How do I lower my trike for flat track?

[ForeverThreeWhe]

I've got an 86 250R which I'll be racing in speedway in a fortnight and I was wondering how I could go about lowering it?
I know that the front can be lowered by raising the forks through the triples and the rear can by lowered by using an adjustable link and/or loosening the nut on top of the spring so there is no preload but is there any other ways?

[Tri-Z 250]

Rim and tire size will also play a roll on your ride height...10" front rim with a FT tire and 8"to 10" rear rims....or stock rims? Get that setup and then lower the machine on feel and comfort. Goodluck

[Dave8338]

That's about it. Possibly find a shorter shock that fits the suspension linkage.

[KASEY]

SINCE ITS SO QUICK,, back off the preload,then take a tiedown strap and go around the back of the frame and the back of the swingarm carrier area,, get a big guy to set on it and pull it down till the footpegs drag the ground!!! them go have some fun!!!!!

[LastFoolerInVA]

SINCE ITS SO QUICK,, back off the preload,then take a tiedown strap and go around the back of the frame and the back of the swingarm carrier area,, get a big guy to set on it and pull it down till the footpegs drag the ground!!! them go have some fun!!!!!

I've seen people do this at the drag strip to their 450r's.. I didn't think it would work for flat trackin, I'd be scared the strap would flap into the chain..

[Keith Salyer]

You have to Duck tape the access strap so that dont happen. Also you can flip the forksprings and use the short one and put it at the bottom of the damper rod (at least on the 85 this works)..

[keister]

You already know the answer to your own question. I will confirm it. Purchase an adjustable lowering link. Extended axle or wheel spacers are also important. Have fun!

[hoosierlogger]

let all of the air out of the tires. Not only will it give you a lower stance, but a larger foot print as well. :wondering

[yamaha225dr]

Will the one on Durablues website for 86model try 250r's work on an 85 model?

[KASEY]

I've seen people do this at the drag strip to their 450r's.. I didn't think it would work for flat trackin, I'd be scared the strap would flap into the chain..
LOL YOU HAVE TO BE SMART ENOUGH TO TAPE THE END UP .. in my racing days i won many a racr with a tiedown intact,,,,

[ForeverThreeWhe]

What about wiring the spring down when it's in the compressed position?

[Keith Salyer]

We made ours adjustable on the 85-86 with Hyme (sp) joints and adjustable linkage. I suppose you could by Kasey's extra linkages and have one shortened. Darn, glad I thought of that------Kaseeeeey.

[ForeverThreeWhe]

We made ours adjustable on the 85-86 with Hyme (sp) joints and adjustable linkage. I suppose you could by Kasey's extra linkages and have one shortened. Darn, glad I thought of that------Kaseeeeey.

Any pics? Sounds interesting. To lower the trike wouldn't you have to lengthen the dogbone?

[yamaha225dr]

We made ours adjustable on the 85-86 with Hyme (sp) joints and adjustable linkage. I suppose you could by Kasey's extra linkages and have one shortened. Darn, glad I thought of that------Kaseeeeey.


I think you're on to something! My father in law has a dirt car and we have a bunch of heim joints and swedge tubes in our parts box! I don't see a problem running that setup if you are like me and don't race motocross or do crazy jumping.

[ForeverThreeWhe]

Can someone please measure the distance from centre of eye to eye of one that's fully lowered. Would it be stock length + 2 inches?

[NOS_350X]

Please Please Please Never lower it u sing the straps. That is a purely unsafe way to lower the bike, It will become rigid, bounce and twichy in the turns, Your better off running it high with suspension.

You have several options, but i would only recommend doing it with the linkage, or buying a shock setup to lower it.

[ForeverThreeWhe]

I think me and the old man are going to make a lowering link tomorrow. I'd buy one but they are $163 locally and I don't have time to ship one over here to Australia.

We'll be using 2 of these...

Spherical Bearing Tie Rod End 12mm

http://bit.ly/15tEs3p

With a threaded rod in the middle. What do you think?

[barnett468]

Can someone please measure the distance from centre of eye to eye of one that's fully lowered. Would it be stock length + 2 inches?

You must shorten it. Your rocker has a progressive ratio of approximately 2:1. Shorten link 2” will lower bike by approx 4”.

xxxxx

The heim idea is a reasonable one when the link is made strong enough to be safe.

The heim you posted a link to looks either low grade domestic or Chinese and I would not use that one. Use a high grade Aussie, US or Japanese made one. The proper and safest way to make an ADJUSTABLE link is the following.


1. a. Buy good heims

b. buy HARDENED all thread, either grade 8 or B7 4140 steel. Do not use std mild steel all thread, this is a high load area and it can easily bend.

c. 4 thin nuts preferably hardened

d. buy 2 us feet of thick wall 4130 chromolloy tubing with an id small enough to be drilled and tapped for your 12 mm all thread maybe between 11 mm or less.

2. Put bike on stand, remove old link, pull rear end up with tie down to desired ride height then measure eye to eye where link goes.

3. measure the distance from the eye of the heim to the bottom of it and multiply by 2, measure the thickness of 1 nut and multiply by 4, add these 2 totals together then subtract it from the new measured eye to eye length of the link then take that number and subtract 5 mm for a little more adjustability and to compensate for any errors in measuring and MACHINE cut the tubing to that length on a lathe. It can NOT be hand cut. The ends must be perfectly square or the nuts will instantly come loose.

4. chamfer top inside edge slightly then tap 90 mm deep.

5. measure your orig link eye to eye and subtract your “new” calculated length from that. Divide this number in1/2.

6. take the number from above and add 20 mm for depth of heim and 40 mm for minimum penetration into tubing at full extension which will be the same length as stock link then cut all thread with whatever you have, lathe, cut off wheel, band saw etc to this length.

7. install heim in vice with shop rag to prevent damaging heim and tighten gently

8. thread all thread into heaim 20 mm then install nut and tighten well on heim then remove heim and repeat process on the other heim.

9. install nuts on all thread, thread until it bottoms out on the other nuts.

10 thread into tubing until it bottoms out, then install on bike and adjust to desired ride height and tighten nuts firmly onto tubing.


PLAN B WHICH I’M GUESSINNG YOU ARE GOINT TO DO.

1. Use hardened rod in place of tubing, measure and cut to appropriate length using the applicable numbers above.

WARNING – T his will be an unsafe link. It should be used for low load conditions like smooth tracks with no jumps. The all thread will bend if used under high load conditions.

BOTOMING OUT – Your bike will easily bottom out using a shorter link without putting the appropriate length travel limiter [spacer] on the shock shaft.

SPRING – You will need to pre load your spring slightly for short track, this will raise your rear a bit [around 30 mm] so account for that in your link length calculations if you want.


LOWERING FORKS – Do as previously suggested by another member by switching springs around, fine tune height by raising or lowering tubes in clamps. If you do not have separate top springs then you can cut your long one by the same amount you want to lower rear by, flatten the ends with a torch and pit the new short spring in bottom side of fork tube.

TIRES – As another member mentioned, if you use lower profile tires than stock you will not need to lower the bike by the link as much, account for what you are going to do in your link calculations.


Have fun at the race!

[ForeverThreeWhe]

You sir are a genius. Thank you.

[barnett468]

Hello

Thanks, it's not really that hard, I've just done this stuff since the dark ages, lol. Feel free to ask any other questions you might have about it. I'm sure if I can't help you someone else will. If you really want to try and make the link the first way I described then just do 1 line at a time, you won't get overwhelmed with info that way. If you can read a tape measure and you can read [which I'm sure you can] you can make the link, lol!

[Bryan Raffa]

SINCE ITS SO QUICK,, back off the preload,then take a tiedown strap and go around the back of the frame and the back of the swingarm carrier area,, get a big guy to set on it and pull it down till the footpegs drag the ground!!! them go have some fun!!!!!

we had a guy do this once at a indoor ice race .... as we line up .. one of the guys notice that it was wrapped up in the sprocket... as thousand watched two guys on ICE try to pull this strap out ... LOL it didnt look good ... and held up the whole show.. couldn't imagine what would have happened in the first corner!

[ForeverThreeWhe]

I managed to lower it approx 2 inches today by undoing the preload.

Before
http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zpsbce782b2.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zpsbce782b2.jpg.html)

After
http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zps5ac2d65b.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zps5ac2d65b.jpg.html)

I also widened the right side 2.5 inches. I'm thinking about widening it another inch by using a Durablue block type spacer. What do you guys think?

http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zps4bd3d911.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zps4bd3d911.jpg.html)

[ForeverThreeWhe]

The Track:

http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zps87001ef1.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zps87001ef1.jpg.html)

It's Big! Approx 450mtrs and 16 mtrs wide. It's very wide as they race cars on it too

http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zps588e970c.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zps588e970c.jpg.html)

http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zps023075d0.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zps023075d0.jpg.html)

http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zps4d8996d5.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zps4d8996d5.jpg.html)

http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zps4f8ff98f.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zps4f8ff98f.jpg.html)

[barnett468]

Hello



That;s a very nice bike!

That is a nice track. Pro 3 wheelers may hit around 120 kph plus on that.

They may require a front number plate with large numbers. Don’t stick them on until you get there in case you can’t run the number you want.

Have you ever raced before?

Do you plan on going WOT or just cruising around in a circle and having fun.

I’m guessing you haven’t raced before.

I suggest you get there early to get acclimated to everything.

I’m guessing your swing arm is stock length and your steering stops are uncut this means that if you get it sideways it can spin out on you VERY quickly. The lower they are the less likely they will tip over when this happens.

There may a few guys in your class that should be in the next higher class and they may “bump” anyone in their way that’s going slower than them.

If your front tire gets more than 30 cm off the inside of the track you will likely get bumped and/or passed. My opinion is the middle of the track is the safest for new riders. You can watch everyone else crash from there too.

I would run your rear tires around 12 lbs not much lower. It will have less traction this way but this means it will slide easier and therefore will be much less likely to “dig in” in a turn and high side you because your bike is so high.


Hop at least some of this info helps.

[barnett468]

Hello


I managed to lower it approx 2 inches today by undoing the preload.

This will only work for low “race” speed non aggressive beginner or novice level racing. It’s a long story.

Look at Bryan Raffas bike, that has a ride height for 80 mph pro oval racing.

xxxxx

I also widened the right side 2.5 inches. I'm thinking about widening it another inch by using a Durablue block type spacer. What do you guys think?

Are you saying you want to bolt a spacer to another spacer? I personally would never do that for several reasons.

[barnett468]

OK, #45 saw it in the second photo cool.

[ForeverThreeWhe]

Thanx mate for all your help. I appreciate it.
I used to race flat track / short circuit as a junior on a 1990 CR 80 many yrs ago.
It's only a practice day. In fact it's the first trike "racing" event in over 25yrs in Australia.

All the details can be found here.

http://www.ozatv.com/forum/viewtopic.php?t=21180&start=0&sid=bcd940a3b3772c9faab0d678aaeb93bb

[ForeverThreeWhe]

Yeah I was considering bolting the 2.5 stud spacers on the right to another 1 inch block spacer. Probably not the safest idea ever.

[barnett468]

Hello


Thanx mate for all your help. I appreciate it.

I used to race flat track / short circuit as a junior on a 1990 CR 80 many yrs ago.

Very cool, I was doing mx and a couple TT races, [smooth track with some big sweeping turns and 1 jump]. Lot’s of fun! I was a pro motocrosser then and our work had a fun day where we all went to the TT night races, huge track 80 mph down the straight. I was on a Yamaha 400 and our shop mechanic who was a pro short track, tt and mile gut blew by me locked up totally sideways feet on the pegs on a little 200cc triumph cub pro tt bike, lol. Embarrassing.

xxxxx

It's only a practice day. In fact it's the first trike "racing" event in over 25yrs in Australia.

25 years that’s horrible, just rent the track and hold your own races.

xxxxx

All the details can be found here.

Cool

[poohbee1]

a 1/4 mile+ sprint car track is not a good place to experiment be carefull and good luck

[Keith Salyer]

That looks bigger than 1/4 mile to me. Maybe closer to 1/2 mile. Go have fun and be careful.

[yamaha225dr]

I made a lowering link yesterday out of 4"swedge tube shortened to three inches and two heim joints. We use these on our dirt car for tie rods and upper a-arms, so they should be plenty strong for flat track racing. I gotta make a couple spacers before installing it though. The link below will show you guys what I used.

http:// http://www.speedwaymotors.com/Swedged-Steel-Tube-for-5-8-Inch-Heim,2092.html (http:// www.speedwaymotors.com/Swedged-Steel-Tube-for-5-8-Inch-Heim,2092.html)

[ForeverThreeWhe]

I managed to knock a few more inches out of the height today.
I didn't use a pull strap, I used chain. It still has about 2 inches of travel so it's not rigid.

http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zps5ef6bfb1.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zps5ef6bfb1.jpg.html)

http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zps8d498634.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zps8d498634.jpg.html)

http://i366.photobucket.com/albums/oo105/ForeverThreeWheels/image-13_zpsc830418b.jpg (http://s366.photobucket.com/user/ForeverThreeWheels/media/image-13_zpsc830418b.jpg.html)

[barnett468]

Hello Forever Three Whee


“I managed to knock a few more inches out of the height today.

I didn't use a pull strap, I used chain. It still has about 2 inches of travel so it's not rigid.”

As previously mentioned by another member, tying the bike down is at the very least, not the proper way to do it however since it is done I must say that at the very least it looks better than using a tie down would.

I suggest 1 additional thing in case you haven’t done it already which is to lower the front of your bike as much as you lowered the back or simply try it with the front 50 mm higher than the rear as it appears to be by amount of fork tube sticking above your top fork clamp in the photos and if it does not turn or slide easily enough coming into the big sweeper turn then try lowering it 25 mm then another 25 mm max if necessary to achieve the best turning effect.

Lowering the back by 4 but the front by only 2 slowed your steering down. This makes it more stable at high speeds but causes it to turn or respond more slowly to steering input. Lowering does exactly the opposite.

High front is good for straight line high speed, low front is good for quick turn on tight trails at low speed etc.


Hope this info helps.

[ForeverThreeWhe]

All your info has been helpful and I do appreciate everyone's input. Because the track is so big and fast with really long corners I'm gonna run it with the front as is and if need be then change it as you suggested.
I wasn't real keen on the idea of a strap because the fear of it breaking and catapulting me over the bars at 100kmh far exceeded the ease in which it would be to fit. Lol

See that metal thing up the top bolted to the frame...... That's a shopping cart wheel holder. Lol

[barnett468]

Hello Forever Three Whee


All your info has been helpful and I do appreciate everyone's input.


Because the track is so big and fast with really long corners I'm gonna run it with the front as is and if need be then change it as you suggested.


Good, nice to know you will be able to come back with a ride report, lol

xxxxx

I wasn't real keen on the idea of a strap because the fear of it breaking and catapulting me over the bars at 100kmh far exceeded the ease in which it would be to fit. Lol


It might have been only 95kph, lol.

xxxxx

See that metal thing up the top bolted to the frame...... That's a shopping cart wheel holder. Lol


No it’s not, now repeat after me, “It is a dolly wheel I bought from the swap meet ergo no receipt Mr. Missing Shopping Cart Investigator/Police Man Sir!, lol

[atc300r]

Ben ,You want it as low and wide as you can get it. My 81 250r flat tracker is 51 inches wide in the back.Also you may want to lower the front alittle. If you have them get 18 inch rears and gear for them.If you dont have jumps you should do great.

[ForeverThreeWhe]

Ben ,You want it as low and wide as you can get it. My 81 250r flat tracker is 51 inches wide in the back.Also you may want to lower the front alittle. If you have them get 18 inch rears and gear for them.If you dont have jumps you should do great.

Cheers, yeah the axle is a lone star + 4 I believe and then I've added an extra 2.5 aswell to the right side (there's only left hand turns) I've got 13/36 sprockets and 18 inch tyres. No jumps either. :)

[atc300r]

Good luck .Get some vids please .

[ForeverThreeWhe]

Thanx and don't worry, we're all getting video. This is a really big thing for trikes in Australia.

[Dave8338]

You'll be fine with that setup. Your left knee is going to get tired I can all but promise you. :naughty:

Make sure your grips are glued on tight. Hate to see you lose a left grip and go arse over tea kettle ! :Bounce

[ratvespa]

the correct way of lowering a vehicle is doing it in the shock internally. granted most people don't have the tools to do this. problem with lowering links is they lower the vehicle, but do not limit the travel. I had this problem on my wifes motorcycle, so the rear tire would contact the rear fender. I imagine on a trike the swingarm would be hitting all the stuff in the sub frame.

to be honest, rebuilding a rear shock is not all that hard, pick up race tech's suspention bible, has a step by step, the only special tools you really need are the nitrogen filler, and possibly a shaft holding tool. lowering is pretty much just placing some spacers in the valve stack, under the stack...and what the hell, might as well toss in a race teck gold valve while you are in there

[barnett468]

the correct way of lowering a vehicle is doing it in the shock internally. granted most people don't have the tools to do this. problem with lowering links is they lower the vehicle, but do not limit the travel. I had this problem on my wifes motorcycle, so the rear tire would contact the rear fender. I imagine on a trike the swingarm would be hitting all the stuff in the sub frame.

to be honest, rebuilding a rear shock is not all that hard, pick up race tech's suspention bible, has a step by step, the only special tools you really need are the nitrogen filler, and possibly a shaft holding tool. lowering is pretty much just placing some spacers in the valve stack, under the stack...and what the hell, might as well toss in a race teck gold valve while you are in there


Hello ratvespa

Just in case you didn't know, one can also limit shock travel by adding an aluminum spacer to the shock shaft thereby eliminating the need for a shorter shock. One can then lower the bike using a shorter link and achieve the same goal. This will also allow one to easily revert back to long travel simply by switching the link[or if they made an adjustable one like the one I showed how yo make in one of my previous posts, simply adjust it] then removing shock shaft spacer. I have made many of them it's an easy deal.

[yamaha225dr]

I made this lowering link our of swedge tube and heim joints yesterday. Both ends are threaded different, to allow adjustability.

http://i163.photobucket.com/albums/t294/Dale06_photo/CAM00133_zps1424212c.jpg

http://i163.photobucket.com/albums/t294/Dale06_photo/CAM00132_zpse680f581.jpg


This is the result. I did end up lowering the front some more to help my low speed steering.
http://i163.photobucket.com/albums/t294/Dale06_photo/CAM00136_zps46eb0a38.jpg

[JasonB]

nice info from everyone, both your guys' 250rs looks great!

and LMFAO at the shopping cart wheel holder, i was sitting here trying to figure out how you made that until I saw you say it hahahah

[Keith Salyer]

Nice looking lowering link I must say, good job...

[ForeverThreeWhe]

I just bought this although I highly doubt it will arrive in time.

Honda 85 86 ATC TRX 250r lowering link

http://bit.ly/YZE0XO