Sprocket choice help needed.

[gonzo-jetsonslc]

I had a 17/46 combination with nearly the same set up, TS1, JL Road, LI150 gearbox. It was way to long, the first 3 gears were unbeliveable, it would do more than 65 mph in third, but in fourth you must be very lucky to not run in headwinds or into some hills. Even on a straight road with no wind it needed quite some time to rev over 5000.
With just me, a tent and a bit of luggage 16/46 is perfect. It's not the fastest TS1 but who cares?

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[jonashford]

Sorry gp200 Indian, franspeed race

[jonashford]

yup, it likes to rev, low gearing is great fun anyway

[Muttley McLadd]

I had a 17/46 combination with nearly the same set up, TS1, JL Road, LI150 gearbox. It was way to long, the first 3 gears were unbeliveable, it would do more than 65 mph in third, but in fourth you must be very lucky to not run in headwinds or into some hills. Even on a straight road with no wind it needed quite some time to rev over 5000.
With just me, a tent and a bit of luggage 16/46 is perfect. It's not the fastest TS1 but who cares?

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Jeepers.. who built it?? Name and shame.
My 185 pulls better than that (same gearing - 17x46 on Li150).

[camel]

think the bottom line is that it WILL work with 5.2
and it MAY work with 4.8.......
like all things lambretta it seams its trial and error

[Special X]

5.2 is standard gearing on a standard gp200 which has about 10bhp, even a s**t ts1 puts out over 50% more power than a standard gp200 and is more than able to pull taller gearing. Imo 5.2 in a ts1 is fine if all your going to be doing is riding localy but is to short for any kind of long distance running.
My cast engine upjetted for long runs (resulting in only around 23bhp) pulls 4.7 very easily and that uses a revy race pipe, there are enough video's of it pulling that gearing fully loaded and two up at both high and low speeds in top gear. If that can do it im sure a well set up ts1 is capable of doing it. Some people take some peoples advice as gospel with out trying other options.

Sent from my GT-I9000 using Tapatalk 2

A TS1 WILL pull 4.8 with 2 up and luggage IF you drop the barrel 1mm to tame the timings. Otherwise the extra power is made at high revs.

[soosh]

5.2 is standard gearing on a standard gp200 which has about 10bhp, even a s**t ts1 puts out over 50% more power than a standard gp200 and is more than able to pull taller gearing. Imo 5.2 in a ts1 is fine if all your going to be doing is riding localy but is to short for any kind of long distance running.
My cast engine upjetted for long runs (resulting in only around 23bhp) pulls 4.7 very easily and that uses a revy race pipe, there are enough video's of it pulling that gearing fully loaded and two up at both high and low speeds in top gear. If that can do it im sure a well set up ts1 is capable of doing it. Some people take some peoples advice as gospel with out trying other options.

Sent from my GT-I9000 using Tapatalk 2

A TS1 WILL pull 4.8 with 2 up and luggage IF you drop the barrel 1mm to tame the timings. Otherwise the extra power is made at high revs.

Is that what you have had done?
Was I just lucky with mine?

[Special X]

5.2 is standard gearing on a standard gp200 which has about 10bhp, even a s**t ts1 puts out over 50% more power than a standard gp200 and is more than able to pull taller gearing. Imo 5.2 in a ts1 is fine if all your going to be doing is riding localy but is to short for any kind of long distance running.
My cast engine upjetted for long runs (resulting in only around 23bhp) pulls 4.7 very easily and that uses a revy race pipe, there are enough video's of it pulling that gearing fully loaded and two up at both high and low speeds in top gear. If that can do it im sure a well set up ts1 is capable of doing it. Some people take some peoples advice as gospel with out trying other options.

Sent from my GT-I9000 using Tapatalk 2

A TS1 WILL pull 4.8 with 2 up and luggage IF you drop the barrel 1mm to tame the timings. Otherwise the extra power is made at high revs.

Is that what you have had done?
Was I just lucky with mine?

Don't run a TS1 I'm on cast barrel. Dropping the barrel 1mm on a TS1 (either by using 110 rod with 2mm spacer or skimming 1mm from the base - not forgetting to shorten the spigot) is a way of bringing down the exhaust and transfer timing to give excellent low and mid range pull eminently suitable to a Taffy touring pipe a famous and respected tuner offered this as a touring tune.

My mildly tuned 230cc cast iron barrels (One by Harry Barlow, and the other a self tune will both pull 4.8 although I do prefer to run them in on 5.2 to give them an easy life)

[bizzly]

Bizzly, I see your going with the 5.21 gearing, please keep us updated as to how it goes when you get it sorted and what your fuel consumption is like on a rally run

is the engine going in the Lambretta in your avatar?

has a TS with a Taffy pipe and that also runs a 19/46 with an Indian gp 200 gearbox. I ride this one 1 and 2 up....runs well. I was just going to try using the Li 150 gearbox in this new build as I have heard good results from them, but was curious as to what sprockets I would need.

Just noticed that you said that it currently runs 19/46 on india GP20 box and that it runs well both 1 and 2 up.........
that is a final drive ratio of 4.84

now i'm confused as to why you have opted for a 5.2 final drive as recommended by MB when you say your self that its good currently with 4.8

Yes eden...in the silver / red one. The moral of the story is......At some stage, I have had a heat seize in the barrel about 3 year or more ago, which I didnt know about until I did a service on it. I cleaned it up, put new rings in (after I dug the old ones out ) and have been riding ever since....I go all over on it...one up and two up..even went to iow in 2009 both ways and came back from iow in 2011 after going down in van I bought a new casing and a new TS1 kit in 2010 so as to have a go at building my first ever engine I have just got round to having a go at doing it. I had an sx200, Indian gp200 and a Li150 gearbox spare. The white and yellow scooter decided to drop 2 teeth from 3rd gear the other day so I put the gp200 gearbox in as a replacement. I am left with the sx and Li gearbox's, so thought about using the Li as lots have commented on how good they are in Ts's. I aint got a clue and could of gone the easy option of buying a ready made engine, but I fancied on having a go myself. The gearbox scenario isnt the problem as I could buy whatever is needed. I was just after info on whether the Li would be better or the Gp or whatever gearbox is best. I was using what I had....not to keep the cost down, but because I had them. If the Gp gearbox would be better, I will buy one and sell the Li or the sx.....choices, choices .....

[Special X]

LI150 has better ratios than an Indian GP200 (which has a fairly large gap between 2nd and 3rd) The GP200 is easier on the clutch due to the usual 18 tooth sprocket delivering less torque to the clutch assembly.

The ideal choice IMHO would be 18/47 on an Italian GP200 box (Same box as GP125 or LIS 125) which would be easy on the clutch and have a good spread of ratios and same overall ratios as LI 150 15/46.

You could use 19/47 on the GP box for 4.95 or even 18/46 for 5.11 if you want to be between the reccomends on here.