Just got into the whole bike thing and I've been slowly dismantling and rebuilding an old spare bike I have to learn the ropes.

Was gifted a crankset but I noticed a ding/bend in the middle chainring and it wouldn't turn without jumping, so I took it all to bits and straightened that out. When I put it back together, I knew right away something was wrong. There's clearly not enough of a gap between the inner and middle rings and the chain gets caught. It doesn't seem to matter which way around I put the two rings – it's too damn close either way.

Couple of pics below. Have I done something impressively stupid or are they just shagged? Time to start a "WTD: cheap crankset" thread?

Middle ring on backwards, also worth checking that you've put the little bumps on the inside of the rings in-line behind the crankarm as it aligns them for better shifting.
Also worth checking if you are missing spacers from the inner ring, some, but not all,chainsets have them.

Hmmm – I tried the middle ring on the other way and it looked far too close to the outer ring. I should have paid better attention when I took it to bits!

Maybe the middle ring is just too twisted and bent to be any use.

What Coatesy said.

Those lump that protrude from the plane of the middle ring are shifting ramps that help the chain up from the smallest ring and need to be facing said smallest ring.

If you do decide to get a new chainset, the lastest Shimano Deore ones are astonishingly good value-for-money and a proper bargain when you shop around.

maybe, defo on backwards in the pic though. Always a bit awkward straightening something that needs to go back in a certain position like rings do.

Cheers, folks. I'll swap it around again tomorrow and see how bad it looks.

Always a bit awkward straightening something that needs to go back in a certain position like rings do.

with respect, straightening would not result in dishing, which is what would be required to throw the alignment out…

Know what you're saying,but they very rarely end up "straight" straight, and often end up with a bit of an angle to them (probably due to the ramps etc pressed into them).I've tried salvaging quite a few for customers, but often end up resorting to new ones in the end.

Swapped around and still looks pretty bent and horrible but it's not even worth buying a replacement for an old bike like this.

Thanks for the info, everyone.

Nice thread name – 29 short of a googlewhack.

Great album title/band name too.

Teenage Death Metal band from Slough?

Sod it. Got a new crankset and a new BB while I was at it. It'll be more fun to get this bike going than to buy another one.

Bugger. I've got something like this which appears to be just the job for the new bottom bracket but the current one is the older style.

I've also got the tools in the picture below, though I don't yet know what they all are. 😳 Do I have what I need to remove the old one?

I also have a hammer btw.

glenp – Member

Nice thread name – 29 short of a googlewhack.

I got a googlewhack a few years ago after reading the book. It was 'rastafarian flapjack'. Not a googlewhack any more though 🙁

Sounds like you need a C-spanner, peg spanner, and 32mm(I think)open ender,(not in your box of tools, very rare kit nowadays)probably cheaper to nip the frame to the LBS than buy the bits.

Cheers for the info, coatesy.

I've just had a go at it and a pair of water pump pliers got one half (the notched half) off no bother. The other side (see below) is stuck fast but I think a bigger adjustable spanner and a hammer might do the trick tomorrow, unless it's siezed.

I'm going to get a dram.

> probably cheaper to nip the frame to the LBS than buy the bits

You were right. Went to B&Q earlier and a big enough spanner would cost about a fiver less than the whole bike did. Bike shop tomorrow.

Get a metal bar welded to the cup – will give you plenty of leverage to remove it.

Welding, eh! That sounds more exciting, certainly.

I think the bike shop will probably try a big spanner first though, however much I might encourage them to try your approach.

Got my mitts on the right spanner after all but I think I'm just going to donate this poor old thing to The Bike Station.

Thanks again for all the wise words, folks.

The nice purple replacement:

I'll try not to put anything on it backwards! :O)

I managed to do it again! I only went and put the outer ring on the wrong side of the spider so it was right next to the middle ring this time.

Jesus wept.

I've managed to get different spring tensions on the two sides of the rear brake when I put that back on as well. They'll have to come off again.

The learning curve continues …