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

New: Take part in the September Giveaway for a Spider Rear Rack and a Heavy Duty Drybag from aeroe


Can I change granny gear on my 1988 Trek mtb?
#1
I have an old 1988 Trek 830 mountain bike. Because it's pretty old, I don't want to put much money into it because it wouldn't take much cost to make it a better choice to buy a newer used mountain bike. Anyhow, the bike has sentimental value and still gets the job done so here is what I want to do.
The freewheel is a 14-32 six speed and it seems hard to find a replacement. I have many broken teeth on the 32 tooth large sprocket on the freewheel so I essentially do not have my lowest gear anymore. I'm thinking about changing the front granny chainring out from the existing 28 tooth to a 24 tooth. That way my granny gear with the second largest chainring on the freewheel (28 teeth) would give me a similar gear ratio to the lowest I had (actually slightly lower). The chainrings on this bike were "Ovaltech" and as the name implies quite oval in shape. I don't think this idea caught on to much but it's what I have and they have always worked fine for me. Can I just buy a 74mm bolt circle 24 tooth chainring and install it? Will this cause and shifting problems? I really don't care if it isn't the smoothest shifting bike as long as it does shift from granny ring to middle ring. middle ring is 38 teeth and "ovaltech" as well. Lastly, when I look at chainrings, Blackspire, I found one 74mm, 24T, that had a description "Designed for 8/9 speed drivetrains". Is there any reason this chainring wouldn't work on my six speed rear freewheel?
Thanks for any advice.
TheBaker

  Reply
#2
As long as your crank has bolts to hold the chainrings on (not welded) you should be able to change out the granny gear without any major problem. I don't think the oval/round issue will matter.
However, if your freewheel has "many broken teeth" I'm guessing it's pretty old and probably due to be replaced anyway. Here (http://www.sheldonbrown.com/harris/freewheels.html#6) is an article about switching to 7 speed and here (http://harriscyclery.net/itemdetails.cfm?id=778) is a 7 sp freewheel 14-34.

  Reply


Possibly Related Threads...

Forum Jump:

[-]
10 Latest Posts
Pedals: Clip vs. Clipless
Today 07:43 PM
90's Raleigh R600
Today 06:21 PM
Know about the Hercules?
Today 04:00 PM
Proper way to torque a crank bolt on a s...
Today 03:37 PM
Where are you from and What is your favo...
Today 02:19 PM
Front Derailer fails to shift to the big...
Today 01:09 PM
Tour de France 2020
Today 12:08 PM
Do Any Electric Bike Allows You to Switc...
09-18-2020 07:23 PM
Raleigh "Trail" bike
09-17-2020 05:41 PM
Wobbling freewheel
09-17-2020 09:46 AM

[-]
Top 5 Posters This Month
no avatar 1. Jesper
34 posts
no avatar 2. G_M
14 posts
no avatar 3. Sagan97
10 posts
no avatar 4. Papa Dom
10 posts
no avatar 5. Zviedrs
9 posts