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Thursday, June 24, 2021

Changing the drive train of a carbon fiber MTB imported from the Mainland

Wheels of Happiness

Rizal Philippines
6.24.2021









1/3 of the new bike which this post bought from a e commerce platform has been changed - its drive train:  the rear derrailleur, chainset, the chain ring and crank the chain, the cogs, the brake set and the changer  with xt Shimano group set, a preloved group by an MTB rider from Marikina.   I nearly had the scare of my life when the axle of the crank was seen as short by a mechanic I saw earlier,  yesterday.   But the mechanic I saw today, analyzed the problem and was able to deal with it.  He simply clamped further the  
the bb pressfit.  The seller recommended having spacers (but would further shorten the reach of the crank axle)   He would have scraped if there was a machine shop:   2 mm from both sides of the bottom bracket and 1 mm from the crank arm (for a total of 5 mm which  was the estimate of the first mechanic.  I would be disappointed if the crankset would not fit.   That would be nearly 2/3 the cost of the purchase.

The more challenging part was the removal of old brakeset since the bike frame is internal cabling.  It meant that the brake hose had to be cut, removed, reinstalled with the fitting and bled;  the new one had to be cut also, and inserted from the back, reinstalled. and bled.  I came prepared because I had the pressfit tool for the barb and the olive.  Now I know how to use this firsthand. 

I removed the  42t chain ring and reinstalled the CST shimano 11-36 cogset.   

I must have shaved off:

      1.  Cogset    -        300 grams
      2.  Crankset          500 grams
      3.   Shifter             200 grams

which could further reduce the bike weight to only 11 kg.  If I use a ridgid fork, this would remove about 2.4 - .6 or 1.8 kg.  reducing the weight of the bike to less than 10 kg.    And 24 holes wheelset.  But the mechanics said I would remove the fun out of MTB if I make this very light.    (And very expensive.

        Cost    -          wheelset P8,000;    rigid fork, carbon   -   P4,000.00  but would negate the                                                                                advantage  of RTL

The upgrade which cost a good low 5 figures adds to the prestige and riding experience - smooth shifting and riding.   

What remains is to have an xt brakeset because it appears to be generic now.   The illusion can be made by buying an XT brake lever.  

It should be said that the mainland sellers are very good in marketing,  They oversold me and many others on the Carbon fiber and its technology, on the German design.  But the actual performance and the sales transaction has not been up to par:    they gave me the wrong color size, and groupset.  Their current groupset while it performs normally has a derailleur that is about to give up being thin and weak in it fabrication;  the crankset is heavy and made of tin cans (hahaha -  iron unlike Shimano which is alum) ragged in construction.    They invest much in bloggers and the e commerce platform.   


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