XL/CB100 cafe - "Mini-Mono" >> she's alive!

[kwazykid]

This is gonna be rad! I've gained an affinity for small engined bikes. Keep those updates coming!

[eyhonda]

Thanks, all!  I'm glad you like the front brake hub and tank! 

Erksine- I was already planning a big bore but later.  I protected for it by changing the cases (100 to 125) and crank (bigger 15mm wrist pin).  With this combo, I can safely bore the cylinder to 58.5mm (133cc) and have a 1.75mm wall. 59mm (135cc leaves only 1.5mm).  Will think about that later but thanks for the reminder.   

Stay tuned!   I have a few more tricks to do!   It's a great experience with every new build.  This forum helps with the creativity too!

[Erskine]

Have you seen this:

http://hondacg125.awardspace.com/how_to_increase_engine_size.htm

[eyhonda]

Yup.  A lot of good info and tips there.   No cbx550 pistons here to try tho.   

[Erskine]

Yup.  A lot of good info and tips there.   No cbx550 pistons here to try tho.   

When you come to do it, PM me if you want me to source you one in the UK.

[JustinLonghorn]

Yes sir, I can dig it.

[eyhonda]

When you come to do it, PM me if you want me to source you one in the UK.

Thanks, I'll let you know.

Yes sir, I can dig it.

Cool, I'm glad you're watching!

I'm not sure what to do about the whole kickstarter issue.   Here are a couple of options:
1.  remove the right footpeg and use the kickstarter .  After it starts, put back the footpeg.   It's a bit of a process to start it this way, especially if it stalls on the street.  Although, it could be bump started.
2.  remove the kickstarter.   put it in 2 or 3rd gear, put it on a rear stand and yank the  rear tire around.   I used this method to check compression before I got the kickstarter.   Cleaner cosmetics, but again bad if stalls on the street.  Bump start it.
3. 2nd or 3rd gear bump start.    This could get tiring if it has a hard start problem.   Ok, if it is starting/running reliably.
4. build a 110v motorized roller starter (a la MotoGP) with a foot switch!   Expensive but not bad if DIY build.   Tempting!
http://motorcyclestarterrollers.com/
http://www.roscosrollers.com/


I'm leaning on keeping the kickstarter during the first startup stage until the motor starts/runs reliably (#1).  Then remove it and use #2 or #3 above.  Any thoughts out there?

[eyhonda]

Bump start it telling yourself this is how Mike Hailwood started () .In a day and age when most cafe racers often don't even have a kick start this is a street cred triumph.()...( Even though it's not a Triumph!).

That's a vote for bump start!   I have a Duc Monster.    So, maybe I can try bump starting that thing in the name of Hailwood!   It is fun bump starting bikes!   I remember running an errand with my cb175 at the local hardware store.   I let her roll down the parking lot incline silently, then drop the clutch, the motor comes alive and I make a clean get away!!   Fun stuff!

[Erskine]

hmmmmmm.
Bump starting gets to be a pain and is quite undignified if it doesn't fire straight up.... Ok if you live somewhere steep, but the cool factor wore off for me.  At 150cc high comp I can't even get it to bump in 3rd now.
I've also done the 'carry a kickstart' version and that gets to be a pain in the arse too.
I now have 0.000000000000001" clearance between my folded up peg and starter as it passes, but it's just enough

[Erskine]

Just looked at your starter ........ there's about a dozen different shapes of starter available for the CB/Cg/Sl/Xl and clones and pit bikes.
I'm currently rocking an Xl one.

[eyhonda]

It's a bit hard to shop for the exact shape if they are not all in front of you.  Sellers get annoyed after I ask them to measure this and measure that....   On top of it all, I have the smaller 13mm spindle.  I have a CT90 kicker and it does not clear the fold up peg or the brake lever toe.   I'd have to have a swing-out type that clears some X amount.  I'd have to measure the clearance, but the brake toe is quite close to the kicker spindle.  It would have to not only clear but the bend would have to start quite early.   Yes, optimally, the correct shape kickarm would solve it.     Let me measure the exact clearance that I need and maybe someone here can help find the right one.

My piston is also supposed to be HC 122cc but the seller didn't know by how much.  After putting it together, the top of piston didn't quite travel the full cylinder length, stopping about a mm before.   So, the squish volume is a bit bigger than I estimated.   I'm still hoping for about 10:1 or so (stock is 9:1 or so).   I had a big thread discussion on calculating compression ratio based on piston top volume and head space on the Yahoo 100/125 group.   

[eyhonda]

This is gonna be rad! I've gained an affinity for small engined bikes. Keep those updates coming!

I am too!   All the same bike building applies here too, small engine or big engine.    A small bike doesn't mean it has to be less fun or it has a smaller build budget.   Sure, it's less horsepower but you can still build it like a bigger bike w clip-ons, rearsets, etc.    I want a small bike for it's handling.  I want it to handle on rails like an RS125/CB50R.   It's a big lofty goal.   I'm sure I will not likely reach it but I'll have fun trying!   Smaller lighter slower means it is less demanding on brakes and suspension. 

[Erskine]

I'm on my 3rd kick start now.
2 of these:



and the most recent:



Which is on it's way out too. All however were (chinese?) pattern parts.
The current XL copy is not coping with the higher compression and the detent ball has already gone.
When I get the next one I'll ride the bike to the breakers yard and search through for an original Jap one that clears the folded peg.

[eyhonda]

It needs to clear 3.5 - 4.0"!    That is a big offset side load on the spindle!   That's just to clear the footpeg.   I'll have to fold back the brake pedal too.

[Erskine]

How far from the pivot point does it need that clearance..........I'll measure mine.