Cheetah Cub kit - which one?

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winner_evo
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Re: Cheetah Cub kit - which one?

#16 Post by winner_evo » Tue Dec 26, 2017 2:45 pm

LC Cnd wrote: lastly purchase a RZ if I can find one meets the current budget (not likely). Kinda leaning towards Rory's logic on this if affordable.
Truth is, a YPVS is still an old frame/geometry. They still have skinny wheels/tyres, fairly skinny forks & quite small brakes.

If you want a two stroke with precise handling and good brakes then you need to look at bikes built 10 years later.

Keep your LC with it's engine, squeeze another 10-15hp from it so it revs to 9500rpm without hitting a wall, make sure the rest of the standard components are as good as they can be and if you still want more, then I don't know what to suggest.

I have bikes that are faster, corner & stop better than my LC, but I still love riding it.

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JonW
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Re: Cheetah Cub kit - which one?

#17 Post by JonW » Tue Dec 26, 2017 8:57 pm

Why not fit a ypvs engine to an LC to give you the power upgrade and also a nice tractable engine using the PVs? Some would argue that this makes the most usable of LCs.

I am doing that with the 'famed' (most people have never even heard of it lol) 51L 250 engine, which makes the same power (within 1bhp) as the LC350 to compare the two. I feel that this should be interesting as while its the same power its a very different delivery. I also dont know anyone who has ever done it, as I said most people dont really know what a 51L motor is, not helped by the fact that very few markets took 250s in the 84/85 model year. Anyway, building what is possibly a new concept with our bikes isnt easy as many things have been done over the last 30+ years, and naturally coming up with something thats 'new' always appeals to me as im sure readers of my threads will know. Of course a 350 ypvs will make more power (upto 15bhp), but I wanted the same power as the old engine, just achieving the delivery of it differently. I really do consider that it may well be the hot ticket for riding round in the huge traffic jam that is located around where I live in this fair city... we'll see I guess. :smt003

Anyway, if you built an RZ engined LC and then found you didnt like the ypvs 350 in the LC or wanted more youve already got the right bottom end for an easy (and cheapish) big bore if you want to go that route. Then also have the option of creating something more hybrid if you decided that you needed/wanted the suspension and brakes later and that would just be a case of locating parts.

As said above I do hear good things about the RZ forks on the LC, so you could go for late RZ forks with PD valves and Triumph calipers and then youre only limited by the skinny wheels and 18inch tyres, if doing this I say why bother with the 83/4 units if you can get the later lower legs and bolt on calipers without brackets etc. Swingarms in various flavours go back to the old school for the LC , some include disk brakes (RZ and modded LC wheels) and longer length units can be built or bought etc etc.

It all depends on how you want to build a bike and how you want your project experience, if you want to build once and just ride then thats one thing, if you want to play then I guess Ive outlined a long and winding path where you could enjoy the natural upgrade routes and also feed back how much better or worse each upgrade is, I dont know anyone whos ever done that step-by-step.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

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hondaror
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Re: Cheetah Cub kit - which one?

#18 Post by hondaror » Wed Dec 27, 2017 3:08 am

In my opinion, winner and Jon make great points.

2smoke, the RZ 35mm forks are a step in the right direction. Not too big to screw up the LC. Peter has done that here in Calgary. Retaining the stock wheels is important for LC characteristics. You can now buy skinny radiales for the LC, and I've heard nothing but good about them. Jon talks about the chassis limitations. Big forks, big wheels ans a big rear end, don't do the LC any favours. The frame behaviour can be changed drastically with gussets, reinforcement. This with the 35mm RZ forks do wonders.
The big stuff adds unsprung weight which sucks up horse power. It also slows down the steering, taking away from the handling. It also means that you have to beef up the frame to handle the new stresses created by the big, stiff components.

You can really make the LC breathe with K&Ns and pipes. Totally changes the power. Makes for real excitement. In this form, it's the best bang for the buck.

My idea of fun will be an LC engine in the RZ frame. A gem of an engine in a gem of a frame. Not the best of either, but a very complimentary duo. The LC is a scream to ride. A few more safe ponies, keeps it reliable, fast, and so much fun. My boss thinks I'm going backwards with this idea, but if you've spent any time on a 350LC, you'd totally understand my concept. The LC in stock form is rather docile compared to making it breathe with the pipes and K&Ns. (Knock off, no name pods do not work, K&N only-the dyno does not lie).

That's a couple of sense to add to my $0.02.

P.S. I will be building one of these RZ/RDs in the future.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

LC Cnd
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Re: Cheetah Cub kit - which one?

#19 Post by LC Cnd » Wed Dec 27, 2017 1:54 pm

Thanks to all for your insights; lots to mull over. Your engine swap is certainly counter-intuitive and be watching how that goes for sure. K&N pods, 'check' - with Mikuni VM26's? Wondering if I could combine the pods with Microns with some modicum of preformace success. 32mm front end and new mono shock replacement seems to be in order for good telemetry regarding rake and tracking. The engine is where I would like to start and it appears that squish is where to begin. I have zero experience on this issue but note alot of info on this subject on the engine thread to mine. Luckily there is a machinist who as experience in mill planing Banchee heads to assist locally. Note finding that correct squish is a one shot deal unless you correct it with a taller base gasket - hope to avoid that. As far as the Cheetah cub is concern that appears shelved for a more comprehensive mod that hopefully widen my grin - that's what I'm trying to capture in this adventure. With respect to the RZ - haven't had the pleasure yet to experience the power hit but understand fm a bud of mine the RD is more visceral hence more exiting. Don't know. Visually I find the RD lines pleasing - almost feline like a Ferrari 250 GT and that why I want to keep it stock looking as possible - no cutting of rear fenders etc yet enhance performance. According to the opintions offered is quite do-able and I'm enthused to get started - squish.

evan_calgary
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Re: Cheetah Cub kit - which one?

#20 Post by evan_calgary » Wed Dec 27, 2017 2:30 pm

LC Cnd wrote:So I sence that from a stock prospective, a LC engine upgrade is do-able only if one consider a systems upgrade on braking, suspension and frame mods; ergo, there is no such thing as a stock upgrade on an Elsie that will allow you safe margin of error for more performance grin safely. That leaves one with the following choices: choose from a myrid of hybrid projects and satisfied customers/builders noted under the custom projects/restorations thread, 2) or go with the techincal service bulletin, that came out of Yamaha Holland circa 1982-83(?) on a 5-7 hp upgrade (surely within the safety margin, or is it), lastly purchase a RZ if I can find one meets the current budget (not likely). Kinda leaning towards Rory's logic on this if affordable.
This is already leaning the way of an ill fated project from the start. Totally second Rory's comment. You are trying to make a race winner out of a glue bucket. Save your bit of cash, go pick up a decent starting chassis then go from there. With the LC prices these days you could easily punt a LC, get a proper Chassis like a TZR then add a RZ motor and jack up the displacement whenever you feel the need. The LC chassis in antiquated. Find something more modern before tossing money at the motor...

LC Cnd
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Re: Cheetah Cub kit - which one?

#21 Post by LC Cnd » Wed Dec 27, 2017 3:48 pm

Upgrades ill fated? I imagine your talking from experience regarding the upgrades I recall you did on a rolling Elsie you had for sale last year or the year before. Hopefully it sold. Ck'd for TZR frames on Kijiji and zero results unfortunately. Found TZR ads on Rare Sport Bikes - one posted this mth up for bids at $6100 - nice but passed the budget. That means I'm left with what I've got in the garage to invest in.

evan_calgary
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Re: Cheetah Cub kit - which one?

#22 Post by evan_calgary » Wed Dec 27, 2017 4:59 pm

The LC I built was completely fine. It was a great bike for what it was.

I was talking about the idea of this post being ill fated. You are already talking about making major compromises and down the road I just can't see you being happy with the limitations of the LC chassis if you want heavy mods such as a 421. Glad to see Rory has helped with some more moderate ideas.

That was likely also my TZR. The bikes we build are excellent.

Frames from Japan are ~$500. Throw a front end on there, I even have a swinger if you need one.
Last edited by evan_calgary on Wed Dec 27, 2017 5:07 pm, edited 1 time in total.

evan_calgary
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Re: Cheetah Cub kit - which one?

#23 Post by evan_calgary » Wed Dec 27, 2017 5:00 pm

LC Cnd wrote:Thanks to all for your insights; lots to mull over. Your engine swap is certainly counter-intuitive and be watching how that goes for sure. K&N pods, 'check' - with Mikuni VM26's? Wondering if I could combine the pods with Microns with some modicum of preformace success. 32mm front end and new mono shock replacement seems to be in order for good telemetry regarding rake and tracking. The engine is where I would like to start and it appears that squish is where to begin. I have zero experience on this issue but note alot of info on this subject on the engine thread to mine. Luckily there is a machinist who as experience in mill planing Banchee heads to assist locally. Note finding that correct squish is a one shot deal unless you correct it with a taller base gasket - hope to avoid that. As far as the Cheetah cub is concern that appears shelved for a more comprehensive mod that hopefully widen my grin - that's what I'm trying to capture in this adventure. With respect to the RZ - haven't had the pleasure yet to experience the power hit but understand fm a bud of mine the RD is more visceral hence more exiting. Don't know. Visually I find the RD lines pleasing - almost feline like a Ferrari 250 GT and that why I want to keep it stock looking as possible - no cutting of rear fenders etc yet enhance performance. According to the opintions offered is quite do-able and I'm enthused to get started - squish.
This is sounding more sane! Moderate mods that keep to the original form!

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winner_evo
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Re: Cheetah Cub kit - which one?

#24 Post by winner_evo » Wed Dec 27, 2017 5:06 pm

LC Cnd wrote: That means I'm left with what I've got in the garage to invest in.

There are a number of things you can do to the motor to wake up the potential. The first two items you should buy are a proven pair of pipes and a programmable ignition. These two items will give the biggest gain when properly jetted with a good ignition curve. After that head, reeds, porting & carbs will give small gains.

The LC is better to ride if you get it to make power at the top end without losing too much in the midrange. (I am not keen on the pipes that peak below 9K).

Standard LC's have very soft suspension front and rear and crap brakes. Fix those along with the motor and you will notice quite a difference in the way it rides.

I've had my LC for 13 years and I've carried out the above tweeks over the years and my LC won't be getting any fork/wheel/engine swaps.........ever.

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JonW
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Re: Cheetah Cub kit - which one?

#25 Post by JonW » Wed Dec 27, 2017 10:41 pm

I actually subscribe to bare's view (yeah i know LOL! :D ) that if you want the best handling ever then you shouldnt start with our bikes , just buy a modern sportsbike... but im sure plenty of us have proven that you can improve the LC in areas where Yamaha was just making it up back in the day, the lessons they learnt with the LC (and racing, and other bikes) are obvious when they got to creating the RZ frame, and so on. I mentioned taht in my write up of my strengthening, you can clearly see some of that lineage. Ok, it is possible to retro fit that knowledge (yamaha would have if they wanted to do a new LC like, but better than, the old one) even if you keep everything else OEM. To me, working on the old LC frame and changing the wheels/suspension/brakes does NOT result in the dog that some seem to suggest, with thought and effort (and a bit of engineering nous) you can create a better handling machine than the original. Sure its not as flighty and quick turning (or slow stopping), thats a factor of many of the things modern bikes makes use of (tyres, suspension heights and rates, length of swinger etc etc), but if youve got more than the OEM bhp then you dont really want the original traits, calming down a short bike with bad suspension is sensible unless youre tired of life lol. Anyway, it seems like this is heading away from where i can help, I just hope that what i hoped was honest insight has helped you decide what to do Scott.
80 XT500 Supermoto!
81 RD350LC Resto
82 RD421LC Hybrid
82 RD350LC decapitation project
82 RD250LC JDM '251LC' YPVS
83 RZ350 Resto
84 RZ500 Resto
85 RZ350 F1 Resto
86 RZ350 F2 Resto
86 RZ350 F2 Hybrid

Like Watches? www.PloProf.com & www.DeskDivers.com

justind97
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Re: Cheetah Cub kit - which one?

#26 Post by justind97 » Thu Dec 28, 2017 9:56 am

One thing to consider if you're going to put an RZ motor in a TZR chassis. Custom cradle will be required and custom pipes. Both cost a fortune.. I know because I'm building one.

hondaror
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Re: Cheetah Cub kit - which one?

#27 Post by hondaror » Thu Dec 28, 2017 9:58 pm

I think Scott will end up going with what he has, based on budget. The thing to know, is how to get the best out of what you have. He needs to find an RZ chassis. That's just what I think. LC in RZ frame equals great mix.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

paulincayman
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Re: Cheetah Cub kit - which one?

#28 Post by paulincayman » Fri Dec 29, 2017 1:09 am

As a relative newbie I feel a bit cheeky but just wanted to pass on a bit of what I picked up on here and the UK crazy site. I started off with a stock 4lo from Canada (4y3), imported unseen. in need of total rebuild.. love the look of the Lc. I looked at big bore options and found a mitaka 400 barrel and piston kit which required machining of the cylinders. Then I learned about a 370 conversion from Mr Fahron in the UK which involves having a set of 250lc cylinders being suitably re-sleved and ported. Just add exhaust and carb up grades and your away. Elsie fun plus plus... well instead of that I decided I wanted pvs so I opted for a 385 pv motor based on a 31k crankcase, clutch and gear box with a long stroke (+4mm) crank. Standard bore cyls mildly tuned for torque by Martin at mbd inn UK. With that crank the engine can be increased to 421 or more At a later date but realistically I think the 385 will suit me here. As to chassis upgrades I wanted to keep the LC look and also had a limited budget. First I bought F2 forks which will be shortened to original 4lo length . Bought lc 2 yokes to fit bigger forks but still allow 4Lo clocks. These forks are thicker/stiffer than 4lo but the caliper mounts also allow the use of Triumph 4pot brakes using the stock mc. Fitted with taper roller bearings that's three not too expensive upgrades. I think a new rear shock is a must ..plus swing arm bearings .. I was able to purchase a set of f2 wheels with all the associated guff very reasonably .. supposedly a fair bit lighter than the stock 4lo wheels . Was then lucky to find a 4lo metmachex swing arm with disc conversion , that should take care of the rear end.So nothing too extreme but should add up to some fun . Best recommendation is go to the rd crazy forum in the UK if you haven't already and do as much research as you can .. it will save you a lot of cash .. trust me on that
Best of luck in the new year with your project.
Paul

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Re: Cheetah Cub kit - which one?

#29 Post by hondaror » Sat Dec 30, 2017 4:50 am

Now Paul, with your beefier engine, forks and swinger, do some research on beefing up the frame. If you ride it anywhere near the limits, you'll need that. Experience on the LC, tells me so. Without reinforcement, your frame will tell you so, by cracking. The steel framed TZs have those problems.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

LC Cnd
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Re: Cheetah Cub kit - which one?

#30 Post by LC Cnd » Sat Dec 30, 2017 3:03 pm

Off topic but I'm curious where the crack points were/are on the LC that would require reinforcement welds.

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