Author Topic: Anyone a Mountain Bike Expert?  (Read 12854 times)

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Anyone a Mountain Bike Expert?
« on: October 21, 2015, 11:08:16 PM »
I have a bike that's been sitting in my shed for at least a year or two now.  Prior to that I used it quite a bit.  There are a few problems that I believe are quite repairable.  The problem is I'm not sure how to figure out compatibility of replacement parts.  I know that many of the main parts are interchangeable.  But bike repair shops in my area would rather me bring my bike in and pay them to fix it rather than help me choose good components to replace myself.  I'd love to buy stuff online but don't know where to start.

The next question, of course, is whether all of the components I'll be replacing will cost me more than just replacing the bike.

If you think you're up to the challenge of helping me identify components and educate me on replacement criteria, please chime in.  I express my great appreciation in advance.  I can take detail pictures of everything as necessary.

Offline nrml

  • Sr. Member
  • ****
  • Posts: 262
  • Country: gb
Re: Anyone a Mountain Bike Expert?
« Reply #1 on: October 22, 2015, 05:00:21 AM »
I am not a bicycle expert, but I am slowly collecting parts for two cycling related future projects, a bamboo bicycle and a recumbent trike. The information on most bicycle components is very widely available on the web and it is pretty easy to identify / source parts. Sheldon Brown's website is a good place to start if you haven't already gone through it and the cycling forums are a goldmine of information.

Whether replacement will be cheaper than a rebuild will depend on the quality of the bike. High end bikes are worth repairing. Cheap supermarket brands are made mostly of stamped sheet metal. They are best treated as a disposable commodity unless the problems are very simple.


Offline Arbalist

  • Hero Member
  • *****
  • Posts: 673
  • Country: gb
Re: Anyone a Mountain Bike Expert?
« Reply #2 on: October 22, 2015, 07:07:32 AM »
Upgrading or replacing worn or damaged parts on bikes is fun provided you have the right tools. I bought a Giant mountain bike years ago that had a pretty decent frame so I upgraded quite a few of the budget components for better quality ones. Shimano used to sell up to five different grades of parts at one time depending on what you wanted or could afford to spend. The Deore parts used to be pretty good and a reasonable price. I've used Wiggle and Chain Reaction for online parts but was also lucky to have a choice of local suppliers as well. Beware though it can be quite addictive! I paid £450 for my bike then spent about the same again on upgrades!
I replaced: bottom bracket and cranks, pedals, both wheels and hubs, front change mech, handle bars (carbon alloy) and stem and added a rear disc brake to match the front one. I also replaced the brake cables and tyres. I did need to buy a few specialist bike tools but these are freely available and not normally very expensive. Have fun!


Offline jcs0001

  • Sr. Member
  • ****
  • Posts: 286
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #3 on: October 30, 2015, 03:06:17 PM »
Sparky:

A few photos might help.  As nrmi mentioned if it is a dept. store bike the frame is likely not the best and putting decent components on it won't make it a good bike.  If the frame is well made and in good shape then it may be worth fixing/upgrading.

You will likely find that replacing chains and rear clusters for 7 or 8 speed bikes aren't too expensive however once you get into 9 or 10 speeds at the back the price goes up.  Unfortunately it isn't as easy to get parts for 7 speed rear gear sets as it once was.  I've had little trouble getting them for 8 speed however.

One source of parts is mec.ca - they often carry parts in their stores that aren't in their catalogues.

John.

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #4 on: October 31, 2015, 12:39:07 PM »
Absolutely, I'll add some photos to this thread and detail the issues I know of.  To the best of my knowledge it's not a department store budget-buy but also not top-end.  I purchased it used from a store that only sold bikes somewhere around 7 years ago and paid approximately $600 if I recall.  Haro is the make, not sure of the model but I'll check for identifiers when I do some pictures.  It's an aluminum frame with aluminum wheels - but I suspect this is probably the norm these days.

It's a solid frame with only front suspension.  I'm a big guy at 6'2" and 220 lbs, and when I looked into getting a bike as an adult it was recommended that rear suspension wouldn't serve me well.  Dissenting opinions are welcome on this, because as I get older the jarring force that's transmitted all the way through the bike's components and into my back is not at all pleasant.

John: Thanks for the tip about MEC.  I know it well, and though I've walked by the bike section many times it didn't occur to me to try them out for parts.

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #5 on: October 31, 2015, 01:49:29 PM »
So, I don't seem to be very productive today so I went and pulled the bike from the shed and snapped some photos.

I had previously replaced the click-shift levers after a crash that left me with my first ever broken bone.  In addition to my clavicle requiring about six weeks to mend, the shift lever on one side was completely smashed.

Also replaced was the rear derailleur.  On a separate occasion a few years after the first incident, a stick along a very woody trail became lodged in a very wrong place and quickly broke the pivot arm.  I can't remember if I was left stuck in a high or low gear but whichever it was I remember that getting back to the truck wasn't much fun.

Here is the list of issues I'm aware of.  It's actually smaller than I remember.  Funny how the severity of a project can get blown out of proportion in one's head, eh?

1. Rear axle/bearing
Can the bearing and race(s) be replaced without replacing the rim or does one just get a new rim?  How to properly measure a rim and ensure compatibility?

2. Crank bearing
This has always been an issue with occasional looseness taken care of by a slight tightening of the nut.  A cyclical "click" has always been present.

3. Front shocks
Some side-to-side wobble, a bit more than I'm comfortable with but not sure what's considered normal play for these.

4. Cracked rim?
I was sure I had noticed a crack in one of the aluminum rims and was going to take a picture of it.  Do you think I could find it though?  I did notice some very straight lines, either parting lines from a mold or where they've joined a rolled flat extrusion to create the rim.  I wonder if I hadn't mistaken this for a crack the first time I saw it.  If the only way to fix the bearing issue is to replace the rim than this problem is solved by default.

5. Upgrades
- Although I was able to find some brake pads that really impressed me, I was never quite satisfied with the performance in wet and/or muddy conditions.  If disc brakes reliably give that performance, I'd consider that upgrade.
- Better derailleurs?  I have yet to find a bike that shifts gears really nicely, especially if you need to do it under load.  I have also, on occasion, been able to overpower the grip/meshing of the chain on the sprockets and have it slip.  Of course this happens at the least opportune moment - like right at the top of a steep incline, heading "up".
Maybe some of my complaints are due to my ignorance of proper technique, but I think if you can solve the problem mechanically than damn the technique. :)

Offline Arbalist

  • Hero Member
  • *****
  • Posts: 673
  • Country: gb
Re: Anyone a Mountain Bike Expert?
« Reply #6 on: October 31, 2015, 03:21:21 PM »
Anything that requires rebuilding of wheels is best done by an experienced technician. Budget Wheel rims themselves are just a simple hoop and the join is normally quite visible, I upgraded to welded Mavic rims. The crank bearing assembly is called a "bottom bracket" and cheap/worn ones often have that annoying "click"! They aren't difficult or expensive to replace but you'll need a special tool. I opted for a Shimano "Octalink" bottom bracket and cranks. Disc brakes work really well in all conditions and the cable ones are more than good enough for normal use.

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #7 on: October 31, 2015, 06:27:46 PM »
Holy crap.  There's a dizzying array of "Bottom Bracket" tools on eBay.

I also learned that there are quite a few different styles according to the Wikipedia entry:
https://en.wikipedia.org/wiki/Bottom_bracket

Offline patuca

  • Jr. Member
  • **
  • Posts: 11
  • Country: 00
    • Mike's page
Re: Anyone a Mountain Bike Expert?
« Reply #8 on: October 31, 2015, 11:06:49 PM »
Stangely enough I just got finished renovating an old friend from the early '80s.  I bought this bike when I had legs to ride back in the early '80s I think, passed it on to my daughter, grandkids, and finally it was ready for the dump.   But I remembered how sweet it was to ride so back it came, and  in the last month I spent weeks taking it apart, polishing  and fixing it up,  it's ready for another 35 years....

Reynolds 453 butted tube,  the usual Shimano fittings, Maillard hubs etc. about 24 lbs.  Nothing fancy, but nothing cheap either.





It's not really worth it to fix these old crates...you can spend hundreds and the value is still low.   But, what the heck, my physio lady says I need a "stationary" bike so why not?  Besides, it's part of the family and it's kinda pretty.

patuca

Offline Arbalist

  • Hero Member
  • *****
  • Posts: 673
  • Country: gb
Re: Anyone a Mountain Bike Expert?
« Reply #9 on: November 01, 2015, 05:52:41 AM »
I like Park Tools:

http://www.parktool.com/category/crank-bottom-bracket

Unless you want to replace the cranks you'll need to replace the bottom bracket with the same type and size as the old one. I chose the Octalink BB partly because Shimano supply lightweight hollow cranks to match. Your first job is to remove your cranks to see exactly what you've got and have a quick measure up for size.

Offline jcs0001

  • Sr. Member
  • ****
  • Posts: 286
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #10 on: November 02, 2015, 11:59:08 AM »
Sparky:

A few comments but please keep in mind that it's been a few years since I've torn one of these apart.

The frame looks decent and having front suspension is nice.  I've got a very similar bike (a kona).  Having rear suspension might be easier on the butt however it tends to add quite a bit of weight.

I believe the brakes are V brakes - in a cable style brake they are quite decent.  Changing the pads and adjusting them should make a big difference.  You could also give the rims a bit of a cleaning as that will make the brakes work a bit better.  Retrofitting disk brakes might be quite a bit of work and expense.

Not sure if the bottom bracket on your bike is uncaged/caged ball bearings but if so then a good cleaning and new balls with some good grease may help - it's a cheap fix and worth trying.  I had a bike a long time back with that system but the threads had problems - installing a sealed bearing bottom bracket/axle was the only thing that fixed it.

Wheel bearings/races - not sure on this but I suspect that they also have a ball bearing set up.  Replacing the bearings may be all you need to do and it's quite inexpensive.  You can always upgrade to a new wheel/hub but it can mount up in price fairly quickly.

Shifters/derailleurs - New cables, chain and rear cluster and possibly the two plastic idlers on the rear derailleur should make it shift quite nicely.  Keep in mind that cables will stretch so you may need to do some adjustment after a few km. on the bike.  You may have to learn to be subtle with the shifting  :).

You will need the proper tool to remove the cluster - I install the tool, held lightly with the nut on the axle and then mount that tool in a vice so that the wheel is horizontal.  Turning the wheel will give you some leverage and make it easy to remove the cluster.

Can't help with the give in the suspension.  You may be able to check out another bike or two and see if it's similar or something to be concerned about.

Patuca - very nice old bike with the reynolds 453 butted tubing - that's good stuff.

John.

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #11 on: November 02, 2015, 05:35:30 PM »
Don't have much time to comment tonight, but I have brought the bike into my workshop as my next somewhat long-term project.  After watching more YouTube videos than I care to admit, I have a pretty good idea what I'm in for.  I'm a bit disgusted by the number of custom tools required for each assembly and every version thereof.  It does, however, look like an opportunity to "make something useful" out of metal.  Certainly cheaper to buy the tools, and I will if making them is a no-go.  But plan to make the attempt for the majority.

I did try to use a simple puller to get the crank off the square taper off the bottom bracket (what a dumb name, eh?  call it an axle or a bearing assembly).  That wasn't successful, so this tool will be the first one I make.

I'll document what I can here in pictures.

Offline jcs0001

  • Sr. Member
  • ****
  • Posts: 286
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #12 on: November 07, 2015, 11:26:35 AM »
Sparky:

You likely have seen the puller you need to remove the cranks - if not I can take a photo of mine.  They are very simple and work well without scratching things up.

John.

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #13 on: November 07, 2015, 11:30:23 AM »
I've made a small amount of progress since the last post.  It is, however, very satisfying to write that the first custom tool was a success.... at least the second time around.

Opening up the plastic cap pressed into the pedal crank reveals a bolt and some much larger threads



Thinking I'd be smarter than the people that sell all the custom tools for bikes, I figured I'd just use my handy little puller to get the job done.  If trying this yourself, don't bother.  There's too much deflection, too little grip, and not enough force to get the job done.  It just made a mess of the aluminum where the fingers were digging in.  No harm done though, I'll just clean it up a bit when I reassemble.  Oh and YES, I did have the bolt undone.  I replaced it loosely to give something solid to push against.



It's tool making time!  I read about a guy that successfully made this tool from aluminum and since I have a bunch of round stock I gave it a try.  Threading is a pain to set up on my machine but with a nice big undercut to run into it isn't bad to machine.



As things turned out, the tool above didn't quite thread in.  I measured the pitch diameter later at work and it was right on what it should be.  So why didn't it fit?  I think the threading tool form wasn't quite ideal and there was a lot of tearing and such.  The threads didn't look great - which is a good indication whether they'll work or not.  I got it to thread in a bit but it started galling and making a mess of things so I stopped and went back to the drawing board.

No worries.  CNC makes things so much easier. :)  About an hour of effort produced a new tool with absolutely perfect threads.  Oh, and this one is 4140 HT steel.  The setup was reversed from how I did it manually and I left a long stub that I could hold in a collet block to put the flats on.  The external thread is a non-standard M22 x 1.  The internal thread is 1/2-20 UNF which was drilled on the CNC but tapped by hand.  It's iffy tapping a one-off hole on the CNC lathe with the tools I have available.



Lots of grease was added to get the most pressure with the least friction.  I could have used a slightly longer bolt but, again, materials at hand.  I ended up sticking a smaller SHCS down inside the hole to take up some extra space and give me enough length to pull the crank arm off the taper.







I was able to remove one side of the bottom bracket without any special tools.  Really big pliers did the trick without any damage.  That said, after what I found I'm not planning on trying to salvage any of the parts.  I'll be installing a new sealed type as long as I can find what I need.  I've been known to pedal through water that's above the bike's axles, so that's likely the cause of some of my troubles.





I still need to come up with a way to remove the nut on the drive side of the bottom bracket housing.  It's really not the brightest design in my opinion.  It's round with two very small flats - which don't give much to get a grip on with traditional tools.  Can anyone confirm that this is a left hand thread?  It would make sense and I've seen a few references to this fact online.

Offline RussellT

  • Hero Member
  • *****
  • Posts: 520
  • Country: gb
Re: Anyone a Mountain Bike Expert?
« Reply #14 on: November 07, 2015, 11:41:48 AM »
I've always found the easiest way to undo those is by picking the bike up, holding the two flats in the vice and turning the bike.

I can't remember which side is LH threaded but one is - so if the one you've taken off is RH - then this will be LH.

Russell
Common sense is unfortunately not as common as its name suggests.

Offline Sid_Vicious

  • Full Member
  • ***
  • Posts: 103
  • Country: no
Re: Anyone a Mountain Bike Expert?
« Reply #15 on: November 07, 2015, 11:44:24 AM »
Think of the way the pedals go thats the tightening way of the treads
Nothing is impossible, it just take more time to figure out.

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8966
  • Country: gb
  • East Sussex, UK
Re: Anyone a Mountain Bike Expert?
« Reply #16 on: November 07, 2015, 12:28:03 PM »
I got the one on my wife's bike off using 3 MT chuck removal wedges - worked a treat - seem to remember mentioning it fairly recently on the forum:

here you are - reply #10

http://madmodder.net/index.php/topic,11047.msg128285.html#msg128285
Andrew Mawson
East Sussex

Offline Arbalist

  • Hero Member
  • *****
  • Posts: 673
  • Country: gb
Re: Anyone a Mountain Bike Expert?
« Reply #17 on: November 07, 2015, 05:17:57 PM »
This page is pretty good for crank/BB info and has a picture of some of the different Bottom Brackets showing how much more rigid the splined ones are.

http://www.sheldonbrown.com/tooltips/cotterless.html

Offline krv3000

  • Hero Member
  • *****
  • Posts: 2183
  • Country: gb
Re: Anyone a Mountain Bike Expert?
« Reply #18 on: November 08, 2015, 08:18:07 PM »
years a go when I was a lad bikes had a oiling point on the wheel hubs and the bottom bracket unfortunate manufactures have   dun a way with them so you ether scrap the bike or by new bearings all bearings on bikes was cup and cone with sepret ball bearings just may bit of rant     

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #19 on: November 08, 2015, 08:48:06 PM »
I got around to figuring out what I needed to measure tonight, in order to figure out what I need to buy. :)

I got 68mm width for the tube that's part of the frame (confusingly referred to as "the bottom bracket", in addition to the bearing assembly itself) and 122.6mm for the axle length.  It seems like there's a few mm of leeway on the length of the axle so I'm not splitting hairs with the measurements.  It's hard to throw away a few decimal places when you regularly work with 10ths.

Since receiving the suggestion of MEC for parts, I've been putting together an order of a bunch of outdoor things plus the bike components.  I've tentatively settled on the following bottom bracket as being a reasonable replacement that should keep me going for a few years without breaking the bank.  Though there may be better designs there's no reason for me to replace the cranks, pedals, or chainring(s) at this point.  So, instead of changing things I'll just replace with a working part.  Hopefully "sealed" cartridge actually means it keeps the water out.

http://www.mec.ca/product/5021-557/shimano-alivio-bb-un26-68x122mm-eng-square-tapered/?q=bottom%2Bbracket%2Bsquare

Now, my reason for pointing out the above is this: I know which tool to buy to install it, but considering I'm trying to build tools as needed I'm wondering if anyone has such a tool and would be willing to send enough dimensions to duplicate it on this end.  If not I can reverse engineer a tool when I get the part.  But I was hoping to make it up and have it ready for when the part arrives in the mail.

Bob: When you were a lad, was it commonplace for the other lads to ride their bikes through a couple feet of water? ;)  I suppose though if you had an oiling point you could also blow the water out of the bearing when you were done having fun.... if you were the maintenance sort.  I considered looking for a new ball cage for the rusted away one, and cleaning it all up and reassembling but with the way I use a bike I can't see it lasting long before I have trouble again.  Sealed is definitely the way to go for me.  On the other hand, if its only sort of sealed it will probably let water in and keep it in there.  <sigh>

Next I'll be on to the rear axle, where I'm sure there will be some more tools required.

Offline CrazyModder

  • Jr. Member
  • **
  • Posts: 86
  • Country: de
Re: Anyone a Mountain Bike Expert?
« Reply #20 on: November 09, 2015, 02:20:48 AM »
- Although I was able to find some brake pads that really impressed me, I was never quite satisfied with the performance in wet and/or muddy conditions.  If disc brakes reliably give that performance, I'd consider that upgrade.

It is what it is. Disk brakes really are far better than rim brakes in muddy weather (or, actually, even in the dry ;) ). They almost are a must when taking long steep downhill rides with constant braking since they do not break down as fast when they get really hot since they don't use rubbery braking pads.

The downside is that you need special attachment points on the frame to fit them, of course, so unless your bike already has those it may be prohibitively expensive. Or if you try to DIY it, it may be a huge effort combined with a rather hefty risk of them breaking (sic) during use. The comfortable ones also use oil instead of cables...

Offline Arbalist

  • Hero Member
  • *****
  • Posts: 673
  • Country: gb
Re: Anyone a Mountain Bike Expert?
« Reply #21 on: November 09, 2015, 04:17:54 AM »

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #22 on: November 10, 2015, 07:23:10 PM »
At £7.88 UK price I wouldn't bother making one of these.

http://www.mec.ca/product/5017-370/filzer-bottom-bracket-tool-shimanoisis-2/?q=Bottom%2Bbracket%2Btool

Ordinarily, I'd agree with you.  In fact, I'm certain I've given similar advice to someone else in the past.

However, part of my goal with this project was to make any tool that I could.  Its good practice for making things that have immediate and direct usefulness.

With that out of the way, it sure is tempting to spend ~$15CAD and have a perfectly serviceable tool arrive along with the part in the mail.  Stay tuned to see if I give in to the temptation.

Offline sparky961

  • Hero Member
  • *****
  • Posts: 844
  • Country: ca
Re: Anyone a Mountain Bike Expert?
« Reply #23 on: November 11, 2015, 07:19:25 PM »
Well, I took off the wheels this evening and got a bit of a surprise.  The one rear axle is really bent!  Rotating it and watching it, I'd say there's 1/16" to 1/8" or runout where it sits in the frame.  I'm guessing this happened at the same time I broke my collar bone.

Spinning the bearings feels about as smooth as if one used topsoil instead of grease.  The front is rough but not loose.  The back is rough, loose, and bent.

So am I correct that there are only so many components that are replaceable in there?  Is my best (or only) option to replace the entire wheel assembly?  I thought of maybe getting new hubs but re-lacing and truing the wheel myself doesn't seem like a good idea.

And hey, while we're on the topic of wheels (and tires)... is there such thing as a bike tire (or car tire) that doesn't slowly lose air?  I hate topping up tires but it's much worse trying to ride/drive without enough air in them.

Offline awemawson

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 8966
  • Country: gb
  • East Sussex, UK
Re: Anyone a Mountain Bike Expert?
« Reply #24 on: November 12, 2015, 02:54:55 AM »
Can you not pull the axle out and straighten it in a press on Vee blocks? It's only short - even a bench vice might do it if no press to hand.

From my dim and distant recollection of bicycles I seem to remember that the axles are only a bar with bearing cones screwed on at each end with possibly flats. If straightening doesn't work, make a new one.
Andrew Mawson
East Sussex