Yamaha SR125 K&N filter? - Page 6
Close

Yamaha SR125 K&N filter?

This is a discussion on Yamaha SR125 K&N filter? within the Project Builds forums, part of the Caferacer.net Forums category; 8.5 eh ? tara,see how easily they go off in a wrong direction ? tight fitting leathers will go along way for speeding things up ...

Page 6 of 7 FirstFirst ... 4567 LastLast
Results 51 to 60 of 65
Like Tree5Likes

Thread: Yamaha SR125 K&N filter?

  1. #51
    Senior Member XB33BSA's Avatar
    Join Date
    Aug 2012
    Location
    grants pass, OREGON, USA.
    Posts
    1,501
    8.5 eh ?
    tara,see how easily they go off in a wrong direction ?
    tight fitting leathers will go along way for speeding things up
    floppy loose garments cause drag
    TrialsRider and Andyshep like this.

  2. #52
    Junior Member tara1234's Avatar
    Join Date
    Nov 2018
    Posts
    16
    Just a thought in regards to gearing. Iv noticed 6 gear bikes seam to have gears 1-5 roughly the same as that of a 5 geared bike. Now im thinking of putting a bigger sprocket onto the front. It comes stock with a 14t and maxes out about 60 mph. If I increased to 16t it would reach 60 mph in 4th gear and go higher in 5th roughly equivelant to what a 125 6 geared bike has, would it be a bad idea to go this far and use 1-4 for normal riding and the 5th gear for bursts of speed on the flat or downhill? Or should I just increase the gearing to 15t?

  3. #53
    Senior Member XB33BSA's Avatar
    Join Date
    Aug 2012
    Location
    grants pass, OREGON, USA.
    Posts
    1,501
    it is all a
    bout hp
    as light as you are it may help,on top end
    beware that gearing up will slightly broade
    n the gap between gears as well as require more clutch from stop
    if you are able to reach the same top speed on a slight uphill or in to a headwind as on the flat
    then you are reaching the rpm power limit and taller gearing may work
    16 is proly too much thats is a big jump depending of course on the cog count on the wheel
    Last edited by XB33BSA; 12-13-2018 at 08:39 PM.

  4. Remove Advertisements
    CafeRacer.net
    Advertisements
     

  5. #54
    Senior Member TrialsRider's Avatar
    Join Date
    Jan 2011
    Location
    Ontario, Canada
    Posts
    5,171
    Quote Originally Posted by tara1234 View Post
    Just a thought in regards to gearing. Iv noticed 6 gear bikes seam to have gears 1-5 roughly the same as that of a 5 geared bike. Now im thinking of putting a bigger sprocket onto the front. It comes stock with a 14t and maxes out about 60 mph. If I increased to 16t it would reach 60 mph in 4th gear and go higher in 5th roughly equivelant to what a 125 6 geared bike has, would it be a bad idea to go this far and use 1-4 for normal riding and the 5th gear for bursts of speed on the flat or downhill? Or should I just increase the gearing to 15t?
    I'm sure I told you to gear it up at least once by now :|
    Gearing change at the final drive sprockets will affect a change in the road speed of all the transmission gears equally. that's just physics.
    Because the front sprocket is much smaller then the rear, a change in front sprocket size by one or 2 teeth difference will affect a greater change then a one or 2 teeth change in the rear sprocket :/ that's just math.

    One tooth change on your countershaft sprocket (that's the front one) in my experience will make a slightly noticeable difference, two teeth bigger will make a noticeable change and provide you with higher road speed, provided you have the power to overcome the resistance associated with that higher speed.

    Experimentation is needed, countershaft sprockets are cheap, in fact that is the least expensive modification you could possibly do to try and make it go faster.
    imho go for the largest one the manufacturer lists which sounds like 16 teeth. The manufacturer usually puts a chart in the owners manual to indicate the maximum road speed in each gear range with stock gearing.


    XB: don't forget it's only a 125, the primary and transmission gear ratios are inherently lower and closer then a bigger motorcycle.
    Last edited by TrialsRider; 12-14-2018 at 05:29 AM.

  6. #55
    Senior Member XB33BSA's Avatar
    Join Date
    Aug 2012
    Location
    grants pass, OREGON, USA.
    Posts
    1,501
    Quote Originally Posted by TrialsRider View Post
    I'm sure I told you to gear it up at least once by now :|
    Gearing change at the final drive sprockets will affect a change in the road speed of all the transmission gears equally. that's just physics.
    Because the front sprocket is much smaller then the rear, a change in front sprocket size by one or 2 teeth difference will affect a greater change then a one or 2 teeth change in the rear sprocket :/ that's just math.

    One tooth change on your countershaft sprocket (that's the front one) in my experience will make a slightly noticeable difference, two teeth bigger will make a noticeable change and provide you with higher road speed, provided you have the power to overcome the resistance associated with that higher speed.

    Experimentation is needed, countershaft sprockets are cheap, in fact that is the least expensive modification you could possibly do to try and make it go faster.
    imho go for the largest one the manufacturer lists which sounds like 16 teeth. The manufacturer usually puts a chart in the owners manual to indicate the maximum road speed in each gear range with stock gearing.


    XB: don't forget it's only a 125, the primary and transmission gear ratios are inherently lower and closer then a bigger motorcycle.
    but all she needs to do is test what she has now
    if the bike goes less quick on slight up hill grade ,then it is a waste of effort to gear it up

  7. #56
    Junior Member tara1234's Avatar
    Join Date
    Nov 2018
    Posts
    16
    Right so going up hills on single carriageways speed suffers a bit on the bog hills.

    On the dual carriageway (a1) once it gets going still goes about 60 going up hills.

    It can do 70 on steep downhills but would assume the bike is running at 60mph and its gaining the extra 10mph from gravity.

    Iv ordered the 15t and gonna fit it next weekend.

  8. #57
    Senior Member Andyshep's Avatar
    Join Date
    Nov 2015
    Location
    Nottingham UK
    Posts
    701

  9. #58
    Senior Member XB33BSA's Avatar
    Join Date
    Aug 2012
    Location
    grants pass, OREGON, USA.
    Posts
    1,501
    how about a hybrid ?

    or better yet a tidy battery powered mono wheeled trailer that you must tow for schoolbooks
    when its time to go mix with the jag-you-ares push the juice button

  10. #59
    Senior Member TrialsRider's Avatar
    Join Date
    Jan 2011
    Location
    Ontario, Canada
    Posts
    5,171
    Quote Originally Posted by XB33BSA View Post
    but all she needs to do is test what she has now
    if the bike goes less quick on slight up hill grade ,then it is a waste of effort to gear it up
    If it's an up hill on the way there it's a down hill on the way back.


    but then I would have also put a full fairing on it,
    stripped off a bunch of weight & removed or disconnected the counter-balancer,
    or even way more likely bought a different bike.

    <- because I always wanted a 125 stinger.

  11. #60
    Senior Member XB33BSA's Avatar
    Join Date
    Aug 2012
    Location
    grants pass, OREGON, USA.
    Posts
    1,501
    Quote Originally Posted by TrialsRider View Post
    If it's an up hill on the way there it's a down hill on the way back.


    but then I would have also put a full fairing on it,
    stripped off a bunch of weight & removed or disconnected the counter-balancer,
    or even way more likely bought a different bike.

    <- because I always wanted a 125 stinger.
    man i drooled over the stinger ,so bitchen with the chrome expansion chambers

Page 6 of 7 FirstFirst ... 4567 LastLast

Sponsored Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Similar Threads

  1. Replies: 0
    Last Post: 11-19-2017, 07:53 AM
  2. Yamaha Sr125 Scrambler (done)
    By lipton in forum Project Builds
    Replies: 15
    Last Post: 11-22-2016, 08:33 AM
  3. Replies: 0
    Last Post: 10-13-2013, 08:05 AM
  4. Yamaha SR125 Cafe racer.
    By TheMotorcycleCollector in forum Project Builds
    Replies: 8
    Last Post: 05-13-2013, 04:01 PM
  5. PUCH SR125
    By champ in forum Bikes For Sale
    Replies: 2
    Last Post: 11-30-2008, 09:49 AM