Advice on new chainset/crank after pedal falls out

spaceford wrote:

spaceford wrote:

Hi kil0ran, 

There doesn’t seem to be an option here for direct messaging. 

Could you shoot me an email to matthewblandford@yahoo.co.uk and I’ll give you my contact details and sort you out for postage. 

many thanks, 

YHM

spaceford wrote:

spaceford wrote:

Thanks for all your comments. 

The crank arm is definitely the right side ie. the one connected to the cogs. 

The arm is 170mm.

I will probably look into fitting a helicoil, but

kiloran – that’s a very kind offer. Yes, it is an Ounce brand chainset.  I’m not quite sure what you mean by the “BB”. What kind of difference would it make if your crank arm is a few mm longer than my original? 

 

Probably very little difference, young bodies are more flexible. I’ve just checked, mine are 175mm. Might just need a tiny drop of the saddle. If you can reply with your contact details I can get it in the post to you ASAP

“BB” = bottom bracket
“BB” = bottom bracket

The crankset on the Triban 3

The crankset on the Triban 3 was usually a B’Twin own-brand Ounce model.

I’ve got a used one in the shed you can have for the cost of postage. It’s probably a 172.5 as it came off a large bike, might be 175.

Something like this will do the trick:

https://www.spacycles.co.uk/m2b0s109p2000/SPA-CYCLES-XD-2-Touring-Triple-Chainset

Word of caution – stick with square taper rather than trying to remove the BB from the Triban. The cups for that BB are plastic and you are absolutely guaranteed to round them off trying to get it out. I ended up having to dremel mine out.

You say it’s the right hand

You say it’s the right hand crank – do you mean the one with the chainrings bolted on?

I ask because the other side (for the rider’s left foot) has a reverse thread and is often damaged by people who don’t realise that.

In contrast to Canyon48, I’d wager your chainset is a [what kil0ran said]. But it doesn’t matter as they’re usually interchangeable. As noted, you can replace it with another 50/39/30 (what would be known as ‘road triple’ sizes) square taper unit, or a 48-38-28 (sometimes called ‘touring’ or ‘trekking’ sizes). You may be able to find just the ‘spider’, i.e. the right crank arm cheaply on eBay – if so, you’d need to be sure it had the same bolt spacing for the chainrings (probably 110mm BCD) and check your chainrings are actually removable – they probably are but some really cheap units aren’t.

You might need to move the front derailleur down a fraction (and adjust its cable tension) to maintain good shifting.

Finally, as kil0ran notes, the cranks come in different lengths. It’s usually stamped somewhere on the back and is often 170, 172.5 or 175. Being the small Triban, it’s possible it’s shorter – 165mm is unusual but possible (it should be more common on smaller bikes). It would be nice to have the exact same size each side but 2.5mm is unlikely to be noticeable. 175mm on one side and 165mm on the other maybe more so… (although I don’t know!)

I imagine the cranks are

I imagine the cranks are either suntour or shimano, it should say on the side somewhere. You can only replace a triple with a triple (3 chainrings). You can replace the crankset with a similar one but with a different number of teeth.

Lots on ebay https://www.ebay.co.uk/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR9.TRC1.A0.H0.Xtriple+square+taper.TRS0&_nkw=triple+square+taper&_sacat=0

It probably has a square taper spindle, this is really easy to remove and install using a crank arm puller https://www.youtube.com/watch?v=cPQyQnNdews

Depending on the price (maybe up to £50), it might be more economical to buy a new bike.