Have questions or want to discuss cycling? Join Now or Sign In to participate in the BikeRide community.

New: Take Part in the new April's Giveaway for a Chance to Win the Euybike S4 Pro Max ebike worth $1299


Replacing crankset - chainline and bottom bracket question
#1
Hi all,

I have a bike that I'm doing up as a project and I need to replace the bottom bracket (square taper). Since the front chainring (single, 46 teeth) is pretty badly worn I was going to take the opportunity and replace that as well. But what to get as replacement?

At the back I've got a 6-speed freewheel with a chain line of 38 mm. The bike is nothing special, it's more for fun and the learning experience (my first project..), so I'd like to keep the costs down. I was looking at some budget cranksets on ebay but most of them don't specify what kind of bottom bracket length to use. How do I find a crankset/bottom bracket combination that will work and also give me a narrow enough chain line? Is it just a matter of trial and error (that could get quite expensive if I'm unlucky I guess..) or is there something I should look out for?

I found a cheap one that for a change specified BB and chain line: 131 mm BB and 50 mm chain line.
https://www.rosebikes.com/article/m-wave-single-crankset/aid:485066
Can I just use a shorter BB to get a narrower chain line or will that not fit? Do you know of a combination that could work?

Thanks a lot!
  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
2011 GT Tachyon upgrade/mod
Today 08:45 AM
Doctors are Prescribing Cycling
Yesterday 09:50 PM
What was your first bicycle?
Yesterday 09:17 PM
New Rider Here — Momo + Viribus = Ready ...
Yesterday 09:15 PM
The great thing about trikes
Yesterday 03:47 AM
New member old rider
04-22-2025 06:32 PM
Tubeless vs. tubes: What are the pros an...
04-22-2025 06:30 PM
Shoes for ingrown toenail
04-22-2025 05:13 PM
Good morning form Alberta CA
04-22-2025 12:24 PM
Let me introduce myself
04-22-2025 09:01 AM

[-]
Top 5 Posters This Month
no avatar 1. GirishH
24 posts
no avatar 2. SPINMAN
14 posts
no avatar 3. Flowrider
13 posts
no avatar 4. meamoantonio
13 posts
no avatar 5. enkei
11 posts