Chain Jumping lots of questions.

rjsterry

Yes, you can by just the big chainring, it's just that they are relatively expensive when compared with a complete chainset. CRC will do you a 52T Tiagra chainring for £30. You will need to check the BCD (bolt circle diameter - the diameter of a circle drawn through the centres of the chainring bolts) of your chainset as there are a couple of different standard sizes - 110mm and 130mm are the most common for 5-bolt chainsets, I think.

sketchley

Pictures

jonginge

More pointy teeth than Jaws

rjsterry

Yeah, wouldn't want to gash your shin on that. Time for a change I think.

<looks sheepishly at similarly pointy rings on Giant, and recalls increasing frequency of occasional chain slip>

sketchley

So new chain ring or new chainset?
If latter replace BB while I'm there or not worth the effort?

rjsterry

No point changing everything unless it's worn. A single chainring is still cheaper than a complete chainset (just), so it depends whether anything else is on its way. You should get a good few years out of a BB, and cranks don't really wear at all, so no need to change unless you just fancy something different.

Clever Pun

mudcow007 wrote:

possibly bent chainring?

cause the big ring's been battered?

veronese68

You're welcome to stop by my magnificent tool collection if you want a hand. It's an easy job. But after the last time is that wise? I would say do it sooner rather than later so the chain doesn't wear into the old teeth too much. Get Evans to do a price match if they've got one.

sketchley

Veronese68 wrote:

You're welcome to stop by my magnificent tool collection if you want a hand. It's an easy job. But after the last time is that wise? I would say do it sooner rather than later so the chain doesn't wear into the old teeth too much. Get Evans to do a price match if they've got one.

I'll stick to middle ring until it's sorted. No problem there.

I'm going to count them but I'm sure big ring is a 50T so I'm guessing a 52T won't work as chain will be too short to run 52/28 (not that I do this often).

sketchley

http://www.bicyclemagic.com/products.ph ... 0s113p2799

£20 sounds like a bargin

Headhuunter

Sketchley wrote:

So new chain ring or new chainset?
If latter replace BB while I'm there or not worth the effort?

I doubt there's anything wrong with your BB, but your big ring does look a bit toothy...

sketchley

or http://www.wiggle.co.uk/shimano-tiagra- ... -chainset/

decision decisions

rjsterry

Sketchley wrote:

or http://www.wiggle.co.uk/shimano-tiagra- ... -chainset/

decision decisions

You'll have to replace the BB with that one (your Sugino is JIS Square Taper), which is sold separately. Sounds like you are trying to justify an upgrade.

jonginge

Sketchley wrote:

or http://www.wiggle.co.uk/shimano-tiagra- ... -chainset/

decision decisions

no BB with that, though...

sketchley

Chainring replaced with a Stronglight one from Spa Cycles. £17 delivered. Just put it on the bike and no jumping on a brief test ride. So that is hopefully that.

Thank you all for advice.