Knowledgable chaps! Help needed.

Is there anyone knowledgeable free around Surrey Quays area to have a quick look at my bike and potentially diagnose a fault? Ive checked all the mechanic/fixing boards and im just not knowledgeable enough and i dont want my pants pulled down when i take it a shop.

Basically, creak/crunch from around crank and bb area. Doesnt do it when coasting, just when you apply force/weight. More force you apply the louder the noise. Doesnt creak when you dont peddle. No lateral movement by hand, slight flex when applying force (is that normal?). Have noticed that the crank teeth are not centre in the chain but rather to one side.

Its a square taper bb, with Pro wheel 170mm cranks, Shimano 46T chainring and a Halflink chain.

Ive Checked all bolts are tightened. Checked spokes are tight. Tightened and loosened the chain to no affect. Checked pedals and one does have a ever so slight play but thats silent.

Help :(

OH! Also, anyone know a good mech around the south east area?

Thanks

C

Have noticed that the crank teeth are not centre in the chain but rather to one side.

Chainline?

Post a photo taken from the rear, showing how the rear sprocket, chainring and chain line-up.

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Half-link chain >>>>>>>>>>>>>

Do you reckon thats whats making the noises?

In order of likelihood, I's suggest, pedals, freewheel (looks like a shimino), bb.

As a general point, I'd suggest chain cleansing / lubrication, check chainring bolts and check no tight spot when rotating the crank.

I don't understand why peple don't like the half link. It is much more airodynamic than an ordinary chain (at leaast if you had it on the other way round).

It is much more airodynamic than an ordinary chain

epic LOL thread >>>>>>>

I lol'd.

nairodynamic

Mostly when my bike makes those sorts of noises it's the crank arms working loose against the BB, probably because they are old and the taper is worn.

I remove the crank arms, clean and grease interface between BB and cranks, do up FT, ride for a bit, do up FT again and it goes away for a few months. One day I'll get new cranks and BB, but not today.

I dont get the half link thing. I googled half link chains and there was lots of posts saying theyre rubbish but no actual reasons given? The bike came with it when i bought it, i didnt pick it. But if theyre so shit, why do lots of bmx's use them?

Thanks for all the info and help guys! :D

bottom brackets fucked

BMX dudes need it to have their wheels slammed. Have you seen how short their drop outs can be?

The half link chains generally don't last as long and are more susceptible to snapping.

Ah i see. So why do you reckon the previous owner fitted one over a normal chain?

Right. Regarding the creak I would take the pedals and crank arms off, take the BB out. Once you have it out, I would clean the threads in the frame, re-grease the threads. Afterwards I would take the BB and clean with a rug (no WD40 or any other solvent shit or water etc). Lightly grease the bb and reinstall. Put a dab of grease on the square taper (again, not too much) and install crank arms. Next, lightly grease the crank bolts and install to recommended torque (in other words, give it beans). Last but not least grease the pedal threads and reinstall the pedals paying attention to which one is which.

Since you would have all the bits off and most likely clean, I would bin the silly chain and put on a new real chain.

To answer your second question, the flex is quite normal on many frames with square taper bb. Having a through spindle such as the one on SRAM omnium helps to alleviate the flex.

Last but not least, if you don't feel like doing it yourself, my boy Harvey at Cycle PS Camberwell will be able to help you.

Peace

Awesome! Ill ring harvey tomorrow.

Guys....it was the chain! Took the chain completely off and then sat on the bike bouncing my body weight off the peddles and pushing against it and it was silent. Chain back on and the creak was there. Next question is..do i have to get a single speed specific chain or can it be any kind? Any one recommend any from chain reaction cycles as i have a voucher? Thanks for all the help!!

Just get whatever's a good price: better three cheap chains, than one expensive chain.

I like Wipperman; plenty of people prefer KMC; the only chains I've read consistently poor reports of are Shimano: ironically, they seem to be the "weak link" in their line-up.

#haveyoutriedtheveal?

I'm not sure how scientific that test is @Cyklonus, the loads going through the bike are very different bouncing about statically to riding around, but the chain is a good [cheap] place to start, just don't be disheartened if it's not the cure.

It's probable you'll need a 1/8" chain rather than 3/32" as most single speeds use a the fatter size, but it's worth just looking for those numbers on your chainring / cog / freewheel to be sure.

I'm not sure how scientific that test is...

True, but binning the half-link is a good call either way :)

Binned the half link. Put a new chain on today cheap knc just to test and its running silent. Took it out for a long run and it was silent all the way. It was definately the chain. I used the wipperman on a dh before and it was really strong and reliable with no stretch. Good advice! Ill stay clear of shimano. Sram any good? Probs just get a Knc. Thankyou so much for the advice guys!

SRAM means "I shit" in Polish language. It reflects the quality of their chains well.

KMC, Wipperman or Izumi are what I would run.