New build - Old bike - GT LTS

[wurly]

I thought i might start a thread for my latest project. (I think i am going to need plenty of advice for this one anyhow).
I have been looking for a suitable full suspension bike as a candidate for the next project. Requirements were, cheap, good condition, steel frame and local to me for collection. There were many aluminium framed bike to choose from and i quite liked the look of a D/H style of bike, but quickly decided that a 50+year old on one of these looks plainly daft....
So setting my sights much lower i ended up with this.
A 1998(ish) full suspension GT-LTS one owner never raced and little use for a princely sum of £114 (and it was only 30mile to collect it).

The 19" frame is just about the right size for me and there is a nice big triangle to fit all the batteries and electrical gubbings.

After a long wait my BPM code 10 hub arrived just after christmas. It was held up in customs and i had to pay a fee to before parcel force would deliver it. Once paid, it arrived next day.

I had bought a new 36 hole MTB rim in readiness some while ago, so it was straight onto the pc and get some spokes ordered.
While waiting for the spokes i decided to fit the hub to the bike and see how it fits.
The drop outs on the rear frame were very shallow in depth, so i had to file them deeper for safety.

The flats on the spindle are now firmly located within the slot. I could have filed it deeper but i already planned to have torque straps

 

[wurly]

The supplied torque washers were a nice fit and substantially stronger than the flat pressed steel washer normally supplied with the smaller 250W bafangs. Being 4 mm thick as well, I can make good use of these.

I wasn't looking forward to filing out a perfect slot in my torque arms. This seemed like the easiest and strongest option. Drill a 23mm hole in some flat steel and weld the torque washer in the correct position.

I wasn't sure if chinese metal was going to weld ok but i need not have worried.

 

[wurly]

Job complete.

 

[banbury frank]

Hi if you where supplied with washers with tags on and the double D hole

Fit them on the outside off frame then get a piece off 3 mm flat bar and drill a hole to pick up the threaded hole meant for mudguards them weld the flat bar to the washer or you could just file the double D in one end off the 3mm flat bar and hole in the other end I would use 4/5 mm flat

Be careful to file the slot in the bike with slack in it as there will be slack in the double D washer provided

if you make the drop out in the bike to tight it may snap the end off

Great bike

Great Kit

Hi Mel Beat me to it

Frank

 

[wurly]

Sorry for the duplicate post (not sure how i did that) :0)

Hi Frank, not sure which bit you mean might snap, the spindle is a snug fit not a tight fit. The slot in the washers closed up a but after welding and needed some work with a flat needle file, but i am pleased with how it turned out.

 

[wurly]

Do you mean i ought to have some support to the torque arms going forward from the rear drop outs?

 

[banbury frank]

Hi Mel The slots in the forks need to be slack as you always get a bit off slack in the drop out slots and the forks are a cast alloy very brittle so any strain can make them snap off

Frank

 

[wurly]

One thing is bothering me though. The spoke holes on the BPM measured 3.1mm and i'm going to fit 2 mm spokes.....mmmmm. How is that going to work out? the holes seem too big to me. There is a deep countersink to them also.

Like clockwork, the spokes turned up yesterday, so i immediately set to work. I think i have laced about 6 or 7 wheels so far since i began biulding ebikes. Each one gets easier and quicker. But i may have messed up with this one.

Here is the complete wheel nice and true (note:i added 2mm countersunk washers to the spokes at the hub end).
I have pretensioned the spoke as you are supposed to do and re-trued the wheel, but i am a bit unhappy with the angle of the spokes at the nipple. There is a fairly sharp pull. I thought about this and decided to bend a slight angle near the nipple end but further up the spoke away from the thread. I figured this would be preferable to the spoke trying bend on the top of the thread (weakest part).

I now know.....i should have used a 1x cross pattern rather than 2X. Live and learn. If it causes problems i'll simply relace it with shorter spokes .

I discovered the supplier cut the thread instead of rolling it. I retensioned the spokes once again and it seems fine. Time will tell and i will be checking no fear!!!

In answer to you above Frank the rear suspension frame is also steel. Had it been alumunium i would design the torque straps differently with a forward fixing position. Thanks for your input :0)

 

[Deleted member 4366]

The torque washers are designed to go on the inside face of the drop-outs, so you'll need additional spacers if you can't get your torque arms on the inside. If it were my build, I'd file the drp-outs a bit deeper to accommodate the tab and spread the force between the tab and the screw.

That's a nice bike as a donor. Are you sure the sub-frame is steel? Wouldn,t that make it heavy? It looks like light alloy in the photos!

Keep us posted with progress. I look forard to seeing it finished.

 

[wurly]

Hi D8veh
No it's definately steel. I think some later LTS's were all aluminium, but i got the ford fiesta version, which is exactly what i was after.

A couple more photos to keep up to date.
Here is the bike with the new wheel fitted. My intentions are to run the motor with my current set up. That is 2 36V ping 5Ah batteries connected via schottky diodes and a bog standard 6 fet controller. My decision over what voltage/batteries etc will be choosen shortly, but whatever i go for, i will be looking for batteries that can provide at least 20amp for sustained periods. Save that for another discussion.

Next thing on the agenda. What freewheel do i choose?

The shifters on the bike are 7 speed and I would like an 11 tooth sprocket if possible. My searches so far have not produced anything. Most screw on freewheels seems to have a minimum sprocket size of 14. Is that right?

D8veh.....the torque arms are going to be fitted outside the rear frame. I'm probably going to be fitting rear discs, i presumed the torque arms would be using what little room there was between the hub and disc brake. The bike has Rockshox forks up front so the brackets are all there ready for discs.

 

[Deleted member 4366]

I beleive that this freewheel might work, but check with them directly before ordering to confirm.
http://www.ebikes.ca/store/photos/FW7Spd1132.jpg
I'm not sure what you meant about the torque arm position in your last post. Here's a diagram of how it was designed. Click on the drawing. Note that the two spoke flanges are not equal from the centre-line so normally you have to dish the wheel a bit, but it depends on your disc and caliper spacings. Sorry about the small picture.
Bafang BPM 48V350W Rear Driving E-Bike Hub Motor - BMSBATTERY

 

[wurly]

I have that drawing and yes, it's so small i missed where the torque washers go.
I laced the wheel with no dish and it sits perfectly in the middle. That is because the rear frame has one side sticking out further than the other side. The hub is offset by 4.75mm according to the drawing, i double checked all measurements before ordering the spokes. Incidently, when adding dimensions into the spoke length calculator is came up with the same length either side....211mm.
On the freewheel, there has to be somewhere in the uk i can get one. Thinking aloud, the crankset will need changing anyway so maybe i can compromise on the gearing arrangment?
At 39V it rotates at approx 25mph no load according to my bike speedo.
It does have a rather metallic sound to it....'mi guessing that is the feewheel in the hub. if i didn't know any better i'd swear it had steel gears.

 

[banbury frank]

Hi you will find 11 tooth in the US

the link below is for sunrace sturmey archer 13/28

SUNRACE SCREW-ON BIKE / MTB FREEWHEEL / COG / SPROCKET | eBay

Frank

 

[wurly]

Ok i think i need to re-evaluate this (hence the reason behind starting the thread).
My crankset has a 42 teeth sprocket. It looks to me that it will be possible to change the sprockets (they look removable)? is it possible to get a 52 or 54 tooth crank sprocket to fit? forget the inner sprockets for a minute. Idealy i need the highest ratio i can find. 54/13=4.15, 54/14=4, 52/13=4, 52/14=3.71, where as my 42/14=3 is my option at the moment unless i can find an 11 toother 42/11=3.81

(PS i have welder and lathe so grafting one sprocket to another shouldn't be a too much of a problem)

 

[Deleted member 4366]

If you stick with 14T on the back, you'll need 52 or 53 teeth on the front. Best would be to get a used 52/42T or 53/39T chain-set of ebay. You'll find that you'll be in top gear most of the time. You definitely don't need a triple chain set. Check that you can move your derailleur up a bit to make room for the bigger chain-wheel.
CAMPAGNOLO CHORUS 170mm 52 x 42 LOW PROFILE CHAINSET GOOD CONDITION c.1997 | eBay

 

[Cyclezee]

Hi you will find 11 tooth in the US

and in the UK from Cyclezee I don't list them on our website as we normally on sell to customers who buy an eZee conversion kit.

 

[Deleted member 4366]

and in the UK from Cyclezee I don't list them on our website as we normally on sell to customers who buy an eZee conversion kit.

Don't keep us in suspense: How much are they? Also, do you do the Stand Alone Cycle Analyst or just the Ezee version?

 

[Cyclezee]

Hi again d8veh,

It depends on the number of sprockets e.g. 9 speed 11 to 32 Freewheels are £29.95, with a 15% reduction untill the end of January. As for Cycle Analysts, I only sell the large screen eZee version. The other types can be bought from here The Grin Cyclery

 

[paulhipwood]

Here is the complete wheel nice and true (note:i added 2mm countersunk washers to the spokes at the hub end).
I have pretensioned the spoke as you are supposed to do and re-trued the wheel, but i am a bit unhappy with the angle of the spokes at the nipple. There is a fairly sharp pull. I thought about this and decided to bend a slight angle near the nipple end but further up the spoke away from the thread. I figured this would be preferable to the spoke trying bend on the top of the thread (weakest part).

I now know.....i should have used a 1x cross pattern rather than 2X. Live and learn. If it causes problems i'll simply relace it with shorter spokes .

I discovered the supplier cut the thread instead of rolling it. I retensioned the spokes once again and it seems fine. Time will tell and i will be checking no fear!!!

In answer to you above Frank the rear suspension frame is also steel. Had it been alumunium i would design the torque straps differently with a forward fixing position. Thanks for your input :0)

Dear Wurley

I am very interested in the lacing pattern you used. I have a front wheel with a motor. I am not too happy with the rim supplied and want to fit a Sun Rhino and some double butted spokes
If you were going to build another wheel would you have a 1 or 2 cross pattern?
Where did you get your 2mm washers?

Have you got any photos of the finished bike.

bet regards
paul
How many miles has tour wheel done to date>

 

[jerrysimon]

I would use x1 on 26" + front wheels. I have been having a go at building a few radial front wheels (they look amazing) both motorized and normal. On my most recent motorised 20" front wheel I have now used radial. Up to now I have always been using x1 on my front 16" and 20" motorised wheel builds. However having built a few wheels, I am convinced that on smaller front wheels radial is fine, as long as you are not putting a very powerful hub motor on it. I recently came across a rear wheel with radial on the non drive side and x2 on the drive side.

On a hub motor with alloy flanges that has counter sunk holes both sides, are washers really required ?

I have used washers on a thinner flat steel flanged rear hub gear wheel build, but not sure if they would be required in this case. I am sure others will comment.

Regards

Jerry