Reed valve with extended intake

[Fabian]

Overgearing (pedalling too slowly, putting too much energy into each turn of the crank) is what weakened my knees in the first place! Damn single speed jump bikes!

Your knees won't give a damn about over gearing with an engine assisting your efforts (sometimes greatly assisting your efforts), regardless of how feeble the effort you choose to put into the mechanical system by pedal power. The whole concept is to be able to gently pedal along with your legs putting in a light amount of effort; a bit like pedaling downhill all the time

A pedal speed of about 50 rpm is just delightful.

 

[Fabian]

it would lower your stall speed even further

With a centrifugal clutch you don't have to worry about a stall speed that stops the engine, because it's operational stall speed is around 2,500 rpm, even if the mechanical drive train comes to a complete stop.
Just keep the throttle nailed and the bike keeps moving forward, though you can't punish the centrifugal clutch for too long under this scenario, but it will be able to get you out of sticky situations, when it would otherwise mean the bike coming to a complete stop with only a manual clutch.

 

[Fabian]

(I always expect bad things lol!)

That's just the way it is; "bad things do happen". The test of your mechanical skills is to be able to engineer your way around a problem and keep making the magic happen.

 

[FurryOnTheInside]

Your knees won't give a damn about over gearing with an engine assisting your efforts (sometimes greatly assisting your efforts), regardless of how feeble the effort you choose to put into the mechanical system by pedal power. The whole concept is to be able to gently pedal along with your legs putting in a light amount of effort; a bit like pedaling downhill all the time

A pedal speed of about 50 rpm is just delightful.

I guess this is just a question of riding style then.. my whole concept is a bit different, I would like to produce the same power with my legs as I do now on a pedal bike, I still want to lose weight and stay warm; but go further and go faster, up hills and into headwinds, and get out of the rain quickly. I can pedal pretty much indefinitely at 90RPM and idk how much power I can produce as I don't own and haven't borrowed a bicycle power meter. Wiki says: "A trained cyclist can produce about 400 watts of mechanical power for an hour or more, but adults of good average fitness average between 50 and 150 watts for an hour of vigorous exercise. A healthy well-fed laborer over the course of an 8-hour day can sustain an average output of about 75 watts."

50RPM pedalling : 3800RPM engine would require some extreme gearing on the SBP shift kit system.. 10:21, 9:54 probably wouldn't even do it (too sleepy to actually do the maths now haha)

 

[Deleted member 12676]

yall ever hear of thread hijacking?
It is extremely easy to start a new thread you know

 

[FurryOnTheInside]

With a centrifugal clutch you don't have to worry about a stall speed that stops the engine, because it's operational stall speed is around 2,500 rpm, even if the mechanical drive train comes to a complete stop.
Just keep the throttle nailed and the bike keeps moving forward, though you can't punish the centrifugal clutch for too long under this scenario, but it will be able to get you out of sticky situations, when it would otherwise mean the bike coming to a complete stop with only a manual clutch.

So the centrifugal clutch will just disengage, as if the engine is idling? That's cool. I didn't realise it did this! I'm not planning to use one myself, at least right away on the first build. Can you still pedal start or must you dismount and use the pull start? I'd like to stop the engine on downhills and even on level ground if there's a tailwind and I'm up to a good speed (for heavy loaded touring, ONE 1-wheel trailer and up to two pairs of panniers).
I don't often come to a stop at the moment, pedal powered using a 28T low range gear so for what I'm doing this really only affects me when negotiating anti-motorbike gates on cycle paths, stuff like that.. but I can just declutch most of the time (I say most as there's a few occasions where a hill would aslo be involved)

 

[FurryOnTheInside]

yall ever hear of thread hijacking?
It is extremely easy to start a new thread you know

I didn't start it! :O I'm just continuing it. I am aware this isn't even the drivetrain section.

To be fair, Jaguar, it did happen a week ago on page one, and this diversion has had some merit, it contains info that has not really been discussed before, anyone who's really interested in high performance MABs reads everything anyway, and a manufacturer has announced they're looking into making a new product that will help us.
And it was quite similar to a thread from 2011 "extended intake for more low end power" by Jaguar in Performance Mods.

 

[FurryOnTheInside]

Back on topic! (kinda)

Is the intake length on the RSE reed valve and Walbro style carb kit (with the thermal isolation spacer, at the dimensions they make it) optimised for low end power, or should I ask them for a specific length T.I.S. when I order this?

 

[Fabian]

Nothing wrong with a little thread hijacking. It eventually tracks back to the original theme.

 

[Fabian]

Is the intake length on the RSE reed valve and Walbro style carb kit (with the thermal isolation spacer, at the dimensions they make it) optimised for low end power, or should I ask them for a specific length T.I.S. when I order this?

You only get one length.
The reed valve intake is what really helps low end torque, which largely makes the length of the intake irrelevant.