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

New: Take part in the October Giveaway for the Haven Bicycle Co. beach cruiser


Im new. Need help.
#1
I have an entry level MB Diamondback Sorrento from 2011 and I need a new crank set and FD. Currently, my bike has a MTB 24/32/42t and my BB width is not specified. I'm looking for a replacement crank set without breaking the bank. If I have to get a new chain or BB then so be it. But I'm trying to avoid a front end rebuild.

For reference, my back cassette is a 7-speed 14-28.

Can I change chainring sizes without getting a new BB? And how do I know it will be compatible with my frame and rear cassette? Insight would be much appreciated.
  Reply
#2
You can measure the BB shell width (in mm) yourself with a ruler. If the specs for the bike list the specific crank just look up the length of spindle that fits it. Your replacement should take the same spindle length. If you replace BB and cranks you need to match "chainline" (Google it).
  Reply
#3
Please also note, that you likely have a freewheel, not a cassette.

Measure your chain for stretch; the only tool you need is a ruler. There are guidelines on the web, each person has their own, I am rather conservative: if there a 1/16" of stretch, replace the chain, if there is an 1/8" of stretch, replace both the chain and the freewheel/cassette.
Nigel
  Reply
#4
If the chain is not "stretched" but you put on a crank with a bigger large chainwheel you may have to replace the chain anyway. Look up "sizing bike chain."
  Reply
#5
Could someone help me out? I recently purchased a new single speed bike sprocket. I put it on my bike and I had to make the chain smaller. Anyways I got everything put together and its as if the bike doesn't have enough tension when you pedal. like when you pedal it feels like the chain isn't even on. the cranks spin almost to freely.
  Reply
#6
(02-13-2015, 10:04 PM)jaydenthecreator Wrote:  Could someone help me out? I recently purchased a new single speed bike sprocket. I put it on my bike and I had to make the chain smaller. Anyways I got everything put together and its as if the bike doesn't have enough tension when you pedal. like when you pedal it feels like the chain isn't even on. the cranks spin almost to freely.

Lift the back of the bike up in the air and turn the cranks. When the cranks turn, does it make the back wheel spin or does the rear sprocket just spin without turning the wheel? And just to confirm, did you put on a single speed freewheel (where you can coast) or a fixed cog (where if you pedal backwards, the wheel turns backwards)?

[Also, it's best to start a new thread when you have a question, don't just add on to an old thread. And you don't need to post the same question multiple times. It won't get you a faster response and it's just going to annoy people. FYI]
  Reply


Forum Jump:

[-]
10 Latest Posts
[Sponsored] Souke Sports Cycling Apparel...
Today 04:19 AM
What was your first bicycle?
Yesterday 03:42 PM
WD40 on chain?
Yesterday 07:29 AM
VINTAGE DERAILLEURS: Campagnolo 50s-80s
Yesterday 02:37 AM
What's your No.1 concern when you purcha...
10-17-2021 09:18 PM
Chain skips under heavy load when pedall...
10-17-2021 06:18 PM
Gears changing by themselves
10-17-2021 06:05 PM
Bike evaluation
10-16-2021 02:06 AM
V Brakes just won’t adjust properly
10-16-2021 12:19 AM
Is this frame dent a concern?
10-13-2021 04:50 PM

[-]
Join BikeRide on Strava
Feel free to join if you are on Strava: www.strava.com/clubs/bikeridecom

[-]
Top 5 Posters This Month
no avatar 1. Souke Sports
27 posts
no avatar 2. Criminal
11 posts
no avatar 3. ReapThaWhirlwind
10 posts
no avatar 4. Zviedrs
9 posts
no avatar 5. JoJoJo
9 posts