Yamaha YZF R125 Forum and Owners Club: Friendly bike community for all. My White '08 | R125 Forum
Change
  1. BOTM Winner
    Congratulations grayej! You are the winner of November's BOTM competition!

    Please visit the BOTM section to see more entries, or to enter this month.

    Click here to enter!

My White '08

Discussion in 'Members Bikes / Blogs' started by NorthCust, Nov 28, 2018.

  1. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    Not really sure where to start to I guess start at the beginning and will work up to date from there...


    20171008_142022_www.jpg

    I've been into messing with cars for years, mostly mk2 golfs but only got into bikes sorta by accident when I fell in love with stretched scooters (they're ridiculous, I know). Somehow along the way I got the idea that I'd quite like to do the blood bikers thing and realised that i'd need a geared bike to get a proper license in order to do so... So after some online research, concluded R125 was the way to go. A friend happened to have one sat in his garage (see pic above, as I found her he'd since got a blade and was bored with the 125) so I did my CBT and here we are...

    I'd only really been planning to be a fair weather rider but have had a bit of a streak of cars breaking on me (or me breaking them) so I spent most of last winter commuting on the bike in the dark, rain and sleet. The broken cars theme has continued this year so by now I'm just like whatever, I'll go on the bike.

    It's pretty much physically impossible for me to own a vehicle for more than a week without tinkering with it so naturally work has started on the bike. So far much of the work has just been about bringing things back up to scratch but unsurprisingly that's escalated a bit.

    R125_track.jpg

    This is roughly where we're at currently. I work nights quite a lot of the time so spend a lot of time riding in the dark, hence reflective everything. I don't know if the red and white was an official colour scheme, seems more of a mishmash to me but I can relate and I kinda like it.

    She's now got a K+N panel and a Danmoto Carbon GP pipe and more recently a power commander V and remap. I put the baffle in since I tried it without and only got about two villages over before turning back...it was painfully loud. With the baffle it's still about as subtle as a military transport plane but sounds nice - lush overrun burbles and splots, and a lovely "cnnaaackpop" at the top of the gear when you nail it and shift up.

    20180309_102023_www.jpg

    Since getting it tuned with the PCV there's a lot better low/mid response which makes it a more usable for daily riding. Beforehand there wasn't really anything happening till 8k so you end up either all out banzai mode or nothing (spoiler: it's always banzai).

    I'm also trying out a 15t front sprocket at the moment since even before getting it tuned I was forever bouncing off the top of the gearing and rpm. So now whilst it does struggle a bit more to get up to *max* speed, up to 70-ish it seems quicker and the gears feel better spaced... and since up to 70 is actually what I use most of the time I'd say so far it's probably been a net improvement.

    I can now cruise around 70 without it revving it's tits off the entire time which is an improvement. Also it means that the actual geared top speed has yet to be determined which I sorta like. I'm hoping with favourable conditions [on a private road or track] we might see 85 or beyond, and am looking forward to finding out ;)

    Since I'm now using the bike as my main/daily transport I'm having to make a few adjustments to it. Daily use as well as longer test rides (a couple of hours or so) showed that it knackers my wrists and shoulders, plus being hunched over all the time isn't great either (previous back injury). I like the sporty position for on the track but also want to be able to go to places and still be able to use my arms the next day, so am gonna see if I can figure something out with the bars to mean I can just reach them when sat a tad more upright. I've got some bits on order so will post any progress.


    Speaking of tracks - After getting into a couple of sketchy situations on roundabouts and having then realised that there's a bit more to this riding lark than I'd thought, I've been trying to improve my riding skills. I read on a forum somewhere that go-kart tracks can be good to improve low-speed cornering skills and some of them let small cc bikes on (like a 125).

    I liked the idea and turns out a place reasonably near me allows bikes, so have been there a couple of times now over the summer - epic fun, especially when it's empty and you have a whole track to yourself. Also surprisingly cheap day out. With the track being small I don't think you'd really get up to much over 45mph but that wasn't really the point (for me anyway). Over the course of the day I was still able to push myself and the bike way harder than I'd ever dare on the road. It seems to have helped my confidence in the bike when riding on the road so all good.

    Being able to practice taking the right line through specific twisty corners over and over again, practice rolling on and off the throttle, getting the weight placement right etc...and then start to link the corners into coherent smooth laps - it's absolute bliss and I learned so much already.

    For me that track time is also some of the purest enjoyment I've experienced in a "omg i'm totally doing gran-turismo"-type way. absolutely recommended with bells on \o/
  2. R125Forum.com Advertisement

  3. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    Just got the winter tyres on - They're "Heidenau K66" and seems like there was no issues with clearance around the mudguards.

    Still gotta break them in but they felt ok to ride on so far. Gotta admit I kinda like how they look (for the winter anyway)

    20181128_160629_www.jpg

    20181128_160716_www.jpg
  4. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    So I did a little test run today, primarily wanting to put some miles on the new tyres...unexpected results in other areas tho.

    A couple of months ago when I got the PCV fitted and bike tuned I also got them to put a 15t sprocket on the front since I'd kept bouncing off the gearing up until then and was looking for better cruising rpm (e.g. so I can cruise at 70ish over longer distances without revving like a twat the whole way). which is fine, but it meant I'd never had a direct comparison with before/after tune on the original gearing.

    In the spirit of seeing just how good my "mud and snow" rated winter tyres are, I'm wanting to do some "local exploring" where I'd likely be wanting acceleration over top end so I put the 14t back on to test. Also for exploring a degree of stealth may be beneficial so I put the baffle in the end of the can (which I've also never tested properly). Without the baffle "stealthy" is definitely not a quality it has.

    So having fitted the 14t and the baffle I take her out for a spin and seemed to be pulling really well - like she was really wanting to *go*...nice :). If felt like the 14t (tuned) did make a difference. I hated the sound though, could barely hear what the bike was doing, no nice overrun burble/splot or end-of-rpm "knaaackpop". It sounded a bit like a dodgy sewing machine. meh.

    Thinking that if it's going well now with baffle on then it should go better without - right? So I went home and pulled the baffle, and set off on my normal test run up to the next town...but weirdly it seemed slower. Disappoint. Also what the hell? Is it even possible that it's quicker with the baffle in?

    This isn't the default baffle which comes with the exhaust (Danmoto carbon GP). It's got that one in too (just before the can) as it was painfully loud without. This is a random aftermarket one I got in case it was still too loud for the track I go to. But the track folks never complained so I never bothered using the baffle.

    I know 2-strokes need a specific restriction on the stinger for max hp, but is it possible that on a 4-stroke it actually benefits from that little restriction in the end?

    I don't know, but it *felt* quicker with the baffle. That's obviously a very subjective assessment though so I guess I'll need to do some sort of test to find out. I guess perhaps it's possible that the baffle helps with low/mid-rpm pull, but then restricts somewhat at wide open throttle...or perhaps it's fine over the whole rev range.

    This wasn't the result I was expecting.


    Gearing-wise whilst it did feel quicker on the 14t I still think I may prefer how the 15t front rides. I'm not sure why that would be the case but since the PCV/tune it's got midrange power where before there was really nothing happening below 8k, so perhaps the way I ride has changed. The 15t certainly seems nicer for just covering distances since you can cruise at 70ish with traffic.

    For the time being I've put the baffle back in to see if I get more of that feeling like it wants to go, and will leave it on the 14t for a bit and see how it is on a couple of runs to work and back, but may well switch back to the 15t once I've figured out the baffle/no-baffle situation.


    If (and its a big if) the baffle were to somehow help midrange pull then I'd be very interested to see how it is back on the 15t front, since it did struggle a bit to break above ~75 on the 15t with no baffle...like it can't quite make it to the next power band unless it's favourable conditions (e.g. downhill w tail wind), and then it's fine. *If* the baffle does something magical to give it more midrange then it might mean it can bridge that power gap and perhaps the mythical 85 might be within range.

    I will have to find a nice quiet stretch of private road and do a bit of testing with and without...and see what happens. Will post results :)
  5. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    So did another quick run across town just now with the baffle in and it definitely seems quicker. I dunno if that's because I'm less conscious of the rpm and so ride differently but it definitely felt like it wanted to *go* again. Much grinning when I got home.

    I guess it's possible that at low/mid rpm the little bit of restriction might improve torque somehow - I guess there's sound waves and stuff going on in there to some extent like a 2-stroke. I didn't really get chance to go flat out though and that's where I'd expect the baffle to be a restriction...will have to see. Didn't seem to be a problem revving high at speeds up to 50ish though, kept finding i had to back off a bit.

    Still not loving the sound but stealth is better and obviously whatever's quicker wins. Interested to see how it does on a test run. I guess I need to figure out some sort of timing malarkey I can work with gloves on first, though even just seeing how it performs when flat out with the baffle would be interesting. Next time she's on the dyno I guess we'll find out for sure but that won't be for a while yet.
  6. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    so I found this thread which possibly explains what's going on with my exhaust (2nd post particularly):

    https://thumpertalk.com/forums/topic/798327-4-stroke-exhaust/?page=2

    i think this may be about gas velocity, which would sorta explain the current counter-intuitive performance improvement by adding the baffle in the can. I've also realised that it might be better still if i take the forward baffle out (the one which came with the exhaust system) and only have the rear one...that way i might get better performance still and regain some of the nice sound.

    It may also do nothing/make it slower in which case it's going back how it was....gonna find out today hopefully.

    Riding again last night - it's definitely quicker now..it's ridiculous, and such fun. The heidenau k66 winter tyres are also so sticky, even in the wet. *Well* pleased with them.

    I'm waiting on some bits to let me hopefully fit some motox bars so I can sit a little bit more upright. I'm hoping it'll make it more comfortable for longer journeys and also perhaps give a little better control in wet/snowy conditions (which i definitely plan on riding in). I've had to borrow bits from different generic riser kits and machined a couple of custom bits to join them together but so far it's looking promising. Pics to follow once I have something solid.
  7. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
  8. Captain Slow

    Captain Slow Super Member

    Location:
    Fleetwood, Lancashire
    Current Bike (Optional):
    R125, R3, CBR929RR, R1
    License Currently Held:
    UK Full Bike
    I presume that you have a very upright riding position now?
    NorthCust likes this.
  9. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    it's not like *super* upright like a naked bike but it's a little less leaned forward than it was before - before I couldn't reach the bars without having my weight forward which put a strain on my back (previous injury), now it's a smidge more upright which just takes the load off my back. I can still tuck down behind the fairing ok without it being uncomfortable but can also sit relaxed and still reach the bars...so I'd say for me it's an improvement :)

    In all the bars have moved back maybe an inch, up an inch and are maybe 1.5" wider each side so it's not a huge change but it's enough to have made it more comfortable for me without affecting functionality too much (as far as I can tell so far ;)).
    seb15243 likes this.
  10. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
  11. Captain Slow

    Captain Slow Super Member

    Location:
    Fleetwood, Lancashire
    Current Bike (Optional):
    R125, R3, CBR929RR, R1
    License Currently Held:
    UK Full Bike
    Do you think the rear handbrake will be beneficial when riding. i.e Trail braking in corners?
    NorthCust likes this.
  12. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    erm I don't know tbh, hadn't really thought about it beyond standup wheelies. I suppose maybe it would be useful, though I don't find the current control set lacking anything when riding normally, apart from no control when not able to cover the rear foot brake when the front is in the air.

    You can do trail braking fine without a hand-brake though can't you? I also thought trail braking was with the front maybe? (I'm no expert though so that may be wrong).

    Given it's a "deviation" from the standard controls I guess I'd sorta kept it mentally "compartmentalised" just for wheelies so as not to become reliant on it, but I guess there may be occasions where having another handle to grab could be helpful...
  13. Captain Slow

    Captain Slow Super Member

    Location:
    Fleetwood, Lancashire
    Current Bike (Optional):
    R125, R3, CBR929RR, R1
    License Currently Held:
    UK Full Bike
    Not too advisable to front brake in a corner as it can stand the bike back up straight again unless you have the lightest of touches.

    Wheelies; practice setting the front wheel down gently or you'll give the forks, seals and bearings a right hammering over time. Surely a naked bike would be a better choice for wheelies?
  14. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    >> Not too advisable to front brake in a corner as it can stand the bike back up straight again unless you have the lightest of touches.

    I don't know tbh, the closest I can picture it is at the kart track arriving with gusto off the straight into the hairpin being almost standing on the brakes till the apex, but I couldn't tell you exactly what hand/foot was doing what at that point, so i don't know if that's trail braking. either way, wasn't really planning on using it for that, it's purely for wheelies ;)

    >> Wheelies; practice setting the front wheel down gently or you'll give the forks, seals and bearings a right hammering over time.

    yeah she's taken a bit of a battering on this journey but am doing my best to keep up with the maintenance. I'm roughly at the point where I can get the front up fairly reliably, but haven't quite figured how to maintain that yet (it all sorta goes quiet/blank). The next thing I was going to try and work on was trying to have softer setdowns, potentially as a way of learning to feed in power earlier and earlier, and hopefully eventually maintain wheelie.

    >>Surely a naked bike would be a better choice for wheelies?

    maybe. I ride in all weathers though so really appreciate a bit of fairing when it's throwing down ;) I know this isn't the perfect bike for doing many of the things I do on it but it's the bike I have, and to some extent for me this is about being ok with where I am, which I pretty much am :)
  15. Captain Slow

    Captain Slow Super Member

    Location:
    Fleetwood, Lancashire
    Current Bike (Optional):
    R125, R3, CBR929RR, R1
    License Currently Held:
    UK Full Bike
    Have you tried adding a little weight to the pillion end of the bike to ease the bike into the air? Problem with the 125 is you have quite alot of engine breaking when you close the throttle so I can understand your problem trying to maintain the balance once the wheel is up, which is why I wonder if some additional weight right at the rear of the tail section could help.
  16. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    >>Have you tried adding a little weight to the pillion end of the bike to ease the bike into the air?

    I noticed the other day actually that if i stand/push correctly on the passenger pegs I can almost pull it up without any forward force so I guess that's sorta similar direction to what you're saying.

    >> Problem with the 125 is you have quite alot of engine breaking when you close the throttle so I can understand your problem trying to maintain the balance once the wheel is up,

    that's a good point, it does have quite a bit of engine breaking... feathering the clutch was also on my list of stuff to try, to try and maintain revs and have some momentum I can drop in when needed.

    really though it all works as it should, the new clutch is great and definitely bites harder, the clutch action is now super smooth and *dialled*, the bike comes up fine, the bottleneck is me getting comfortable enough to stay in it when it happens and to not to chop the throttle and bring it down. But then I started off practising bringing it down right away as a safety thing, so even that is fine at this point. I just need to gradually loosen off on that till I start to find balance point, which is just going to take practice and more practice.

    Currently some my "discomfort" when the front is up comes from lack of control when standing (hopefully addressed by rear handbrake) and also worrying about what happens when I drop it..hence a cage is hopefully imminent too in this next round of maintenance...
  17. Captain Slow

    Captain Slow Super Member

    Location:
    Fleetwood, Lancashire
    Current Bike (Optional):
    R125, R3, CBR929RR, R1
    License Currently Held:
    UK Full Bike
    Have you ever considered using both the front and rear wheel on the ground at the same time, which is what I think Yamaha intended when they made the R125. It works for me. I have 3 bikes and they are all ace at working with two wheels on the ground.

    Are you wanting to be a stuntman or just have a fetish for A&E?
  18. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    lol yep xD

    archer_column_a.jpg

    I'm not actually sure I'm working towards anything other than personal satisfaction. It's been a very tough year and for some reason riding and specifically wheelies have sorta kept me motivated though the shitty bits (ridiculous as that might sound). I don't really know why but it's something I'm just really drawn to learn how to do.

    going fast is awesome but would probably be a bad thing for me to get too interested in, whereas this sort of slow speed control stuff is something I can focus on and get right into and get a lot of satisfaction out of, and all at pretty slow speeds...so I'm happy to indulge it for as long as my back holds out ;)
  19. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    Not about the bike directly but related: The spare engine to experiment on has arrived \o/. Apparently it's been run without coolant and is a non-runner.

    I expected it to be seized with a hole in the piston since I was planning to replace that anyway. I know it clicks through all the gears ok and I think it turned over but I don't remember exactly. I wasn't able to check for compression but the adapter for the narrow spark plug has arrived so I should get another look soon.

    If there's no compression I guess it'll need to come to bits as soon as I've got somewhere to put all the pieces, see the state of it but hopefully new bearings, new 180cc cylinder, new cam, then *hopefully* see if I can get it running on speeduino, though that seems a loooooong way off right now.

    Also, I don't know how it's going to work exactly yet but I sorta need to build some sort of measuring setup/mini-dyno based on ardyno. I'm thinking more a minimal rig to hold an engine, with a swingarm and a weighted rear wheel on a fixed base. It doesn't need to be "absolutely accurate", just accurate vs itself and repeatable. that way I can a/b test components till I get the combination I'm happy with.

    Someone already did something along these lines re measuring:


    I'm thinking that could perhaps be improved with a weighted rear wheel (and possibly gearing) which would provide enough load to give a more meaningful measurement from the engine as well as letting you measure engines both in a bike and not. And wouldn't be too huge to store when not in use either.

    Of course if there's compression I'm sorta inclined to try my luck and find a stock loom and see if i can get it to run as is, since that would be the best baseline..but there's no way it could ever be that simple ;)
  20. NorthCust

    NorthCust Active Member

    Home Page:
    Current Bike (Optional):
    2008 Yamaha R125, Gasgas TXT 280, Stretched Neos
    License Currently Held:
    UK Full Bike
    stunt cage for the bike is done \o/ - that should *hopefully* provide a bit more protection for when I drop it or loop it trying to wheelie and do other dumb stuff on it.

    Whilst only half-planned that way, the forward mount doesn't stick out much, and the top mount is actually the R+G frame slider mount, so I can just remove 3 bolts (per side) and put the front boomerang panels back on - back to full fairings/stock in just a few mins \o/. The rear mounts is all you'd see with the cage triangles removed and they can be easily removed too if I wanted to revert to stock permanently. The front mount is on the same bolt as the R+G sliders so is also easy to remove.

    P1050960_cropped_2k.jpg

    P1050953_2k.jpg

    I don't know if the cage will stay forever, but I am definitely doing more with this drifting and wheelies nonsense, and I see it sorta like training wheels. I don't necessarily know if I plan to be doing wheelies 24/7 forevermore (though that does sound pretty good) but this is something I want to be able to do and if you're gonna do dumb sh!t at least wear armour (also for the bike), so at least till I'm confident enough to send it with little risk of droppage, this should hopefully help.

    next up is to make a double rear caliper bracket so I can connect up my handbrake, and I'm also going to switch to motox bars using the style of adapter I made for a friend's R125.

    pic below shows what I'm hoping to do with the handbrake bracket - cut/grind along red line and then weld the two carriers together.

    yzf-r125_twin_rear_brake_caliper_mount.jpg
    20190718_212009_2k.jpg

    I don't have this yoke anymore as it's on a friend's bike now but I was really impressed with how sturdy it came out so will make mine the same.

    The clipons I have are mostly great, but in making 2 90-degree turns there's an awful lot of metal to make it sturdy, which gets in the way of cables etc, particularly when you're trying to squeeze in an extra brake lever on the left. Motox bars negotiate that height offset with bends instead of clamped joins and offer a bit more space to put that extra brake lever.

    Also I want the bars orientated slightly up as in this pic, since then they'll be comfortably towards me in a standup, rather than angled away like the current clipons are when you're in that position - which should make for a slightly more natural hand position and possibly push my weight back a bit, helping to reach balance point. The motox bars will probably actually sit a little lower than my current clipons but possibly with a slightly better angle, and hopefully less bashing of the master cylinder on the screen too. I prefer the clipons a little lower but raised them in an affort to push my weight back more (with mixed success).


    20190717_165023_2k.jpg

    it did all fit on the clipon, just, and there's no compromise on placement (the levers are where I'd expect them to be) but it's all super tight and I'm not 100% sure this brake lever is gonna be happy in this orientation. It uses a separate reservoir so I *think* it ought to be ok but it's the left lever from another set with the switch and stuff removed to make it fit. i reckon it's like 50:50 chance it will/won't work :-\

    I have a different lever to replace that one but it doesn't fit on the current clipons, but should fit on motox bars.. and I think i'd prefer that setup.

    20190717_143053_2k.jpg


    I actually noticed the front wheel was coming up a little naturally *in second gear* the other day (when changing up) whilst riding, and that's on the standard 14T sprocket too..wtf? That EBC clutch (and all the mucking about making sure it was engaging sweetly) made so much difference. £30~ well spent :D

    I think if I'd had my weight in the right place there would have been enough acceleration to pull up properly, which is really nice to see, since till now I haven't been able to wrap my head around how I'd get wheel up in anything higher than first gear, so it's like pieces of understanding starting to fall into place gradually.

    Attached Files:

  21. Captain Slow

    Captain Slow Super Member

    Location:
    Fleetwood, Lancashire
    Current Bike (Optional):
    R125, R3, CBR929RR, R1
    License Currently Held:
    UK Full Bike
    I still think you would have been better starting with either the MT-125 or the MT-07.
    NorthCust likes this.

Share This Page