1976 TY175 Rear Sprocket?

[Dozer]

Hi all,

I've bringing another TY175 back to life and am looking for a low budget rear sprocket, steel if possible but I'll take aluminum if that's the only option.The bike has currently has a vintage "PBI 7033-49" aluminum sprocket, PBI still sells these for about $60 shipped. I just tried a JT Sprockets JTR1842-49 ($20) which is supposed to fit, the holes line up however the sprocket is milled very thin where it meets the hub so the bolts wont seat all of the in. Unless there's a aftermarket spacer or something to get I'll have to return the JT sprocket. I plan on calling JT Monday morning (they are made in USA) and asking them for details as well.

 

Here's the milled JT so you can see what the problem is:

 

Anyone got a lead on a sprocket known to fit a TY175 rear?

 

 

[lineaway]

 So are you saying the shoulder is too long now?

[feetupfun]

The threaded holes in the hub normally go all the way through so maybe there is just some crud in the holes stopping the bolts going all the way in.

If that is the problem and you don't want to clean out the holes, you could fit some 8mm washers under the bolt heads or buy some shorter bolts..

Edited March 8, 2020 by feetupfun

[turbofurball]

1 hour ago, splatered stu said:

never heard of a cheap sprocket being crappy or not fitting  (yeah right)...congratulations on saving $50 hows the bike working?? crappy parts on a crappy bike makes for a crappy time."bringing back to life"? sounds like you are actually killing it slowly with bogus parts.

I have a super cheap unbranded steel rear sprocket on mine and it works just fine.

It's not unreasonable to keep spending within your budget - not everyone can afford to splurge unlimited funds on their bikes!  Of course, money has to be spent wisely, since a cheap part that doesn't work is false economy, but many people manage with second hand bits or making stuff themselves.

[b40rt]

I dream of $3 screwdrivers, and capital letters.

[Dozer]

20 hours ago, turbofurball said:

I have a super cheap unbranded steel rear sprocket on mine and it works just fine.

It's not unreasonable to keep spending within your budget - not everyone can afford to splurge unlimited funds on their bikes!  Of course, money has to be spent wisely, since a cheap part that doesn't work is false economy, but many people manage with second hand bits or making stuff themselves.

Agreed, you can still get quality parts, suitable for the application, and not break the bank. I buy from Rocky Mountain ATV/MC a lot and run their "primary drive" chain/sprocket sets on several bikes and they are very affordable. I have 12 bikes (5 are TY's) so I try to get the best quality I can at the best price. Wash and lube them after use (like you should any chain) and they last several years. Judging by some of the responses maybe I wasn't clear in regards to this bike, it was a near basket case when I got it and I got it for my wife to use as a trail bike and my son to play with trials stuff on (when he's not on his KTM). When the next shipment of parts arrives I'll have <$1k in this bike and it will be fully functioning. 

AKA, a "beater" bike that can be dropped without me worrying about it, 3 of the 5 TY's I have are "very good" & all original condition bikes that I try not to bang up. Thanks to those that gave positive feedback, I found a Sunstar 50T in steel for $30 that will work fine.

[Dozer]

On 3/8/2020 at 12:43 AM, feetupfun said:

The threaded holes in the hub normally go all the way through so maybe there is just some crud in the holes stopping the bolts going all the way in.

If that is the problem and you don't want to clean out the holes, you could fit some 8mm washers under the bolt heads or buy some shorter bolts..

Hi, yes you are correct, the bolt holes go all the way through, they were just caked with several decades of brake dust, grease and mud past where the bolts normally seated so the bolts felt like they were bottomed out.