Chain sizing error - too short?

[mojomonkey]

Flubbed chain replacement this weekend. I normally go with 106 links, but am now at 104. 106 is what the shop that initially assembled the bike used so I've just been blindly replicating that. I can still shift into big-big (hanging in a stand) but I'm wondering if it is cutting it too close given how extended the rear derailleur is. Still a little play in it, but not sure it is sufficient when actually riding if I were to try and hit that combo.

Pics in big-big and small-small below for reference. What do you think? I'd obviously not regularly use either extreme, but don't want to risk damage if I'm not paying attention. Chalk it up to a lesson learned on being more careful before trimming the chain and just put on a new one at 106 links? Think the shop's length was not ideal anyway?

In any case, fine for an easy ride after work as long as I stay out of the extremes until I can pick up and put on a replacement?

[mcduff]

There's not very much right about that.

If you are using 28t or less on the back then size the chain by wrapping it round big-big WITHOUT threading it through the mech. See where the ends would join (outer to inner) then add two links.

[JayKosta]

I think that will be adequate.
Problems happen when the chain, jockey pulley, or the cage cannot move 'inward' enough because it rubs against the SIDE of the larger cog. There needs to be enough clearance for the chain, pulley, and cage to easily move UNDER the cog without any mechanical interference other than the chain jumping from 1 cog to another.

Jay Kosta
Endwell NY USA

[mojomonkey]

mcduff - I'm not following your comment. I understand the idea on sizing a chain but wasn't sure of the takeaway since it was already on. Were you indicating you think it falls well short of that guideline from eyballing in the pics as-is?

Jay - thanks for highlighting some items to keep in mind / check.

I did throw caution to the wind and ride on it Monday, taking extra care to not avoid the bigger gear combos. I picked up a new chain and am planning to go back to 106 links, though I'll test it on the big rings first to see how it fares. I have logged thousands of miles with the chain at 106 links so I'm not too concerned about it being too bad

[King Boonen]

Do this with the new chain:



Always works.

[mcduff]

Do this with the new chain:



Always works.

For 28+ toothed cassette .

For 27 or smaller its better to size chain through mech in highest gear and aim for jockey wheels to be vertically inline

To be honest, whilst stuff often works, its often better to read the actual installation instructions as there are subtleties. For example always fit Shimano chains with logo facing outwards as the links are chamfered for smoothest shifting. You even have to join them a particular way round for maximum strength. Wipperman chains need the quicklink installed a particular way up. Etc etc

Can you tell I'm bored?

[mcduff]

mcduff - I'm not following your comment. I understand the idea on sizing a chain but wasn't sure of the takeaway since it was already on. Were you indicating you think it falls well short of that guideline from eyballing in the pics as-is?

Yes, not for long term riding, but you probably won't die with cautious riding whilst waiting for a new one

[King Boonen]

I've found it works fine, even for a 23 tooth to be honest.

[mcduff]

Oh it'll work yes. But there's 'fine' and then there's totally anally perfect

[King Boonen]

Oh it'll work yes. But there's 'fine' and then there's totally anally perfect

I've bought a 2nd hand groupset (10-speed Ultegra 6700 if you wondered) and have three cassettes, 23, 25, and 28 with it. My plan is to use the same chain and deal with the imperfectness of it and I was going to use the 2 links method on the 25, which I think should give me the leeway for both the 23 and 28. What do you reckon? I'm also going back to a compact. As much as I like the small gaps on the 53/39, I hardly ever use 53-11 and I can get similar changes on the 11-23 which will probably be the most used cassette.

[mcduff]

I'm sure it'll be fine (just not anally perfect )

I don't use 53\39 anymore. Mid compact and a 28t will get me up anywhere, but I do have a compact in the bike that gets luggaged up.

Lost the 53\39 for the same reason as you, plus compact or mid compact makes even more sense with 11sp.

Good luck with the build!

[King Boonen]

I was imagining you reading that and coming out in a cold sweat

To be honest I think I'm unlikely to use the 28 cassette much at all. It'll be put on for big days with lots of climbing in remote areas where saving the legs might mean the difference between making it back in the light or not, but I'm likely to use the 23 or 25 block pretty much all the time, especially on a compact.

The best racers I know are on compacts, they occasionally change for mid-rings but hardly ever. I know some people really like the bigger gears on the standard and I do ride big fixed gears, but I won't lose that much with the compact and I'll gain a couple that might help with the terrible roads in Scotland

[mcduff]

I was imagining you reading that and coming out in a cold sweat

I had to have a lie down

To be honest I think I'm unlikely to use the 28 cassette much at all. It'll be put on for big days with lots of climbing in remote areas where saving the legs might mean the difference between making it back in the light or not, but I'm likely to use the 23 or 25 block pretty much all the time, especially on a compact.

The best racers I know are on compacts, they occasionally change for mid-rings but hardly ever. I know some people really like the bigger gears on the standard and I do ride big fixed gears, but I won't lose that much with the compact and I'll gain a couple that might help with the terrible roads in Scotland

My size of my gears changes in an inversely proportional way to the size of my beergut

Whereabouts in Scotland are you?

[King Boonen]

Having very recently moved and not riding for a while I know the feeling! I'm in Glasgow, some fantastic riding around here north and south.

[mcduff]

Having very recently moved and not riding for a while I know the feeling! I'm in Glasgow, some fantastic riding around here north and south.

I'm ashamed to admit I've never been to Glasgow, but pretty much everything north of Glasgow is amazing all the way to the top. I did the obligatory E2E a decade ago and routed south from Betty hill down the Strathnaver road to Lairg, on to Inverness the alongside Lochness to Fort William. Then I hit the west coast and the islands.

It was sunny. No midgies. I think you know just how lucky I was

[King Boonen]

It's a brilliant city. Loves to play of the hardman/friendly image but it's changed significantly even in the decade or so that I've been here. The Barras is now a hipster drinking mecca!

My usual weekend rides will take in a few climbs North of Glasgow with Dukes Pass, Crow Road, Tak Ma Doon, Glen Fruin and Glen Douglas being fairly regular along with a good number of lesser known climbs to the North. I don't head south much but I'm starting to and there's some good stuff down there around Wanlockhead and Glen Taggart, Brisbane Glen out west etc. Then there is Argyll and Bute, Arran (which I still haven't ridden) Arrochar Alps and the Rest and Be Thankful and Hells Glen...

I'm actually really spoilt for riding from my door and a train journey makes it even better!

I need to get further North this summer, Bealach Mor is on my list of events to do.

Groupset all fitted, just need to add the cables, chain, cassette and tune it all up.

[mcduff]

I know Wanlockhead and Leadhills. I routed there on the E2E. We went from Lochgilbhead to Tarbert, to Arran, round it, then crossed to Ardrossan and rode to Leadhills (quite a long day). I had a rudimentary GPS and after about 115 miles I'd was expecting to arrive at Leadhills...but Leadhills just didn't want to appear. We went up and up and up. One eternally long climb on those red tarmac roads. Around every corner we expected Leadhills to appear...but it didn't. Eventually we arrived in Leadhills to be greeted by a sign which said " Leadhills...highest village in Scotland ".

For many money the best bit for riding is in the region of Bealach. All the way up the coast to Ullapool. It gets pretty bleak beyond there.

[King Boonen]

Sounds brilliant. There's loads of good riding around here. Sometimes you have to put up with some horrible roads though, like the A82 and the A9.

[mcduff]

That's Scotland. If there are two major towns and only in be road between them you know its going to be hairy...even though it might look like a minor rural road.

[mojomonkey]

FWIW, I did finally get back around to putting on a new chain. Using the big/big method above (I have 28 in the back) I ended up with 106 (the original value from the shop-installed initial chain).

I also got in a handful of rides with the short chain on without accidentally ending up in the big/big combo and thrived on the daring