MotoGP replica project - Long Term

[Brass_Machine]

Thought I would start a thread on my project Hawk.

Background:

I have had this Hawk since the mid 90's. It was stolen but later recovered. Unfortunately, the guy who stole it, also wrecked it. Not insured, so I took a loss on it. In the process of him losing the front end in a corner, he over revved it and snapped the cam chain. At the time, I had no money to do any real repairs. I parted it out with the intent of just getting rid of it. I held onto the frame and other parts for as long as I could. Later I bought a ZX-7R and then a TL1000R... The frame and parts lay forgotten. I had gone through various project ideas but it just sat there.

Fast forward to close to the present. After selling my TLR, I wanted another project. So the idea was hatched to put a different engine in the Hawk. Been through it all... CR500, CRF450, TDM650, Ninja 650R... Settled on something different. One of my original ideas was to stuff a RZ500 engine in. Would take a lot of work. At the time, I had a custom builder in central Florida look at it... he thought it could be done. Just didn't have the cash.

Since I have moved, I am far from him. I am going to go with an engine I know pretty well. One that I can do the conversion on without a lot of outside help (except the welding). Going to put a hybrid RZ350/Banshee engine in it.

This is where it stands:



Unfortunately, the only thing that will be original Hawk will be the frame. But even that will be modified.

This project will be extended and may take over a year. Finances are not the best...

Eric

[dsquire]

Eric

Well, it looks to me like it is started. You have it up on the bench so it's all downhill from there. I am sure you will have a good following on watching the pieces come together over time. I am just glad that with the setbacks you have had over the last few years that you are able to make the start that you have dreamed about. Good luck and I'll be watching.

Cheers 

Don

[madjackghengis]

Hi Eric, in my world of experience with motorcycles, you are in good shape, as jap bike parts are generally cheap and easy to find in junk piles behind dealers.  I've been using jap brake calipers and clutch slave cylinders on custom harleys for decades, mostly because jap brakes work, and harley brakes are shiny and chrome.  A clutch slave cylinder cost me about ten bucks for a box with two sets of parts, and they turned out to be exactly an inch and a half bore, I'm running one on my own personal chopper, right now.
     Mix and match parts with no regard to who made it, focus only on the performance you want, and don't settle for anything less, and you can still do it on a small budget.  It helps a lot if you have a tig welder, and know how to weld aluminum, or have a good friend that does it.  If you really want to ride it, and get the most out of it, find a discarded small diesel engine from behind a diesel repair business, the ones that come off highway warning signs get run twenty four seven, and are usually replaced because they accumulated too many hours, and are not worth their time to fix them, and the generally just replace them.  I got two which are worn, but their real problem was being carboned up till they wouldn't run, and had fifty or sixty pounds of dirt and oil attached to them.  Cleaned up and out, valves lapped, and they run fine, just smoke a bit.  What ever you do, make it unique and absolutely yours, you'll enjoy it more that way. mad jack

[Rob.Wilson]

Hi Eric

Looking forward to watching  this build come together    

Rob

[MrFluffy]

What are you doing for swingarm/forks? im with madjack, just use what you want and don't worry too  much about compatibility. Forks we can make yokes for easy, and usually with swingers there is some element you can shave off or alter to get them in.
Thought about a single sider arm? vfr400 or vfr750/800 if you need the extra dimensions? maybe score some rvf400 inverted forks to give you matching wheel spoke patterns... Ive got vfr750 dimensions around here somewhere if your interested.

[Brass_Machine]

Hi Mr Fluffy!

The Hawk gt frame (bros where you are) comes standard with the single sided swingarm. As much as I love the sssa, I am not going to go with one on this project. Currently I can fit the TL1000R braced swingarm in there without some serious modification. However, I am going to go in a different direction. I have been toying around with the cbr600rr swingarm (later model) and I REALLY like the looks of it. Plus it has the indentation I need to clear the 2 stroke expansion chambers. It will require some serious mods to do that. I will have to chop the frame and fab up new swingarm pivot mounts etc...

Will be using late model cbr600rr forks with the radial brakes etc... right now I have a set of cbr600 F2 forks o as a place keeper. That should keep the wheels looking identical. All this stuff although beefier/stronger is considerable lighter than stock. The RR USD forks with the extra rotor are still lighter than either the Bros items or even the F2 forks. The RR swingarm is a feather weight compared to the stock Bros item.

Originally I am planning on a heavy modded RZ350 2 stroke engine (RD350 YPVS to you in Europe). 2 types of motorcycle engines I love... 2 strokes and twins. I have most of a RZ350 engine for mock up and a full TLR engine as well. I am thinking that if I have to cut up the rear of the frame anyway for the swinger, why not make the bigger TLR engine work? Some serious modding to get that in... the stock Bros twin is a 52 degree 650cc twin. The TLR is a 90degree 996cc twin. Physically a bigger engine. Heavier than the RZ350 but the same weight as the Bros engine.

These are all just thoughts right now though. I am currently out of town so the bike isn't in front of me to confirm what I want to do. This has been a dream I have had for awhile. A completely custom one off bike that no-one else has (although the RZ engine in the Hawk/bros frame has been done).

Count on a lot of custom carbon fiber bits. Whatever engine it has, it will be the lightest bike it can be.

I fly home tomorrow so there will be pictures forthcoming with my ideas...

Eric

[MrFluffy]

On the TL motor front, I reckon it'll have that frame for breakfast, and the RZ sounds a much better option
The vibration from the big v-twin tl motor coupled with the torque output tends to destroy frames and even the stock tl frame was prone to cracking in the odd place due to it.
The tuned xt500 engine thats in my supermoto project was originally housed in a modern CR250 motocrosser with lightweight ally frame, but it was prone to cracking the main front frame loop around the headstock and downtube area etc. The builder added lots of bracing etc but never fully cured the issue, requiring regular inspection/tig attention and a replacement front loop per season, eventually tiring of it hence breaking it and selling me the lovely engine  

With the tl motor it'll be a weird tl that probably wont be much of an improvement over a stock one with all the excess hacksawed off, but with the rz shrieking away through expansion chambers itll be like a little historic gp rep... If its not already obvious I think the stroker is the better option, though they must be getting rarer to find decent once even stateside.
Do you have the dimensions of the cbr swinger and forks? Im trying to collate a list of swingarm dimesions for another website Im involved with that involves modifying older jap 4 strokes with more modern running gear...

This is what I have for the hawk if its any help :-

Hawk (shock is direct-mounted to top of swingarm)(shock end is an 'eye')
Length: 545
Pivot width: 235
Pivot diameter (right): 15
Pivot diameter (left): <22
Eccentric outside diameter: 105
Eccentric width: 70 (+3 crenelated 'edge')
Caliper carrier diameter: 75
Caliper carrier width: 14
Brake rotor diameter: 240
Brake rotor mount diameter: 100
Sprocket mount diameter: 165
Wheel drive diameter: 100

Im currently weighing up stuffing a late model z1000r swingarm/190 wheel, and some zx9r-b2 inverted forks, with a zx9r-c2 wheel, a zxr750 top triple, with a zr7 bottom triple, and some random toxico 6 pot calipers I found in the shed into the gpz1100b2 I have. But I need my workshop to have a concrete floor and the lathe/mill set back up before starting that or it'll be another bike in bits in the shed waiting for eternity progress blocked by waiting for some bracket or bush to be turned/milled, like the other 6...

[Brass_Machine]

Do you have the dimensions of the cbr swinger and forks? Im trying to collate a list of swingarm dimesions for another website Im involved with that involves modifying older jap 4 strokes with more modern running gear...

Sure! I don't have the RR forks just yet. I have the swinger and can take whatever measurements you need. I also have a TLR swingarm here if you want those. Do you have a link for the other website?

Eric

[Brass_Machine]

...
With the tl motor it'll be a weird tl that probably wont be much of an improvement over a stock one with all the excess hacksawed off, but with the rz shrieking away through expansion chambers itll be like a little historic gp rep... If its not already obvious I think the stroker is the better option, though they must be getting rarer to find decent once even stateside.
...

You are probably right. Thinking (writing) out loud helps me clarify some points. Think I will save the TL engine for my other frame project. That one will have a FFE (hossack style) front end. May even steal a BMW duo lever setup to do it.

Gonna stick with the RZ engine for now. Though the Ninja 650R engine might be interesting...

Got some links for you Mr Fluffy...

Crazy RD500 build <- long thread but worth the time going through for just the pictures
Beautiful custom framed Ninja 650R engined race bike
V4 race bike build originally for Moto2 before they went to single engine. He is still building it as a track/race bike. Scratch building a v4 engine.

Are you familiar with the MC frame list?

Eric

[Brass_Machine]

All right... So a different mock up picture...



I love the look of that swingarm much better!

Thoughts?

Gonna be a pain to make work, but it can and will be done.

If you look carefully, there is a white box behind the mock up engine. Just to the right of that you can see a TL1000R engine.

Eric

[Rob.Wilson]

Much better Eric   

Rob 

[jtech]

I have done something similiar while building a red bull replica, rizla replica, and a zxrr replica. The swing arm conversions are fun. The unit pro-link swingarms are very nice.

[Chas2]

Sewa

[Chas2]

Oops, pocket post