24.02.2018 Revised 3 Years Review: 2014 Trek Fuel EX7 29er

how the bike looked like may 2018

I  needed a full suspension bike, at minimum 120 mm travel, I got the best bike, I could as fast as I could.but I knew I might need to change few things, but I test rode the bike around the store, but that was not good enough test.

It was a lot better to ride than the 2010 Trek 6300.

This is my first full suspension bike, and my first 29er, I have never ridden other full suspension bikes, so can’t compare it to others.

Don’t let others decide for you if 29er is the right choice for you. The ride quality not only depends on the bike but the person sitting on it and the correct size.

The first rides:

I noticed the bike was also easier to ride, the steering was easier, I also noticed the bike is more stable than my 6300, pulling wheelies was easier to control,  the front was heavier so it helped to make wheelies more stable.

I think this bike is easy to ride, much better compared to my 6300(100mm stem & 720 bars) even its heavier it goes much faster, no matter if its downhill steep up hills, even doing a wheelie.

The bike does not accelerate as fast as a 26er would do, but it maintains the speed longer, but the bike is fast & stable in corners.

Technical climbs is not an issue with this bike, but with most trail bikes there is not.

 

Handling & geometry

The steering and handling was a huge improvement going from Trek 6300 with very steep headangle, but I want even more stable steering & handling bike.

The Fuel EX struggles at tight switchback climbs, the steering is not stable enough,  it’s easy to ”lock” the front wheel, it requires very precise mode movement, good balance to be able to tun and go up smoothly.
also at straight climbs the is a struggle, you have to shift the upper body position to get grip, it’s a balancing act,
I can climb most of the steep climbs on my local trails, but does not mean the bike is doing a great job, it could be better.
there are something about the geometry that are not to my liking: the reach is too short, the wheelbase short, the bike is very easy too wheelie, and manual, it’s very agile, and ”flickable” as reviewers wants to call it, but most bikes will be for me, unless they are a tandem.

The video below  by Pole, does a good job at explaining & showing the issue with the geometry old bikes have and even some current bikes, it’s the same issue I got, on the Trek 6300 the problem was very noticeable, and steering was unstable, but the Fuel ex, was much more stable, but on tight switchbacks and doing precise trails moves I really notice the flaw.

 

I got a Dropper post

the lack of dropper post hides the capabilities of this bike.

with a dropper post, I can get my body in the correct position for going downhill.

Even the dropper post adds more weight, it gets you in the correct pedalling position when its up, and for technical sections, you just lower it, and the capabilities of the bike increases, the dropper post made me alto faster in descents and on technical climbs.

The frame supports both internal and external dropper post routing.

The cable should go alongside the brake hose, For the Race Face Turbine 440mm 150mmdrop dropper post.

if you use 1x drivetrain, you can use the front dérailleur routing for the external dropper post.

My setup for susmmer 2018:

Worked ok, for me I am a bit more than I am somewhere close to 75 kg with gear on. So I ride with 210 in the shock and 110 psi in the fork, 5-6 clicks rebound both front and rear, which work pretty well for me, I am somewhere close to 75 kg with gear on.

I installed Cush Core which greatly improved the ride:
Installation of Cush Core tyre inserts greatly improved the ride comfort, the tyres where tracking well I noticed I was faster, I dropped the air pressure for suspension by 20psi, and 4psi tyre pressure.

The bike is 13,600 Grams(I did not measure it) in size 18,5 so it could be too heavy for you if you really need a light bike, but for me, it’s not that heavy I can ride pretty fast with it anyway, in fact, it’s a huge upgrade from my 26 inches 6300.

 

after 2 seasons the original bearing in the chainstay worn out,(by worn out I mean they did not turn smoothly and they made noise even when I repacked them with grease, but they had no noticeable play in them) so I had to change them,So I did,but even though I have had repacked them with grease once, I think I should have done it sooner, but I  replaced the original bearings with Enduro bearings, and I regularly maintained them so they lasted alto longer.I have been riding with the second bike in -11 degrees, and on wet rainy days, and all kinds of weather, I had to repack the bearings after few weeks of winter riding, but the bearings were running smooth, So I guess I will just have to check the bearings more often.

 

PROS:

  • handlebar got stripes to help you with brake and gear lever alignment.
  • Shimano Deore SL-M610 Shifter triggers give smooth and very easy to shift, a lot better than the 2010 Deore, more ergonomic than the past model like the 2010 from my 6300 bike.

 

 

  • holes for internal cable routing for a dropper post
  • external top tube routing support for shock remote or a mechanical dropper post.
  • the bike is stable in the descend and climb
  • the frame got SCG-05 chain guide mount
  • decent clearance for my feet and legs

 

CONS:

  • The Bontrager Duster 29 wheel set is way too flexible & get untrue way too fast, 
  • I experienced some knocking, clicking sound from the spokes grinding, in turns or when the temperature was way over 20 deg Celsius, but upgrading to a proper wheelset fixed the issue.
  • The headset bearings failed after few months:
  • Top bearings were the first to fail. This is from a bike rode few months. (bike Nr1) I was doing headset bearing service, and there was a lot of crushed metal in the grease, all over. the rest snapped when I touched it. Some bearing balls fell out when I took the bearings out of the cup, the other is crushed or they were never there in the first place, but I don’t know. The bearings on the other bike lasted for longer, but they wore out quite fast, But I switched to Cane Creek bearings, the type with the seal on top and bottom, they lasted for much longer.
    • the rims had alloy machining residue, on the inside of the rim, it came out of the spoke holes.
    • bad selection of components
    • front resin brake pads got worn out in ca. 2 months, I upgraded to Shimano J02A IceTech, but this worn out the Resing only rotors, which wore out the rotors in about 4 months, I had to upgrade, so I went for Hope Tech Floating rotors, which was a great improvement.
    • The suspension:

      do not have every adjustment there is, but the CTD (climb, trail, descend), But I need more adjustment.

    • Shock & fork compression goes out of adjustment, if you ride fast down a hill and over kerbs, down technical trails, or riding fast over technical trails, this has happened quite often, I had to use zip ties to lock the dial on the for and shock, this also happens on Fit grip dial, which I have on one of the bikes because it got replaced under warranty on service.

     

    • Saddle: Bontrager Evoke 2 choice is not no great.

    19697882404_e5dc9fd34c_b

    Pros:

    • The saddle grips well.
    • it flexes and got cushioning
    • I don’t feel the rail inserts
    • the foam cushioning does not work that well, my weight compress it all the way down(  I am somewhere between 170 and 180 KG + gear)
    • I can feel folded synthetic leather where the fabric and the synthetic leather is stitched
    • the saddle is not so comfortable as it should be, I can feel the sides of the saddle.(I notice it if I use the climb mode on the rear shock)

      26156162020_97a7da149b_h
      I can feel the bump where the fabric and pleather is, I can feel the side of the saddle
    • The screws on the seat post are too long for mounting lower saddles with shorter rails, the Bontrager saddle got the rails higher s other is more space between the saddle and the screws.if you are using a carbon saddle with higher rail profile, instead of round rails, it’s nice to have long screws, but not that if you plan to upgrade saddle to a lower profile saddle like I did, you might need to cut the screws. But I upgraded to Fabric Scoop Shallow Race, which is more comfortable for me, but the screws on the seat post hit the plastic underneath the saddle, so I had to replace them, but later I upgraded to dropper post so the issue was gone anyway.

 

Drivetrain

the 10 spd 11-36 x3: I don’t need the 42 tooth ring at the front where I live,  but if you have long roads or steep 40 degrees downhill(where you can run out of gears with 36T) its nice with a 42T ring. I have upgraded to 11-46T cassette and 36T Race Face Narrow Wide ring, I will test it out without chain-guide.

You can watch  Seth’s Bike Hacks review to see how the narrow wide chaining performs

  • The rear bolts on the Evo Link are getting loose very fast, it takes few weeks for them to get loose, but the other bolts stay tight, I think this is caused by the flex in the chain stay and down tube, which then flexes the chainstay so the bolts get loose.

The Shimano Deore BL-M615 brake is awful as they flex causing the threads for the Torx screws to fail. On one the main bike/the bike with hamburger bell) the threads on the rear/right master cylinder failed, so the brake was leaking fluid, and NO I did not over tighten the Torx screws, first I tough the brake just needed a bleed, so I bled them, so there was no air but the next day I lost a lot of braking powers, there was air in the master cylinder, and oil was leaning,I checked the screws they were just spinning endlessly, I opened up the master cylinder and I saw the threads were polished away, I don’t thin kit was caused by a crash, at least not this particular brake, because I have never hit the brakes in a crash with this master cylinder.

The brake felt nice and worked for a short while, but they are just too weak.

  • one of the frames had uneven welding for the zip ties the gap was too small for the big zip ties on the upper cable guide on the down tube,.I could use bit zip tie all over but the one spot.
  • The first months the bolts did not show any signs of wear, after a lot of maintenance work, but after that, they showed signs of wear and got very worn, the hex slot measured at 40.70mm.
  • The bolts:

    they have tight tolerances, so the park tool Allen/Hex bits & keys fit in tight, but of course, bolts wear out, but these bolts got worn out quite fast in my opinion, few bearing services and they were worn out.

    from the left, the original worn out bolt & to the right the replacement bolt, which does not have the Hex all the way through, but it starts from the middle.

    I replaced the bolts in the rear of the Evo link

     

     

     

    This bolt rounded off very easily, I barely turned the Allen key it just shredded the bolt.
    I had to make the hole a bit bigger to remove the already damaged material, then I hammered a bigger Torx bit into the bolt as hard as I could, until I felt it sat firmly in, I then carefully took it out and used Torx key to remove the bolt.

  • Noticeably flexible chain stays & seat stays fast wearing chainstay & rocker link Which are causing many issues:

I think the damage in the Evo link is caused by the flex in the frame, forcing the shock into the Evo link. the Evo link is also quite stiff, but not everything on the frame is so lack of stiffness in other palaces makes this frame horrible.I noticed the bike was frame & the wheels were too flexible the first months I rode the bike, but when leaning the bike against something with rear wheel only I could see it flex, I upgraded to stiffer wheels, which greatly improved the almost constant tyre rub, upgraded cranks which improved the ride greatly, but this also affected the flex in the frame, which already was horrible, but I needed stronger & stiffer cranks, so that’s where the Turbine & Atlas came in.

Frame flexing into the tyre is causing the inner tube I wrapped the chainstay to tear the rubber part sticks out and rubs against the tyre.

Mis-aligned/pushed out/dislocated bearings:

The issues were worse over time, so in October 2017 it got to the point where I had to press in the bearings in the Evo link after every ride, even riding on pavement without any aggressive moves, or hard technical trails,  what did it that day was just riding on a bike path, the rear end felt awkward, I could feel it happening, eventually I heard squeaking, which was the seat stay rubbing against the Evo Link.

This picture shows the bearings dislocated.
So I had to press the back in place, in this picture they’re pressed in.
This is due to the bearings moving due to too flexible 2014 Trek Fuel Ex 7 29er frame

damaged paint due to slipping bearing, the left bearings were almost ruined, it was quite rough, so I installed new bearings.
There you can see the bearing is so far out that the arms were girding.
  • Bent rear dérailleur hanger caused by flex in the bb area, causing the hanger to bend under load because the chain line changes too. Such extreme, and twisting the chain, this is why I am sure the time I bent a KMC x 11 silver, and crushed the threads in the axle on the Shimano m8000 rear dérailleur cage, was caused by the flex in the frame. I have had to true the hanger after almost every long ride the past months, this is getting very annoying.
  • The bent cassette cogs happen on several cassettes I had to use a flat head screwdriver to get the cogs straight.

A Xt m8000 cassette was also bent due to the flex in the frame, which happens very often in September & October 2017

In September-October 2017 the chain wear got significantly worse. This is basically a new chain which will soon wear out, I did not decrease it, I just rode few times in a week, and did few minutes of MTB, I was sick so I could not do much riding because I was sick, but this is a new record in chain wear, the hanger had a significant bend, at least between 10-20 degrees.
The bike was always flexible, I felt it was too flexible for the first months I rode it, I had to upgrade many components, stiffer wheels with proper spoke nipples & hubs, stiffer cranks, wider bars, better drivetrain, but the frame was too flexible but the summer of 2017 I had so many problems with the drivetrain & bearings, that its really annoying.

    You can see the tyre is pretty close to the chainstay.
  • I would not recommend using tyres wider than 2.3, the seat stay & chainstay are too close for bigger tyres.
  • SHIMANO RT56 RESIN ONLY rotors, After few months of use with Metal pads I wore out the rotors, the holes are rounded off, and I lost a lot of bite.

Noticeable flex in the Shimano Deore M552 crank arms, the cranks were way too flexible for me, the cranks failed on both of the bikes, without any abuse, so faulty crank arms, or they are just too weak for a track stand, flexy cranks like this should not be on a trail bike.

  • like any suspension bike, there is some pedal-bob, but it’s minimal, I get about 10% of the travel.
  • no chain guide, the chain fell off more than 10 times the 2015 season, when jumping and riding ruff places hard, I jumped from 3 steps of stairs and if fell off)
  • Awful housing routing, the housing gets kinked in a twisted S shape, causing premature wire coating wear & housing wear.
  • (as you can see the paint got stripped off by the chain)
  • one Allen bolt, on the EVO link, was overtightened from the factory, but I managed to unscrew it by using warm water and Allen key in the freezer for few minutes & the big bolt on the chain stay and seat tube fell off, but the bike shop replaced it.
  • chain fall off when jumping sometimes, my plan is to get 11 speed and get a chain guide.
  • Tyres: Bontrager XR3 Expert, is not a very lasting tyre, because of the soft rubber, l the rear tyre lasted me few weeks, so I upgraded the rear with SE4 Team Issue tyres, which has last me to the winter came.
  • the weight is 13,6 on 18,5(virtual)(real 17.5)
  • the Fox 32 has flex/twisting, from side to side, I am about 75 kg, There is noticeable twisting in the fork when riding over huge roots fast, or through potholes, or front wheel pivot, this is quite common for 32 mm stanchion forks, my Rock Shox Tora sl 2010, Marzocchi Corsa 2012, the flex is a lot less than these forks, but when the wheel is on it can be flexed to about the same, but when wheel is off the fox 32 Evo is clearly stiffer.
  • no dropper post.
  • Bontrager RL(Race Lite) lock on grips: got good grip, but they are too hard a or me and give no dampening.19525248243_5d21846fca_b
  • 3 chainrings for a trail bike is not optimal, the problem is over big roots or obstacles you can hit it some time times, and as bigger the chainring is as more chance there is for you to crash or damage the ring.
  • The chain-stay protector does not work well, the chain will hit the zip-ties, and they will snap so the protector will be loose and will scratch the paint,and because it does not cover the whole chain-stay the inside of the chainstay will get hit by the chain, I replaced the protector with an old inner-tube instead.
  • chain slap on the Front Dérailleur: which crapes of the pant and make visible scrapes on the puller arm.
  • 24391495434_71c35e73f8_b
    Chain slap scratches
  • 24726582220_68fffd2f17_b
    Chain slap scratches
  • Bike nr1 got a bend in the headtube wall:
  • I have not received any answer why this happens or what could cause it, I will update you on that since I do.
25185797391_0cfdb76e37_o
This is how the crank looked like before it eventually failed.
  • like any suspension bike, there is some pedal-bob, but it’s minimal, I get about 10% of the travel.
  • no chain guide, the chain fell off more than 10 times the 2015 season, when jumping and riding ruff places hard, I jumped from 3 steps of stairs and if fell off)
  • Awful housing routing, the housing gets kinked in a twisted S shape, causing premature wire coating wear & housing wear.
  • (as you can see the paint got stripped off by the chain)
  • one Allen bolt, on the EVO link, was overtightened from the factory, but I managed to unscrew it by using warm water and Allen key in the freezer for few minutes & the big bolt on the chain stay and seat tube fell off, but the bike shop replaced it.
  • chain fall off when jumping sometimes, my plan is to get 11 speed and get a chain guide.
  • Tyres: Bontrager XR3 Expert, is not a very lasting tyre, because of the soft rubber, l the rear tyre lasted me few weeks, so I upgraded the rear with SE4 Team Issue tyres, which has last me to the winter came.
  • the weight is 13,6 on 18,5(virtual)(real 17.5)
  • the Fox 32 has flex/twisting, from side to side, I am about 75 kg, There is noticeable twisting in the fork when riding over huge roots fast, or through potholes, or front wheel pivot, this is quite common for 32 mm stanchion forks, my Rock Shox Tora sl 2010, Marzocchi Corsa 2012, the flex is a lot less than these forks, but when the wheel is on it can be flexed to about the same, but when wheel is off the fox 32 Evo is clearly stiffer.
  • no dropper post.
  • Bontrager RL(Race Lite) lock on grips: they are way too hard for me, but got good grip, but they are too hard for me and give no dampening, so I replaced them with ESI Extra Chunky green grips in is a pretty good match.19525248243_5d21846fca_b
  • 3 chainrings for a trail bike is not optimal, the problem is over big roots or obstacles you can hit it some time times, and as bigger the chainring is as more chance there is for you to crash or damage the ring.
  • The chain-stay protector does not work well, the chain will hit the zip-ties, and they will snap so the protector will be loose and will scratch the paint,and because it does not cover the whole chain-stay the inside of the chainstay will get hit by the chain, I replaced the protector with a old inner-tube instead.
  • chain slap on the Front Dérailleur: which crapes of the pant and make visible scrapes on the puller arm.
  • 24391495434_71c35e73f8_b
    Chain slap scratches
  • 24726582220_68fffd2f17_b
    Chain slap scratches
    https://www.youtube.com/watch?v=rlMSxm1otmg
  • Bike nr1 got a bend in the headtube wall:
  • I have not received any answer why this happens or what could cause it, I will update you on that since I do.
  • Full Specs:http://www.vitalmtb.com/product/guide/Bikes,3/Trek/Fuel-EX-7-29,12595
  • Other reviews:
  • http://reviews.mtbr.com/review-trek-fuel-ex-7-29
  • http://www.bikerumor.com/2013/05/22/first-look-2014-trek-fuel-ex-29er-weights-details-ride-impressions/

While working on my bike  I noticed  the frame protection I put on a while back, looked awkward, it looked like there was a dent in the frame,  So I  I took a closer look and indeed there was a dent

When I took the fork off to send it for service, I took pictures of it. But there was never an impact on the frame, to make such dent in the frame by impacting it I would have to land on a sharp object,  in that exact spot, which I didn’t. I of course never rode with the bearing outside of the frame with loose fork.

After replaced Evo Link & chainstay:

The bearings in that came with the frame parts were crunchy, they had little grease, I had to grease them.

After I had replaced the chainstay and rocker link, the bearing dislocation issues were gone, for a while at least, but the bolts back in the rocker link kept loosening up, which I heard and read about, apparently loose bolts are still an issue on the newer bikes.
The bent cassette cogs were still happening, but the premature chain wear was gone, the chain wore at the normal rate.
The gear hanger was getting out of true, but nowhere near as bad as when the worn out chainstay was there.

December 2017 I noticed wear on the crown race on bike nr1:
Worn crownrace December 17, 2017https://flic.kr/s/aHsmaUB1Xb

(Click on image to see all pictures in The album)

I got the forks back fro service, but I put on the fork that the less worn crown race, but after few weeks it also showed signs of wear.

I also noticed the bearings sit skewed in the headtube

there was also very noticeable signs of wear on the bearings:

very noticeable scratches.
The forks have been serviced by Ccyklon and the CSU has been replaced to the 2018 model.

 

I have swapped the fork with the most wear on the crown race in March, so far no creaking, so it looks like it was steerer & crown issue.

 

 

February 2018 update on the frame issues:

The seat stay becomes twisted

Damage to the new chainstay:

Crushed alloy from bearing slot:

 

I had to install the seat stay from the other frame.

In this period did not do any technical trail riding, but I rode some skitracks and rodeo n pavement, rode some stairs few times, did some bunny hops some wheelies, but nothing out of the ordinary, a trail frame should take this, but this frame, can barely take any commuting.

 

 

 

 

Upgrades I did:

how the bike looked like may 2018

 

  • 24173105230_3bcbca165c_c
  • the pressfit Shimano BB, is hard to remove or service without destroying it, but I had  to switch to BB30 press-fit,  I could have chosen 24 cranks,  I But I wanted 30mm spindle, direct chainring, So I went for Race Face Turbine cranks, but by doing So I had to switch the Shimano BB with to 30mmPressfit BB, So I went with the Race Face BB30, but  unlike the Shimano bb the race face BB has the has the bearings pressed directly in the BB shell, and has no plastic insert on the inner ring in the on the bearing, so the Shimano BB will not wear the spindle, but as the RaceFace has not, there will eventually be wear on the axle, but So far I have not seen any visible wear, I like how Chris King does it, the bearing play can be fine-tuned, adapters are used, the adapters keep the spindles from wearing & easily switch to other spindles/cranksets, the bearings are better sealed from contaminants and is easy to repack/regrease with special tool.  So that is what I wish for my next trail bike. So this is why I went for Chris King Threadfit BB for the 6300, I have seen a lot about Praxis BB lately, which I will look into further.
  • After upgrading to the much stiffer Race Face Turbine Cranks, I felt more of the flex in that the frame is flexing on the right side in the chainstay when turning /leaning the bike to the left, and it hits the tyre 2.3 tyre, I have a tube wrapped around the chainstay, It’s  between 1-2 mm. So by upgrading to the stiffer cranks instead of the cranks flexing the chain stay is flexing, so the flex in the frame is more significantly more noticeable with a stiffer crank. But riding while seated on asphalt the flex is not as noticeable.
This is how the Race Face BB30 looks like inside the bike. But I wish it had better protection against wet weather.

Sometime in 2016 I uninstalled the bottom bracket, I was about to install the new BB when I noticed, there was crushed alloy there.

Verdict/Conclusion:

The bike is horrible.

  • has design flaws causing fast wearing chainstay and cracks in rocker link, which cause many other issues, so it’s not good enough for me.
  • I need a much stiffer & stronger frame & stiffer fork.
  • replacing the tyre is the first thing you have to do.
  • If you ride very steep downhills a, A dropper post will definitely be the next upgrade.
  • the bad choices of components, and chainstay& seat stay, is Disappointing, the must be some flex in a frame or it will snap, but this is too much in one place.
  • The bike rides well, very stable no matter how I rode it,but ,trek did not do a good job on selecting all the components, the drive train is outdated, The wheels are too flexible and get out of true way too easily, triple chainrings is outdated, and the crank arms have too much flex. In my opinion, most riders do not need triple chainring setup, wider range cassette just replaces the Front RD so there is no point in having a front Rd.
  • Bad selection of components and too flexible frame make this a bad choice.
  • A trail bike should handle major abuse, a proper bicycle should handle an average weight rider to a heavier muscular or slightly overweight rider,  this bike can clearly not,  I am 182 and weight weighed about 74kg with gear on last time I weigh my self, but I am sure I ma heavier due to more muscle mass & heavier gear.
  • a trail bike should handle a rider commuting or sprinting, which this bike does not, the increasing issues might be to fatigue, so basically, the frame wearing out, and becoming more & more flexible.
  • Trek has been contacted: I translated it to English: ”The bearing in the Closed Convert link at the rear wheel has moved out of the chainstay. This happens when the chain has expanded, so the bearing is no longer sit securely. This can also contribute to the wheel rubbing the frame.” Even If this is the case, there is downtube Flex so much it takes the chainstays with it, so it will still be too flexible, So I basically need the whole frame that is much stiffer & stronger, that can withstand my weight, but of course frames eventually wear out, but this bike is bout 3 years.
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REVIEW: 2010 trek 3900 disc & Bontrager LT-3, 26×2.0″

MSRP (new) $529.99

http://www.trekbikes.com/us/en/bikes/2010/archive/trek/3900disc/#/us/en/archive-model/details?url=us/en/bikes/2010/archive/trek/3900disc

http://www.bikepedia.com/QuickBike/BikeSpecs.aspx?year=2010&brand=Trek&model=3900

this bike is made for commuting I have it in size 18,and in orange

the geometry so, not good for Mtb, for me, but for people with short armed and short back, this is not a bad thing, but I am about 180 cm high and i am average sized  everywhere,so  I get a very upright position, But when I was a teen i was not as big as I am now so it was ok.

which is too small of mountain biking  but for commuting its OK, you will sit upright.

the bike is no real mountain bike, frame is way too short and the handlebar is too short too, this make the bike too responsive.

ignore the sticker that say trek mountain bikes, it just refers to the standard for mountain bike frames. it’s not a mountain bike,but it can be with some upgrades.

the frame can withstand mountain biking, but the geometry is horrible for mountain biking.

cons:

  • fork : the SR Suntour SF9 XCT V2, 100mm travel  does not have the promised 100mm travel, but more like 20mm, the fork had play and it got even more play so when i was braking hard i felt like the fork would snap or fall apart. lack of adjustablity.
  • ( I upgraded to RockShox Tora sl 2010 from my 6300)
  • Shifters/triggers: the stock are v brake lever and shifters, shifters are horrible you need to swing the lever way too long to change gear.
  • Brakes: the mechanical brakes don’t work well you need to press very hard to brake. these brake are so bad that V-brakes actually are better for braking wise,not wear wise of course.so i upgraded  to hydraulic  & shifters/triggers,
  • Saddle– saddle is way too big for a fit guy like me, it wears out fast because of flex in the saddle the plastic under  it that  have screws in it will flex too so the screws will pop out.
  • tyres/tires:
  • The Bontrager LT-3, 26×2.0″ got horrible grip in the wet they are a death trap. on wet asphalt they slip and you will crash.
  • i upgraded to Bontrager XR1 Team Issue witch roll very well but have the necessary grip when you turn. http://www.bontrager.com/model/11869
  • grips- best to upgrade to silicone og lock on grips
  • pedals – pedals made of plastic is silly,the will break if you crash into something,they wear out very fast, plus no grip, and in the wet they are useless and dangerous , I recommendd straightlines defacto pedals.
  • i have defacto’s on all my bikes.
  • Handlebar–  i out crown the handle bars but they should still be wider.
  • Saddle:  the plastic plate holding it in to the rails wear out fast.screw jump out.
  • Acera rear Rear derailleur: unpractical nut on the wire clamping,and its not as durable as the Deore an up wards.
  • the headset: the plastic cover does not help much, so dirt and water qill coem in and dirt water with grease will come out,so you have to re grease it often.25221077486_cf268d17c3

my upgraded 3900 :

winter ready & upgraded 2010 Trek 3900 Disc

conclusion:

waste of money, unless you need a bike fast and it’s the only bike you can then at the point you are i the store.

I only use the 3900 as winter bike,I will run 1×9 drive train, don’t need all the gears, plus the front dérailleur does not work in  below -2 degrees.