Going from 190 tire to 180..how much gear to add?? Hello all, switching from a 190 50 P1 to a 180 55 P1. I was happy with my gear and i know with making this move the 180 tire is actually taller. How many teeth do i need to add to the rear to get back where i was with the 190?? Ive read 2-3 will get you close...sound right?? thanks in advance. fyi they are mounted on a set of pvm 10y's rear is 6" i believe

why in the world would you use a 180?

The 180 has a lot less contact patch than the 190 and you will have traction issues unless you're over 200lbs

The 180 has a lot less contact patch than the 190 and you will have traction issues unless you're over 200lbs :+1: if you got a 180/50 it would be a different story somewhat. I would stay with the 190. and the height difference will probably be about 1 tooth, 2 tops.

Well, I'm not a drag guy, so I don't know how this would apply, but.... The 180 is designed for a 5.5" rim, so sticking it on a 6" rim would flatten the profile out quite a bit and increase the contact patch from its original design. So I'm not sure if traction would be affected all that much. But the 180 tire will be lighter weight, so it should help spin up faster than the heavier 190. In practice, I'm not sure how it would get you down the track, but I do see why someone would want to try it. As Op said, the height difference should work out to about adding a tooth on the rear, if at all. Www.gearingcommander.com should get you closer to what you need to know.

Using Skydorks train of thought though, being that it is going on a 6" rim instead of the designed 5.5, seems to me that although normally taller, being spread out wider may make it close to the same height as the 190/50.

No, spreading the smaller tire to fit s wider rim shortens it.

Also remember the sidewall height is a percentage, 180 /55= your sidewall is 55% of 180mm. So I get 99 mm for the 180 and 90 mm for the 190, imo I think the 180/55 would still be taller on the rim. Now I was always told the reason for going to a 180 was for weight mostly. I also can not see how a 180 could have a lot less contact patch when at 15 to 18 psi, it not like we're using the whole tire anyway. So can you elaborate Madness? BTW I'd say a tooth or 2

i to did this swap to save on weight... when i was runnin a 190 i was -1 +2 but when i switch to a 180 to get the gearing back like i wanted i went up +2 and it was perfect... so i say +2 should get you back to where you want if you make the switch.

My reasoning, is the 180 will give me a wider contact patch and save some rotational weight. I drag race only the bike will never see the street. Dont think i will have traction issues with a p1. Its fairly common, in drag racing to make this move. If it is i have a 190 p1, on the street bike that i can swap out.

i to did this swap to save on weight... when i was runnin a 190 i was -1 +2 but when i switch to a 180 to get the gearing back like i wanted i went up +2 and it was perfect... so i say +2 should get you back to where you want if you make the switch. exactly the answer i was looking for...thanks:thumbsup:

Huh... I just mounted a 200/60 SC2 to reduce wheelspin at lean. Good luck with that 180. :wink:

Well, I'm not a drag guy, so I don't know how this would apply, but.... The 180 is designed for a 5.5" rim, so sticking it on a 6" rim would flatten the profile out quite a bit and increase the contact patch from its original design. So I'm not sure if traction would be affected all that much. But the 180 tire will be lighter weight, so it should help spin up faster than the heavier 190. In practice, I'm not sure how it would get you down the track, but I do see why someone would want to try it. As Op said, the height difference should work out to about adding a tooth on the rear, if at all. Www.gearingcommander.com should get you closer to what you need to know. :thumbsup:

Huh... I just mounted a 200/60 SC2 to reduce wheelspin at lean. Good luck with that 180. :wink: drag bike ..straight line!!...only time it will lean is turning on to the return road:lol:

My reasoning, is the 180 will give me a wider contact patch and save some rotational weight. I drag race only the bike will never see the street. Dont think i will have traction issues with a p1. Its fairly common, in drag racing to make this move. If it is i have a 190 p1, on the street bike that i can swap out. You learn something new everyday.:thumbsup::thumbsup:

exactly the answer i was looking for...thanks:thumbsup:no problem you'll like the switch :occasion1

drag bike ..straight line!!...only time it will lean is turning on to the return road:lol: Ah... well that actually makes sense. Reading fail on my part. Gotta tune for your intended purpose, I suppose. :mrgreen: Good luck man. Post up if you see a measurable improvement from that 180.

so hows the 180 workin compared to the 190? Im curious about this because Im about to order a hook-up for my spare rim, and might order a 180 instead

I would rather choose 190 , I feel it's better.

no problem you'll like the switch :occasion1 Is it really that much better? Im gonna order a shinko tomorrow and am trying to decide on which one. I would rather choose 190 , I feel it's better. could you elaborate more? just curious to hear the reasoning behind it.

[QUOTE=-Op-;1842217]Is it really that much better? Im gonna order a shinko tomorrow and am trying to decide on which one. I believe its hard to pick up or feel a difference by only doing one mod, its a bunch of little things that produce good numbers. You may not see a ET gain from going to 180 but that doesn't mean it doesn't help. I have a 180 P1 take off just waiting for my current tire to be done.

i picked up 1/2 tenth just switching to 180 once i got the gearing correct from a 190 shinko.

Im running stock/+5 right now. Was gonna get a -1 for the front too. I only do 1/8 cuz there isnt a track around here for 1/4. Sound like a good gearing setup?

Im running stock/+5 right now. Was gonna get a -1 for the front too. I only do 1/8 cuz there isnt a track around here for 1/4. Sound like a good gearing setup?the gen1's love gearig man so i def throw the -1 on the front. helps get you outa the hole quicker and saves on clutch life.

the 180 is perfectly fine there is nothing wrong with it and you don't have to change anything. you can go just as fast on a 180 as a 190. gearing is a different question all together and is up to you on how you want your bike to perform

what the hell then, Im gonna toss on the 180 Hook-up and see what itll do.

what the hell then, Im gonna toss on the 180 Hook-up and see what itll do. Give it a try. At the track the weight loss will help out(rotational mass) plus the effect of adding a rear tooth almost. On the street with any Hook-Up you won't have any traction problems either. I wouldn't go putting a 180 PP 2ct on it. Would be asking for traction problems. But a Hook up is a whole nother animal.

Give it a try. At the track the weight loss will help out(rotational mass) plus the effect of adding a rear tooth almost. On the street with any Hook-Up you won't have any traction problems either. I wouldn't go putting a 180 PP 2ct on it. Would be asking for traction problems. But a Hook up is a whole nother animal. There's a guy here runnin 5.70's on a 180 Power Pure and I never seen it spin, out does hook tho. I wouldn't use a pilot power on a dragbike either.

thats why this shit is funny. Ive been riding with a 190/55 Pilot Power for my drag racing. Time to get a real tire for this is what the plan is. Even with that tire though, Ive been 6.59. My hookup is gonna literally go on the 10 to ride to the strip, race and ride home or for when we stop for food on the way home. Not for street riding, so Im figuring it should work just fine and not wear out in the next 2 months

question, was it difficult to get the tire to bead on the rim? I just got my 180/55 Hookup in the mail today and need to get it situated on the rim. Looks a shit load smaller than the rim, so Im just curious

question, was it difficult to get the tire to bead on the rim? I just got my 180/55 Hookup in the mail today and need to get it situated on the rim. Looks a shit load smaller than the rim, so Im just curious I also have a 180 on my bike a never had a problem and I put it on with no machine