sold my crf250l

[MarantzManiac]

6 minutes ago, quickshoe said:

Are you speaking of only the clutch upgrade?  It's one I haven't done, mainly because I don't ever feel or hear my clutch slip.   That tells me that the coupling force is adequate.   I am perfectly fine with throwing money at this bike to make it better, I just want to do so wisely.   

Any supermoto guys have any engine rpm to countershaft rpm data acquisition traces they would be willing to share?  Clutch manufacturers have these traces available on any of their websites?

IMO if you do any time in the dirt the clutch upgrade is an almost mandatory upgrade

Edited April 20, 2017 by MarantzManiac

[quickshoe]

3 minutes ago, MarantzManiac said:

IMO if you do any time in the dirt the clutch upgrade is an almost mandatory upgrade

I'm in the dirt 95+% of the time.  The pavement is simply my means to get to the trailhead.   I haven't noticed the clutch as a limiting performance factor at all.   Tires, weight, suspension, power....sure.   Clutch,not at all.   I am looking for something other than anecdotal evidence, if such exists.

A plot of engine rpm vs. countershaft rpms over time in milliseconds with a stock clutch and clutch upgrade would be quite telling, either way.

Perhaps my stock tires don't grab hard enough to reveal the clutches' limitations.

 

[MarantzManiac]

41 minutes ago, quickshoe said:

I'm in the dirt 95+% of the time.  The pavement is simply my means to get to the trailhead.   I haven't noticed the clutch as a limiting performance factor at all.   Tires, weight, suspension, power....sure.   Clutch,not at all.   I am looking for something other than anecdotal evidence, if such exists.

A plot of engine rpm vs. countershaft rpms over time in milliseconds with a stock clutch and clutch upgrade would be quite telling, either way.

Perhaps my stock tires don't grab hard enough to reveal the clutches' limitations.

 

here in the northeast trails are mostly steep, muddy, rocky terrain... if you're not feathering the clutch you're either too slow or a much better rider... I found the ~$100 clutch upgrade (and removal of judder spring) made a huge difference in overall confidence while off road.

The major benefit is much finer control on the power delivery to the rear wheel which is very useful in tight trails. The stock clutch by design has no feel, it is basically numb which is fine for street or fire roads, of course ymmv.

Edited April 20, 2017 by MarantzManiac

[quickshoe]

48 minutes ago, MarantzManiac said:

here in the northeast trails are mostly steep, muddy, rocky terrain... if you're not feathering the clutch you're either too slow or a much better rider... I found the ~$100 clutch upgrade (and removal of judder spring) made a huge difference in overall confidence because you gain control on the power delivery. The stock clutch by design has no feel basically numb which is fine for street or fire roads...., of course ymmv 

 I don't encounter much of anything that requires feathering the clutch to pass.   I never feather the clutch and can't remember the last time I stalled trying to get over/around/through something.    Likely a difference in terrain type and technique required.  Even our rocky and steep hills don't require it; you either try to blast up it like you are climbing the Widowmaker or you try to crawl it like a jeep going through the Hammers.  

I can see how feathering the clutch like you have a peaky 2-stroke bike would quickly cause the stock clutch in our bikes to cry uncle.   

 

Edited April 20, 2017 by quickshoe

[MarantzManiac]

13 minutes ago, quickshoe said:

 I don't encounter much of anything that requires feathering the clutch to pass.   I never feather the clutch and can't remember the last time I stalled trying to get over/around/through something.    Like a difference in terrain type and technique required.  Even our rocky and steep hills don't require it; you either try to blast up it like you are climbing the Widowmaker or you try to crawl it like a jeep going through the Hammers.  

The MSF courses teach clutch slipping (friction zone) as the preferred way of control in some situations. Feathering the clutch on a 2 stroke or small 4 stroke is nearly mandatory for going fast. The pros are all good at it and do it constantly.

Additionally look at the parts diagram for a jeep clutch. I've only ever seen one friction plate. Look at a diagram for a motorcycle clutch. The fewest number of plates I've seen is 7. Apples and oranges my friend.

West coast terrain is also typically very different than East coast so ymmv.

Edited April 20, 2017 by MarantzManiac

[gnath9]

1 hour ago, quickshoe said:

Are you speaking of only the clutch upgrade?  It's one I haven't done, mainly because I don't ever feel or hear my clutch slip.   That tells me that the coupling force is adequate.   I am perfectly fine with throwing money at this bike to make it better, I just want to do so wisely.   

The CRF250L uses a judder system in the clutch and is designed to slip intentionally for a smoother less jerky ride for beginner riders. Many people have reported early clutch failures as well. 

Everyone one that has done the clutch has been amazed and very happy I believe. You can read this thread for the part numbers and input from other riders as well. In my mind it is one of the top mods you can do to this bike and have even said if I had done the clutch before the 305 I may have not opted for the Big Bore kit. 

 

 

[quickshoe]

44 minutes ago, MarantzManiac said:

The MSF courses teach clutch slipping (friction zone) as the preferred way of control in some situations.

Feathering the clutch on a 2 stroke or small 4 stroke is nearly mandatory for going fast. The pros are all good at it and do it constantly.

Additionally look at the parts diagram for a jeep clutch. I've only ever seen one friction plate. Look at a diagram for a motorcycle clutch. The fewest number of plates I've seen is 7. Apples and oranges my friend.

West coast terrain is also typically very different than East coast so ymmv.

Certainly, those "some situations" are situations where the power you need is not available at the current rpm for that road speed and gear.  You need to raise the rpm immediately without losing much forward momentum.  I get it, I just don't need to do it with the type of riding and terrain I encounter.    

If you want to believe the technique is nearly mandatory for going fast and that the pros do it constantly, you are certainly welcome to that belief.  I have been racing and riding various bikes and vehicles for 39 years and believe otherwise. 

Lots and lots of high performance clutches are multi-disk variety.   It's almost a requirement where more friction area is required for the torque output but the added inertia of a larger diameter clutch is undesirable.   

As to apples and oranges I wasn't comparing the types of typical automotive clutches and typical motorcycle clutches; I was comparing the types of approaches utilized to get up a rocky/steep/slippery hill.   

 

[quickshoe]

59 minutes ago, gnath9 said:

The CRF250L uses a judder system in the clutch and is designed to slip intentionally for a smoother less jerky ride for beginner riders. Many people have reported early clutch failures as well. 

Everyone one that has done the clutch has been amazed and very happy I believe. You can read this thread for the part numbers and input from other riders as well. In my mind it is one of the top mods you can do to this bike and have even said if I had done the clutch before the 305 I may have not opted for the Big Bore kit. 

 

 

Thanks gnath9 for the link.   Respectfully, it's my understanding that the judder spring is more of a "feel" and "noise" thing for initial engagement.   In and of itself it has nothing to do with available clamping force and isn't allowing the clutch to slip once it is engaged.   What eliminating the judder spring is going to allow for is a more aggressive feel and initial "bite" if you will.   It also allows one to utilize an additional friction disc in the stack; add a friction disc, heavier springs and elimination of a judder spring is certainly going to change the feel of the clutch.  Adding friction disc and heavier springs is certainly going to increase the torque capacity of the clutch.  It isn't going to provide more performance in any instance where the previous clutch was up to snuff (clamping force, friction and cooling capacity).   Likely that is the point...our stock clutches aren't up to snuff if you like to dump them at 7000rpms in 3rd or slip it repeatedly instead of gearing lower and adding throttle. ?

 

 

Edited April 20, 2017 by quickshoe

[Evan D]

It appears that it's a wasted amount of effort to try to convince certain people to remove the jutter spring and create a better clutch.It appears that it's a wasted amount of effort to try to convince certain people to remove the Jetter spring and create a better clutch.

I'll also add to the group that the clutch "mod" gives you a much better feeling clutch.

[quickshoe]

It isn't a wasted effort.    I have no doubt that removing the judder spring, adding a friction disc and heavier springs improves the feel and capacity of the clutch.  

If the mod is to improve the feel and durability.  Great, I get it!  If the goal of the mod is otherwise, I believe it to be "dog turd on the hood syndrome".

 

[gnath9]

26 minutes ago, quickshoe said:

Likely that is the point...our stock clutches aren't up to snuff if you like to dump them at 7000rpms in 3rd or slip it repeatedly instead of gearing lower and adding throttle. ?

Exactly ....  the stock clutch just slips when you dump the clutch hard at a lower speed in a higher gear and can not loft up the front high enough to ride out the wheelie ...   

Also the stock clutch makes it harder to lift the front up in the woods when you encounter a small log or ditch which could make for a messed up day if you endo over the bars ...  

In this pick you can clearly see how much less suface area the judder friction plate has and is the reason it wears out so quickly ... I do believe a person could benefit from just adding stiffer springs but heck ... once it is apart you might as well just remove the judder system entirely ... ? 

I am not trying to convince anyone into doing the clutch if they do not want to. I just simply like to share my experience when I find something that works great and could possibly increase someones enjoyment of this fine little machine we all happen to love around here. 

these are my old parts at 1,200 miles 

Edited April 20, 2017 by gnath9

[MarantzManiac]

Thank you for the explanation Gary, your wealth of knowledge has been spot on and helped me enjoy this bike 10 fold! 

[gnath9]

11 minutes ago, quickshoe said:

If the mod is to improve the feel and durability.  Great, I get it!  If the goal of the mod is otherwise, I believe it to be "dog turd on the hood syndrome".

Hard to see in that pic but, the judder friction disc was mor than 50% worn while the others were like new. I also do not thrash on my bike too hard. 

It is one of those things that you have to experience to fully comprehend .... it honestly feels like you add 5hp to the bike just by doing the clutch. I find it nothing short of amazing but hey ... that's just me and my opinion has never mean't to be confused with actual facts ... 

[mott555]

If it helps get the front end up and over logs, that alone sounds worth the upgrade IMO.

[alucard0822]

The problem I had with the clutch, (and why I replaced it with 500 mi on the bike) was the feel.  The judder basically acts like the 1st stage in a 2 stage clutch, it engages before the friction material, so you get enough bite to roll the bike forward, but not enough to put down more than a small amount of power, being metal on metal it heats quick, and feels inconsistent too, when cold it bites harder, and you have to pull the lever in far to completely disengage it, or get into gear at a stop, when hot, it might feel like it isn't even there.  There isn't a ton of power to begin with, so when it's lost through slippage, it makes it tough to clutch up the front end, or get the rear spinning offroad, or put power down quick coming out of a corner on the street.  The stock clutch feel was an inconsistent light bite somewhere between 1/3 and 1/2 of the way out, then actual engegement about 2/3 of the way out, with a little slip if you pop the clutch hard.  Also makes it tought to "2 finger" the clutch from a stop, when pulling it apart, the judders were starting to wear a groove in the steel.  Without the judder, I probably wouldn't have replaced it, being used to "normal" clutches, on the good side the stock clutch lever is feather light, and the way it engages is very beginner friendly, making it harder to stall, or lug the engine from letting it out too quick.  The < $100 upgrade eliminates the initial judder "engagement", there is 0 engagement till you get to a consistent spot about 2/3 of the way out, then a more aggressive "normal" bite.  Being able to 2 finger it easier, having a much more predictable clutch, and being able to better use the "flywheel effect" to bump up the front and compensate for the mild power makes it worthwhile to me.  Excuse the poor look and bad scale of my graphs, but this is the general comparison I'd make between the stock on the left and EBC clutch & springs on the right, basically friction vs lever travel

Edited April 20, 2017 by alucard0822

[Kompact]

7 hours ago, quickshoe said:

I haven't noticed the clutch as a limiting performance factor at all.

Upgrade the clutch and you will immediately understand. You might not notice how much slip the stock clutch has until after you do the upgrade.

[2timer]

10 hours ago, vwjetta2l4 said:

 

 

What kind of gains do you get with that setup ?

 

 

Our bike shares conmon engine components with the street cbr250r. The cbr has more hp from stock compared to our bike. Pattly from factory detuning with smaller 36mm throttle body and ecu map. Those parts with the bank angle sensor will give you the cbr spec. The duckydog pipe is popular within the connunity to give our bike much needed torque down low and will give +2hp gain low conpared to the fmf headers. Ducky dog is a reputable member on thumpertalk who spent alot of time doing R&D on his named pipe. I can con firm tbrough my own dyno testing the pipe is an upgrade over several other aftermarket pipes.

[gnath9]

12 hours ago, 2timer said:

I can con firm tbrough my own dyno testing the pipe is an upgrade over several other aftermarket pipes.

according to the Dyno I gained 1.5hp down low and lost 0.5hp off the top going from the FMF megabomb header to the DuckyDog Torquer head pipe .... ? 

Edited April 21, 2017 by gnath9

[Mr.G]

All very interesting.  I am new to TT and the CRF I have done some mods to the bike, gearing, FMF, EJK and the like but I too feel that the clutch is "soft".  I wondered if this was due to my relative low experience but reading the above feel it may be the clutch after all.  It feels to me like it needs more bite and is too progressive for any situation where you need to lift the front, (log hopping).  It may be my inexperience shining through or it maybe the clutch?  If I did the clutch upgrade would the stronger springs create fatigue on longer/technical rides?  Can someone tell me what the new clutch feels like from a strength/rider input point of view not just bike feel?

[Kompact]

The stock clutch has a "judder spring" that is designed to slip.

You can replace the stock firction plates with EBC1313, remove the judder spring and upgrade the springs and it makes a world of difference.

The stronger springs do contribute to hand fatigue although you can still just use the stock springs with the new friction plates so it will pull the same as it does now.