BGF Hongdu/Solex

cannonball2

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Oct 28, 2010
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I know this has been discussed on the forum before, but I could find no post about the complete installation of one of these. Being the risk taker I am I ordered one. It is in fact a complete kit, with no instructions as advertised. I have identified all but one part, and the installation looks very easy. Am waiting on a Micargi Rover 24" which is in transit. Got a black one to roughly mimic the Velosolex. It was earlier stated that these dont have the clutch like the Solex, but looking throught the cooling slots there is in fact a clutch drum. I can only assume at this point. It is a clone of the Solex, but the execution is typically Chinese. Still looks perfectly useable. Any one have hand on with one of these?
 

cannonball2

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Oct 28, 2010
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Finished the build on the H-Solex. Was a perfect match for the Macargi 24. Once I tweeked the hardware a bit it was a 30min. bolt on. Its a really cool bike, very smooth and runs great. Its a leisurely ride, top speed around 20. It is also very quiet. I really like it. I have three other bikes with top speeds from 30- 50mph, so figured this one rounds out the collection. This little thing is just plain fun to ease around on!
 

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cannonball2

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Oct 28, 2010
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Yeah, they havent changed much since 1946. I would like to scare up a set of bumper rails to complete the look, and also protect it if it falls over. I have got to come up with a better stand, its a fall waiting to happen. The muffler is pretty cool, I still have to fab a mount to tie it to the fender stay. This was the easiest kit I have ever done.
 

wheelbender6

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Sep 4, 2008
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You may need a center stand (two legged) to keep it upright. I'm a frame mount guy but I love that H-Solex.
 

Colony Five

New Member
Feb 14, 2011
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i am really wanting to order one of these for my first build but i am hesitant because it comes with no instructions. it may be easy for someone already familiar with an original solex but i am not, and i can't find much info about the hongdu anywhere...this thread is about the most detailed i have seen about one that has actually been used. perhaps if i was familiar with the vintage solex it might help, but then i have no idea how closely the copy mimics the real thing...

what are the 2 handlebar levers for? i am guessing one is a clutch and the other is an accelerator, right? and what is the proper way to break in a new one?
 

cannonball2

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Oct 28, 2010
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BGF has these available now with free shipping, thats what tipped the scale on buying. It is a much easier installation than most kits. I did spend some time looking at how the parts went together but that didnt take too long. I replaced the original hardware and just bolted it on. Instructions are really not necessary. The lever on the right is the throttle and the one on the left is the compression release. I really like the simplicty of its design and operation. I believe this is the same engine installed on the current Velosolex being sold. The original tooling was sold to a firm in China from what I have read. The finish looks better on the French assembled version, but for $1895 it should! It does not have a clutch as the Velosolex does, but it is a simple matter to pull the lever to raise the engine just before a stop. It will run at a slow walk, so raising the engine is only necessary at a complete stop. I am breaking it in on the suggested 16:1 ratio, plan on running 32:1 afterwards. It gets better every time I ride it. The Velosolex parts fit it and there is a wealth of info on the net. I would be happy to talk anyone throuh an installation. Just remember it has a realatively slow top speed, if easing along quietly is you thing, then its way cool!
 

cannonball2

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Oct 28, 2010
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I would estimate thats about right. In theroy the 24" wheel should get close to 21mph at the listed top rpm of 3800, but I imagine 20 or slightly below is more real. I found a site that has tuning info. They actually race these things somewhere! That would be like watching paint dry. The engine is built like a tank, they are supposed to run for ever, that is of course dependent on the quality(or lack there of) of the Chinese version. Still I havent seen anything glaringly defficient, and I tore it down to the piston to see. I did readjust the comperssion release as it was screwed down too far, but that was about it. I also modded the carb lever to have the spring at the top, so the carb returns to idle. The way it is made the spring pulls it to WOT. Makes sense on a log trip since it is run pretty much wide open anyway, but might me an issue in a fall. Anyway its a simple mod.
 

camlifter

Active Member
May 4, 2009
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acme labs marion ohio
thanks for the info, i'm looking forward to getting this kit. on my 3800 solex the throttle locks in place at wot, then when you want to stop the right hand lever acts as a brake and also pulls the motor down to idle, then when you release the brake it automaticly goes back to wot, prety cool feature and usefull for such a low powered bike.
 

Colony Five

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Feb 14, 2011
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that's about as fast as i want to go on a bicycle anyway. i'm just hurting for transportation right now because my car is broke down and could be for some time and i am pedaling a bike around which is a real drag, especially on windy days. i need to get something together asap, so i really don't care to tinker around with a frame mount at the moment. i also need to haul cargo on a rear rack so a rear friction drive is out. this looks like the easiest and quickest way to go, and if it will get me and 20 or 30 pounds of cargo a couple miles down the road to the bus stop or the dollar store it's a keeper.

looking at the pictures though it does look like i may need to get a different bike. i was hoping i could use the one i already have, but it is a MTB with front suspension and brakes, and it doesn't look like the kit will clear it. but i would need a different bike for a frame mount anyway so it's a wash.
 

deacon

minor bike philosopher
Jan 15, 2008
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I saw this kit last year and was looking for info on it. I'm glad to see some now. I am a friction drive lover and like someone else said twenty mph is fine with me. I have a lot of hills here those are a problem for small friction drive though. I am going to look into one of these kits.
 

camlifter

Active Member
May 4, 2009
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acme labs marion ohio
on friction drive the larger dia. wheel gives a lower top speed, right, with a 26 in. wheel the top speed will be lower than the 20mph you get from a solex and it's 19 in. wheel.
 

cannonball2

Well-Known Member
Oct 28, 2010
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Colonial Coast USA.
With out going into a long diatribe about how I arrived at the figures taking a 45mm drive roller and using the circumferences of the tires, I arrived at the ratios of rpm vs distance traveled. assuming I did the math right(questionable) the 24" wheel rolls one more revolution/mile(about 80") so is only slightly faster. I am sure I will be corrected on this, lol. I chose the 24" not only because it is so cute, but gut said the bigger wheels might gear it up too much. I have seen pics in China of the units on the standard fare 28" bike, so it seems maybe(without calculating all sizes) the reduction of rpm of the wheel about equalizes with the increase of the distance traveled. Long explanation short it may not make a huge difference, but the smaller wheels may have slightly more pulling power.
 

cannonball2

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Oct 28, 2010
3,662
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Colonial Coast USA.
Just ran several runs on GPS the best was 19.7 mph on the flats with the average speed in the upper 18s. Gets down to 15-16 on average hills, its definately not a hill climbing demon but if you are patient it will climb most all but the really steep ones above 10mph, the real steep ones require a little help some times. Its still not broken in completely, so it may still gain a little performance. It amazes me how slow it will go, will ride along contentedly at a walk. Got the light working and have just about all the detailing on the installation done to suit me. Would advise slipping a ring of 5/8 heater hose over the exhaust manifold to slide down to the pipe joint. This joint is some what loose to allow the engine to be raised and lowered. This causes a little oil blow back, the hose ring fixes this. I also switched to a recommended Bosch projected nose plug and it made a world of difference. All in all it has been pretty trouble free to this point and pretty much performs as advertised.
 

MotorBicycleRacing

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Jul 28, 2010
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on friction drive the larger dia. wheel gives a lower top speed, right, with a 26 in. wheel the top speed will be lower than the 20mph you get from a solex and it's 19 in. wheel.
The diameter of the driven bicycle wheel makes no difference to your ratio or speed on a friction drive.
A 16" wheel will go the same speed as a 26" wheel
Only the diameter of the drive roller changes the ratio and speed.

What size is the roller on this kit?
 

Zman

New Member
Sep 10, 2010
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germany
Hi !
I've restored an '69er Velosolex back in 2006, you should try to get a france version of the drive roller, the diameter is slightly larger then other models.
Also they used an other cylinder with bigger channels (dunno the right technical term^^)The original france solex runs up to 50 km/h ( 31 mp/h), they are not restricted....
 

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