Chain ring upgrade-- Is it safe?

GoldenMotor.com

nubikeshop

New Member
Aug 23, 2009
5
0
0
In Virginia
Hey all. A build of mine has a 68.5cc with a 44 tooth rear chain ring. Gets above 30 easily, max of 39 downhill. I was curious if it would be safe to upgrade to a 36 or lower tooth chain ring. It would be cool to get some extra speed out of this thing, but would I be seriously compromising safety, structural integrity, ability to start easily, etc...?

Thanks everyone
 

azbill

Active Member
May 18, 2008
3,358
5
38
63
Fountain Hills, Arizona
a 36 will give more top-end at the cost of bottom
ie...more speed but less torque
hills will be harder and so will launch
your rpms will be lower for same cruising speed = longer engine life
hope that helped :)
 

Retmachinist

New Member
Oct 21, 2008
635
22
0
Urbandale Ia
Hey all. A build of mine has a 68.5cc with a 44 tooth rear chain ring. Gets above 30 easily, max of 39 downhill. I was curious if it would be safe to upgrade to a 36 or lower tooth chain ring. It would be cool to get some extra speed out of this thing, but would I be seriously compromising safety, structural integrity, ability to start easily, etc...?

Thanks everyone
I would say it all depends on how safe you think your bicycle is at 40 m.p.h. Most of these bikes weren't made for that for any extended period of time.
Myself, I only use the best components and some very good tires, and still don't care to go 40.m.p.h.
That is strictly my opinion!

John
 

turtle tedd

Member
Jul 18, 2009
153
0
16
florida
40mph ..safe..no..a bicycle is not a motorcycle....I also use the best moving parts and the best tires..I think 30mph is pushing your luck
 

azbill

Active Member
May 18, 2008
3,358
5
38
63
Fountain Hills, Arizona
do you pedal a lot now ?
when I did mt lemon, I was on the deviate and was using a 48,,,never pedalled once
but, on the jag I pulled the trailer all over the hills here with a 40