80 MPH mobility scooter: Sold

Document and share your build!

80 MPH mobility scooter: Hydraulic brakes, speedo - 8/6/15

Postby the german » Thu Aug 06, 2015 10:43 pm

Well, I finally gave up on the cable disc brakes. with different length cables the stretch was unequal from one side to the other and they were impossible to balance, which meant that every time I grabbed them I would swerve to the right. Not super confidence inspiring...

As an added bonus, when I took it out on Halloween one of the calipers froze up and locked the front left wheel while I was evading some.. uh..concerned parents, leading to an eventual blowout.

I finally concluded that hydraulic was the only real way to get balanced braking. Conveniently the pressure ratio between the MC and calipers actually work out in my favor with hydraulic unlike the motion ratio with the cable brakes which does the opposite. As a bonus, they have also now been around for long enough now that you can get old used ones on eBay for cheap. The bad news is that bike brakes have only one caliper per brake lever.

A "T" in the line is an obvious solution, but proved hard to find and more expensive than I wanted to spend on this. Instead, I found a rather elegant idea on a Trike forum (because of course there is a forum for that..): Remove the bleed screw from one caliper and connect the hose for the second caliper to it, placing both in series on the same circuit and effectively using one of the caliper as your "T". Brilliant.

I picked up a set of used Hayes HFX9 brake calipers + levers for $35 shipped on eBay. Of course the fitting that connect to brake lever is completely different from the one that connect to the caliper, so that needed some adaptation. Knowing pretty much nothing about bike brakes, I took them down to the local bike shop (Gregg's Bellevue Cycle) to see what kind of fittings they had. After I explained what I was trying to do and after they stopped laughing at me, a guy named Don took me back to see what kind of fittings they had that we could make work.

Here is what I ended up with.. for Free!

Image

Image

Cut the old lever connection off of one caliper, attached the new fitting, and screwed it into the bleed port on the other caliper:

Image

Ran the lines, installed the lever, and tied everything up so it won't chafe while in use:

Image

Image


Bleeding bike brakes requires a very large syringe full of brake fluid on the caliper side, and a tube going to a catch can on the lever (master cylinder) side. They sell kits for like $25-$30 online. I'm too cheap for that so I went to my cat's Veterinarian instead and they hooked me up.. for free! Add $0.10 cents of vinyl tubing, an empty beer can, and you're in business. Behold my classy brake bleeding setup: :lol:

Image

I used the large syringe to bleed the system, then used the small one to pre-load they circuit and take the excess lash out from between the pads and the rotors. This is important with this setup because my master cylinder is still the same size but I now have two calipers worth of lash to take up before the pads contact. Without doing pre-load on the system the pads barely make contact before the master runs out of travel.

I downloaded a speedometer app for my phone, taped it to the dash of the scooter, and took it for a spin around my neighborhood tonight. The new brakes are FUCKING AWESOME!! Perfectly balance, powerful, and immediate. Exactly what this thing needed to make it less sketchy. Cruising the neighborhood I got it up to 31 MPH. Need to take it to a back road and see how fast I can comfortably go now. :D

Oh, and get some more videos!!! 8-) :drive:
Last edited by the german on Thu Aug 06, 2015 10:56 pm, edited 2 times in total.
Kirk

1990 ABZ CQ
1990 lifted CQ
2005 S4 6MT
2011 A4 2.0T Avant (ok, it's my wife's car but it's sexy and I love it)
the german
 
Posts: 604
Joined: Feb 15, 2014
Location: Bellevue, WA

Re: 80 MPH mobility scooter: The Mask! 3/21/15 update

Postby the german » Thu Aug 06, 2015 10:55 pm

i just realized: this might be the worlds first mobility scooter with a BBK and braided stainless brake lines ;)
Kirk

1990 ABZ CQ
1990 lifted CQ
2005 S4 6MT
2011 A4 2.0T Avant (ok, it's my wife's car but it's sexy and I love it)
the german
 
Posts: 604
Joined: Feb 15, 2014
Location: Bellevue, WA

Re: 80 MPH mobility scooter: Hydraulic brakes, speedo - 8/6/

Postby loxxrider » Fri Aug 07, 2015 7:27 am

Nice work! I love the resourcefulness :D
-Chris

'91 Audi 200 20v - Revver/BAT project
'91 Audi 200 20v Avant
'01 Anthracite M5
'90 M3
'85 Euro 635csi
'12 X3
E34 530i (maybe rear-mount soon)
User avatar
loxxrider
 
Posts: 6640
Joined: Feb 27, 2013
Location: Jupiter, FL / Somewhere, PA

Re: 80 MPH mobility scooter: Hydraulic brakes, speedo - 8/6/

Postby scubagli » Fri Aug 07, 2015 6:55 pm

We need more video!

Sent from my SAMSUNG-SM-G870A using Tapatalk
User avatar
scubagli
 
Posts: 604
Joined: Feb 5, 2014
Location: leeds ny

Re: 80 MPH mobility scooter: Hydraulic brakes, speedo - 8/6/

Postby the german » Sat Aug 08, 2015 12:00 am

you're right! I went out and got more tonight - more to follow
Kirk

1990 ABZ CQ
1990 lifted CQ
2005 S4 6MT
2011 A4 2.0T Avant (ok, it's my wife's car but it's sexy and I love it)
the german
 
Posts: 604
Joined: Feb 15, 2014
Location: Bellevue, WA

Re: 80 MPH mobility scooter: MORE VIDEOS - 8/8/2015

Postby the german » Sat Aug 08, 2015 2:13 pm

Got out for some more fun last night! Unfortunately it was cut short by two things:

1. Smacked the exhaust pipe on a curb and broke a mounting tab off of the frame
2. Lost the chain at about 45 MPH on a test run, before I went for a real high-speed attempt. I looked and looked but could not find it so I need to get another repair link and make up a new one.

Kirk

1990 ABZ CQ
1990 lifted CQ
2005 S4 6MT
2011 A4 2.0T Avant (ok, it's my wife's car but it's sexy and I love it)
the german
 
Posts: 604
Joined: Feb 15, 2014
Location: Bellevue, WA

Re: Re: 80 MPH mobility scooter: FOR SALE

Postby the german » Sat Jul 02, 2016 12:48 am

Ok, the time has come to sell the scooter and make room for more rediculous projects. Here is a link to the CL ad:

http://seattle.craigslist.org/est/mcy/5661862750.html
Kirk

1990 ABZ CQ
1990 lifted CQ
2005 S4 6MT
2011 A4 2.0T Avant (ok, it's my wife's car but it's sexy and I love it)
the german
 
Posts: 604
Joined: Feb 15, 2014
Location: Bellevue, WA

Re: 80 MPH mobility scooter: FOR SALE

Postby heartlessnomad12 » Sun Jul 03, 2016 8:27 pm

How have i missed this thread and WTF is wrong with you?!?! that thing has to be terrifying to rip around on LOL
heartlessnomad12
 
Posts: 15
Joined: Aug 20, 2013

Re: 80 MPH mobility scooter: FOR SALE

Postby alxdgr8 » Mon Jul 04, 2016 1:38 am

Have you gotten any replies to your ad? I bet some of the questions must be entertaining.
-Alex- @vexartmedia on Instagram
1992 Porsche 968 (07K transplant in progress)
1983 Aud UrQ (20vt swap in progress)
1995 Audi 90QS (Previously 32v V8, now AEB 1.8T)
1986 Audi Coupe GT (7A swap and more)
2010 VW Touareg TDI (DD, tow rig)
2001 Ducati ST4
User avatar
alxdgr8
 
Posts: 887
Joined: Feb 28, 2013
Location: Federal Way, WA

Re: Re: 80 MPH mobility scooter: FOR SALE

Postby the german » Tue Jul 05, 2016 12:45 am

Lol! Adam- yes, it is. Megan asks the same question about me several times a day.

Alex- it has gotten some great responses. My favorite so far is:

"this is the absolute DUMBEST, most AMAZING thing I have ever seen."
Kirk

1990 ABZ CQ
1990 lifted CQ
2005 S4 6MT
2011 A4 2.0T Avant (ok, it's my wife's car but it's sexy and I love it)
the german
 
Posts: 604
Joined: Feb 15, 2014
Location: Bellevue, WA

Re: 80 MPH mobility scooter: Sold

Postby the german » Tue Apr 11, 2017 2:51 pm

To close the chapter on this- the scooter was sold to a new owner in Oregon during July 2016. A liability waiver was signed as a condition of the sale :lol:
Kirk

1990 ABZ CQ
1990 lifted CQ
2005 S4 6MT
2011 A4 2.0T Avant (ok, it's my wife's car but it's sexy and I love it)
the german
 
Posts: 604
Joined: Feb 15, 2014
Location: Bellevue, WA

Re: 80 MPH mobility scooter: Sold

Postby the german » Tue Dec 19, 2017 12:40 am

I was going through some old pictures and found this. For those who never say the ad for this thing, here it is:

Image
Kirk

1990 ABZ CQ
1990 lifted CQ
2005 S4 6MT
2011 A4 2.0T Avant (ok, it's my wife's car but it's sexy and I love it)
the german
 
Posts: 604
Joined: Feb 15, 2014
Location: Bellevue, WA

Previous

Return to Projects

Who is online

Users browsing this forum: No registered users and 4 guests

cron