A question for TY175 owners.

Nathan S · Post by **Nathan S** » Wed Jun 20, 2007 8:30 pm

Can anyone with a TY175 measure the length of the swing arm for me please?

Specifically, I want to know the distance from the centre of the pivot bolt to the middle position for the rear axle.

TIA! :)

Oh, and if anyone has links to accurate specs and/or to good pics, I'd appreciate them too.

Post by **David Lahey** » Wed Jun 20, 2007 9:30 pm

Nathan S wrote:Can anyone with a TY175 measure the length of the swing arm for me please?

Specifically, I want to know the distance from the centre of the pivot bolt to the middle position for the rear axle.

TIA! :)

Oh, and if anyone has links to accurate specs and/or to good pics, I'd appreciate them too.

382mm

What specs and photos of what do you want?

Nathan S · Post by **Nathan S** » Wed Jun 20, 2007 9:40 pm

Wow, that was quick! Thanks!

I'm interested in the standard Yamaha specs (gear ratios etc), but I'm particularly interested in steering geometry - head tube angle, etc.

Tee-Why · Post by **Tee-Why** » Wed Jun 20, 2007 11:52 pm

Geez Nathan you being a Yamaha wiz, I'd thought you would know where to look for this info - your friendly Yamaha Parts web!!

Gear Ratios
http://www.yamaha-motor.com/sport/parts/home.aspx

Some Geometry
http://www.yamaha-motor.com/sport/parts/home.aspx

TY175 swingarm mounts behind the frame rail, not inside the frame rail as per DT175 or YZ125 of that era, hence the real short swingarm length.

Cheers,
Roger

Nathan S · Post by **Nathan S** » Thu Jun 21, 2007 9:35 am

Touche!

Where do you get the geometry stuff? I know I can dig out the gear ratios from the parts manuals (which I was hopingto avoid, 'cause we've only got dial-up at home).

Post by **David Lahey** » Thu Jun 21, 2007 9:37 pm

Nathan
I've never come across any drawings showing the geometry of the TY175.
What is it you are wanting to work out?
David

Nathan S · Post by **Nathan S** » Thu Jun 21, 2007 10:17 pm

Well, you see....
I can't find a remotely decent TY175 or 250 for what I consider to be reasonable money.
But I do own a TY175 motor and a DT175A rolling chassis... so I'm wondering if the DT frame can be used/modified to be a workable trials frame.

I know it sounds like a dumb idea, but I've got a DT125A and it forever strikes me how much it feels like a trials bike, plus I'm keen to learn more about handling and this seems like a relatively safe way to experiment....

And yes I am a tight a#$e!

At this stage it would appear that the TY and DT are actually quite similar in geometery, but the TY's engine is mounted much further back in the wheelbase.

restoremaz · Post by **restoremaz** » Thu Jun 21, 2007 10:34 pm

nathan, you can get good 03 model bikes for about 3 or 4 grand these days,and TYs pop up on ebay and the like for under 2 grand,and TY80s are only worth 700 bucks, Just buy one man!! :lol:

Although i would like to see photos when its done!

What year model is your DT 125?

I had one as my first bike,and would like to buy another one to restore.....does it look like this one?? I think its a 79 or an 80 model?

Post by **David Lahey** » Thu Jun 21, 2007 11:00 pm

Yes you can make a workable twinshock trials bike out of your DT125A.

Shorten the swingarm. Aim for a wheelbase of 49 inches.
Fit new upper shock mounts to suit the shorter swingarm. You'll probably need to move the top end of the rear frame tubes forwards for this.
Move the footpegs backwards to line up with the front edge of the rear tyre.
Find much softer shockie springs
Find much softer fork springs
Move the brake pedal back to suit the new footpeg location
Fit decent trials competition tyres
Slide the fork tubes up as far as you can without the front guard hitting the lower fork clamp
Find a way to get about double the steering angle (left to right travel) (you will probably need a different fuel tank and/or triple clamps for this)
Fit a thinner and narrower seat.

No problems hey. Just like we did in 1973 before the TY175 came out.

Tee-Why · Post by **Tee-Why** » Fri Jun 22, 2007 12:06 am

Nathan S wrote:Touche!

Where do you get the geometry stuff? I know I can dig out the gear ratios from the parts manuals (which I was hopingto avoid, 'cause we've only got dial-up at home).

Hi Nathan, only joking, seeing that you are a bit of a Yamaha guru on your site. I have a DT175 at home, '75 twinshock, I wouldnt go there, far too heavy frame and a taller frame, wheelbase longer etc. Seems the 125 is the better option.

About the info on the Yamaha parts web, go to the pages listed for that bikes details for Service Data or Technical updates. :wink:

A question for TY175 owners.

A question for TY175 owners.

Re: A question for TY175 owners.