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Lowering front end on a Yamaha dt100

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I have a 1976 Yamaha dt100 I am customizing. I found a front end off a Yamaha dt200 I want to use. I have everything figured out how to do it but I am concerned that it will lower the front end around 3 1/2".  I am not planning on using it for off-road use, only road riding. I know this will affect the rake and trail and I am concerned it could be dangerous. The rd200 has a 27 1/2 degree steering head and the dt100 is 30 1/2 degrees.  The front wheel on the rd200 is 18" and the wheel on the dt100 is 19". I want to do this because the rd200 front end is in way nicer shape and has a nice chrome fender. Can anyone offer some advice? 

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Could you also lower the rear to even out that rake?  Reducing OR increasing rake substantially will start to give handling problems.  Choppers don't turn worth a crap if you really push them.  Some scooters with little rake will turn OK  - UNTIL - the front wheel suddenly tucks in and you probably go on your face.  

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At a 3-1/2" difference I don't see it happening. 1/2 or an inch but not 3 plus. Unless you can replace the fork tubes with longer ones it's not going to work. You could put sleeve extentions over the forks then bore the clamps to match. 

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I am going to measure the rake and trail to see what it is. I have come up with an idea to maybe lower the rear end.I have never used a sleeve extension and I think it might speared out the forks to much. I have to shim out the wheel an 1/8" on each side already. I think I am going to modify the rear swing arm to lift the wheel up an inch or so.I am also going to see if I can get shorter rear shocks. I am a welder fabricator and  this is an experiment before I do up my dt250.

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I did some measuring and found that the rake would drop almost 6 degrees. That is Over 1 degree per inch and is Way to much. I didn't realize that it would change that much. I have an idea to extend the forks but I would have to sacrifice the original tubes. Oh well at least now I know. Thanks for the replies.

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Steering would be way quick.

Contact Forking by Frank regarding getting tubes and springs that will return the bike to the proper length with the smaller wheel. I do think that you are not making the right choices by modifying the bike. Restore it if it worthwhile, otherwise, find a more suitable machine/

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This is not my primary bike William1. I bought an rd200 parts bike for 50$ and already made all my money back. I was hoping to use the front end because it's in great shape and the fork tubes on my 100 are questionable. Nothing lost and some knowledge gained. I will google forking by Frank because I have a dt250 project has well.

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I have 2 dt250s and I want to make one into more of a street machine. They are fun bikes but the handling could be improved. I am doing some engine and exhaust mods and changing the handlebars and hopefully a 19" front wheel. 

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8 minutes ago, barleydog said:

I have 2 dt250s and I want to make one into more of a street machine. They are fun bikes but the handling could be improved. I am doing some engine and exhaust mods and changing the handlebars and hopefully a 19" front wheel. 

Early DT's had a 19 in. front wheel so that shouldn't be too hard.

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Thanks for the replies you guys. I have found some really nice looking 280 millimetre rear shocks (11") which will lower the back end about 1 1/2". I am going to change the rake by about 2 degrees or so after some serious measuring. If this all works out and I am confident that it will, I have a 175cc engine I may install in the frame. 

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