Honda HRC 450RR

[250rfan]

I'M GOING TO PUT A 2006 TRX 450eR WITH HRC POWER UP KIT, INTO THIS 85 250r
ROLLER,,,,,,

Any suggestions on how to go about it?????,

[3leggeddog]

yeap,sell that roller,and use a 350x roller instead.it will makeyour life alot easier

[Aka_am]

350x engine cradle is alot bigger. Whenever i see swaps that what i see people use. I mean it doesn't look as good as a R..but you could always swap parts i think...

[250rfan]

Okay guys, here goes, first things first -
As you can see in the picture, i have removed the original engine mountings, basically so i can see what room i have to play with.

I know i'll have to lower the bottom part of the frame, to accept the 450 engine, i guess about 2" or so. This will obviously lead to losing some ground clearance, but am not bothered about that.

[Jason Hall]

Before you cut anymore on the R frame, measure the height of the carb on the 450r engine. I will never clear the top of the shock. You would have to lower the shock alot to make It fit.

[250rfan]

[QUOTE=Jason Hall;543453]Before you cut anymore on the R frame, measure the height of the carb on the 450r engine. I will never clear the top of the shock. You would have to lower the shock alot to make It fit.

Okay,
Thanks for the suggestions guys, firstly am not interested in building this bike using a 350x frame and running gear, it's definitely going to be the 250r the R looks better and handles better than the X , IMHO.

Thanks, for pointing out the shock issue's Jason, i have done some measuring and yes i will have to lower the top shock mount about 1", but thats because i want to keep the ride height the same as standard 250r, as for the carb - the issue will not be the carb hitting the shock but the carb hitting the upper frame tube, i have two options -

Option 1 - cut out a piece of the upper frame tube so the carb fits.

Option 2 - Obtain a shorter carb (aftermarket).

I should have stated earlier, i am going to use the complete back end of the 450r on this project. So as the 450 rear shock is shorter i will have to lower the shock mount to keep the ride height the same as standard 250r.

[250rfan]

Okay, here's some pics of the start of the frame alteration, as you can see i have cut the frame in 2 places, i have the rear end and axle on adjustable jacks, so i can keep the frame square and level while modification takes place.


You can't really see it in these pics but i have heated the 2 front lower frame tubes and used the leverage of the now cut and seperated lower sub frame to bend them causing a gap of 2.125" between the main frame tubes and the rear sub frame tubes. The bending of the front tubes aslo puts them in the correct angle for when i come to cut and splice that area.

[250rfan]

Okay, here are some pics of the frame now lowered, i have inserted pipe inside the frame tubes to give the cut sections a stronger join. Then placed OEM pipe over the inserts, welded then ground to flush, this keeps the frame looking like it was never joined.

[Tri-ZNate]

your biggest issue is like stated, carb routing.

When we did it to brapp's 250r it was misleading because everything lines up (swingarm and sprockets) but in order to fit it with some room we either were going to drop the cradle or give the top frame a trim job and make it like a tri-z. We went with a tri-z method, frame was destroyed beyond repair and now the 450r engine is in a 350x

[250rfan]

Here's some more pics of the frame,

Pics 1,2,4 show the finished main frame tubes.

Pic 3 shows the rear sub frame re-strightened with inserts installed ready for the OEM pipe to be overlayed then ground to flush.


This is the part of the build i've been waiting for - to see how the 450 engine sits inside the 250r frame. I dont need to weld up the front down pipes to check if the engine fits, so i have put on the radiators and one of the radiator hoses in preperation for the engine installation.

[250rfan]

your biggest issue is like stated, carb routing.

When we did it to brapp's 250r it was misleading because everything lines up (swingarm and sprockets) but in order to fit it with some room we either were going to drop the cradle or give the top frame a trim job and make it like a tri-z. We went with a tri-z method, frame was destroyed beyond repair and now the 450r engine is in a 350x

Ye, i was wondering how you guys were getting on with your 250/450r project.

So you went down the 350x route, i guess you'll be watching how my project turns out now.

[jeffatc250r]

I hope it turns out good for you using the r frame. If it is possible to not destroy the frame in the process, i think you will end up with a much better machine handling and looks.

[johnny's X]

Well I must say you are dong things the right way with making all your welds non visible.

[250rfan]

Well, here's the engine in the frame, the TRX 450 rear swingarm and exhaust are also installed .


The radiators are position'd at the Hrc short coarse kit position ie - 1" back from standard. I was planning on running the HRC short coarse kit on this bike, but after some advise from other board members, i have decided to use the short coarse kit as a second option, i will be running the standard OEM fuel tank.


So the radiators will sit 1" or so forward than in this picture, the 450 swinger is on with no altering to the frame needed for the main Swingarm/pivot bolt to be installed.

However, there is some alterations to be made before fitting the lower shock linkage to the frame, and also to fit the top of rear shock to the frame.

[Jason Hall]

Well, looks like your makin It fit. Looks ((SWEET)), did you test fit the tank? Does It clear the engine? The only thing I personally would'nt want is the loss of ground clearance. Other than that It looks like It belong's their. It's pretty amazing what you can do when you are determined. You said you wanted It In the R frame & your doing It. You are obviously very handy and also determined, Nice Work. I wonder if you could use an older valve cover to gain some space on the top. The older engines did'nt have the big square breather on the top.