Recently bought a Giant Defy road bike. Bought for a good price but had some issues which meant I’ve not been able to ride it yet. Firstly I couldn’t get the standard non-drive pedal off. Managed to round off the metal and also the Allen key. Started to strip down the pedal so that I could remove the crank and get it in a vice. Managed to mess up the threads when using the extractor tool (bb is a square taper). Therefore I need some new cranks – square taper BB, 170mm arms, any recommendations or anyone got a spare set laying around?

Should I look to change the BB or is square taper still fairly standard on road bikes?

I didn’t realise square taper was still a thing outside of the lowest budget options. External BBs are cheap, lighter, and feel better. And you don’t have to deal with them randomly working their way loose. If I were buying a new chainset I’d be going down that route.

Should I look to change the BB or is square taper still fairly standard on road bikes?

Nope, same as mountain bikes, square taper BBs are a relic from ye olden days of steam-powered cars and stuff. Shimano and most other modern road cranksets use an outboard BB just like a mountain bike. Shimano Tiagra, which is kind of Deore level and perfectly good, is about 80 quid for a crankset. All assuming you can remove the in situ BB.

Or you could get something like this I guess:

https://www.sjscycles.co.uk/chainsets/alloy-compact-double-square-taper-chainset-5034t-170mm/

If you are changing cranks then you’ll probably need a different length BB anyway. Id just go for something better with an external BB.

Spa cycles will do a set of crank arms if you’re going to keep the bb and chainrings. There’s nothing wrong with square taper bbs, the ones on my two commuting bikes have been in place for years with no maintenance or issues

How old is the bike? Any pics?

Have a look at these crank arms before you decide to drop some cash on a whole new chainset:

https://www.spacycles.co.uk/m8b0s109p0/Drivetrain/Chainsets

I’ve not a pic that is hosted anywhere. It’s not that old I don’t think.

Never heard of spacycles but two mentions, any good?

Giant Defy 5 2014 Road Racing Bike – Frame Size Xs – Wheel 700c

You need to get a chainset that is compatible with how many gears you have. How many sprockets on the cassette? Shimano 105 is a decent chainset (5800 or 7000).

Never heard of spacycles but two mentions, any good?

Proper old school touring specialist.

The 2014 Defy 5 was 8-speed Claris with an FSA chainset. The Defy 3 and above had external BBs, the 4 and 5 were square taper. You should be fine with a 9-speed chainset, Something like R3000 Sora with external BB.

I’ve managed to get the crank off, drive side off and the bottom bracket out. The bb appears fine and no play/marks. It is indeed an 8 speed cassette, I don’t really want to do a full drive train upgrade so would need crankset that works with an 8 speed.

Any thing noted as such from Spa would be a good start.

Never heard of spacycles but two mentions, any good?

The Sugino cranks they sell are good, good range of options. I have a set on a steel road bike, no issues with the performance. Maybe not the right match for a super stiff carbon race bike but otherwise very good value and the square BBs last years, though road HT2 BBs last a lot better than the MTB equivalents anyway.

Any 8, 9, 10, 11 speed chainset will work

SJS and Spa as mentioned are best.

PS Square taper is miles better than external bearings, push fit etc. **** lasts.
Running a BB71 and BB91 on my road bikes, been there 30 years – both cartridge. Ultegra and DA/XTR equivalent.

Square taper BB on my vintage mtb, and it just lasts way longer than my external bearing-ed MTB.

I’ve a set of 170mm FSA Velo 50/34 that are more than useable – I’ve just fitted a 42/28 instead…

£30?

Matt, they square taper? If he’s not interested I may be persuaded potentially.

Square taper is fine, I’d leave as is.

Some of the best cranks currently on the market still utilise square taper, see these Rene Herse cranks. They look old school but are light and strong as they are forged. Also, some prefer internal BB’s as they tend to spin smoother and can last significantly longer compared to the modern external.

Matt – could you please send me some pics please

They look old school but are light and strong as they are forged

Can’t think of a crank you can buy now that isn’t forged though, apart from welded BMX or MTB cranks. Rene Herse were promoting about how they pass EN as if it’s something special too, practically every crank does. They’re nice but they’re a mainly a styling exercise (and why not, I like the old school look and most cranks since silver Athena or Ultegra 9s look out of place on many bikes imo)

If you messed up the extractor thread on the crank it doesn’t stop you refitting it.
I’m sure you don’t need reminding that the left side pedal has a left hand thread.

any recommendations

From the list of things you’re stripping and rounding out? I’d recommend you guve it to the LBS mechanic. And maybe while you’re at it enquire about the price of a HT2 chainset (Sora or Tiagra?)…

“ From the list of things you’re stripping and rounding out? I’d recommend you guve it to the LBS mechanic.”

Cheers, however have built plenty of bikes over the years with no problems. The pedal thread has completely seized and been unable to remove even in a vice. The threads stripped on the crank when extracting the tool. Other side no problem! The other 20+ cranks I’ve removed on my other bikes over the years have also seen no issues…

Can’t think of a crank you can buy now that isn’t forged though

I bow to your superior knowledge but I think I’m right in saying my bike has one – isn’t the cannondale SiSL2 crankset a bonded CNC Machined clamshell, they were always fairly radical when they first came out. There are other rare things like this Ingrid crank which appear to be CNC machined. Am no expert on these engineering principles but vaguely recall something about how the differences between forging and machining affect the material grain structure, or in the case of the Herse cranks he appears to be saying there is no post forge machining. Would rather have any of these than the recent Shimano self-imploding crank design, the ‘open’ clamshell design as it were…

The threads stripped on the crank when extracting the tool

When I’ve done this, it was the washer still in place and hence not enough thread engaged. Not all extractors are equal. Now using the park ones rather than the socket type. A better experience and worth the money.

Square taper is fine. Track bikes use them for a reason. Nothing spins as freely as cup and cones and no seals!

Can’t think of a crank you can buy now that isn’t forged though

3D printed Ti cranks are a thing. As are CNCed Alu ones.

Eewings? Admittedly they probably aren’t the sort of thing that the OP was looking for, but definitely not forged.

We may be deviating significantly from the OP, but this is fun…these ones are definitely ‘grown’, not mass market by any means but very pleasing: (Sturdy Cycles 3d printed)

Typical STW responses missing the point completely and discussing cranks costing more than what the OP paid on for the bike 😂🙈

…I know, but someone may have said something wrong on the internet so it stands as key importance for it to be corrected…(tongue firmly in cheek in case that’s not obvious)

For the Op: Internal BB’s are great, Square taper is fine, old looking cranks can be fine too..just remember to check the retaining bolts tightness occasionally.

Typical STW responses missing the point completely and discussing cranks costing more than what the OP paid on for the bike

While this is true, I think the OP’s question has been answered well enough, so there’s no harm in a crank porn digression.