R1 with girder front end

[Bendito]

How cool is this...

This bike popped up in Bike Pic of the Day a little while ago, and I just found a whole page about it

R1 with Girder Front Suspension – Update

Yamaha R1 with Arc Girder front suspension



The start of summer is around the bend which means for some builders another winter project is getting close to completion. Jason Rodman sent us an update on his very cool girder project. The impressive aluminum, arc’d design is carried out with excellent machining.

During the intial mockup, RMD and Jason found proper trail numbers could not be achieved using the original straight legs with the stock 24 degree rake of the Yamaha R1. RMD Billet and Jason eventually came up with the arc in the legs to obtain the desired trail instead of cutting the neck of the frame (for new rake) or fabricating offset races.

After 60 hours of machine work, the resulting milled lattice structure retains rigidity while reducing weight (and also looking trick). The weight of the front-end is about 30 lbs. with 12 pounds attributed to the Penske shock.

Look for his bike at the following events this summer to get a close-up view:
• LA Calendar Show in Long Beach
• Laguna Seca at the MotoGP in July
• BUB Moto Speed Trials at Bonneville in September

Imagine a mass-produced and affordable modern sportbike with little dive in the front-end….

John Britten’s racebike worked very well with a modern interpretation of the girder front-end. The Kneeslider looks forward to hearing about the performance of Jason’s hard work being adapted to the R1. Great job Jason and RMD!

Awesome ^_^

[Desmo]

Interesting.
I'd still have a Wraith in my garage.

[Melchior]

I can certainly appreciate the fabrication work gone into this project and I do like most of the bike. But that girder is as ugly as a hatful.

[Desmo]

I wonder if it's changed the trail and rake much?

[Bendito]

Sounds like the rake stayed stock, and drawing some iaginary lines with my brain, it doesn't look too different for trail

Still yet to have a ride on one of these fancy no-dive front ends, I can't imagine it not diving

Edit: ^ just stop

[Melchior]

It looks odd because the girders are mounted so far forward, but I don't think the rake has changed much at all, though the wheel looks a bit further back than normal, I suspect it may not be so. The entire look is very deceptive.

Any drawbacks over conventional forks?

[bobinatcat]

^ my point too.

What are the advantages/disadvantages to this setup compared to normal?
I read it has less "dive" but apart from that and my limited knowledge it leaves me wondering why it would be worth all the effort and cost.

[Sprint]

Got me wondering about the aspect of spung vs unsprung weight - what bias does this setup exhibit when subjected to heavy braking or a succession of ripples/bumps, or mid-corner changes of direction... anyone here ridden a girder-clad beastie?

I like its fugly look - a tough looking bike IMO.

S.

[Melchior]

it leaves me wondering why it would be worth all the effort and cost.

If no-one went to all the effort and cost of doing the R&D of alternate technology, we'd never have anything new

[Bendito]

Not too sure on the finer details, but as far as I know:

Pros - No dive
Cons - Weight

I don't think there's really any kind of suspension that can beat telescopic forks for weight...

[Sumatie]

Very very ugly and doubt it would retain much of it's original handling ability.

[BigTim]

I'm still trying to get my head around how it doesn't dive, but there's a lot of physics involved, and I really can't be bothered with it atm (this is a pre-emptive stfu, polony).

Looks tough as hell, and the bracing on the girders is CNC porn.

[bobinatcat]

Are they not saying it reduces weight of the front end in the article?

[Bendito]

Reduces the weight of the previous design girders I think.

[Bendito]

Don't know my R1's well enough to pick the year. but here it is nose to nose with an 08