My bike has deveoped a knock

My bike has deveoped a knock

Author
Discussion

200bhp

Original Poster:

5,665 posts

221 months

Thursday 28th July 2011
quotequote all
Back at the end of 2010 I decided to buy myself a new bike, having had the same one for 10 years. I diddnt ride it much over the winter and have only recently started going out on it once or twice for a few hours at a time each weekend.

However, last weekend I noticed a knock which seems to be coming from the pedal area. It's a dull mechanical knock that sounds once per revolution of the pedals - Only when under reasonable heavy load (going up hills).

It's a £500 Carrera from Halfords.

Could something need tightening as it is now bedded-in ?

Any ideas?

anonymous-user

56 months

Thursday 28th July 2011
quotequote all
Could be where the crank arm joins the bottom spindle... on mine there are 2 x 5mm allen bolts attaching this & they do work a bit loose, causing the problem which you describe.

BliarOut

72,857 posts

241 months

Thursday 28th July 2011
quotequote all
Make sure the crank arms are tight then try rocking them side to side. The bottom bracket could be worn out, they don't last that long these days. I assume you're stood up when going up hill so it's not the seat?

200bhp

Original Poster:

5,665 posts

221 months

Thursday 28th July 2011
quotequote all
Thanks for the help - I doubt it's worn that quickly as I've probably only done 20-25 hours on it since new.

Yes, it does it when standing up.

voicey

2,456 posts

189 months

Thursday 28th July 2011
quotequote all
It sounds like it's less than a year old - get it back to the shop.

chopper602

2,195 posts

225 months

Thursday 28th July 2011
quotequote all
Mine did something similar, but I found it was my shoe 'very' slightly catching on the chain stay protector . . . .

Sheets Tabuer

19,161 posts

217 months

Thursday 28th July 2011
quotequote all
My bike is 8 weeks old and the crank arm has worn itself loose 3 times, I never leave home without tools now as walking home with a pedal arm in your hand is quite humiliating and it kills your feet.

So check bolts before you go out and carry a multi-tool.

Mars

8,795 posts

216 months

Thursday 28th July 2011
quotequote all
Pedals. They take a lot of knocks and are first to get wet. I bet it's one of those. It is on mine.

bleesh

1,112 posts

256 months

Thursday 28th July 2011
quotequote all
I had very similar this week - seemed to tie in with pedal rotation when under tension. Changed when I stood up and disappeared if I leant sideways trynig to find out where it was coming from.

Quick visit to LBS - they greased the stem and the handlebar assembly - and that sorted it :-D.
To my "expert" ears it was obviously a major issue with the frame or bottom bracket!!!!!