Chainwheel positioning

attica · January 2009

I took apart the erm, struggling for terminology here...
<starts again>
I removed two out of three chainwheels from the spider today in an attempt to get at some of the more obscure winter grime.
Everything cleaned up a treat and then I came to re-assemble it all...

The big ring is obvious, it has a little spigot to prevent the chain getting caught twix chainwheel and crankarm, but then I noticed that the second and third rings do not have exactly the same pattern repeated 5 times (I'm referring to the little indents and gubbins designed to make shifting easier).

Having not removed the granny ring I tried to work out how the middle ring should sit.
It's far from obvious, there's are no real markings as such and nothing to suggest any one hole should match up with any one arm of the spider.

I re-assembled taking a rough guess and rode it around a bit, no problem shifting at all.

So my question is:-
Have I just been lucky or does it not matter which position you put the chainwheel on at?

By the way, any suggestions for a quick way of cleaning these or is it really a dismantle and fanny around job.

I spent 3 hours cleaning my bike today ready for the HOTA next weekend so I'm sticking to the SS for the rest of the week!

redvee · January 2009

You ride a bike with gears :shock: Shame on you

When I've stripped chainsets down the outer is obvious with the spigot or hole for spigot, the other rings I've lined up by trying to get the markings for the teeth number adjacent.

itboffin · January 2009

Snap school boy error :oops:

I did the same myself, during the massive overhaul this weekend I put the inner ring back on the wrong way and instantly noticed noisy chain and slight rubbing in certain ranges, more so than normal cross over gears. It would seem that sneaky Shimano uses a small triangle on compact inner rings and the size lettering on doubles - the cads

So are you using Shimano? is so I CAN help.

An Redvee that simply not funny you don't understand the pressure we're all under, btw why aren't you doing the HOTA.

Attica oh wise and old one, do you think short fast SS training for the rest of the week or some SS and some hill reps would be best or complete bed rest :shock:

attica · January 2009

itboffin wrote:

Snap school boy error Embarassed

I did the same myself, during the massive overhaul this weekend I put the inner ring back on the wrong way and instantly noticed noisy chain and slight rubbing in certain ranges, more so than normal cross over gears. It would seem that sneaky Shimano uses a small triangle on compact inner rings and the size lettering on doubles - the cads

So are you using Shimano? is so I CAN help.

An Redvee that simply not funny you don't understand the pressure we're all under, btw why aren't you doing the HOTA.

Attica oh wise and old one, do you think short fast SS training for the rest of the week or some SS and some hill reps would be best or complete bed rest :shock:

How dare you call me wise

If you're not up to doing the ride now you won't be by the end of the week, you'll just be more tired.
You need to recover, build up your reserves and do some easy rides just to keep your legs turning over, the last thing you want is to get on the bike on Sunday and feel like your legs are made of lead.

In your schoolboy error, did you actually put the chainring on such that the wrong side was facing out, or just in the wrong position on the spider? Mine is Shimano triple but I can't see any markings other than the tooth numbers, nothing on the actual spider arms at all.

andrewjoseph · January 2009

All the chainrings I've ever seen have a tag to mark position. this tag is to be in line with the crank arm.

this is on all chainrings for mtb's that I've seen, but I've only seen truvative and spesh on our road bikes.

itboffin · January 2009

Okay you're just OLD then

Well now then let me see ....

[lab coat on]
Whilst generally messing around with my bike and various spare parts I took both my compact & double cranksets apart I put one of them back together the right way with the logo at the top and the triangle at the bottom, the other had no such markings so I slapped it back together best I could, but knew when re-indexing the bike that something was not right, a quick search on Shimano's tech docs showed me my error, i'd put the inner on the wrong way around and not aligned, if you have a recent Shimano triple then this is the doc you need http://techdocs.shimano.com/media/techd ... 646763.pdf

It has a nice diagram showing the chainring alignments.

failing that go to the main tech docs page and download the right version for your cranks.

As for training I rested yesterday and am just about to don 50 layers of warm clothes ready for a steady 3-40 mile jaunt the rest of the week will be short fast single speed rides with perhaps some hill reps, the rest is in the hands of the gods.

I feel I might be bringing a knife to a gun fight, should I run a triple????

attica · January 2009

Thanks ITB, I'll check it out when I get home.

The purpose of compacts is to make getting up hills achievable at a high cadence but that doesn't mean you won't be able to honk your way up most of the climbs, the really really steep ones you might struggle on but so will people on triples.

If it's any consolation I have hauled my SS up Cheddar Gorge and only briefly had to consider bailing out on the very steepest hairpin, riding 42-16

Whatever gears you've got 1st gear will be enough to get you up most things, my old bike had 52 42 up front and 11 21 at the back, I never had a problem.

itboffin · January 2009

Well....?

Did you fix it?

redvee · January 2009

itboffin wrote:

Well....?

Did you fix it?

If Attica can't, BTB can

attica · January 2009

Well it's hard to say.

Seeing as it's working OK I'll leave it as it is for now. The good thing is that I didn't actually remove the chainwheel from the spider, so I know it's at least on the right way around.

Expect the owls to reverberate around Kent if I have screwed the pooch!

Cheers ITB

Chainwheel positioning

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