revtothelimit - motorbike forum

Yorick wrote: Thu Nov 24, 2022 11:17 am

mangocrazy wrote: Thu Nov 24, 2022 10:55 am

Skub wrote: Thu Nov 24, 2022 10:50 am The no brakes brigade. I didn't even know such a cult existed until recently.

I clearly remember a couple of guys deciding to do a 'no brakes' session around Cadwell at a track day I attended in the early 90s, so it's not a new thing.

I bet they lost 20 seconds a lap.

And caused a traffic jam of slower riders...

mangocrazy wrote: Thu Nov 24, 2022 11:18 am

Mr. Dazzle wrote: Thu Nov 24, 2022 10:57 am Engine braking doesn't wear the clutch out, that's another example of IAM not understanding how engines work.

Genuine question - does engine braking cause quantifiable wear on gearbox teeth due to back loads, or is it so negligible as to be not worth even thinking about?

I always smashed down the gearbox on track. Never had clutch trouble.

mangocrazy wrote: Thu Nov 24, 2022 11:18 am

Mr. Dazzle wrote: Thu Nov 24, 2022 10:57 am Engine braking doesn't wear the clutch out, that's another example of IAM not understanding how engines work.

Genuine question - does engine braking cause quantifiable wear on gearbox teeth due to back loads, or is it so negligible as to be not worth even thinking about?

Not even worth thinking about.

There would be some argument that the 'front' side of the teeth, the side you normally drive with, might be designed to be stronger or something but in practice the way gears are made means they're symmetrical. So they're "overrated" for back drive if anything.

mangocrazy wrote: Thu Nov 24, 2022 11:18 am

Yorick wrote: Thu Nov 24, 2022 11:17 am

mangocrazy wrote: Thu Nov 24, 2022 10:55 am
I clearly remember a couple of guys deciding to do a 'no brakes' session around Cadwell at a track day I attended in the early 90s, so it's not a new thing.

I bet they lost 20 seconds a lap.

And caused a traffic jam of slower riders...

And dangerous. Darent go above 100 on straight where every bugger else is doing 150.

Yorick wrote: Thu Nov 24, 2022 11:20 am

mangocrazy wrote: Thu Nov 24, 2022 11:18 am

Mr. Dazzle wrote: Thu Nov 24, 2022 10:57 am Engine braking doesn't wear the clutch out, that's another example of IAM not understanding how engines work.

Genuine question - does engine braking cause quantifiable wear on gearbox teeth due to back loads, or is it so negligible as to be not worth even thinking about?

I always smashed down the gearbox on track. Never had clutch trouble.

Yebbut it was the gearbox I was more concerned about...

mangocrazy wrote: Thu Nov 24, 2022 11:22 am

Yorick wrote: Thu Nov 24, 2022 11:20 am

mangocrazy wrote: Thu Nov 24, 2022 11:18 am

Genuine question - does engine braking cause quantifiable wear on gearbox teeth due to back loads, or is it so negligible as to be not worth even thinking about?

I always smashed down the gearbox on track. Never had clutch trouble.

Yebbut it was the gearbox I was more concerned about...

Didn't have those either

Mr. Dazzle wrote: Thu Nov 24, 2022 9:40 am

Trinity765 wrote: Thu Nov 24, 2022 9:11 am Economic and fun are at different ends of the scale.

Even F1 and MotoGP racers worry about fuel consumption.

'Course, the real challenge is to travel fast AND economically, which is totally possible. Just more difficult.

My 1.4 petrol Leon will typically do 50+ fully loaded. I struggled to get our old 1.4 petrol Altea up to 40 mpg.

I'd say that's an engineering challenge done well.

Mr. Dazzle wrote: Thu Nov 24, 2022 11:21 am

mangocrazy wrote: Thu Nov 24, 2022 11:18 am

Mr. Dazzle wrote: Thu Nov 24, 2022 10:57 am Engine braking doesn't wear the clutch out, that's another example of IAM not understanding how engines work.

Genuine question - does engine braking cause quantifiable wear on gearbox teeth due to back loads, or is it so negligible as to be not worth even thinking about?

Not even worth thinking about.

There would be some argument that the 'front' side of the teeth, the side you normally drive with, might be designed to be stronger or something but in practice the way gears are made means they're symmetrical. So they're "overrated" for back drive if anything.

Yorick wrote: Thu Nov 24, 2022 11:29 am

mangocrazy wrote: Thu Nov 24, 2022 11:22 am

Yorick wrote: Thu Nov 24, 2022 11:20 am
I always smashed down the gearbox on track. Never had clutch trouble.

Yebbut it was the gearbox I was more concerned about...

Didn't have those either

In that case I shall continue to bang down the 'box in the same carefree way I always have...

In simple terms - engine braking is less 'input' than engine driving innit? So if you accept your engine/cluch/gearbox can do full power "forwards" then why would you worry about doing less input "backwards"?

Smashing through anything is probably unwise But if you're smashing through stuff hard enough to fuck something you'll notice the unpleasant riding somewhat too. Hopefully!

I've been riding bikes for over 50 years and I've never had a gearbox (or clutch) failure yet, so I think my mechanical sympathy must be at least reasonable. That's my story and I'm sticking to it...

It's saved my bacon a couple of times, with both car and bike...the most recently was on the Bonnie, when the clutch lever bolt shook itself loose when I was 10 miles from home Being able to ride without a clutch was most helpful.

mangocrazy wrote: Thu Nov 24, 2022 11:42 am I shall continue to bang down the 'box in the same carefree way I always have...

Your personal life should probably not be aired in this thread

Yes, I had my clutch cable break as I left the boat in Liverpool on the way back from the TT on my CB77 in the early 70s. I made it back to Stafford without too much drama, but was helped by the fact it was late at night and traffic was pretty sparse.

mangocrazy wrote: Thu Nov 24, 2022 11:56 am Yes, I had my clutch cable break as I left the boat in Liverpool on the way back from the TT on my CB77 in the early 70s. I made it back to Stafford without too much drama, but was helped by the fact it was late at night and traffic was pretty sparse.

A few weeks ago the clutch cable broke on Pen's enduro bike.
I pushed her off then she grabbed first gear. Through the intercom I could tell her what to do. We were about 15 miles from home. Decided it easier to take roads home.
Any tricky bits we were able to avoid by going back to dirt paths

Le_Fromage_Grande wrote: Wed Nov 23, 2022 11:08 pm I got about 40 mpg out of either of my FZ750s, but if you thrash them they will go under 30 mpg, I could get my R1 down to under 20 mpg quite easily, probably best not to try and remember tuned LC mpg.

I now ride like an old woman and get 50 mpg out of the GSXS

It was quite noticeable that fuel consumption on my bikes went up in the early 2000s - I believe that was when various combustion modifiers started to be added. I reckon it went up around 10%. That would probably have dropped the FZ to high 40s if I still had it.

Despite what others have said, I can't say the 10% ethanol makes any difference to my bikes - I'm still getting 55 mpg almost every ride out of the XJ and the Hornet's the same, but I am rarely ragging them. Maybe it's riding with big throttle openings where the ethanol makes a difference.

Trinity765 wrote: Thu Nov 24, 2022 9:11 am Economic and fun are at different ends of the scale.

Try the conservation of momentum game down a mountain... that can be fun... and VERY challenging

Rockburner wrote: Thu Nov 24, 2022 10:03 am It's something that's advocated by the "tutors" on the speed awareness courses. Don't know where they get it from.

Blimey! What do they tell you if you have a seven speed auto? Just askin', like.

The Spin Doctor wrote: Thu Nov 24, 2022 4:20 pm

Le_Fromage_Grande wrote: Wed Nov 23, 2022 11:08 pm I got about 40 mpg out of either of my FZ750s, but if you thrash them they will go under 30 mpg, I could get my R1 down to under 20 mpg quite easily, probably best not to try and remember tuned LC mpg.

I now ride like an old woman and get 50 mpg out of the GSXS

It was quite noticeable that fuel consumption on my bikes went up in the early 2000s - I believe that was when various combustion modifiers started to be added. I reckon it went up around 10%. That would probably have dropped the FZ to high 40s if I still had it.

Despite what others have said, I can't say the 10% ethanol makes any difference to my bikes - I'm still getting 55 mpg almost every ride out of the XJ and the Hornet's the same, but I am rarely ragging them. Maybe it's riding with big throttle openings where the ethanol makes a difference.

My car does about 10% better mpg on E10 compared to when we had E5, personally I find this a bit weird as I doubt if much of the E10 actually has that much ethanol in it and I suspect it's not much different to the pre E10 petrol, but my car now consistently does 330 miles on a tank of petrol when it used to do 300, maybe I've slowed down a bit.

Bike wise, the only one that gets ridden a lot now is the Suzuki and I've always ran that on E10, the Kawasaki gets super unleaded because it is prone to gumming up the pilot jets, but I also drain the carbs after every time it's run, the FZ750 languishes in a corner with whatever petrol is in it, but starts on the button, it could do with a good thrashing to clear the carbs out and the YPVS carbs are on a bench waiting for me to show some enthusiasm for the bike.

E5 and E10 don't have to contain Ethanol, they just can. Shell V Power for example is marked E5 but is ethanol free.

Ethanol is also a good knock suppressor, so depending on how smart your engine is it's entirely possible that using Ethanol allows it to run as if it's on Super and tune the ignition accordingly.

Mr. Dazzle wrote: Thu Nov 24, 2022 4:51 pm E5 and E10 don't have to contain Ethanol, they just can. Shell V Power for example is marked E5 but is ethanol free.

I knew that, which is why I said I don't think the E10 is much different to what I was putting in before E10 was about, I also think ordinary petrol is cheaper than ethanol, so why would the fuel companies put in ethanol when they don't have to, but if someone says ethnanol is cheaper I can see why they'd put it in.