Wednesday, May 19, 2021

Chain kept jumping off, and chain rub at FD and other fitment pains of 2 b by

Wheels of Happiness

Rizal Philippines
5.19.2021



The chain kept falling off the front chain ring.  I was tempted to go to the LBS mechanic.  
I found out the cause - the high position of the front derailleur relative to the largest chain ring.  Since the large chain ring has been removed, the clearance between the lower edge of the FD and the tooth line of the chain ring should be at least 2 mm (a coin thickness)  The current clearance is about 150 mm.  

So I lowered the front derailleur.  

Furthermore, there is a chain rub that would not diisappear despite the adjustment of the limit screws.  There is where the barrel adjuster was useful.  I turned it CC or CCW until the sound disappeared.

Two problems solved..  No need to go to the mechanic.



Tuesday, May 18, 2021

Knowledge of use of limit screws for fd and rd, and barrel adjusters a must for diy bike owners with one by or two bys

Wheels of Happiness

Rizal Philippines
5.18.2021

Happy birthday to my deceased brother Sixto who could be in heaven.   

I gained a lot of experience as did a DIY two by set ups lately;  installing Deckas 34t as the main drive, removing the 42 t, and retaining the 24 granny gear.

You encounter a lot of challenges:   the FD would not shift to the granny gear,  the FD would not shift to the 34t.    The chain falls off and jams the smallest gear (11) and or falls off the largest gear.  Or that the 
gears are noisy.   

How do you deal with them?  Mechanics call it turning

Actions of the limit screws:   fd and rd, and barrel adjuster.

RD (rear derailleur) limit screw

   `1.  Top is the high gear (smallest gear) marked high limit screw, lower one is for the lowest gear
           (marked HI)

         HI - turning clockwise brings the the chain to the left, away from the smallest gear; turning this
                 counter clockwise brings the chain to the right.     Thus if the chain is falling off, you turn
                  the limit screw to the right - clockwise.  If the chain remains at next gear, instead of the 
                  lowest,  you turn the limit screw counter clockwise (to the left)

       LO -  turning this to the left brings the chain further to the left and may cause the chain to fall off
                 So if the chain is falling off, you turn the screw to the right.  If the chain does not shift to 
                 the biggest (aside from the cable being loose) it could be a limit screw maladjustment.  Turn
                 this CCW (the left)

FD.

      HI  - controls the outer movement of the FD, its of the guide relative to the chain ring.    Turning
               this CC brings in the guide inwards and prevents the chain falling off when in high (the
               biggest chain ring)   Turning this CCW (to the left lets the guide move farther to the right.  
               So if the  FD does not allow the big ring shift, you loosen (turn the HI) screw left CCW

    LO  -   controls the movement of the guide relative to the low gear.  (smaller ring).  Turning this 
              CCW (left) moves the guide inwards  nearer the frame.  So if the FD does not shift to the 
               smaller gear, turn this CCW to the left)  If the chain falls off, turn the screw to the right  (CC)

Barrel adjuster:

           Before fixing the cable, turn the adjuster clockwise until it stops and then turn CCW about 4 
            turns for eventual adjustment.   This is used for really fine tuning of the cable especially
            if the gears are noisy. 

           Turning the barrel left  CCW tightens the cable and moves the chain inward;  turning this 
           clockwise moves the chain outward (to the right)   Turn the front barrel adjuster until the noise
            disappears.

Mastering the above is a matter of simplex algorithm - trial and error.   

Monday, May 17, 2021

Upgrades of two MTBs complete - mostly Do It Yourself

Wheels of Happiness

Rizal Philippines
5.15.2021










This post has completed all the planned upgrades of his MTB - mostly done cheap and at hisi own effort.  This reflects the higher level of technical skill, and the longings of a bike rider to be better everyday - indeed fulfilling one of our mandates as a creature and as a creature.

The upgrades where:
1.  Bigger cogs from 11-36 to 11 - 42.;   for added lower gears in ascent/climbs
2.  Bigger front disc rotor from 160 to 180 mm for greater braking power
3.  Two by set up from 3 by using Deckas chain ring.

The upgrades were a result of seeing a barrage of ads at a social media and e commerce platform; tantalizing you with their cheap price and availability and how these stuff will make you look better.

1.  Cogs -  I bought the S brand from an on line seller a biker too;  He told me his experience that the installation is straightforward - remove the old cog using the cog removal tool, install and presto.  No need for goat link or additional chain link (for as long as you have long cage RD).  No need to adjust the rd settings.   It cost me P1,000 each.   I bought two.   True enough the installation was simple and straightforward.  No need to go to mechanic if you have crank removal tool.

The move gives you added 6 teeth (from 36) and other power when in difficutl climbs (say Mahabang Parang or quarry road)  and gets your bike ready for one by.

2.  Brakes - for extra braking power.  I was first tempted to buy quad piston brakes which cost P3k for a W brand and no less than P12K for an S brand.  But other riders said that gains can be minimal because only 30% of brake pad area is increased;  the brake pad is costly;  uses a lot of oil, is difficult to bleed.  The cost differential is about 500%

And so this post opted for the increase of braking area from 160 to 180 mm.   The cost is very minimal.  One floating disc 180 mm 3Pro is only P400.00 plus the adapter priced at P143 each.  

The process is again simple and straightforward.  Remove the old disk using a Torx tool (number T25)  This is where my tool box of 46 pieces came in handy.  The torx screws could not be removed with handheld tool.   They were tough screws to remove.    Then replace the disk rotor after carefully cleaning the disc hole of oil and grime.   The fiddly thing is the adjustment of spacers   And centering the brakes.   

3.   Two by set up.    This post ordered Deckas chain ring with wide narrow teeth; 34 t  I will do the two by because it has wider range (since you retain the 24 granny gear) and literature at the net says it is the best set up and is longer lasting 

  As for the gears, at 34 t front chain ring and 10 cogs at the rear, you achieve a high end gear inches of 34/10 =  3.4 x 29 =  98.6  nearly same ratio of a road bike with 50 x 12. = 41.66 x 27  =   112.   I would have achieved this with 36 front chain ring   3.6 x 29 = 104.4 (No wonder  29ers even with one by are fast).  

For the low end using a granny (24t)  I would achieve  24/42 = .57 x 29 (a super low2 gear).  Even at 34, the low end ratio would be .809  (less than one)

There is dearth of literature on 2by set up;   even mechanics and other rabid MTB could not say much on the 2bys system (we are just following the RB set up)  But I am confident of the fact that when
I have to have a much lower gear (lower than one offered by one by) I could always count on a granny
chain ring.  I have seen many elderly who went on an outwardly looking one by but had a reserve 24 chain rin,  

The process is more complicated.  

      1.  Remove the crank set from the BB.  Remove the pedal for ease of work
      2.  Remove the chain ring.  It is more difficult for the xt because the old model crank requires
           that you counter the counter sink nut with a stopper (they say you can use a screwdriver but
           it keeps on slipping) And you need a T30 torx (glad I had the toolbox with torx set).  Initially
           this post thought this required at  T25 or T27.  But the T30 is perfect.

     3.  Next step is to determine the the placement of the Deckas 34 T.   Initially I thought this would 
           be outside of the spider.  But this would be far away from the 3rd gear (the 24t) and this would
           position the chain ring at the former location of 42t.  Initiallly this post thought that the  XT 
           will not accept the Deckas.  

           But installing this behind the spider would be perfect fit:    It would be in the 2nd position of 
           the FD shifting;  and near the 24t (the #1)

     4.  And so this post thought so  But he protrusion of the crank bolt caused the chain to jump 4x
          every revolution  Rather than filing or sanding the protrusion, the post reversed the installation
          of the crank bolt  - with the flatter head on the inside and the protrusion on the outside.  Not 
          good looking but its the cheapest solution.   

    5.  And then adjusting the FD.

        1.  Screw in the high limit screw (at the outside) all the way in so that you cant shift to #3, and
              have the chain fall off.

       2.  Loosen the low screw so that the chain will fall off to Number 1. (the grannie).  You have to
            to make the adjustment, because the chain ring Deckas being wide narrow will not cause chain
            fall off on the lower gear.   The adjustment will bring the chain guide to the farthest end and the
            therefore the shift to take place.  

All in all the upgrade cost me (for the two MTB)
  
     1.  Cogs S brand   11 - 42   @ P1,000  x 2                                            2,000.00
     2   Deckas    round, 34t  @ 290 x 2                                                          580.00
     3.  3 Pro 180 mm rotor    @ 440 x 2                                                         880.00
     4.  Adapter     143 x 2                                                                                286.00
     5.  Tool box 46 pcs                                                                                    280.00

                                                                  Total                                           4,026.00
     
One kapdyak  I know spent P4,000 on the Sunrace cogset alone   My cost covered 3 upgrades:

    1.  Cogset
    2.  Braking system
    3.  Two by set up

My cost is a mere 1/4 of a quad piston, or 1/5   SRAM or Shimanao upgrade kit.  (about P20K)

The results on my riding?

     I could not tell much now. 

    1.  For the 11 - 42 - effortless riding;
    2.  For the braking system - I am still bedding them in.
    3.  For the two by set u -  lighter by a few hundred grams.  Great cosmetic.
         Unless I hit the trail, I would not be able to appreciate the benefits of a two or one by system

         Again, my upgrading is a result of:
   1. Desire to being better, or desire for having a better set up;
   2.  Being competitive with other fellow bikers.
   3.  Being a sucker for ads (being  marketing man)