Quad Pedal Car - 2025 late Xmas/early Birthday present ?
- Thread starter stormbird
- Start date
Should you shorten the tank levers to lower your arms, will the steering force and sensitivity increase then and steering become twitchy ?
As for the devious twisted chain i only have a tube on the untensionned return of the tadpole. Crude, suboptimal and effective as soviet mechanics.
As for the devious twisted chain i only have a tube on the untensionned return of the tadpole. Crude, suboptimal and effective as soviet mechanics.
So today's work
Again in no particular order:-
1) steering levers to tall [ as can be seen in this picture ]
Old and new lever , rescued from racing Python.......................So new lever will look like this and if it works I can cut off the unwanted vertical portion and tidy up the remaining parts - no idea if it is in right place as car currently on work table and I am unable to sit in it. Need to do other
side before I try it as well
2) to far forwards for my arms - see above
3) not angled forward enough- see above
4) clicking right hand rear wheel [ grub screw problem identified earlier ]
Changed both troublesome grub screws for shorter ones = result now quite
5) left brake binding
Spent some time on this and I either :-
Need a greater selection of shims or I have a sticking piston ?
At this point I came in it is now very cold outside and tomorrows ride on the Python will be in or around -1c [ deep joy ]
6) pedaling getting harder and harder [ only did about 1/2 kilometer ] - found power side idler had lost 1 bearing and other one halfway out.
Now this may or may not be a fix ?
The original I built allowed the pulleys to float over the un-threaded portion of their axle , so stuff that idea !
So now fully threaded axle with a washer-pulley-washer-pulley-washer + locknut , there is now only enough room for the washers to spin freely.
I have done the same ride as yesterday and arrived on the drive with it still working and NO errant bearings = result
Will it hold up to 68+miles in a race ? who knows, of course if I get to do 100+miles at home before hand I will have abetter idea.
Looking at the pulleys it is easy to see which one is the power side.
regards Paul
Again in no particular order:-
1) steering levers to tall [ as can be seen in this picture ]
Old and new lever , rescued from racing Python.......................So new lever will look like this and if it works I can cut off the unwanted vertical portion and tidy up the remaining parts - no idea if it is in right place as car currently on work table and I am unable to sit in it. Need to do other
side before I try it as well
2) to far forwards for my arms - see above
3) not angled forward enough- see above
4) clicking right hand rear wheel [ grub screw problem identified earlier ]
Changed both troublesome grub screws for shorter ones = result now quite
5) left brake binding
Spent some time on this and I either :-
Need a greater selection of shims or I have a sticking piston ?
At this point I came in it is now very cold outside and tomorrows ride on the Python will be in or around -1c [ deep joy ]
6) pedaling getting harder and harder [ only did about 1/2 kilometer ] - found power side idler had lost 1 bearing and other one halfway out.
Now this may or may not be a fix ?
The original I built allowed the pulleys to float over the un-threaded portion of their axle , so stuff that idea !
So now fully threaded axle with a washer-pulley-washer-pulley-washer + locknut , there is now only enough room for the washers to spin freely.
I have done the same ride as yesterday and arrived on the drive with it still working and NO errant bearings = result
Will it hold up to 68+miles in a race ? who knows, of course if I get to do 100+miles at home before hand I will have abetter idea.
Looking at the pulleys it is easy to see which one is the power side.
regards Paul
Absolutely no idea , I will let you know
tried that in post #130 it was very noisy as the chain really wants a pulley to keep it in place.
Paul
Original zigzag lever indeed
You are very methodical in fixing the bug list
Good luck
You are very methodical in fixing the bug list
Good luck
Yes it is confusing as I can't cut the old off till I am sure the new will work and I can't do that till I can drive it and I can't do that till I can sit on it and I can't do that till ...........So, the old lever was the vertical part, and the new lever is the part with the bar end shifter, out on the horizontal arm?
I'm sure, obvious to you, but I'm trying to understand
A pattern is developing here
Paul
Currently can't get the left hand disc brake to work properly it is catching and stops the wheel very quickly when it is spinning free.
Struggling with trying to shim it to get the gaps even on the pads I watched a video about ' un-sticking ' a stuck piston it showed the caliper mount is slotted so you loosen off the fixing bolts apply the brake and tighten them up and viola all set up and dandy .....
Err no it does not seem to work like that , also this is the caliper that is upside down so I cannot get good access to those fixing bolts nor easily see what clearance I have , oh and also I have almost zero experience with disc brakes ...
This is holding things up so it will have to be left for more pondering while I build some seat mounts.
Paul
Struggling with trying to shim it to get the gaps even on the pads I watched a video about ' un-sticking ' a stuck piston it showed the caliper mount is slotted so you loosen off the fixing bolts apply the brake and tighten them up and viola all set up and dandy .....
Err no it does not seem to work like that , also this is the caliper that is upside down so I cannot get good access to those fixing bolts nor easily see what clearance I have , oh and also I have almost zero experience with disc brakes ...
This is holding things up so it will have to be left for more pondering while I build some seat mounts.
Paul
This car was stood for over 2 years , it has taken it's visible toll on the chassis and body work , would not be surprised if the brake calipers suffered as well.
Well I agree with you up to the point where you say ' They're cheap enough ' these are Magura hydraulics , not my first choice for a race car ?
Almost impossible to repair track side if anything goes wrong with the plumbing.
I do have some brand new cable Avid BB7's , what do you think the chances are they will fit the existing brackets ?
I think I am trying to adjust them wrongly and/or have a sticking piston [ or 2 ] least 1 works properly. I could remove the sticking one and cable tie a rotor between the pads just to get it on the road ?
Paul
Oh, that makes a big difference - I was thinking cable brakes.
I "believe" disc calipers of recent vintage use a standard "ISO" mount, but I am assuming here - And you know where that can get you
So 2 days of work and the first failure at making some seat mounts for my seat - so NO pictures !
needs a rethink and maybe some input or research.
So I spent 20 minutes on the duff brake caliper.
No way it can be replaced on it's mount with a BB7 , compared to the Magura they are massive and the duff one is mounted upside down much to close to the side frame , of course the no-duff one is sat completely in fresh air and could be replaced by a BB7 if I fancied [ thank you Sod ! ]
So I undid it from the frame and peering into it I discovered both pads were nice and loose however the outer piston was frozen solid , so I pushed it in with a small screw driver and then squeezed the lever , did this a few times till it appeared to be working then refitted it.
Did the centralising and then fastened on the wheel and gave it a spin , now it is the first to stop , however no where near as quick as before and trying this a few times it did appear to get better [ or is that wish full thinking ?
Paul
needs a rethink and maybe some input or research.
So I spent 20 minutes on the duff brake caliper.
No way it can be replaced on it's mount with a BB7 , compared to the Magura they are massive and the duff one is mounted upside down much to close to the side frame , of course the no-duff one is sat completely in fresh air and could be replaced by a BB7 if I fancied [ thank you Sod ! ]
So I undid it from the frame and peering into it I discovered both pads were nice and loose however the outer piston was frozen solid , so I pushed it in with a small screw driver and then squeezed the lever , did this a few times till it appeared to be working then refitted it.
Did the centralising and then fastened on the wheel and gave it a spin , now it is the first to stop , however no where near as quick as before and trying this a few times it did appear to get better [ or is that wish full thinking ?
Paul
I do think they are OK apart from the sticking piston , the lever is not spongy in any way and the car certainly seems to stop OK at the low speeds I have achieved so far
Paul
Popshot
0
If it doesn't free off successfully it may need a rebuild. Magura are famous for not selling rebuild seal kits. They'd rather you send them the caliper and pay a large sum. It'd likely be cheaper to buy a cheap Chinese replacement. Hydraulics generally provide much more braking force than cables. If you need to brake a lot in a race that could add up. If you rarely brake then swap to cables if it doesn't free off enough.
I wanted to swap , however that would mean at least 1 new brake mount....
Just no time at present.
When I have done 100 mile and there is no improvement , it may then be at the top of what I hope is a short list
Paul
So front seat mount , no hiding the fact the seat mounting holes are not in the right place for the cross member , also they are a long way around the front slope oh and point forwards at some craze angle.
So 2 new mounts and a rusty piece of square tubing underneath the seat front positioned for the visible seat bolts to use.
Brackets cut from some big section square tubing 3mm wall , however the large sections have a very generous radius on the corners causing some problems for TIG man ! [ this weld is much more in MIG territory ]
Still I can make a blobby neat[ish] weld , just it won't be in the very root of the corner [ not skilled enough ]
Seat can't get any lower [ honest ] as it is chain runs up to rear cassette large sprocket in the channel caused by the rear seat ribs ...
We are living on the edge....
Still got to weld front part seat bolted to in , then on to a better rear seat mount.
As this one turned out to be pants , under to much tension , to close to cassette and used the existing seat mounting bolts that are far to low down.
Paul
Brackets cut from some big section square tubing 3mm wall , however the large sections have a very generous radius on the corners causing some problems for TIG man ! [ this weld is much more in MIG territory ]
Still I can make a blobby neat[ish] weld , just it won't be in the very root of the corner [ not skilled enough ]
We are living on the edge....
Still got to weld front part seat bolted to in , then on to a better rear seat mount.
As this one turned out to be pants , under to much tension , to close to cassette and used the existing seat mounting bolts that are far to low down.
Paul
DannyC
0
Need a better angled shot really but can you not take support struts off the rear/top face of that rearmost chassis-rail straight up to that angle-iron you have across the back of the seat? The angle of the ones seen in the picture will give no real vertical support I feel. The angle from rail to seat angle-iron needs to be a lot steeper I think. Clearly, you don't want a floppy parallelogram formed but you don't need to cross them over to prevent that, just put additional triangulation up from that crossrail to the strut itself. The triangle formed prevents the pantograph/parallelogram from collapsing HTH.So front seat mount , no hiding the fact the seat mounting holes are not in the right place for the cross member , also they are a long way around the front slope oh and point forwards at some craze angle.
So 2 new mounts and a rusty piece of square tubing underneath the seat front positioned for the visible seat bolts to use.
Brackets cut from some big section square tubing 3mm wall , however the large sections have a very generous radius on the corners causing some problems for TIG man ! [ this weld is much more in MIG territory ]
Still I can make a blobby neat[ish] weld , just it won't be in the very root of the corner [ not skilled enough ]
Seat can't get any lower [ honest ] as it is chain runs up to rear cassette large sprocket in the channel caused by the rear seat ribs ...
We are living on the edge....
Still got to weld front part seat bolted to in , then on to a better rear seat mount.
As this one turned out to be pants , under to much tension , to close to cassette and used the existing seat mounting bolts that are far to low down.
Paul
Last edited:
I don't like the position of the angle iron IMHO it is much to low on the seat back , it needs to be up where the M8's can be seen protruding from the plank of wood.Need a better angled shot really but can you not take support struts off the rear/top face of that rearmost chassis-rail straight up to that angle-iron you have across the back of the seat? The angle of the ones seen in the picture will give no real vertical support I feel. The angle from rail to seat angle-iron needs to be a lot steeper I think. Clearly, you don't want a floppy parallelogram formed but you don't need to cross them over to prevent that, just put additional triangulation up from that crossrail to the strut itself. The triangle formed prevents the pantograph/parallelogram from collapsing HTH.
However there are no mounting holes there just a hole in the seat for a hand to grip it , so what I am going to investigate is filling the hand hole with wood and tying it to the existing seat mounts and as you say coming straight down from those higher M8's to the rear cross member then adding some cross braces ?
Paul
