TV175: quality piston options?

[vegansydney]

My TV175 needs new rings and on inspection realized the piston is the early Borgo 2 ring type with the thick 2.5mm cast rings.

Meteor has begun manufacturing 125/150/175 and 200cc Lambretta pistons with 1mm rings under their 'vintage racing' line. Unfortunately the 62mm piston they currently make has a 39mm compression height, so it's a 'conversion' piston.

Is anyone aware of any decent quality, thin wire ring TV175 pistons? If not, any real advantage using a later 3 ring Borgo type with 2mm rings and just leaving the bottom ring out? While a stock TV is not going to win any races, all I can think about is drag.

[Storkfoot]

I didn’t find any. I got a GOL thick ring one. Touch wood it’s been fine over, maybe, 800 miles.

[vegansydney]

Thanks Paul, I figured so, but love to be proven wrong

[Cgt75b]

My TV175 needs new rings and on inspection realized the piston is the early Borgo 2 ring type with the thick 2.5mm cast rings.

Meteor has begun manufacturing 125/150/175 and 200cc Lambretta pistons with 1mm rings under their 'vintage racing' line. Unfortunately the 62mm piston they currently make has a 39mm compression height, so it's a 'conversion' piston.

Is anyone aware of any decent quality, thin wire ring TV175 pistons? If not, any real advantage using a later 3 ring Borgo type with 2mm rings and just leaving the bottom ring out? While a stock TV is not going to win any races, all I can think about is drag.

Hi Vegansydney


Have you considered the Suzuki TS185 piston?


I think I’m gonna go down that route.

[vegansydney]

Have you considered the Suzuki TS185 piston? I think I’m gonna go down that route.

I'm a fan of the TS185ER piston conversion (the non-ER requires a ring peg relocation) and have done 1000s of klicks on them. This is a 62.0mm bore TV cylinder, so has plenty of rebores left before I'd consider this option. That said, it's a great option for oversized TV cylinders.

[GExS]

^ exactly what I would do. The only thing you have to do is get the head reprofiled

[GExS]

Also, I’m also running one TV-175 S3 with the original bore and piston. I swapped the original rings from top to bottom. It almost seems indestructible. I replaced the original exhaust for another new type that was the same size. The only critical problem I have is the standard gears with a final ratio of 4.8 which makes it tough on hills and a headwind.

[Adam_Winstone]

Straight LI150 with the standard 15 / 46 sprockets is fantastic with an iron 175. The 5.2:1 top ratio is the same as Innocenti GP200 and SIL Stg IV both of which input out about 10 BHP.

You should also consider that the SX200 is basically a TV175 with 66mm bore; very similar porting, 20mm carb and same spec exhaust. If that is correct for the TV175 gearing then it supports the smaller 175 really only pulling top correctly unless conditions are right.

[Storkfoot]

My TV175 needs new rings and on inspection realized the piston is the early Borgo 2 ring type with the thick 2.5mm cast rings.

Meteor has begun manufacturing 125/150/175 and 200cc Lambretta pistons with 1mm rings under their 'vintage racing' line. Unfortunately the 62mm piston they currently make has a 39mm compression height, so it's a 'conversion' piston.

Is anyone aware of any decent quality, thin wire ring TV175 pistons? If not, any real advantage using a later 3 ring Borgo type with 2mm rings and just leaving the bottom ring out? While a stock TV is not going to win any races, all I can think about is drag.

Benji, did you make any progress finding a thin ring piston?