm

That's not a freewheel

206er · Post by **206er** » Sun Jun 11, 2006 9:02 pm

here's my new townie/drunk/commuting bike that I have $0 into.

isotopeman · Post by **isotopeman** » Mon Jun 12, 2006 6:51 am

Those springs and many other parts will wear out quick for the front der. shifter. One of the best things I did for my commuter bike was buy a set of brake levers (not the brake/shifter combos) and an old set of friction shifters. Nothing shifts easier, faster, or more reliable.

On that fixed-gear setup, is the sprocket on the other side a different size allowing a different gear ratio by putting the wheel on in the other direction?
It looks great!

206er · Post by **206er** » Mon Jun 12, 2006 9:33 am

the short answer is yes to the two sprockets, either that or he decided to go to a smaller/bigger gear on the other side and was too lazy to remove the old one.
I am a fan of friction shifters for something like a townie but any kind of performance oriented bike they suck. the fine tunabiility is nice, and they are very reliable since a small amount of misadjustment is ok. but fast, no way. very slow.

G-reg · Post by **G-reg** » Mon Jun 12, 2006 11:41 am

It's a White Industries ENO hub. The axle on the hub is off set to allow a bit of movement to allow chain tension adjustment on a bike with vertical dropouts. I highly recommend any of WI's Single Speed parts, especially for bikes with "shifting problems."

Fuzzylee · Post by **Fuzzylee** » Tue Jun 13, 2006 4:15 am

I highly recommend any of WI's Single Speed parts, especially for bikes with "shifting problems."

No shift = no problem, right?

BAC5.2 · Post by **BAC5.2** » Wed Jun 14, 2006 9:01 pm

G-reg wrote:I've got to disagree with BAC regarding some of his cable advice. Gore cables were over priced and not much of an advantage in 1996, that's just an opinion though. Using derail housing as brake housing on the other hand is flat out wrong. Derail housing is not even kind of designed to take the forces from brakes. The Derail housing will blow out and leave you with nothing. Getting the most out of cables has more to do with the initial set up and install than anything else.

Gore cables were never over priced, but then again, I never paid retail. I think I paid like $2.00 per cable or something like that. They performed well.

When I ran mech. discs, I used derailuer housing instead of brake housing religiously. I NEVER had a problem with it. I've used the same stuff on standard v-brakes without a problem either. But I never used shitty brake hardwear, so I could imagine with bad brakes requiring tremendous lever effort, you could easily pop a housing when you ham-fist the shit out of the lever. I also changed my cables and housing probably 2 or 3 times a season (depending on conditions). It was cool not having to pay for labor or cables/housing.

slowjoe · Post by **slowjoe** » Fri Apr 04, 2008 5:53 am

wow, i never knew there were bikers here. thats good to know! i think i would have come here alot sooner had i known this. i was always in the bike forums before i could drive searching for information. and then i became a bike mechanic. haha. i like working on bikes alot more than cars. they are much simpler and you dont have to worry about the motor. cars are fine to work on as hobbies but i'm going to dread it when i finish my two year T-TEN program.

Post by **Legacy777** » Fri Apr 04, 2008 5:56 pm

I started working with working on bikes and other things.

I still don't mind working on my bike. The only thing I really hate is adjusting brake pads and getting the toe adjusted properly so they don't squeak.

I'd really like a set of disc brakes, but am not sure if there are any decent conversion kits.....as I don't ride my bike enough to justify getting a new one.

Post by **Legacy777** » Fri Apr 04, 2008 6:04 pm

You know....when I made the above reply, I didn't even realize I started this thread....hahaha

slowjoe · Post by **slowjoe** » Sat Apr 05, 2008 8:38 am

if you dont mind getting a set of V-brakes, shimano makes some pretty nice ones that set adjust the pads to keep them parallel to the rim as they clamp in. very kool and they give plenty of stopping power. they are also lighter than discs. but if you want discs, i would recommend the avid mechanical disc brakes. those things are made very very well and are very easy to adjust. i would go with avid for discs and cantis but shimano for the v-brakes.

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Mtn bike tune-up

Mtn bike tune-up