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Discussion Starter · #1 ·
I was hoping to get some information from anyone who may be in a helping mood. I just bought a 2007 CRF70 and am interested in building a mini supermoto. I was looking into wheels and found a company called TBoltUSA who makes a 1.85"/2.15" super moto wheel set. I have just a couple questions I was hoping to get answered. They are:



First, I've decided to go with an aftermarket "pit bike" front end with 12". I am going to swap that front wheel with the 1.85" that comes with that set. As long as I get a 15mm to 12mm bearing "adapter" then that wheel should bolt right up, correct? Is the disc and caliper mount going to cause any clearance issues? Is there a better setup for the front other than the absurdly expensive Marzocchi setup?



Second, the rear wheel poses mounting issues. I suppose I will need a +2" longer swing arm and probably more 15mm to 12mm bearing adapters. How have you guys mounted a rear hydraulic setup to the stock frame? Is that possible or must I look into a new frame? I am building the bike to stunt and possibly race as well. I was looking into the rear foot master that Full Throttle Inc. offers, but I am stumped as to how to mount it. Will I need a swing arm that accommodates hydraulic brake caliper? What caliper should I use?



I've attached a picture that I found of what I am looking to do. I would be the utmost appreciative for any information/tips from anyone who has conquered these issues. I guess, I am trying to keep the project relatively cheap and it's looking like it might be hard to do. Thanks a bunch.
 

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your on the right track. that swingarm in the picture is an sdg style swingarm that you can get off ebay. some good economical forks with adjustability would be Fast Ace AS02 or AS01 that you can get on ebay as well. with that fork and swingarm combo, you can just use a 15mm axle instead of the adapters. they are also ready for a disc brake setup front and rear. pretty much everything you need can be had off ebay if thats the way you want to go.
 

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Discussion Starter · #3 ·
How/where would you mount the master cylinder for the foot brake? On my street bike I tapped the rear master with a Full Throttle Inc adapter and use both a brembo 16x18 master and a foot brake for rear brake control. I want to have a similar setup on my moto. Where and how did you mount the master cylinder for foot control? I suppose I will need a different brake lever for a hydraulic setup?
 

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if you can weld or have access to one it isnt too hard. the frame is steel so you can easily weld some tabs to the frame to mount the MC. The arm on the stock brake pedal can also be cut and rewelded to accomodate the MC linkage.



look at some pics of bikes that already have this setup and you will see there's not much to it.
 

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you can get a complete rear disc setup on ebay. that swingarm you showd already has the tab on it to accomodate the bracket for the caliper. some of those setups also come with a brake lever too.
 

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No, he just painted the upper portion nicely.



If you're looking to run import hubs, and an import front end, I'd grab an import rear swingarm as well. Mine (the pic you posted) is off an SDG Pro Mini. With the Pro Mini's front end (you'll either need different clamps, or the stem on the Pro Mini clamp turned down) and the SDG swingarm I'm at 48" for a wheelbase, without being crazy tall. Handles great.



The SDG Speed Mini front end is also a great bolt up option that I've beaten the snot out of. You get a standard 15mm axle import front wheel and disc setup. Replace the brake pads with EBC units, MX Sintered for extra stopping power. It's heavy, but bullet proof.



There are brackets from Takegawa and G-Craft that let you mount an NSR50 or comperable rear brake master to your motor. I have one on the bike you pictured, my other bike uses a similar bracekt I made. The brackets allow you to retain the stock brake pedal, and keep the brake master off the pavement should you dump.



That said, stock CRF70 geometry isn't that bad. In back, there is enough room to run a wide rim with the stock swingarm, just have a 2.15" Cyclone hoop laced to your stock hub. Just keep an eye it, you won't be able to put your axle all the way forward as the tire will rub. Up front you can lace a 1.85" or 2.15" rim to the stock hub and be ok. The front drum works ok if you maintain it properly. EBC makes good shoes that'll get you a bit more bite, keep it clean and as long as you're not on real tight tracks where the drum doesn't get a chance to cool, you'll be fine. HD springs up front, a lil heavier oil, and an adjustable works shock in back, and you've got a good setup to work with.
 

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Discussion Starter · #13 ·
Kurlon said:
No, he just painted the upper portion nicely.



If you're looking to run import hubs, and an import front end, I'd grab an import rear swingarm as well. Mine (the pic you posted) is off an SDG Pro Mini. With the Pro Mini's front end (you'll either need different clamps, or the stem on the Pro Mini clamp turned down) and the SDG swingarm I'm at 48" for a wheelbase, without being crazy tall. Handles great.



The SDG Speed Mini front end is also a great bolt up option that I've beaten the snot out of. You get a standard 15mm axle import front wheel and disc setup. Replace the brake pads with EBC units, MX Sintered for extra stopping power. It's heavy, but bullet proof.



There are brackets from Takegawa and G-Craft that let you mount an NSR50 or comperable rear brake master to your motor. I have one on the bike you pictured, my other bike uses a similar bracekt I made. The brackets allow you to retain the stock brake pedal, and keep the brake master off the pavement should you dump.



That said, stock CRF70 geometry isn't that bad. In back, there is enough room to run a wide rim with the stock swingarm, just have a 2.15" Cyclone hoop laced to your stock hub. Just keep an eye it, you won't be able to put your axle all the way forward as the tire will rub. Up front you can lace a 1.85" or 2.15" rim to the stock hub and be ok. The front drum works ok if you maintain it properly. EBC makes good shoes that'll get you a bit more bite, keep it clean and as long as you're not on real tight tracks where the drum doesn't get a chance to cool, you'll be fine. HD springs up front, a lil heavier oil, and an adjustable works shock in back, and you've got a good setup to work with.


Thank you so very much for the enlightening info. I've been searching for a way to put a larger rear rim on the rear with the stock hub. I am probably going to go with a fastace fron end with hydraulic brakes in the front. I'd rather keep a stock hub in the rear though because I stunt a lot and I'd like to keep my ability of running a hand brake setup as well. I think I will go with a swing arm like the one you have mounted and go with an ishock. I'm 6' but only weigh 150. I think that suspension setup should be fine.



Is that Cyclone wheel a 36 spoke? I think the stock CRF70 hubs are 36 spoke. Where could I procure that Cyclone 2.15" hoop for the rear that will be be compatible with the stock hub spoke pattern?
 

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yes cyclone makes a 2.15 36 spoke rim .. in black i think?..stock hub both front and back is 36 spoke ...only way i know to get in touch with him is look up cyclone rims on ebay and then just message him and ask about them....good luck..let me know how running that front end works out as a motard and a stunt bike as i am doing the same with my 70..just a stock front end and stock swinger
 

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Discussion Starter · #15 ·
After some research, I think I am going to go with a 1.85" wheel with disc brake up front and a 2.15" rear rim from Cyclone and have it laced to my stock hub. I'd like to have a disc brake in the rear, but it would take substantially more loot and work to set up the bike with a handbrake in that manner. I am going to build the bike mostly for stunting with some occassional racing as I progress.



Does anyone have an opinion on an 88cc kit for that setup and whether or not I can expect ample enough power? My hopes are to run a full 88cc kit with a +2 rear sprocket.
 
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