A pack of TY175's!

[Da Nag]

Spent a fun morning yesterday at John's with Mark (Lotus54) going over some "new" bikes. I've finally taken the plunge into the vintage world.

My primary focus has been on trials over the last year, and then - only new bikes, given my Vertigo dealership. Still, I've been intrigued with the vintage scene, which usually has a healthy representation at the events I've been attending.

I happened to be in the right place at the right time recently, attending an event down in California. An opportunity presented itself, and I just arrived back home from fetching a gaggle of vintage trials machines. Coming home in the trailer was one Triumph Cub (I'm told it's a '61), but I'll save details on that special bike for another thread of its own. It's definitely the looker of the bunch, and certainly has the most character. It's a runner and in pretty decent shape.

The other bikes were four Yamaha TY175's, all in need of attention - some more than others. In speaking with many who engage in vintage trials competition, the TY175 seems to be one of the hotter tickets. Parts are plentiful, both original and aftermarket. Reliability is great and they're actually quite sought after for their performance. I had a chance to hop aboard one last weekend, and was pleasantly surprised at its capability. It's no Vertigo - but it's easy to see why it was such a game changer when introduced.

I had pick of the bunch, and plans are to bring it back way better than new with significant cosmetic and performance enhancements - while still keeping it legal for vintage competition. The remaining three TY's, a spare engine and various parts were left with John - their fate to be decided, but it sounds like John will be joining me in this little venture. Given they're all related, I'm sure he'll chime in here as he makes progress and decisions.

Below are some examples of TY175's that have been restored and upgraded. I rode the first one this last weekend, and it was most impressive. Wonderful geometry, plenty of grunt for the intended purpose and easy on the eyes. It's a custom color scheme, but otherwise not terribly far from stock.



Here's a pair of them, also restored but looking a bit more traditional.



Here's a very tricked out example. This is likely close to what I'll be aiming for.



And lastly...here's what I'm starting with. Wish me luck.

[John H]

Yes Bill, it's going to be exciting bringing these TY's back to life. Hopefully putting big smiles on youngsters in the the sport of Trials. Should be fun.

[Da Nag]

By chance, I stumbled upon an incredible resource for these bikes yesterday. Spent close to an hour on the phone with a guy who has been around the block with them. I took a couple pages of notes from my talk with him, which I'll start posting here as time allows - but I'm also going to invite him to our little playground here. Hopefully he'll have time to check out our progress and continue to offer up advice on occasion.

I found him in a roundabout way. There's an ultra fancy aluminum swingarm I picked up made by an outfit called AJG in the Netherlands. Seeing what others in this group have done, I shouldn't be embarrassed what I paid for it...but let's just say, it could arguably be more than any one of these four tired TY's are worth in their present shape. Such is the world of customization, I suppose. Anyway, one of the TY Facebook groups had mention of the swingarm, and it included the pic of the yellow bike in my initial post. I reached out to the owner, he replied with phone number, and man...there's not a thing about these bikes he's not familiar with. He's been modding them for years and knows all the tricks.

While you can see the AJG swingarm on the yellow bike above, here's a closeup of a batch of them. In addition to shaving weight, they're just a tad longer - two more chain links is what I've read, compared to stock. I lucked out - AJG only had one left in stock, and they won't be building any more for the TY's until November.

[Da Nag]

A very common upgrade to the TY175 is putting TY250 forks on. Stock 175 forks are 28mm, 250 are 35mm. Significant stiffness is gained. Maybe not a huge deal for those little grandkids, John - but my fat azz and lack of smoothness in sections won't be so kind on the skinny tubes.

From what I've read, the triples are cast from the same mold - so you can simply bore out the 175 triples and it's a bolt on.

Unfortunately, they're getting a little tough to find. I started scanning eBay yesterday, and as luck would have it - a set turned up this morning. Not terrible - $150 delivered. Pics look OK (eBay photos attached), hopefully nothing too unexpected upon arrival.

[Dragonknee]

Always cool to see when the vintage bug bites... Cool bikes for sure.

[John H]

You are moving fast Bill. Some bugs cause loss of sleep you know.
Here's a shot of the past and future all together. And the push is on to get one running.
Garrett is a natural when it comes to balance and agility.

IMG_4370.JPG (354.54 KiB) Viewed 100109 times

[spinner]

You are a little off on your fork sizes, Ty175's have 30mm forks and TY250's have 34mm forks and the TY350 mono has 36mm forks

[Da Nag]

Thanks for the correction, Steve.

Related to forks - are you running a modified stock top yolk/clamp or did you go with aftermarket? There's a guy in the FB TY group that gets great reviews - Bryan Dix. He's a fair bit less expensive than others I've seen. A pic of his is below.

And, John - any chance you know somebody who could bore out the stock lower 175 yoke to accept the larger TY250 tubes?

[John H]

Yes Bill, we can bore the tree to fit the larger tubes. I'd be curious to know if the 250's use the same tree or one a bit beefier.
I just noticed the 350 has taper bearings. Also curious to know if those would fit the 175. I see them on a TY80 also.

[Da Nag]

I've read - and perhaps Steve can confirm - that the 175 and 250 stock trees are identical castings, just with different bore sizes for the 175/250 tube size differences.

I'm getting a TY250 billet top like shown above and will use the stock lower, bored out. The aftermarket tops are flat, which lends to better steering geometry since the bars are in a more modern placement being up over the tubes. The guy who makes the one pictured in my last post will make the clamps to support standard or fat bars (I'm getting fat), and offers them in your choice of height between 30-45mm in 5mm increments. I've not decided on height yet.

The stock top may be adequate for many, but a common modification to improve the steering is to mill the lower portion of the handlebar block so it's flat instead of sloped so far back. I'm assuming the top clamp then gets drilled/tapped, and any number of blocks could be used on top of them.

Here's a stock upper, showing the significant tilt back:



Here's a stock upper milled, flatter profile:



And, as far as taper bearings go - you can get these aftermarket, which I plan on doing.

Fair warning: TyOffroad is quite the candy store for TY's. They'll gladly lighten your pocketbook. I'm fetching a bunch of goodies from there.