Upgraded Carrera Subway e bike

[ArtNuevo]

Hi,
I have just converted my Carrera Subway e-bike with a KT controller, LCD5 screen and 8 magnet PAS. All works fine i think I need to tweak a few setting on the P and C parameters but overall happy at the moment. My question is now I would like to change the crankset, the existing crankset housed the torque converter and weighs nearly 2kg, and is now not needed. Can I simply replace with another 42t crankset from online. Or is the alignment going to be different. Thanks in advance.

 

[thelarkbox]

I dunno.. but derailleur gears are Very forgiving especially when you consider many bikes use 3 chain rings 1 cm or so apart. so you should have in the region of circa 3 cm to play with..

So i would suggest its worth a punt especially if distance buying from a seller with a no quible returns policy..

since you will need an extraction tool (cheap under a fiver iirc) if you know anyone with a standard crankset on a bike invite them over or pop by with your bike n tools and check it out in advance.. or are you also replacing the bottom bracket too, and not just the crank.

 

[Waspy]

I replaced my triple crankset for a single chainring crankset from eBay.

You will want a 'narrow wide' chainring, it stops the chain falling off apparently.

Your chain line is the distance from the chainring to the centre of your frame, it should be about 50mm.

I also ordered some triple chain ring bolts and some 2mm chainring spacers.

I had to add 4mm of spacers between the spider and the chainring to bring the chainring inboard 4mm

I have links to all these things if you want.

 

[Nealh]

What is the current crankset /chainring set up ?
1X, 2X or 3X ?

 

[ArtNuevo]

I replaced my triple crankset for a single chainring crankset from eBay.

You will want a 'narrow wide' chainring, it stops the chain falling off apparently.

Your chain line is the distance from the chainring to the centre of your frame, it should be about 50mm.

I also ordered some triple chain ring bolts and some 2mm chainring spacers.

I had to add 4mm of spacers between the spider and the chainring to bring the chainring inboard 4mm

I have links to all these things if you want.

Thanks for the advice. With existing chain ring 50mm to centre as you state. Tried chainring from my other Carrera (newer version with BB sensor) and it is 55mm so yes there is a difference.

 

[ArtNuevo]

What is the current crankset /chainring set up ?
1X, 2X or 3X ?

Thanks for response. Current front chainring is a single 42t. 9 speed at the rear. Have taken chainring to 3 shops and they all want the bike in to look at. I did assume that it would be slightly simpler than they were all suggesting.

 

[saneagle]

Hi,
I have just converted my Carrera Subway e-bike with a KT controller, LCD5 screen and 8 magnet PAS. All works fine i think I need to tweak a few setting on the P and C parameters but overall happy at the moment. My question is now I would like to change the crankset, the existing crankset housed the torque converter and weighs nearly 2kg, and is now not needed. Can I simply replace with another 42t crankset from online. Or is the alignment going to be different. Thanks in advance.

Yes you can. I'm pretty sure that the bottom bracket is standard 68mm Shimano/BSA type. You can use a much lighter one. I recommend 44T to 48T, maybe 42 if you like pedalling fast or you're a big guy and don't want to go fast.

 

[Waspy]

Thanks for response. Current front chainring is a single 42t. 9 speed at the rear. Have taken chainring to 3 shops and they all want the bike in to look at. I did assume that it would be slightly simpler than they were all suggesting.

Some pictures of your BB/ crankset / chainring would help this thread

 

[ArtNuevo]

Some pictures of your BB/ crankset / chainring would help this thread

Hi have added photos as requested.

 

[thelarkbox]

not much visible taper to the square keys so with spacers you should be able to position a replacement where you want it

 

[ArtNuevo]

not much visible taper to the square keys so with spacers you should be able to position a replacement where you want it

Thanks for reply where do you put the spacers. Am I right in thinking you would by a crankset with replaceable chain ring ie 130 bcd then put spacers in the chain ring. Presumably not spacers on the square drive.
Thanks

 

[ArtNuevo]

I replaced my triple crankset for a single chainring crankset from eBay.

You will want a 'narrow wide' chainring, it stops the chain falling off apparently.

Your chain line is the distance from the chainring to the centre of your frame, it should be about 50mm.

I also ordered some triple chain ring bolts and some 2mm chainring spacers.

I had to add 4mm of spacers between the spider and the chainring to bring the chainring inboard 4mm

I have links to all these things if you want.

Hi, Waspy
Yes links would be great.
Thanks

 

[thelarkbox]

tbh first i heard about crank spacers was in @Waspy 's post above, a more standard cycle would have a round 'axle' with square tapers onto which you mount the crankset

 

[Nealh]

Thanks for reply where do you put the spacers. Am I right in thinking you would by a crankset with replaceable chain ring ie 130 bcd then put spacers in the chain ring. Presumably not spacers on the square drive.
Thanks

If you buy Shimano Hollowtech ll BB's then one can use spacers in between the BB shell & the bearing cups.

 

[Waspy]

You don't HAVE to correct your chain line but it helps gear changing and reduces wear and tear on your drive train.

Your pictures show a square taper bottom bracket so the crankset I show below would fit your bike no problem.

Crankset: https://www.ebay.co.uk/itm/124899141841?var=425979343809

Bolts: https://www.ebay.co.uk/itm/285486386713?

Spacers: https://www.ebay.co.uk/itm/234195876381?var=533810878935

 

[Waspy]

Once you have it set up you can play around with chainring sizes, you can buy them separately.

I started off with 34 tooth, currently on 42 tooth. The bigger the chain ring the less you will spin out in top gear.

 

[ArtNuevo]

Once you have it set up you can play around with chainring sizes, you can buy them separately.

I started off with 34 tooth, currently on 42 tooth. The bigger the chain ring the less you will spin out in top gear.

Thanks for the advice and explanation. I understand it better now. Think I will purchase a good quality second hand crankset and then as you said I can change chainrings and spacers to get it set up right. It makes sense now.
Thanks

 

[Waspy]

Don't forget, without a front derailleur you will need a 'Narrow Wide' chainring or your chain may fall off.

Currently you have a guard on your chain ring to keep it in place.

Alternatively you can fit one of these: