Yamaha RD421LC Restomod / Hybrid – BikeBound


Yamaha RD350LC 421cc Restomod

Colin White’s 421cc Cheetah Cub LC… 

In 1980, Yamaha launched the RD350LC (Liquid Cooled) because the successor to the air-cooled RD400, together with a 250cc model aimed on the British learners’ market. The “Elsie” shortly grew to become a favourite of power-hungry tuners and two-stroke aficionados:

“For riders searching for excessive efficiency on a low funds, no different bike got here shut. With a 110mph prime velocity, wheelie-popping acceleration and racetrack credibility, the “Elsie”…was the bike of a speed-crazed teenager’s goals.” -Roland Brown, Hagertys

Supply: rd350lc.web

In 2020, MCN printed their very own retrospective on the beloved LC:

“Arguably probably the most beloved and inspirational Japanese bike of all – Yamaha’s RD350LC – went on sale for the primary time 40 years in the past…the skills of the 47bhp stroker twin at the moment are the stuff of legend…” –MCN, 2020

Supply: rd350lc.web

The 250 model was no slouch both. Legend has it, the riotous RD250LC single-handedly spurred new laws that restricted UK learners to 125cc machines from 1983 onward!

Yamaha RD421

Nonetheless, as two-stroke road bikes died off within the years to come back, a rising contingent of shed builders and tuners started creating “hybrids” — Yamaha RD specials that melded the nostalgic sound, scent, and energy of a modified two-stroke engine with up to date suspension, brakes, wheels, and extra. Just like what we consider at this time as restomods, however extremely targeted.

Yamaha RD421

As we speak’s hybrid comes our method from Colin White of the UK, who’s owned the bike for 26 years!

“It’s solely the fourth bike I’ve owned — the opposite three have been additionally Yamaha RD’s (two 125’s and one other 350 earlier than this one), so it’s truthful to say I’m a Yamaha 2-stroke fan!”

Yamaha RD421

There are loads of hybrid RD specials within the UK — the Hybrid Membership is devoted to them — however Colin wished a motorcycle that might stand out from the gang:

“I wished to construct a single-minded excessive efficiency street bike, and because it’s such a generally constructed bike within the UK, I wished to attempt to do one thing that didn’t look the identical as anybody else’s bike, I wished to attempt to do a couple of bits that no-one else had!”

Yamaha RD421
Colin’s LC hanging with a Langen!

It took him years to assemble the entire elements he wished. Highlights embody the one-piece tail unit and solo seat made to his design, bespoke subframe and braced chassis, Ducati 916 forks with customized yokes, 320mm discs with six-pot calipers, Dymag magnesium wheels, Spondon swingarm, and titanium fasteners all through.

Yamaha RD421

The engine is now a 421cc with a TSS crank, Cheetah Cub barrels, Air Stryker carbs, hydraulic clutch, and pipes handmade by Mark Dent of Efficiency Fabrications.

Yamaha RD421

It’s been dynoed at 95 rwhp, and Colin says the non-YPVS energy supply provides the adrenal glands a critical squeeze:

“Using the bike is loopy — it doesn’t have energy valves so the facility supply when you hit the powerband is such a rush — the facility hits unexpectedly. In comparison with the inventory bike the dealing with is superb, it feels taut and effectively balanced because of the intensive body bracing, extra trendy working gear, lighter wheels, and extra trendy tyres…”

Under, we speak to Colin for the total particulars on his 421cc LC!

Yamaha RDLC Hybrid: Builder Interview

Yamaha RD421

• Please inform us a bit about your self, your historical past with bikes, and your workshop.

I’ve owned the bike for 26 years, and it’s solely the fourth bike I’ve owned — the opposite three have been additionally Yamaha RD’s (two 125’s and one other 350 earlier than this one), so it’s truthful to say I’m a Yamaha 2-stroke fan! I’ve bought a small single storage in my backyard at residence with a motorcycle ramp, which in all fairness effectively outfitted — I take pleasure in spending time on the market!

Yamaha RD421

• What’s the make, mannequin, and yr of the bike?

The bike began life as a 1985 Yamaha RD250lc, however by the point I purchased it had been transformed to a 350cc.

Yamaha RD421

• Why was this bike constructed?

I have a tendency to switch every thing I personal, and so I began modifying it from the primary day I owned it. Initially it was small modifications, because it was my solely day by day transport and I couldn’t have it in items for lengthy, however after a very laborious thrashing one sunny Sunday I managed to grab the engine after which determined to go all out!

The bike was pulled aside to be constructed correctly — though it stayed in items for years, and through that point I saved shopping for elements for it as and after I may afford them. I modified my thoughts quite a bit throughout this time, however lastly began on a correct closing dry construct round 5 years in the past as soon as I’d bought just about all of the elements in place to place it collectively.

Yamaha RD421

• What was the design idea and what influenced the construct?

I wished to construct a single-minded excessive efficiency street bike, and because it’s such a generally constructed bike within the UK, I wished to attempt to do one thing that didn’t look the identical as anybody else’s bike, I wished to attempt to do a couple of bits that no-one else had!

Yamaha RD421

• What customized work was finished to the bike?

As far as customized work, there’s not a lot that isn’t both extremely modified or a whole one-off. The body has been closely braced to deal with the additional energy and brakes, the entire subframe was rebuilt by an area forge to accommodate the one-off single seat bodywork. The bodywork was made to my design by moulding the unique LC aspect panels and tailpiece right into a one piece unit and was single seat — it was one thing I actually wished to do, but it surely brought on a LOT of complications and additional work to make it work!

Yamaha RD421

The yokes are one-off and maintain early Ducati 916 Showa forks, with one-off CNC-machined caliper hangers, twin 320mm Brembo discs, and six-pot ISR calipers on Dymag magnesium wheels — it stops effectively!

Yamaha RD421

The rear finish is a one off Spondon Engineering swingarm, a single piston AP Lockheed caliper, and Dymag magnesium wheel.

Yamaha RD421

The engine is now a 421cc with a +4 mil TSS crank, Cheetah Cub barrels, and 35mm Air Stryker carbs, in addition to an entire host of different modifications together with a hydraulic clutch. The pipes are additionally handmade by Efficiency Fabrications and are one of many bits most frequently commented on — the welding is wonderful!

Yamaha RD421

Each fastener on the bike is titanium to maintain the load down, and weight saving was a giant a part of the construct all through. The one a part of the unique bike is the entrance half of the body (modified); aside from that each single half has been modified.

Yamaha RD421

• Does the bike have a nickname?

I don’t have a nickname for the bike as such, however to me all LC’s are referred to as Elsie!

Yamaha RD421

• Any thought of weight or energy numbers?

 I’ve by no means bought spherical to weighing the bike, though I’m actually curious to know what it weighs. It’s spent a little bit of time on the dyno; it places out simply over 95bhp on the wheel — I believe we may get it over the 100 mark pretty simply (it’s working normal porting for the time being and doesn’t have notably giant carbs), however because it’s a street bike, 95 is greater than sufficient to make me grin like an fool and get me in bother!

Yamaha RD421

• Are you able to inform us what it’s wish to experience?

Using the bike is loopy — it doesn’t have energy valves so the facility supply when you hit the powerband is such a rush — the facility hits unexpectedly. In comparison with the inventory bike the dealing with is superb, it feels taut and effectively balanced because of the intensive body bracing, extra trendy working gear, lighter wheels, and extra trendy tyres — it’s an actual pleasure to experience when you will get a good little bit of street!

Yamaha RD421

• Was there something finished throughout this construct that you’re notably pleased with?

I’m pleased with most of it — notably because it’s my first construct, there are a great deal of little particulars that nobody notices that I like; there are additionally some wonderful elements on it made by folks way more intelligent than me — however most likely the one half that I really feel units it aside most is the tailpiece/rear bodywork, because it’s the one one!

Yamaha RD421

There are lots of people to thank, however prime of the record are my mates Darren, Andy and Pete — with out their assist and steerage I’d by no means have been in a position to construct it. Additionally RSK 2 strokes for setting it up on their dyno and the remainder of the Hybrid Membership boys too.

Observe the Builder: @thatblackranger8