[Walshinoz]

Hi,
Be grateful for views and experience. I am building my own bike, first time but I have done extensive research    . I am going for a 1 x 11 set-up and it is for use as a road / gravel / firm off-road bike, so the tyres will be approx between 30 to 35mm. My question is how important is it to get the ‘perfect’ chainline given that: a) there is only one drive chain and skinny tyres so little chance of chainrub, and b) modern chains are a lot more flexible. I am not saying I will be lining up with cogs 1, 2, 3, 8, 9, 10 or 11. But if the line was somewhere between, say, cogs 4 to 7 would that be OK? Or do I really need to be aiming for the perfect line between drivetrain and 5.5 on the cassette?
Thanks all

Topic

[Walshinoz]

Thanks for this example. It

Thanks for this example. It may lead me to think it through a bit more. I have a 32t chainwheel and a Sunrace 11:46 cassette (my trip has some pretty tasty gradients!). Thanks for the advice on chainline and spacers etc. Much appreciaetd.

Cheers

[Ihatecheese]

I changed my 2x roadbike to

I changed my 2x roadbike to 1x as I amended to a flat bar. I lined up the chainlines with the 4-5 gear, more towards 4 as I pedal in the higher gears Vs lower on the flats round here. 

I used a combination of BB spacers and metal washers on the direct mount crankset to get it lined up correctly for me. 

Still if I had a cassette larger than around 28t then the chain may skip Down the cassette if you backpedaled. Fine with my 11-26 with a 40t chainring (so fairly easy gearing and the chainline was more of a challenge with larger chainrings).

If the chainstay was shorter then could cause more problems. It is 415mm on my frame. It’s not a gravel bike, just a regular roadbike with bsa30 BB thankfully. so 24mm tires which are about 28mm when mounted on the roval rim brake wheels.

[Walshinoz]

Wow, thanks for the tip. He

Wow, thanks for the tip. He certainly sounds like the kind of expert I need to read up on. Appreciate the heads-up.

Many thanks both

[mike the bike]

Definitely look him up, he is

Definitely look him up, he is a genuine legend.  Skilled and versatile rider, mega-successful author, collector of useful facts, fount of technical knowledge and all-round good egg.  He’s done it all and, despite the advancing years, is always looking for new stuff to do, even if it’s done at a more stately pace.

[Walshinoz]

Many thanks for the response.

Many thanks for the response. I’ve not heard of Zinn so I’ll have a look at that. Appreciate the heads-up on that and the advice, much appreciated.

Cheers 

 

[Drinfinity]

According to Zinn, you would

According to Zinn, you would go for a 47mm chainline. This will give you best shifting and least wear.

[Author]

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