Re: Another A55 build

My 90 degree micro grinder and carbides should be here tomorrow so I can start raising and widening the exhaust port! On another note I'm not happy with second gear shift. I'm using the real friction material shoes and a green spring and unless I'm going slightly down hill I have to let off the throttle for it to shift. If I try to power threw the shift it slips and shudders. I couldn't find any spring charts for the TOMOS but it was my understanding the green spring was one of the lighter springs. Iv had some lighter riders on it and it does the same thing. Could I have gotten a spring that was marked wrong? Iv read most run a blue or yellow on second but if they are stiffer than the green spring that's not going to help me. Any suggestions as to why it's not wanting to shift with the green spring or what to do to slightly lower the shift point. I am running type F trans fluid. Thanks everyone

Re: Another A55 build

Didnt realize my other post went threw, thought it didnt (edited)

Re: Another A55 build

I don't know what shoes you're talking about, oem cork you mean?

Is your sprag clip intact? That will hammer your gears to bits is it's missing.

I don't run atf in anything, I like to run either 'motorcycle' 10w40 valvoline brand seems to be the most common, or rotella 15w40 diesel oil for the most slip.

I only have one tomos that has the stock cork shoes, stock a35, you almost can't even feel when it shifts. Downshifting is always tricky with tomos because of how the trans works, but it should never chatter or shudder.

Re: Another A55 build

Wasn't talking about downshift, was talking about the second gear upshift/clutch engagement. If u look they now sell 2nd gear clutches with friction material instead of cork. But to simplify my question what's the next weakest spring under a "green" spring

Re: Another A55 build

Yeah i just meant downshifting is the only time the tomos trans acts funny, it should never chatter or shudder on the upshift. Even with ATF they shouldn't shudder. I reline my clutches with friction material (haven't run the commercially available ones) and if anything they shift smoother.

Maybe someone else can chime in on the springs cant help ya there.

The only other thing it could be is that lots of a55's are way out of balance from the factory, the countershaft gear cluster and the clutch bell itself can be way out of wack. That can cause a shuddering feeling but its not the 'shudder' that most people describe from the sprag clip missing.

Re: Another A55 build

I went ham tonight before I left the shop and completely tore the trans down and pulled the cylinder so I can start porting, j spring was missing, first gear bushing was worn and all the teeth on first were chewed up which I already knew from when i put the clutches in, but sent it anyways after just to see what kind of speed I could get out of it. The shudder in my opinion is coming from the second gear clutch slipping at high rpm but if I let of the gas it shifts without issue. I'm going to rebuild the trans, buy new clutch drum and true it on the lathe and finish port work and see what happens afterwards. Iv hand ported many small 4 stroke heads up to pairs of V8 heads but never a 2 stroke. Would be nice to be able to find some examples of porting the a55 airsal but I haven't had such luck. Only info I have is what iv read. Learning from mistakes can get expensive LOL. Thanks for the info Graham! (edited)

Re: Another A55 build

The shudder is 100 % caused by that missing spring, it keeps the one way clutch in mesh. If you don't have it, the second gear will engage, the 1 way bearing will release, then the clutch will disengage, then the bearing will grab, then the clutch will grab, then the bearing will release.... Over and over, Causing the shudder. If you haven't yet, check out the a35 manual posted online, it's got a reply good drawing showing how the trans works.... It's kind of a trip, took me years to actually understand what is happening in there.

Eventually that hammertime will chew up the cast iron soft counter shaft gears and also destroy the one way clutch/bearing Cracking the gear housing. If your gears are chipped, your one way bearing housing is probably already cracked. The chipped gears isn't actually that bad, I've run chipped gears before, as long as you fix the underlying issue. The gears are iron on purpose so they will be sacrificial and not chew up the clutch bell gears which are steel. If it was steel on steel and you had a chip like in a differential, they would quickly destroy each other.

I dunno about that airsal kit, I've never built one but the ones I've ridden are lackluster. I would start by making a degree wheel and plotting out the port timing. Go a little wider on the exhaust and get it up to like 150 deg. There is no reason it can't rip.

Re: Another A55 build

The gear dogs actually look great and there not cracked. I agree the spring is there for a reason but on a performance build I'm curious if it's worth the chance of the spring failing rather quickly and doing damage elsewhere. That seems to be a pretty common debate. As for the shudder the only way I could see it being caused by that is if the one way bearing was slipping/jumping upon hard acceleration but my only thinking it isn't is because of the shudder is only if I let the 2nd gear clutch slip at the shift. If I release throttle for split second it shifts immediately with no shudder. I guess what I'll do is re assemble with the non worn gears and other new parts without spring and see what happens. If it still shudders I'll install j spring and see if it remedies it. Thanks Graham!

16117667980775686145523955674778.jpg

Re: Another A55 build

The gear looks fine but it's the outer race that holds the rollers that usually develops small cracks. Once the bearing clearance is off because of the cracks, it will bang harder and stick breaking the gear teeth.

It's not really a debate if you need it or not, there are just dummies out there who don't understand how shit works. I'm also guessing they don't install it right because I've never had one fail, when I get a new bike I usually replace it. I've had a couple bikes come to me with it failed but it's definitely not a common occurrence.

Re: Another A55 build

Here's a picture of that as well. Graham have u ran the spring on any hopped up bikes without issue?

16117732329618738195486795648118.jpg

Re: Another A55 build

You want the sprag clip

IMG_2766.JPG

Re: Another A55 build

Hard to tell from the pic but it looks like a crack is starting to form at almost exactly 12 o clock position in that photo? Can definitely see the bearing ramp surfaces starting to show damage.

I always install the clip and I've built quite a few tomos motors making good power, 50 plus, including one that was into the 60s at 12k rpm.

Re: Another A55 build

I'll order a spring with the other stuff. Thanks

Re: Another A55 build

Guys I spun the clutch bell while holding it in my hand and it's so far unbalanced it's not even funny. By far the worse iv ever seen any clutch or bell out of balance!

Re: Another A55 build

Yup.

Still not causing the chatter, you'll feel it at higher rpms though.

There was a dude on here machining them but I just swap out for a better a35 one when I get one that's crazy bad.

Re: Another A55 build

I looked for an a35 clutch bell but there all listed as a35/a55. I'm guessing u ment a used a35 bell? I found a used tomos arrow cheap, going to pick it up tomorrow and will decide if I use it for parts or not.

Re: Another A55 build

Yeah technically they are the same- technically the entire transmission is all backwards compatible- but when tomos switched to the a55 they moved manufacturing from slovenia to India and the quality tanked. The clutch bell, countershaft gears and crankshaft are the 3 parts where you usually have problems. If you get a 'good' one they are fine but I've seen some that are just totally out of whack and shake like a washing machine

Re: Another A55 build

Listen to Graham on the needs of the sprag clip. Every tomos needs it, no matter the speeds. But especially on tuned fast bikes.

For shifting especially on a tuned tomos I will always release the throttle at the shift point then gun it again once the connection is made. Just helps things move a little smoother.

Ryan from Cranks is machining tomos gears. He said it would be about $150 for it all said and done. The ones he did recently look amazing and have like half a mm in tolerance, before he started they were jumping about 3mm difference. I'm sure a nice balanced setup like that would make worlds difference. It is on my to-do list for sure.

Re: Another A55 build

Nice! Thanks for the info!

Re: Another A55 build

I picked up a trashed arrow today with non electric start A55, the gears and clutch bell on it are in almost perfect condition. Both side covers were busted but the crankcase is in great shape. Im thinking about using this case for a Gila topend, and using the gear set and the non electric start cdi on my Streetmate. After all the shit talk I read about the j spring I was pleasantly surprised to see it in tact and now understand what it does. 100% agree it needs to be in there!! If anyone needs any arrow chassis parts let me know.

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