BCD Help…Again! 😬🙄

[Jimmy oldskool]

Can anyone tell me what BCD I have please?




I’m relatively sure it’s 110 and not compact, however as I’m a f@ckwit and haven’t yet got around to purchasing a set of verniers, I’m clueless!?

Cheers

Jimmy...

 

[Spankyfart]

Use a measuring tape?
Verniers is like bringing a baseball bat to a sushi bar.

 

[Jimmy oldskool]

Use a measuring tape?
Verniers is like bringing a baseball bat to a sushi bar.

Normal practice no?...You obviously don't eat in the same sushi bars that I do!...

 

[Spankyfart]

It's handy as you can circumvent the cranckarm, but the smallest increment is 2cm iirc.

 

[TreaderSteve]

If you're taking apart I like these sort of guides:

https://cdn.shopify.com/s/files/1/0230/9291/files/Measure_BCD.pdf?v=1655387295

I've got a cardboard one from the back of (I think it was) a TA Specialities chainring packet which lives on the shed shelf in readiness.

 

[nicklej]

I use this guide :https://www.wolftoothcomponents.com/pages/how-to-measure-bolt-circle-diameter-bcd

You don't need verniers and a tape measure is fine since there is a large enough gap betwen sizes so you don't need to be 100% precise.

 

[Guinessisgoodforyou]

This should help.

 

[Imlach]

I just use a normal ruler, as nick says there's a fair gap between the various sizes

 

[Dr Dremel]

Chainrings are Shimano SG 46/36/26, so it´s 110 BCD, no ruler needed.

 

[MattiThundrrr]

Measure the exact distance (center to center) between 2 adjacent bolt holes. Then find that number on the correct chart below to determine the BCD for your chainring. (I know you only need the 5 bolt, but wanted to include 4 bolt information for future researchers)