3x8 to 1x8 conversion (Tourney bcd)

Hexz

Hey guys, i want to ask about the shimano tourney crankset. More exactly the bcd. I ve searched everywhere for it and i can’t seem to find it. If you re gonna ask why i don’t measure it myself the tourney comes with a guard and i really don’t want to take it off so if any1 knows the bcd please tell me. Thank you.

larkim

If you want to do a 3x to 1x conversion but don't want to unscrew the guard, I think you may be barking up the wrong tree...

Are the chainrings actually bolted in, or are they riveted in? It wouldn't be that unusual for a lower-end spec to be rivetted so converting down to to 1x wouldn't be possible.

keef66

I've looked at the exploded diagrams on Shimano Tech Docs and all the Tourney chainsets appear to be, as Larkim suggested, one piece jobs. Indeed the only things you can take off are the left hand crank and the chainguard

Hexz

My friend, i just need the bcd of the crank arm so i know what narrow wide chain ring to buy. After i have this information i will obciously remove the guard and all the 3 chain rings and replace them with a narrow wide chain ring to prevent the chain from falling off. I just wanted to know the Shimano Tourney Fc Tx801 crank arm bolt circle diamater so i know what chain ring to buy without buying a new crank arm.

Edit: Oh ok i understand thank you for your help. So i need to buy a new crank set. Thank you for the information and keep riding safe.

larkim

Yep, sorry about the slightly (unintended!) sarcastic tone - glad I was on the right track, it's a shame that you can't do the conversion with that crankset but better to know that now than after you'd ordered a NW ring!

New crankset is the only option, though that would feel like a waste just to throw away the two unused rings as I'd be surprised if you can get a square taper single crank with a NW ring already fitted (I might be wrong, not my area of experitise).

Alternatively you might be able to replace the BB with a newer one and then have more choice about the new crankset to go with it, but again we're talking shelling out (proportionately) a lot more cash than I suspect you were expecting if you were just hoping to ditch a few rings and replace with a £20 NW one (the £20 option is exactly what I did on one of our bikes, so I know how temptingly cost effective that option seems!).

larkim

Edit: the other option of course is just to sit the chain on the middle ring, drop the front DR completely and ride like that. With 32 middle ring it will be similar to the NW ring you might have got anyway, and if you put some sort of chain retention system on it that might be a decent enough compromise?

Hexz

larkim wrote:

Yep, sorry about the slightly (unintended!) sarcastic tone - glad I was on the right track, it's a shame that you can't do the conversion with that crankset but better to know that now than after you'd ordered a NW ring!

New crankset is the only option, though that would feel like a waste just to throw away the two unused rings as I'd be surprised if you can get a square taper single crank with a NW ring already fitted (I might be wrong, not my area of experitise).

Alternatively you might be able to replace the BB with a newer one and then have more choice about the new crankset to go with it, but again we're talking shelling out (proportionately) a lot more cash than I suspect you were expecting if you were just hoping to ditch a few rings and replace with a £20 NW one (the £20 option is exactly what I did on one of our bikes, so I know how temptingly cost effective that option seems!).

No worries my friend it's good enough that you're providing me with solid information. Thank you for taking your time to help me. To be completely honest, i might just keep it the way it is and build a new bike. But hey, maybe it isn't such a bad thing because i really do give my bike a workout in one week i would do about 210 km. I just wanted to drop some weight off and thought that it was a good idea. The bike i have is a 2017 Cube AIM Race 29 grey´n´flash orange so upgrading it maybe isn't a great idea. Thanks for the help again brother.