Cb100 with a 200cc motor: debating brakes?

C

cb100cafe

Been Around the Block
I'm building a cb100 with a 200cc motor.

I'm thinking either a 17" wheel with a larger drum and stock triple tree or with disc brakes. That solution is somewhat old school.

Allternatively to that is a rebel 250 triple tree, wheel and rotor and caliper setup but that is with a 18" wheel and I kinda wanted to stay 17" front and rear.

If this bike weights in around 180-190ish pounds would a larger drum front brake setup be ok? The forks i'm getting has provisions for a caliper mount but i'm not sure if I really want it yet.

I weight 140 pounds soaking wet btw.

Opinions? I really like the idea of keeping it simple with a drum setup but I don't want to regret it. I kinda designed this so far that both setups are options and I could try both setups. Cost isn't to much difference or additions.

Thanks a ton.
 
No idea on the answer to your question, but I must know what was done to get 200cc out of or into a CB100...Lifan/Chinese motor?
 
I, like valvesprung want in on this too.

But yes, a drum brake should work just fine.
 
Yup, me too. I do have a lead on a big bore piston that will use the same wrist pin as the CB100. Other options are sleeves, but I don't think you actually get 200cc.
 
valvesprung said:
No idea on the answer to your question, but I must know what was done to get 200cc out of or into a CB100...Lifan/Chinese motor?
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Yes for now it's getting a lifan. Then I'm building a honda motor 200cc for it if it shits the bed. Hides in corner.. I'll build a real honda motor for it next winter.

I've been up all night thinking about this stuff.

Seemingly it's getting the rebel front end and disc brakes. I'd like to stay with newer parts that i can get my hand on them. Also i've figured out a matching wheel setup for it now. It's 18x1.85 front and rear. I had a hard time finding a 18x1.85 rear wheel that i thought would work but i am picking up a few parts bikes to make it work.

I liked the idea of keeping it oldschool and on 17s with drums but there really isn't alot of info out there to some degree. Plus ditching the 27mm front forks i think might be a good idea now. I was just worried it look like it was on dumbo wheels if the wheels and tire setup was to wide but i think i'll be content with 1.85x18s.
 
Erik said:
Yup, me too. I do have a lead on a big bore piston that will use the same wrist pin as the CB100. Other options are sleeves, but I don't think you actually get 200cc.
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There are a few write ups on the web about going to 200cc. via a Xr200 setup. Alot of them say start with a 125 bottom end. I didn't have a motor so I choose to go with the lifan setup for now.
 
CB100/125 bottom cases and bottom end plus XR200 topend equals CB200!

This is a popular conversion for the Superlite races around here, as a 200cc single-cylinder (aircooled w/2v head) is the largest you can use. You can easily get over 20hp out of them, and on the track they're competetive against 85cc, 28hp two-strokes.

To your braking question, the single Rebel disc will be more than enough. If you run a twin-shoe (stock or otherwise) drum it will be adequate but i'd make sure its running new, sintered shoes and has a properly adjusted cable. It may also be worth giving the inside hub a quick rub down with some 400 grit sandpaper. This will remove any glazing and/or rust and give your new shoes a better sufrace to bed into.

The drum should be fine, but it wouldn't stand up to competetive or hard use - going fast down a mountain, for example. You would probably also find that you have to use more force at the lever to get the amount of braking you want. Feedback would also be worse compared to a disc setup.

Cheers - boingk
 
boingk said:
CB100/125 bottom cases and bottom end plus XR200 topend equals CB200!

This is a popular conversion for the Superlite races around here, as a 200cc single-cylinder (aircooled w/2v head) is the largest you can use. You can easily get over 20hp out of them, and on the track they're competetive against 85cc, 28hp two-strokes.

To your braking question, the single Rebel disc will be more than enough. If you run a twin-shoe (stock or otherwise) drum it will be adequate but i'd make sure its running new, sintered shoes and has a properly adjusted cable. It may also be worth giving the inside hub a quick rub down with some 400 grit sandpaper. This will remove any glazing and/or rust and give your new shoes a better sufrace to bed into.

The drum should be fine, but it wouldn't stand up to competetive or hard use - going fast down a mountain, for example. You would probably also find that you have to use more force at the lever to get the amount of braking you want. Feedback would also be worse compared to a disc setup.

Cheers - boingk
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Thanks for the reply. I'd like to have fun on the bike and be safe. I think I will wise up and stick with the rebel 250 setup. It's modern and parts are avaliable for it. I spend to much time scratching my head trying to figure out how to deal with the Cb100 parts.

I should have the rebel front end in a week or so. I have to pick up another parts bike up this weekend first to source the rear wheel, gauges, lights, handle bars and accessories.

Thank you for all the replies. I'm a bit of a newbie to motorcycles but I do all my research and like to read up on all the forums.
 
So do any of you have a write-up/info on the 200cc build up or the Rebel front end? Are both pretty basic bolt together builds? I have a '71 CL100 in the garage without and engine and 20bhp and a disc brake sound fantastic...
 
The XR engine from what I understand will almost fit and may just require the front mount to be altered. CB100's have a smaller wrist pin and therefore need the rod and top end from the 200. There are some big bore pistons out there and swapping some 125 parts back and forth to achieve different bores with 125 big bore kits. As far as braking, twin shoe or disc setup should be good either way.
 
Yeah I've seen lots of good big-bore kits, but you're talking about $750-950 before machine work, and then really have to run race gas too...not a great set up for riding around town...
 
valvesprung said:
So do any of you have a write-up/info on the 200cc build up or the Rebel front end? Are both pretty basic bolt together builds? I have a '71 CL100 in the garage without and engine and 20bhp and a disc brake sound fantastic...
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The bearing match. I haven't sourced the parts yet but thats the plan. I'll have to check out the stem lengths at some point but my friend builds bikes for a living and i'm not to worried about it.
 
valvesprung said:
Yeah I've seen lots of good big-bore kits, but you're talking about $750-950 before machine work, and then really have to run race gas too...not a great set up for riding around town...
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Sammy Miller (UK trials guru type) does a 150 kit for this engine at about $170 using the standard length con rod. And a few other goodies too. ;)
I'd be interested as well regarding any info on 200 builds from the CB base.
 
Just reading all of the posts and I am wondering something...


Can the lifan 200cc bolt into the CB100 frame? Have you tried it yet? Really curious...
 
MOTOCAFERACER12 said:
Thank you surrffly. Does anyone else know? Can you bolt a Lifan 200cc into a CB100?
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That whole family use the same cradle, the only bit you may have to change is the front bracket but I doubt it.
 
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