Hub Centre Steering

[Le_Fromage_Grande]

Hub Centre Steering bikes like the Bimota Tesi and Elf Honda Endurance racer were hailed as the future of motorcycle chassis design in the 1980s, but never caught on, and many people questioned whether it was an unnecessary complication, what do you think, are we all riding round on motorised safety bicycles, or are telescopic forks the pinnacle of motorcycle front ends, and what about BMWs Telelever or the Hossack front end

[Horse]

They're engineering solutions to problems that many don't see as problems and are comfortable with, and forks manufacturers have worked hard to accommodate.

I'm probably not the best to give a 'test rider' experience feedback / report, but I never had any issues with the R series Telelever. To me, the RTs always felt 'lighter' and more nimble than a bike that size and weight ought to.

From the engineering PoV, it's interesting how the requirements of headstock strength and rigidity usually result in a massive frame around the motor (or battery box in future).

[MingtheMerciless]

I think conventional forks have had 70 odd years of R&D by a lot of suspension companies so "funny" front ends are always playing a lot of catchup despite all the touted advantages. You've also got a lot of inertia in the industry for tele's as well as riders not wanting to change/getting burnt as early adopters.

I've not ridden a motorbike with a "funny" front but I've got a PRST-1 mountain bike which resembles a telelever and that had the best small bump and XC feel of anything I've ridden, only getting overwhelmed when it got really bumpy (though a longer travel more hardcore version was being prototyped when the manufacturer sadly lost interest).

[Rockburner]

I think conventional forks have had 70 odd years of R&D by a lot of suspension companies so "funny" front ends are always playing a lot of catchup despite all the touted advantages. You've also got a lot of inertia in the industry for tele's as well as riders not wanting to change/getting burnt as early adopters.

Don't forget the motorcycle media are inherently ultra-conservative and invariably disparage anything with a 'Funny-front-end'.



I've not ridden a Hub-centre design*; but both BMW's implementations work very well indeed (Telelever, Duolever). After the initial 'lack of feel' is accommodated for (something which generally takes more than a few days of riding, hence why journalists rarely appreciate them), they are just as good, if not better for road riding than telescopic forks.

Yes they tend to be heavier, but not by a huge amount.

I've also ridden on 'Girder' forks (Vincent Comet), and fucking hated them. Fine at speed (lovely and stable on a heavy bike), but very heavy steering at lower speeds.




* But would jump at the chance if anyone offered. I once came past a Yamaha GTS1000 on the A3, I was on the Rockster, and I was really surprised at how small the Yam actually was in the flesh, the Rockster towered over it.


Funnily enough - a lot of these systems date back to very start of motorcycling, ie 1900 - 1935. IIRC the Neracar was a HCS design, Girder forks were common, even upside-down telescopics. (The 1953 Bantam, based on a pre-war DKW, had upside down forks).

[Horse]

Yes they tend to be heavier, but not by a huge amount.

Where do you stop weighing (ie 'fork' becomes 'frame'. Plus, some of the Hossack designs are light, open, trellis.



From here:
https://www.citybike.com/stories/talkin ... n-hossack/

[Mr. Dazzle]

I don't think it's anything to do with any technical advantages (or not) in the bikes themselves. I think it's almost entirely down to riders. It's not even an image problem, it's rooted deep in everyone who rides a bike.

How do you ride a bike? As in, how do you actually stay on it? How do you corner, brake and all the rest of it? You can't explain it can you? No-one can, you just "do it". Sure you can teach some of the idea, but fundamentally it's something you have to learn for yourself via practice. It's deep seated memory isn't it? You will also never forget! It is - literally - like riding a bike.

All of that mean we are deeply deeply attached to the way a conventional bike (even a pedal bike) feels. Thus anything differnet 'feels weird' and we don't like it.

It gets even more extreme in racing. Racers have spent years and years honing their reaction to the feedback coming through a bike and a huge quantity of their understanding is subconscious. Most people couldn't tell you how they know the front is about to let go - they can just feel it. That again means any time they ride something different all their knowledge/experience is less use. Which is why funny front ends don't seem to do well in racing, which in turn leads to the argument "well if they were any good racers would use them".

[lostboy]

Why are the MotoGP boys are still rocking forks and have no interest in changing. If it's good enough at the cutting edge why would we be on anything else?

As has been said, it's engineering solutions to a problem that doesn't exist.

[Horse]

Why are the MotoGP boys are still rocking forks and have no interest in changing. If it's good enough at the cutting edge why would we be on anything else?

As has been said, it's engineering solutions to a problem that doesn't exist.

It does exist. But the fork designers have worked hard to overcome them.

For example, bigger diameter tubes for rigidity.

[Yorick]

Why are the MotoGP boys are still rocking forks and have no interest in changing. If it's good enough at the cutting edge why would we be on anything else?

As has been said, it's engineering solutions to a problem that doesn't exist.

You can bet the big boys have tried it. If it was any good they'd have built race bikes.

[Bigjawa]

Why are the MotoGP boys are still rocking forks and have no interest in changing. If it's good enough at the cutting edge why would we be on anything else?

As has been said, it's engineering solutions to a problem that doesn't exist.

You can bet the big boys have tried it. If it was any good they'd have built race bikes.

They did....

[Yorick]

Why are the MotoGP boys are still rocking forks and have no interest in changing. If it's good enough at the cutting edge why would we be on anything else?

As has been said, it's engineering solutions to a problem that doesn't exist.

You can bet the big boys have tried it. If it was any good they'd have built race bikes.

They did....

Quite. And it was shit. But I meant they'd try it again when technology moves on

[Le_Fromage_Grande]

Ron preferred the conventional NSR to the HCS one
I think the only bikes I've ridden with anything other than teles have been mopeds and scooters so I've no experience to draw on for these, they are interesting though, Dazzles point about being able to feel the front end tucking is very valid, a different tyre is enough to change the feel of the front end

[Yorick]

Ron preferred the conventional NSR to the HCS one
I think the only bikes I've ridden with anything other than teles have been mopeds and scooters so I've no experience to draw on for these, they are interesting though, Dazzles point about being able to feel the front end tucking is very valid, a different tyre is enough to change the feel of the front end

One day BMW brought 6 bikes for us instructors to play on.

We got bollockings for scraping the heads, but that's a different story .

Braking was the bit we all struggled with. Lack of feeling was one bit.
But trail braking was main one.

Top lads brake right to the apex, which makes the forks dive, which in turn steepens the steering angle, to help the bike turn.

On the FFE bikes we rode, they didn't turn into tight corners.

[Mr. Dazzle]

Thing is....you can brake in a car right up to the point where you're about to lock the wheels, just like on a bike, if you know how. Cars are obviously more 'detached' than bikes 'cause there are more bits between you and the wheels, but you can still feel right up to the limits of adhesion. So why is that?

That's kinda my point really, I don't think it's a case of FFE's having intrinsically more/less feel (or anything else) than a conventional bike, I think it's a case of trying to undo 20* years of experience.

*maybe a few more

[Rockburner]

Yes they tend to be heavier, but not by a huge amount.

Where do you stop weighing (ie 'fork' becomes 'frame'. Plus, some of the Hossack designs are light, open, trellis.



From here:
https://www.citybike.com/stories/talkin ... n-hossack/

Classic example of derogatory journalism there in the first few paragraphs.

[lostboy]

Ron preferred the conventional NSR to the HCS one
I think the only bikes I've ridden with anything other than teles have been mopeds and scooters so I've no experience to draw on for these, they are interesting though, Dazzles point about being able to feel the front end tucking is very valid, a different tyre is enough to change the feel of the front end

One day BMW brought 6 bikes for us instructors to play on.

We got bollockings for scraping the heads, but that's a different story .

Braking was the bit we all struggled with. Lack of feeling was one bit.
But trail braking was main one.

Top lads brake right to the apex, which makes the forks dive, which in turn steepens the steering angle, to help the bike turn.

On the FFE bikes we rode, they didn't turn into tight corners.

What did they put on the front end of of the S1000RR? That speaks volumes.

As well as increasing the steering angle the weight transfer also increases the contact patch of the tyre.

[Yorick]

Ron preferred the conventional NSR to the HCS one
I think the only bikes I've ridden with anything other than teles have been mopeds and scooters so I've no experience to draw on for these, they are interesting though, Dazzles point about being able to feel the front end tucking is very valid, a different tyre is enough to change the feel of the front end

One day BMW brought 6 bikes for us instructors to play on.

We got bollockings for scraping the heads, but that's a different story .

Braking was the bit we all struggled with. Lack of feeling was one bit.
But trail braking was main one.

Top lads brake right to the apex, which makes the forks dive, which in turn steepens the steering angle, to help the bike turn.

On the FFE bikes we rode, they didn't turn into tight corners.

What did they put on the front end of of the S1000RR? That speaks volumes.

As well as increasing the steering angle the weight transfer also increases the contact patch of the tyre.

You can't stop the weight transference. Me being geeky

[Rockburner]

Ron preferred the conventional NSR to the HCS one
I think the only bikes I've ridden with anything other than teles have been mopeds and scooters so I've no experience to draw on for these, they are interesting though, Dazzles point about being able to feel the front end tucking is very valid, a different tyre is enough to change the feel of the front end

One day BMW brought 6 bikes for us instructors to play on.

We got bollockings for scraping the heads, but that's a different story .

Braking was the bit we all struggled with. Lack of feeling was one bit.
But trail braking was main one.

Top lads brake right to the apex, which makes the forks dive, which in turn steepens the steering angle, to help the bike turn.

On the FFE bikes we rode, they didn't turn into tight corners.

What did they put on the front end of of the S1000RR? That speaks volumes.

As well as increasing the steering angle the weight transfer also increases the contact patch of the tyre.

As Yorick said - the weight transfer happens anyway.

It's true that Telelever 'lengthens' the wheel base as the suspension compresses (because of the geometry involved), but I think that the Hossack/Duolever system doesn't. It might not shorten the wheel base 'as much', but I'm pretty sure the movement of the wheel is 'upwards', not 'forwards' (like Telelever).

FWIW, IIRC the head angle on the BMW K1200R is bloody steep, steeper than most forked bikes. (and steeper than the K1200S, interestingly).

You can brake all the way through a corner with most all of the 'different' front ends, I believe it's because the suspension and steering forces are separated.

[Mr. Dazzle]

You can't stop the weight transference. Me being geeky

He's right you know.

You can also have really steep steering angles on a FFE if you want, along with angles that increase as you load the front. Or decrease. Buyers choice really! That's one of the beauties of it.

[Horse]

It's true that Telelever 'lengthens' the wheel base as the suspension compresses (because of the geometry involved), but I think that the Hossack/Duolever system doesn't. It might not shorten the wheel base 'as much', but I'm pretty sure the movement of the wheel is 'upwards', not 'forwards' (like Telelever).

FWIW, IIRC the head angle on the BMW K1200R is bloody steep, steeper than most forked bikes. (and steeper than the K1200S, interestingly).

IIRC, it my determined by the lengths of the wishbones.

See TF's pages for angle info on forks!



https://motochassis.com/articles/experi ... -geometry/

You can brake all the way through a corner with most all of the 'different' front ends, I believe it's because the suspension and steering forces are separated.

And probably, for most riders, that's more of a real benefit than any quicker steering.