New bike! :) New problems :(

peat

Hello all, This is my first post at bikeradar.

So, i recently redicovered the riding bug and decided it was really time to renew my ageing equipment. So, this weekend i purchased a Trek 4300 Disc (2011). Seemed to be a good value all-rounder for trails and roads.

Anyhoo, i have few issues.

1 - The seatpost keeps on sliding down when going over bumps etc. The guys in the shop had stuck a bit of silver grease on the post as you'd expect but i thought that it might be the problem. I de-greased it and it doesnt seem to have made much of a difference. Marginally better if at all, but i dont want to ride around with it totally unprotected like that.

2 - The supplied forks are 'Spinner 300's' (coil springs). When i take off from a hump/kerb, the forks top out (when in the air) with a large clunk. This is my first bike with suspension so i don't know if this is normal or not?

Cheers for any advice

supersonic

Is it a quick release seatpost collar? Ask them to change it for a allen key bolted one.

You most probably need stiffer springs for the fork. Hopefully the shop can supply some. But how much sag are you getting?

cooldad

1 - tighten the seatpost clamp.
2 - bottoming is ok, but not off a kerb. Springs too soft for you.

peat

It's a quick release, yes. I would prefer an allen bolt one anyway....

2 - Maybe i phrased that wrong. I suppose it would be 'topping out'. Its when the wheel lifts off the ground that the clunk occurs.

(Edited first post now)

supersonic

AH, the curse of the budget fork. They don't put the bumpers in! There is not much you can do unless you try and modify it. It is normal for a fork like this unfortunately.

peat

Thanks, i thought that might be the case.

benpinnick

Topping out is a bad sign - consider replacing those ASAP. Forks that top out badly have little or no damping (no damping in the case of the Spinner 300). The net effect is that rather than absorbing bumps, your shocks simply delay the shock until further down the trail (the energy dispersal capability of a spring is about zero). This is in fact worse than having no suspension at all IMHO.

sparrie

I agree with the last post. The fork is useless. I bought a Giant Talon 2.5 for my wife then started using it myself. I had the same problem with the forks. I persuaded Giant to Replace them and I got a set of Dart 2s fitted free of charge. Result.

peat

Ok, problem No.3.

The rear gears were slipping on day2 of ownership, i fixed it by twiddling the rear mech adjuster screws. Went out for a ride tonight and they were slipping in the mid sprockets again. Found that i was'nt even getting to the 2 larger sprockets. I adjusted the cable this time and it seemed to do the trick. In the quest for a solution, i also took the rear wheel completey off to make sure it was seated correctly.

Anyway, now i am getting some kind of vibration from the rear disc brake when its applied. Totally foxed on this one.. :?

Are all these problems typical 'new-bike' things? Does a bike take a few miles to shakedown? So far this thing has been a heartbreaker....

Cheers

sheepsteeth

when you adjusted the mech, did you need a screw driver or did you adjust the barrell adjuster?

peat

Screw driver on the H(igh) & L(ow) screws.

sheepsteeth

those screws are responsible for determining the furthest that the mech can move, they dont affect shifting other than stopping you from pushing the chain off the top or the bottom gears, they need to be set very accurately.

if you fin you have "lost" some of your gears then you need to re index the mech

im sorry to report im too lazy and not a good enough wordsmith to do a better job of explaining it than this page does:

http://www.sheldonbrown.com/derailer-adjustment.html

peat

cheers

Raymondavalon

As for the vibration on the rear brake, check/torque caliper bolts and also ensure the rotor and pads are not contaminated, grubby fingerprints can contaminate braking surfaces.
Clean them up with a decent disc brake cleaning solvent or Isopropil Alcohol.
If need be, give the pads a very light dusting with some fine sandpaper, but that's only in extreme circumstances

sheepsteeth

Peat wrote:

cheers

you're very welcome.