hdscarbro Posted April 18, 2019 Report Share Posted April 18, 2019 I've been pining for more flywheel mass on my TRS125. A commercial flywheel weight is not available. Here's the solution I came up with. On my 125, there's about 5mm space between the flywheel and the crankcase. I machined a 4mm disc from mild steel that attaches directly to the back of the flywheel via tapped holes added to the flywheel. I haven't ridden the bike too much yet. My first impression is that perhaps for me the weight should be a bit less. This one weighs about 11oz. Does anyone know what is typical for a 125? 2 Quote Link to comment Share on other sites More sharing options...
reggie Posted April 18, 2019 Report Share Posted April 18, 2019 I think by trial and error you are going to be the expert when it comes to adding weight to the TRS 125 flywheel! Keep us posted. 1 1 Quote Link to comment Share on other sites More sharing options...
briangg Posted April 19, 2019 Report Share Posted April 19, 2019 Out of curiosity why do you feel you need more flywheel weight on a 125? What type of feel are you trying to get out of this? Usually on 125 your wanting a fast revving bike to get to the mid range and most importantly wide open where the power is quick when it is needed. Increasing bottom end is also a big thing to do but only so much can be done there without harming top end. I just dont see the benefit of more flywheel weight on a 125. Just would make the throttle response slower, rev slower even though it would hold rpm longer thats why you see guys keeping the throttle on at the top of obstacles on 125 more often. Then again its probably my riding style and being able to push a 125 to the limit on big obstacles is why i feel this way. But im still curious on your thoughts. good luck on your experiment. 1 Quote Link to comment Share on other sites More sharing options...
crashmonkey Posted April 19, 2019 Report Share Posted April 19, 2019 I ~think~ the flywheels were lightened mid way through the 2018 production run in order to quicken the engine response, could be worth trying to find out via importer or factory and see what was different? Quote Link to comment Share on other sites More sharing options...
hdscarbro Posted April 19, 2019 Author Report Share Posted April 19, 2019 10 hours ago, briangg said: Out of curiosity why do you feel you need more flywheel weight on a 125? What type of feel are you trying to get out of this? Usually on 125 your wanting a fast revving bike to get to the mid range and most importantly wide open where the power is quick when it is needed. Increasing bottom end is also a big thing to do but only so much can be done there without harming top end. I just dont see the benefit of more flywheel weight on a 125. Just would make the throttle response slower, rev slower even though it would hold rpm longer thats why you see guys keeping the throttle on at the top of obstacles on 125 more often. Then again its probably my riding style and being able to push a 125 to the limit on big obstacles is why i feel this way. But im still curious on your thoughts. good luck on your experiment. I'm looking to make the engine a bit more stall resistant. I'm a 63 and have been riding trials for a hand-full of years. Prior to the TRS, all of my trials experience was on a ty175. The ty, by comparision, is impossible to stall. I'm hoping that with some percentage more flywheel mass, there's a sweet spot. A place where the engine is less likely to stall, but not too sluggish either. 1 1 Quote Link to comment Share on other sites More sharing options...
hdscarbro Posted April 19, 2019 Author Report Share Posted April 19, 2019 8 hours ago, crashmonkey said: I ~think~ the flywheels were lightened mid way through the 2018 production run in order to quicken the engine response, could be worth trying to find out via importer or factory and see what was different? Interesting. I'll inquire. Thanks. Quote Link to comment Share on other sites More sharing options...
rabie Posted April 20, 2019 Report Share Posted April 20, 2019 for UK conditions (mud, rain, more mud, etc) they are popular on many model, many betas come with them as standard (for UK models) Quote Link to comment Share on other sites More sharing options...
DirtDogs Posted January 20, 2020 Report Share Posted January 20, 2020 Hey David, Would you consider making me a flywheel weight? I am trying to tame a 2018 300rr. Quote Link to comment Share on other sites More sharing options...
carlos Posted February 7, 2020 Report Share Posted February 7, 2020 My Dad machined an extra bolt on flywheel weight for my sons Gasgas 200 (176cc) in 2003 and 2005 models, really made the bikes smooth and manageable, had no problem pulling my 210 pounds around. I believe it weighed a little over a pound. 1 Quote Link to comment Share on other sites More sharing options...
Antonio Posted January 31, 2021 Report Share Posted January 31, 2021 I have a 250, with 800gr. extra, i love the rsponse! Quote Link to comment Share on other sites More sharing options...
hdscarbro Posted January 31, 2021 Author Report Share Posted January 31, 2021 10 hours ago, Antonio said: I have a 250, with 800gr. extra, i love the rsponse! How is the weight attached to the flywheel? I saw in another post that you said it was a prototype. Production timeframe? Quote Link to comment Share on other sites More sharing options...
Antonio Posted February 10, 2021 Report Share Posted February 10, 2021 On 1/31/2021 at 10:27 PM, hdscarbro said: How is the weight attached to the flywheel? I saw in another post that you said it was a prototype. Production timeframe? I can't tell you the exact details as I don't remember how they exactly do it, they did many units with different weights for Adam Raga to test, which he did, as reserch, they can build almost any weight for you. I ask if it was possible for the ES model and the answer was no possible as there is the no space. You can contact Albert at Non Stop Shop Bikes, Tona, Spain for the service or details. He speaks excellent English. Quote Link to comment Share on other sites More sharing options...
Mikhail Posted February 23, 2021 Report Share Posted February 23, 2021 Pretty please - I have been reassembling the engine and I wasnt able to find torque specs for the flywheel. Unfortunately it slipped off the crank, destroyed the keyway, mangled the mating surfaces on both crank and flywheel, and keyholes are both chewed by 0.5-1 mm, so the timing will be all messed up:(. Can ANYONE advise the torque specs for the damn flywheel on TRS 250/300? Seems like only producer without engine torque specs available:( Quote Link to comment Share on other sites More sharing options...
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