Chainring upgrade
05-16-25 | 11:34 AM
#1
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Joined: May 2020
Posts: 41
Likes: 2
Chainring upgrade
My son is 11 and competes in triathlons/ duathlons and a few road races throughout the year
He has an HUPcc road racing bike I got from the UK in size 48. It's a kids specific road bike which takes full size adult wheels
it came with a single chainring (recommended) size
38T. He uses 150 cranks
The cranks are just plain SQT cranks 104bcd 4 bolt with narrow Q factor. (Taken from their website)
I want to upgrade him to either a double chainring set up which will involve a new 2x11 chainring keeping tie same length cranks like tie Croder spirit modular along with a new left hand shifter for the chainring and front derailleur
Or
Get him a bigger chainring 46 or 48 and increase the range in his cassette from an 11-32 which he currently uses
Most if not all of the bigger chainrings are either 107 or 110 bcd. How will this affect the sizing and fitting or is it even possible
i want to spend as little as possible as he'll likely grow out of the bike in a year or so
any thoughts
thanks
He has an HUPcc road racing bike I got from the UK in size 48. It's a kids specific road bike which takes full size adult wheels
it came with a single chainring (recommended) size
38T. He uses 150 cranks
The cranks are just plain SQT cranks 104bcd 4 bolt with narrow Q factor. (Taken from their website)
I want to upgrade him to either a double chainring set up which will involve a new 2x11 chainring keeping tie same length cranks like tie Croder spirit modular along with a new left hand shifter for the chainring and front derailleur
Or
Get him a bigger chainring 46 or 48 and increase the range in his cassette from an 11-32 which he currently uses
Most if not all of the bigger chainrings are either 107 or 110 bcd. How will this affect the sizing and fitting or is it even possible
i want to spend as little as possible as he'll likely grow out of the bike in a year or so
any thoughts
thanks
05-16-25 | 12:13 PM
#2
Senior Member
Joined: Apr 2016
Posts: 3,849
Likes: 1,777
My son is 11 and competes in triathlons/ duathlons and a few road races throughout the year
He has an HUPcc road racing bike I got from the UK in size 48. It's a kids specific road bike which takes full size adult wheels
it came with a single chainring (recommended) size
38T. He uses 150 cranks
The cranks are just plain SQT cranks 104bcd 4 bolt with narrow Q factor. (Taken from their website)
I want to upgrade him to either a double chainring set up which will involve a new 2x11 chainring keeping tie same length cranks like tie Croder spirit modular along with a new left hand shifter for the chainring and front derailleur
Or
Get him a bigger chainring 46 or 48 and increase the range in his cassette from an 11-32 which he currently uses
Most if not all of the bigger chainrings are either 107 or 110 bcd. How will this affect the sizing and fitting or is it even possible
i want to spend as little as possible as he'll likely grow out of the bike in a year or so
any thoughts
He has an HUPcc road racing bike I got from the UK in size 48. It's a kids specific road bike which takes full size adult wheels
it came with a single chainring (recommended) size
38T. He uses 150 cranks
The cranks are just plain SQT cranks 104bcd 4 bolt with narrow Q factor. (Taken from their website)
I want to upgrade him to either a double chainring set up which will involve a new 2x11 chainring keeping tie same length cranks like tie Croder spirit modular along with a new left hand shifter for the chainring and front derailleur
Or
Get him a bigger chainring 46 or 48 and increase the range in his cassette from an 11-32 which he currently uses
Most if not all of the bigger chainrings are either 107 or 110 bcd. How will this affect the sizing and fitting or is it even possible
i want to spend as little as possible as he'll likely grow out of the bike in a year or so
any thoughts
https://www.aliexpress.com/item/1005004208531123.html
05-16-25 | 12:35 PM
#3
Senior Member
Joined: Jul 2015
Posts: 7,413
Likes: 3,250
From: NW Oregon
Bikes: 1982 Trek 930R Custom, '91 Diamondback Ascent w/ XT, XTR updates, Fuji Team Pro CF road flyer, Specialized Sirrus Gravel Convert, '09 Comencal Meta 5.5 XC, '02 Marin MBX500, '84 Gitane Criterium bike
watch out for Chain ring hitting the chain stay of the frame....
Chain rings up to 52t can be found for 104BCD on Ebay... my Sirrus gravel bike has a Shimano 48-36-26t triple on it, 104BCD...
Origin8 has a wide selection of short crank arms and configurations. I'd up the length in advance of his pending growth surge...
https://origin8.bike/
Chain rings up to 52t can be found for 104BCD on Ebay... my Sirrus gravel bike has a Shimano 48-36-26t triple on it, 104BCD...
Origin8 has a wide selection of short crank arms and configurations. I'd up the length in advance of his pending growth surge...
https://origin8.bike/
Last edited by maddog34; 05-16-25 at 12:55 PM.
05-16-25 | 12:37 PM
#4
Senior Member
Joined: Jul 2015
Posts: 7,413
Likes: 3,250
From: NW Oregon
Bikes: 1982 Trek 930R Custom, '91 Diamondback Ascent w/ XT, XTR updates, Fuji Team Pro CF road flyer, Specialized Sirrus Gravel Convert, '09 Comencal Meta 5.5 XC, '02 Marin MBX500, '84 Gitane Criterium bike
Something like this? 152mm 39/50 complete with bottom bracket:
https://www.aliexpress.com/item/1005004208531123.html
https://www.aliexpress.com/item/1005004208531123.html
05-16-25 | 02:49 PM
#6
Facts just confuse people
Joined: Jul 2017
Posts: 19,341
Likes: 7,062
From: Mississippi
Bikes: Tarmac Disc Comp Di2 - 2020
Why do you want to stick with square tapers? That frame probably has a BSA threaded BB that is 68mm wide. You could put most any two piece Shimano road crank on it. The BB is inexpensive and easy to change out with just a few special tools. You do realize you'll need a front derailleur and STI for it. The FD is inexpensive, but the STI will cost some depending on what you get.
Contacting HUPcc might get you the answer of whether or not the more normal size 2 piece Shimano cranks will rub on the stays or not..
Your son may not fit that bike too much longer. So consider how much you want to put into that size frame.
Contacting HUPcc might get you the answer of whether or not the more normal size 2 piece Shimano cranks will rub on the stays or not..
Your son may not fit that bike too much longer. So consider how much you want to put into that size frame.
