GoldenMotor.com Forum
General Category => General Discussions => Topic started by: austindenny on September 01, 2008, 02:45:36 AM
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I bought a used 2005 Gary Fisher Marlin yesterday on CraigsList and began disassembling it today to do a full clean/tune up. I did not see much detailed information on the web site as far as the differences/dimensions for the two different set ups. I'd like to keep my 9 gear sprocket and have an easier conversion for when I want to go trail riding. I'd appreciate some advice from those who have been there and done that. Pictures would be nice too.
Thanks,
Austin
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I took my bike on the trail, rear motor and batts, today and it did good but I did keep the speed down on the downhill with no trail and took a more gradual hill on a dirt road back up so I did not have to exert myself to much. For the stealth look and I believe for strength the rear is best but that means finding a place for the batteries. Most put them on racks on the rear and things can get a bit unstable at very low speeds or on mounting or diss-mounting the bike. The batteries need to be installed in the triangle to get better balance and lower is better. Front installs are easy to balance better as putting them in bags slung low on a rear rack is about all you need to do. You loose traction with the front mounted motors on steep uphill grades from what I have read and one can break the dropouts. It's tuff to make these bikes light mine is 60lbs. Making the bike lighter means less battery and possibly a geared motor I have seen a couple of nice ones but not for the trails. Building a full suspension, with a 10 lb geared motor, now and agonizing over battery placement once again my self. As with most things there are trade offs so build a few and keep the one you like best? ;^) GM shows their motors installed both ways.
http://www.goldenmotor.com/
Endless Sphere has lots of info and pics.
http://endless-sphere.com/forums/viewforum.php?f=6
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OOPS did I ferget to say no 9 speed on a rear wheel and if it's a GM then only a 5 will werq. You can manage a 7 on a bmc geared rear but they costs much more. So if you want the gears it needs be a front wheel drive. Motors are near the same size front or rear. Specs are on the Golden motor site.
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Interesting old post....
Why is nobody using front wheel mount? Is it that bad?
80% of bike braking is done by front brake so it would be logical to mount it on front (no matter the less traction due to weight distribution).
And yes I wanted to ask. I have bike that I like going offroad jumping and doing a little agressive riding, but I wanna be able to use it as eBike also for longer trips
So thats why I wanna make it front wheel mount.
How fast/easy you can dissasamble the whole thing if you wanna quickly convert it into "normal" bike?
I have extra wheel ready for swich, so how fast can I remove the Front wheel (motor) and battery if I decide to buy MagicPie motor?
thank you
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I took my bike on the trail, rear motor and batts, today and it did good but I did keep the speed down on the downhill with no trail and took a more gradual hill on a dirt road back up so I did not have to exert myself to much. For the stealth look and I believe for strength the rear is best but that means finding a place for the batteries. Most put them on racks on the rear and things can get a bit unstable at very low speeds or on mounting or diss-mounting the bike. The batteries need to be installed in the triangle to get better balance and lower is better. Front installs are easy to balance better as putting them in bags slung low on a rear rack is about all you need to do.
Hi Bioman.. 8)
Haven't seen you here for some time.
Pacing batteries in the triangle is the best way with rear motors. Lowish is good, too low creates a lower centre of gravity impeding the riders ability to rebalance out of turns. Simply said she turns into a slug to lean.
Strange enough if the pack is heavy, placing it lower, lowers the centre of gravity making the bike top heavy to control. Rider weight becomes less effective to the balance in and out of turns, making the rider have to work harder to lean.
(http://i29.photobucket.com/albums/c251/soulelectronique/COG.jpg)
Balance of a bike is not all as it seems.. The riders ability to shift his or her weight makes a very large difference to the way things work. A battery is dead weight.
The way a bike stays vetrtical is like magic isnt it?
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It seems I didn't found answer to my question below... still... I have another :)
What is the main difference between MagicPie front and read? Dimensions? Something else?
Can I put my front mount Magic Pie on my rear wheel?
Thank you
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The front wheel Magic Pie motor is physically
similar to the rear one.
The difference is that the rear Magic Pie comes
with requires a thread-on freewheel gear cluster.
The difference in the bike requirements is major
however.
If you are using a front wheel Pie, then you must
have steel forks on the bike. I tried with an aluminum
fork and my wheel ripped the drop-outs right out
of the fork.
I have replaced the fork with a chrome-moly fork
and added a torque arm to the shaft and am very
happy with it.
The front wheel does feel more balanced to me
since the batteries on the rack weight about the
same as the motor on the front.
The rear wheel is a little more difficult to get set
up properly, but the rear drop-outs for the axle
are a little more forgiving of the material.
This is just my opinion.
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The difference is that the rear Magic Pie comes
with a freewheel gear cluster.
They come with a threaded boss to accept a screw on freewheel, but the freewheel unit itself was only supplied if specified and paid for as an additional option to the standard kit.
As far as I'm aware, they still don't come with a freewheel as standard, unless GM have changed the kit specifications. ;)
The rear wheel has a different right hand side cover and a much longer axle to allow for the additional width of the freewheel:
(http://www.arhservices.co.uk/GoldenMotor/Pie16FOffset.JPG) (http://www.arhservices.co.uk/GoldenMotor/Pie16ROffset.JPG)
Front Wheel Rear Wheel
Alan
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Sorry, I was shooting from the hip, I knew that the
wheel didn't come with the freewheel, but that the axle
was a different length to accommodate it and that the cover
was different (threaded).
I was trying to indicate that there were not any
internal differences.
I will be more careful, since I am being watched.
:)
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The front wheel Magic Pie motor is physically
similar to the rear one.
The difference is that the rear Magic Pie comes
with a freewheel gear cluster.
The difference in the bike requirements is major
however.
If you are using a front wheel pie, then you must
have steel forks on the bike. I tried with an aluminum
fork and my wheel ripped the drop-outs right out
of the fork.
I have replaced the fork with a chrome-moly fork
and added a torque arm to the shaft and am very
happy with it.
The front wheel does feel more balanced to me
since the batteries on the rack weight about the
same as the motor on the front.
The rear wheel is a little more difficult to get set
up properly, but the rear drop-outs for the axle
are a little more forgiving of the material.
This is just my opinion.
When your front hub tore out of your drop out, where you using a torque arm at the time? I am looking to install this same set up using my aluminum front suspension forks, but with torque arm, so just wondering if this would be OK?
Also, anyone out there having tried both the 36V 500W motor and the 36V 250W mini geared motor? I would like a real life comparison between the both in terms of how they climb up hills? Such as, how much more/less effort is required to pedal up hills etc.........
I currently am using 36V 500W rear hub (direct drive/gearless), but as mentioned in earlier topic, with battery pack on rear rack, front end is becomes way too light when trail climbing..........options would be too custom mount battery pack inside triangular frame to lower centre of gravity and/or goto a front hub motor for better balance........I know that there is a trade off either way, but if someone can get me some sort of input between the 2 motors would be much appreciated! Thanks, David
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It was not a very long torque plate,
but the problem is that most aluminum
forks don't have flat drop-outs, but instead use
shaped dropouts for quick-release.
I did not even ride it, I just goosed the motor
with the wheel off the ground and ripped out
the drop-outs.
It cost me a bit, but I replaced the fork
with a suspension steel fork. ($300USD on
a $200USD Bike.)
I am very happy with it tho.
The whole shebang doesn't sit flat then.
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.
The front wheel does feel more balanced to me
since the batteries on the rack weight about the
same as the motor on the front.
I like the rear motor better. I guess its just a silly preference thing. But I was wondering whether or not that the battery in the back with the front wheel makes the balance so much better that considering the front hub over the rear is the better choice.
Some of my rides are very loaded at times and I would always get concerned about dragging lots of weight using the forks. I am willing to get a full suspension steel bike that I can put a pack in the triangle but these frames vary so much and getting something in the frame triangle could be a waste of time.
Anything you could point me towards would help.
(http://shop.kmart.com.au/wcsstore/KmartOnlineRetail/images/catalog/41201749-z.jpg)
I was looking at this job at Kmart. The frame is a little on the light side but I am sure it is steel. It has both front and rear disc brakes so going for a 20" cast rear wheel is an exciting option.
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Hi Leslie
I'm sure you already realize, but a simple test to see if the frame is steel is to take a magnet with you on your nest visit to Kmart. ( They have Kmart is Australia too?)
Gary
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Hi Leslie
I'm sure you already realize, but a simple test to see if the frame is steel is to take a magnet with you on your nest visit to Kmart. ( They have Kmart is Australia too?)
Gary
Yes we have Kmart in OZ.
We get these Currie tech E-bikes sometimes for as little as $130. Includes batts charger and motor. A whole E-bike.
No I didnt know to take a magnet with me, :'( but I did know about Iron (steel) being magnetic and aluminum not. .
I used to tap them with something. Aluminum sounds different. But the magnet Idea is grouse and more reliable. Thanks for the suggestion.
:D
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Here is a side view of the green machine I am contemplating building, Its hard to see the rear disc brakes in both pics.
(http://goldenmotor.com/SMF/index.php?action=dlattach;topic=335.0;attach=2794;image)
I was thinking I could squeeze a GM pack into the triangle on the bottom bar under the rear shock there. Not much room in there though.
Any thoughts Gary?
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My winter bike has a 24v 250w mini motor at the front. The 250w motor is an EU-limitation and this is the last time I’ll follow this regulation, its ability to climb the hills are way too low. Front wheel drive is a must because I drive in deep snow occasionally and by pedalling I then have an AWD (which sounds better than 2WD). The front wheel motor has helped me a lot and the low weight is a great benefit too. Unfortunately the lead batteries didn’t worked to well when the temperature dropped to -25°C and they was quite heavy too. For the winter to come I’ve bought a frog style battery pack from GM which should be better to handle cold weather and is a bit lighter.
The negative thing with the front wheel drive is that it can spin when there’s gravel on the road or it’s icy, and a more powerful motor probably increase this problem. If this happens when you’re in a turn you will very likely hit the ground, I have done this a few times and it really hurts. So for my summer bike project there will be a Magic Pie rear wheel and the battery pack will be located somewhere in the triangle.
Peter
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My winter bike has a 24v 250w mini motor at the front. The 250w motor is an EU-limitation and this is the last time I’ll follow this regulation, its ability to climb the hills are way too low. Front wheel drive is a must because I drive in deep snow occasionally and by pedalling I then have an AWD (which sounds better than 2WD). The front wheel motor has helped me a lot and the low weight is a great benefit too. Unfortunately the lead batteries didn’t worked to well when the temperature dropped to -25°C and they was quite heavy too. For the winter to come I’ve bought a frog style battery pack from GM which should be better to handle cold weather and is a bit lighter.
The negative thing with the front wheel drive is that it can spin when there’s gravel on the road or it’s icy, and a more powerful motor probably increase this problem. If this happens when you’re in a turn you will very likely hit the ground, I have done this a few times and it really hurts. So for my summer bike project there will be a Magic Pie rear wheel and the battery pack will be located somewhere in the triangle.
Peter
You can keep the SLA's warmer on the float charge. Charging SLA's in very low temperature you can go higher with the volts. Almost to 16v.
If you can manage to get 16v on each SLA. Recharge to 15v each SLA and keep on float charge, and before you ride top them up to 16v, this will warm them up.
SLA's should be ok with the minimotor. If you can program the controller to do 10 amps continuous and 12 amps max the SLA's may work better, I found 250 watt motors are really cool with a 20" or a 24" wheel, 20" rocks. I own a 20" brushed bike and motor. It goes about 30 kph and has no problems towing stuff around. . 26" wheel at 250 watts may have some problems when you need some guts.
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Ok, maybe a little bit off topic but I just gave the new battery a chance on the road. Despite I have the studded tyre on, it felt real well. I live in a very hilly area and there is almost no flat terrain at all. There’s a street beside my house the motor didn’t managed to climb by its own with the lead batteries, now it was no problem at all. I’m happy right now; let’s see how happy I am when the temperature drops to -25°C.
The old batteries were 2 lead-gel 12 V, 8 Ah, 7,4 kg.
The new a GM frog style 24 V, 10 Ah, 2,7 kg.
That’s 4,7 kg lighter battery pack with more power and better look.
It has something to do with the topic after all. Now I have to be more careful with the throttle when it’s icy.
Peter
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Ok, maybe a little bit off topic but I just gave the new battery a chance on the road. Despite I have the studded tyre on, it felt real well. I live in a very hilly area and there is almost no flat terrain at all. There’s a street beside my house the motor didn’t managed to climb by its own with the lead batteries, now it was no problem at all. I’m happy right now; let’s see how happy I am when the temperature drops to -25°C.
The old batteries were 2 lead-gel 12 V, 8 Ah, 7,4 kg.
The new a GM frog style 24 V, 10 Ah, 2,7 kg.
That’s 4,7 kg lighter battery pack with more power and better look.
It has something to do with the topic after all. Now I have to be more careful with the throttle when it’s icy.
Peter
Maybe keep that battery on the charger on cold nights and not let it stay discharged over night. A while ago I was reading that charged batteries resists the cold better than a discharged battery. And a battery on standby is better again.
Maybe worth taking it off the bike and bring it inside on real cold nights too.
The froggies look sweet.
Well done and god speed with the new pack,
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All my bicycles stays inside my warm and cosy garage all the time they're home.
I've now measured the batteries with and without load, both cold and warm. The lead batteries are a joke when they’re cold. I never understood why the motor stopped working just after a few km but now it’s clear that it was the LVP. Now I don’t understand why the LVP didn’t cut-off earlier because the voltage dropped significant under load when they were cold.
Oh, and the topic: Front wheel drive is best in snowy weather which makes the bicycle an AWD but this only apply to weak motors. The stronger motors should only be for rear wheel for safety reason but the rear wheel is more complicated to convert.
Peter
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All my bicycles stays inside my warm and cosy garage all the time they're home.
I've now measured the batteries with and without load, both cold and warm. The lead batteries are a joke when they’re cold. I never understood why the motor stopped working just after a few km but now it’s clear that it was the LVP. Now I don’t understand why the LVP didn’t cut-off earlier because the voltage dropped significant under load when they were cold.
Oh, and the topic: Front wheel drive is best in snowy weather which makes the bicycle an AWD but this only apply to weak motors. The stronger motors should only be for rear wheel for safety reason but the rear wheel is more complicated to convert.
Peter
Maybe controller isnt designed to switch off at the speed SLA's slump especially when failing. They must of been up and down like a yo yo.
I am using some cheap SLA's I got from Jay car om my 250 watts brushed bike atm.
My SLa have had problems. Like I used a 24ah batt with the two 12ah slas and it discharged the 12ah batts a few times to far and I forgot to hook up the charger. They were like trashed. I seemed to loose a set amount of range and she would slow. One SLA was really bad.
I got another 12ah SLA so now I have three 12ah in series. I lost no added range moving the three SLA's.
To get my range back I fully charged each cell then I left the string stay on a 1.2 amp 46v charge for about 2 hrs yesterday and the capacity has jumped through the roof. I don't have cold weather problems like that though.
But I did a 15 km trip and brang back a big trailer of shop home after the 46v solar 2hr bulk charge. Then charged it again the same and I did a 25km trip with no pedals and my bike survived a good hill climb without the pedals again. If Ive fixed the batteries, I will use them now and not push the long bulk voltage charges. Try balance them without the shunts. These on my 250 watt bike could last me a few more months.
There is no reason you cant salvage your old SLA's and shelve them or make useful purpose from them. Get a bigger 12v charger and leave them on for three days and discharge by 10% and do again.
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There is no reason you cant salvage your old SLA's and shelve them or make useful purpose from them. Get a bigger 12v charger and leave them on for three days and discharge by 10% and do again.
There’s nothing wrong with my lead batteries. Lead batteries that can give enough current, especially in cold weather, are too heavy for a bicycle. I’ll hereon stick to LiFePo4 batteries because I couldn’t find any difference in my new frog style battery even if I had it in the freezer. But we have summer with 25-30°C so the charging can’t be tested in real life situation.
The lead batteries will be serving as start batteries in old style vehicles for the rest of their life.
Peter