Low CC Sport Bike Review | Page 2 | GTAMotorcycle.com

Low CC Sport Bike Review

Brian P

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This is going way off topic because none of the bikes in question have drive-by-wire throttles or downshift-throttle-blip systems or anything of the sort. But the previous point is that momentary, manually-applied throttle blips for rev-match downshifting are NOT in ANY way going to be harmful to the engine the way Trials suggests ... and they'll sure be easier on the driveline than not doing so, and if you are riding on the racetrack and need a couple of quick downshifts on corner entrance in order to be in the right gear coming out of the corner, doing the throttle-blip means the downshift will be smoother with less risk of starting a rear-wheel slide at an inopportune time. "Slipper clutches" help some with this, by limiting engine braking, but out of these budget bikes, the only one that has a slipper clutch as far as I know, is the Kawasaki. I don't know if the KTM does. The Honda and Yamaha certainly do not.

"Sudden increases and decreases in engine speed" being "harmful"? How? In what way? Lots of bikes nowadays come with quick-shifters as standard equipment. Those cut ignition for about 60 - 80 milliseconds to unload the transmission enough to let it change gear and then the engagement dogs bring the engine to the new post-gearshift engine speed as quickly as the cush-drives in the rear wheel and the vibration damper inside the clutch will allow. It's not like the camshafts are going to keep spinning at the old speed and break the timing chain - that ain't happening. What harm will come from abrupt changes in engine speed? If anything's going to break from that, it's going to be transmission and driveline related, not the engine!

And yes, I have broken transmissions in roadrace bikes. Wasn't because of a quickshifter ... bike didn't have it. (Probably had something to do with an aftermarket wheel which, at the time, had inadequate cush-drives)
 

Trials

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This is going way off topic because none of the bikes in question have drive-by-wire throttles or downshift-throttle-blip systems or anything of the sort. But the previous point is that momentary, manually-applied throttle blips for rev-match downshifting are NOT in ANY way going to be harmful to the engine the way Trials suggests ...
What did he suggest?
 

Brian P

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Blipping an engine :/ while nothing is actually 'good' for a motor except maybe oil, you are certainly not doing your valve train drive any favours,
your Fi computer uses a collection of sensor inputs to make the motor operate efficiently under normal operating conditions, normal operating conditions doesn't normally include a whole bunch of superfluous and sudden increases and decreases in engine speed. Operating efficiency and engine wear is probably reason enough to not constantly blip your 4-stroke engine if you care about such things, otherwise have at it.
Uh, no. Momentary throttle blips won't hurt anything. "Sudden increases and decreases in engine speed" won't hurt anything. "you are certainly not doing your valve train any favours" - if the throttle-blip is within redline (and it's enforced by the rev limiter anyhow) it won't hurt anything.
 

Trials

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Ok how about this: if you and I are standing at the top of some big rock in the hope of catching a flying motorcycle, you might well hear me say to you; if he blimps the motor a whole bunch on the run up get ready to catch because he ain't going to make it! Would you understand what I said?
 

Brian P

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I don't have a clue what you mean by that. The circumstances that you are suggesting for "blipping the throttle", if I take that sentence "as written", are not even remotely close to those of what I use it for, and they should never exist for the motorcycles that are the topic of this thread.
 

Trials

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it does sound very cool on all those bikes,
and I agree that's about the extent of blipping relevance to this thread.

and I still like all those bikes especially the orange one.
 

Mad Mike

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I think most beginners have an idea as to what they want, they fall in love with a bike then they buy it. Any of those bikes is suitable for a beginner, on the street, I think newbies make their buying decisions on price, style, and whichever dealer salesman convinces them to pull the trigger.
 

Jayell

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Also, like to blip the throttle/accelerator on a downshift but have read elsewhere that this is not good for FI computer controlled motors - true/false?
100% false. Absolute nonsense.

Keep on blipping!
 

-Maverick-

Well-known member
Brake pads are dirt cheap, clutches and gear boxes are not.

Use rev matching, front brakes and a bit of trail braking with the rear on spirited rides and my bikes last forever.

Engine braking on an R3 shouldn't even be a conversation.

Sent from my ZTE A2017U using Tapatalk
 

lakshan

Member
This thread took a turn and reading through the comments about blipping the throttle has me scratching my head.

In order to get to the right gear on any manual transmission, you should be matching engine speed to the road speed for that gear. If you are slowing down and you are in the lower rpm range of that gear, you need to shift down and simultaneously increase engine speed to maintain the road speed for that gear. That act of increasing engine speed is 'blipping the throttle' and it's necessary for smooth downshifts. If you don't, the engine will bog to try and catch up to speed, and weight shift on the vehicle will occur. It not only decreases wear but when done right, is a stable technique and would prevent sudden weight shift in the vehicle.

When you down shift and have rev matched, you are now in a higher rpm range and will naturally incur some engine braking (assuming you're not accelerating). I don't do this coming to every light, but if I see traffic slow down up ahead and am expecting to slow down, I will always down shift, rev match and use some engine braking. Also, I wouldnt be at like 8k rpm and let it engine brake all the way down. More like I'm crusing at 2.5k, down shift and now I'm at 3.5k, down shift again and now I'm at 5.5ish k. From either 3.5k or 5.5k rpms it's not an aggressive engine brake and it's still useful.

My experience with this is only on a car, and I've used it on track several times where rev-matching is necessary to safely take corners at speed. If for some reason the mechanics above differ for the R3 or other bikes let me know... but I don't see why it's fundamentally any different.

Rev matching/blipping throttle is a necessary skill for manual transmissions in my opinion, it's not "ABS for old people" or just for fun...
 

Trials

Well-known member
Everything in the thread other then stuff about the small displacement bikes
Is about throttle control.

How's your throttle control, good? (y) bad, or unpracticed.
 

lakshan

Member
Does it differ from cars to bikes? I am well practiced with many hours on the track with throttle control on my car.

Isn't increasing throttle/engine speed to match the gear "good throttle control" ? Blipping doesn't have to be aggressively fast or very high rev, just enough to get into the right rpm range..
 

Trials

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Ice riding is probably the next opportunity to seriously practice it.
Lake froze over last week, now we just need some serious cold and no snow (y)

lots of engine blipping even at stand still is very typical, likely required at times on a 2-stroke,
was first thing I had to totally unlearn when I went to 4-stroke competition bikes. ymmv.
 
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Brian P

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^ That sort of thing is NOT relevant for the 4-stroke street bikes that are supposedly the topic of this thread. Throttle blipping for the purpose of rev-matching downshifts is perfectly normal, will not hurt anything, and will reduce the chance of a rear-wheel slide caused by the rear wheel becoming responsible for accelerating the engine up to the higher speed in the next lower gear.
 

Trials

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^ pretty sure we all got that concept from the get go Brian.
relevant for the 4-stroke street bikes that are supposedly the topic of this thread ?
yes it would indeed be relevant if you just came off learning to ride on a 2-stroke motorcycle :|
 

Brian P

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Hardly anyone in the market for the bikes that are the subject of this thread would have any experience at all with two-stroke anything. But still ... As long as the tachometer and the temperature gauge are within bounds it's STILL not going to hurt anything, so why on EARTH would you state the following:

Engine braking = ABS for old people, WRONG
if everything you ever drove had an automatic transmission, you might not even know what it is or when to use it. That's possible ...

Blipping an engine :/ while nothing is actually 'good' for a motor except maybe oil, you are certainly not doing your valve train drive any favours WRONG it will not harm anything as long as the tach and the temp gauge are within bounds ,
your Fi computer uses a collection of sensor inputs to make the motor operate efficiently under normal operating conditions, normal operating conditions doesn't normally include a whole bunch of superfluous and sudden increases and decreases in engine speed Yes it does. Gearshifts. Operating efficiency Insignificant effect when used for rev-matching as intended and engine wear WRONG as long as the tach and temp gauge are within bounds is probably reason enough to not constantly blip your 4-stroke engine if you care about such things, otherwise have at it.
 

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