problems since p*ncture repair

E11a

New Member
I'm very new to bike repairs but want to learn - please be gentle with me!

I had my first ever p*ncture on Tuesday, managed to patch the inner tube and put everything back together, making sure the chain went back onto the smallest sprocket and reconnecting the brakes. The wheel looks and feels as though it's in properly but just to make sure I've undone the wheel lock and put pressure on the saddle before locking it again.

I took my bike out for a test ride (c. 7 Km) and found that right rear brake pad was rubbing on the rim. A kind cyclist stopped to see if I needed any help, pulled the brake pad very slightly and it was fine. Use the rear brakes and it stuck. I adjusted the screws, sprayed some GT85 on the pivots, and oiled the brake cable and it looks and feels a lot better.

On tonight's test ride (c. 12 Km) the chain was rubbing against the front derailleur when on the middle front chain ring and the smallest rear sprocket. All the other gears when using the middle chain ring seem fine. I've had problems changing from the small to middle chanring since I bought the bike (new) but the LBS says there's nothing wrong, although I had to go back a couple of days after I bought the it because the wheel wasn't true.

I'm happy to keep making adjustments and oiling/greasing but does this sound right? I think I'm a bit nervous about doing something wrong and damaging my bike (cuts and bruises heal!).

Thanks.
 

cyberknight

As long as I breathe, I attack.
You should only be using the smallest ( fastest i assume you mean? ) sprocket with the biggest chain ring at the front anyway.Otherwise you can get as you described chain rub that wears your chain faster.

Is it a new bike?
if so you will get a bit of cable stretch anyway and the shop you bought the bike from should adjust it free of charge.

Finally check this website out for repairs / maintenance and good luck with the bike, it gives you great satisfaction to maintain your own bike :blush:

http://bicycletutor.com/
 

Tynan

Veteran
Location
e4
cyberknight said:
You should only be using the smallest ( fastest i assume you mean? ) sprocket with the biggest chain ring at the front anyway.Otherwise you can get as you described chain rub that wears your chain faster.
really?
 

cyberknight

As long as I breathe, I attack.
Tynan said:
If you cant post constructively mate don't bother , i might be wrong and would gladly accept any other reasoning based on experience etc that would be correct .Please use a meaningful reason why rather than a one liner that does not help the OP at all.
 

Mark_Robson

Senior Member
IMHO you can set up the trimming on the middle ring on a treble to whichever side that you prefer.

I have trimmed mine so that there is no rub on the smallest cog on the cassette as I very rarely use the bigger cog while using the middle chain ring.

I guess that this is purely up to personal preference as there doesn't seem to be much of an issue with the chain line regardless of which way that you trim for the middle ring.

I'm waiting to get shot down in flames here. :wacko:
 

battered

Guru
My rule of thumb is that I set up the shifters so I can use all the gears on the middle ring without anything rubbing. I do avoid running for extended periods with it on either extreme but I'm not too hung up about it. Certainly on my old 3x 8spd MTB commuter I spent years riding around mostly in "middle-top" and the transmission mechanicals lasted for ever. Shame the wheel bearings and rims weren't the same!

Obviously it's best practice to avoid the bottom 3 gears or so when using the big ring and the top 3 gears on the small ring, but again you won't actually break anything. It's wearing the chain a bit faster, of course, and it's inefficient pedalling, but if we are only talking about a few minutes while you sort out a better arrangement it's not worth getting too hung up about it.
 
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