Zoöid Third Times a Charm CB175

[Texasstar]

Not unless there is a good reason to do so like say a combination of corners that needs you to be in a higher gear than you would be in. I guess if you had a huge lead, you could short shift (change up at lower revs) to save teh motor, but I'm not that fast and need every rev I can muster.

Why do you ask? What are you thinking there?

We had a certain AHRMA racer with the numbers 555 stop by the shed yesterday and she took Victoria for a ride and told us that she was racing against competition that were upshifting without the clutch in the gp200 class and that she needed to learn how to do that....
As you know we had Victoria set up with an extra clutch plate and with the short clutch control lever. Well it is not the easiest clutch pull in the world. So Stacie was giving us advice on making the shifting smoother and easier.

Now to make our shifting and rear sets better. We originally had Victoria set up for GP shift for the Bostroms but recently we put CBR600f rear sets on for the standard shifting. It is easy to miss the upshift from 1st to 2nd.

What do we need to do to make the shifting smoother and closer?

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[Texasstar]

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[teazer]

That's clearer. The term Short Shifting usually means changing at lower revs and not letting teh motor rev all the way out.

Upshifting without the clutch is a must for quick lap time and can be done in one of two ways. On a simple race bike just back slightly out of the throttle and as it unloads the gears press the shift lever and get back on the gas. You can try that in your car too if it's a manual. It is much faster than the regular pull in clutch, close throttle, change gear etc sequence.

That will work every time once you get used to it - as long as the dogs engage easily. If there is a lot of play or too many dogs the shift will be messy. First to second usually needs the clutch and if you miss shifts, change the leverage so that the shift lever moves less. On a TZ there is almost no movement - barely press on the lever and it's in the next gear, but with a worn or sloppy linkage you could have way too much motion.

Short and crisp is the plan. We use heim joints on ours and I had to change the lever arm lengths a couple of times to get the right feel.

The other technique is to use a switch of some sort in the shift lever connected to a momentary kill circuit and with that set up you keep the throttle open and just press the shift lever.

Both approaches only apply to upshifts.

 

[Texasstar]

Zoöid Third Times a Charm CB175

That's clearer. The term Short Shifting usually means changing at lower revs and not letting teh motor rev all the way out.

Upshifting without the clutch is a must for quick lap time and can be done in one of two ways. On a simple race bike just back slightly out of the throttle and as it unloads the gears press the shift lever and get back on the gas. You can try that in your car too if it's a manual. It is much faster than the regular pull in clutch, close throttle, change gear etc sequence.

That will work every time once you get used to it - as long as the dogs engage easily. If there is a lot of play or too many dogs the shift will be messy. First to second usually needs the clutch and if you miss shifts, change the leverage so that the shift lever moves less. On a TZ there is almost no movement - barely press on the lever and it's in the next gear, but with a worn or sloppy linkage you could have way too much motion.

Short and crisp is the plan. We use heim joints on ours and I had to change the lever arm lengths a couple of times to get the right feel.

The other technique is to use a switch of some sort in the shift lever connected to a momentary kill circuit and with that set up you keep the throttle open and just press the shift lever.

Both approaches only apply to upshifts.

Thanks Teazer today we will learn to upshift without the clutch! I know how to do it in a car but never considered it until Stacie mentioned it the other day. She also told us that she has the longer stock levers on her race bike because she "lives" at the end of her bars when racing.

So now there is a big difference between the cb200 clutch feel and the 175 clutch feel and that matters especially after Stacie's visit. Last night Zeke was going around to all our bikes and comparing. The cl200 was the smoothest and it has long leavers. The Harley Sprint was smooth but a little more difficult. The Bultaco was abrupt...kinda like a long trigger pull then bam! Then Victoria with the short lever was tough to pull. Of course our modern bikes with hydraulic cylinders are easy.

So is there anything else we can do to the 175 with the push bar mechanism other than lubing the cable? (Remember we have aluminum clutch plates and I would assume that it would also make a difference.) Zeke found a video a of a guy joining two paper notebooks by alternating the pages back and forth and he demonstrated trying to pull the two apart. Here is Stacie's reaction after commenting about the clutch pull and the shifting mechanism. Not good...https://vimeo.com/149555958 https://vimeo.com/149555984 We are thinking maybe it would be better for Bryan's build to go to the Cb200 like you had mentioned earlier. We are taking Stacie's and your advice as maybe a fork in the road or at least a road sign


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[teazer]

Something wrong with the cable if it is hard to lift. We use stock Honda or aftermarket levers and the clutch pull is a two finger job. I use stock springs and extra plates and the clutch is almost too light.

I would start with cable run - as straight as possible is good. Then I'd check the cable itself to see if it has too much friction and then I would adjust it again - starting at the side cover/screw, Cable slack at the lever comes last.

Send me some pictures of the shift lever linkage and a shot with someone on the bike foot above the lever and fit below it to see how awkward it is to use.

 

[crazypj]

Re: Third Times a Charm CB175

Thanks guys...I really liked the 21's but Zeke HATED them. We are mocking up 19's front and rear tonight. Found this little jewel. Did Akront make a 1.85x19 40 hole?

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Isn't that a Triumph Tiger wheel?
After taking a good look, it's one of the earlier ones with long operating arm. Most people think they are superior to the later short arm style
As for fast gearshifts, you can also wire the clutch override switch or horn button as a kill switch , 2~3mm clutch lever movement kills motor long enough to shift at full throttle (powershifting)
Need to wire a bypass so you can make starting line though.
Just don't do it on corners
It doesn't take too long to learn to shift up or down without clutch but you do have to practice and it saves doing any ignition system modifications. I'm so out of practice I can only change up nowadays

Not sure if AKRONT made 19" 40 hole. Probably as a replacement may be a bit difficult to find?
. I used Borrani's back in the day

 

[Texasstar]

Re: Third Times a Charm CB175

Isn't that a Triumph Tiger wheel?
After taking a good look, it's one of the earlier ones with long operating arm. Most people think they are superior to the later short arm style
As for fast gearshifts, you can also wire the clutch override switch or horn button as a kill switch , 2~3mm clutch lever movement kills motor long enough to shift at full throttle (powershifting)
Need to wire a bypass so you can make starting line though.
Just don't do it on corners
It doesn't take too long to learn to shift up or down without clutch but you do have to practice and it saves doing any ignition system modifications. I'm so out of practice I can only change up nowadays

Not sure if AKRONT made 19" 40 hole. Probably as a replacement may be a bit difficult to find?
. I used Borrani's back in the day

thanks for the info on the powershifting...don't exactly know about whether it is a tiger hub it does weigh a ton though! I will post it on a triumph forum and ask.

 

[Texasstar]

- The TRX ring lands look wider than the Tbolts.. if true, this could cause a ring flutter issue at rpm.

- What is the top displacement of the TRX piston? IIRC the Tbolt is 5cc yes/no ??

I am copying your post from the cb200 string to this string:
Hi Patrick

I get confused with all your builds, but ran across a couple things that may be useful. If your still searching for a piston, visit the Wiseco site, and use their search for the following:

2013
Suzuki
DR-Z125 L

This should bring up three flavors, 57, 58 & 61 mm.

The 57 & 58 mm pistons have a dome height of +10.6cc
P/N 4815M05700 and 4815M05800 respectively

The 61 mm piston has a dome height of +9.5cc
P/N 4815M06100

These all have 14 mm piston pins
I do not know weight or heart-line dimensions or what the actual (physical) displacement of the domes are. They seem plenty high though. They are a tad pricey but can be found for less elsewhere. I am curious if you have already reviewed these.

GEARING
Have you looked into the possibility of using the 5th gears from a Honda CB125Twin (or CB125B6)? If your running out of rpm, these may help.. I do not know (for sure) if they will slide onto the CB175 main and counter shaft. Discussing with simo, we think they will or have you already looked at this? If they will work, they can provide lower gearing than the CB200 (or CB350 for that matter).




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[Texasstar]

Q it looks like the top of pin to deck and top of pin to deck are more comparable to the cb200 than the cb175. The measurements that I have found on the web for the DR-Z125 piston are 17mm pin to deck and pin top to dome 25mm

http://www.thumpertalk.com/topic/751539-drz-125-piston-qs/


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[crazypj]

61mm is stock CB750 sohc size.
I machined a set for my 550 in 1978 ;D
I have a couple of sets of NOS 0.75mm @1.00mm OS here if you need measurement

 

[simo]

Those DZ pistons look alot like Suzuki GS 125 ( stock 57mm but plenty of 61mm big bore kits around)

 

[Texasstar]

61mm is stock CB750 sohc size.
I machined a set for my 550 in 1978 ;D
I have a couple of sets of NOS 0.75mm @1.00mm OS here if you need measurement

Crazypj are they 14mm pins? We have been trying to find a more cost effective way for those who want to upgrade to a more modern piston design for the cb175.

We have several Pistons that we have been collecting did you see the 54mm TRX? We are also getting several from AKUNAR in Thailand. They sent me measurements last week and their top of pin to deck is close for the cb175.

You can find the Suzuki forged Wiseco that Q was suggesting for 80-85 ea but it's measurements would require machining.

The goal would be to try and find a better piston design that could replace NOS for others.

 

[Texasstar]

Those DZ pistons look alot like Suzuki GS 125 ( stock 57mm but plenty of 61mm big bore kits around)

is the GN125 and GS 125 the same piston? Do you have any measurements?


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[Eleganten]

Just have to say that I'm really impressed with the craftsmanship and the design work. It looks just amazing!


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[simo]

is the GN125 and GS 125 the same piston? Do you have any measurements?


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Amend that its the GN125 that has the high top that im thinking of the GS125 are flat

 

[Texasstar]

Just have to say that I'm really impressed with the craftsmanship and the design work. It looks just amazing!


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thank you! I will tell Zeke.


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[Quixotay]

I am copying your post from the cb200 string to this string:

OK (I wasn't sure where it should be posted)... and I see what you mean after looking at the Honda piston comparison chart... they are better for the 200 engine...

I will look further into this after the new year... need your range of acceptable bore sizes

NOTE: Might think of sponsership opportunities; or combining efforts with other members; or use Kickstarter to fund an acceptable piston design ... dunno

 

[crazypj]

Crazypj are they 14mm pins? We have been trying to find a more cost effective way for those who want to upgrade to a more modern piston design for the cb175.

We have several Pistons that we have been collecting did you see the 54mm TRX? We are also getting several from AKUNAR in Thailand. They sent me measurements last week and their top of pin to deck is close for the cb175.

You can find the Suzuki forged Wiseco that Q was suggesting for 80-85 ea but it's measurements would require machining.

The goal would be to try and find a better piston design that could replace NOS for others.

Yep, 14mm.
On phone with Dennis while looking for stuff ;D
I tend to modify stock parts, usually easier and safer when lightened.
Pistons I have are 61.75mm and 62mm

 

[Texasstar]

Yep, 14mm.
On phone with Dennis while looking for stuff ;D
I tend to modify stock parts, usually easier and safer when lightened.
Pistons I have are 61.75mm and 62mm

Crazypj do you see your post to the left? See pix. It is not showing up in my feed but it is showing up in the preview window???

and here is what I found on the web for the cb750 piston measurements

Happy New Year!!!


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[Texasstar]

Zeke and I worked till 2am last night and bent some tubing and turned some chrome moly for the rear sets