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Well have finally got my act together and got the final brazing jobs done. I had Rich turn up some rings for the head tube, and I brazed some of the vent holes over that were there from the main pivot tube etc.
It looks pretty crisp and sharp in "refrigerator" white also courtesy of Rich and the boys at Skope, thank you again, it would have been a longer process without his help!
It rides very well and I am quite stoked and surprised, it does what I originally set out to achieve which is sweet, just have to take it to the beech forest for a true kiwi test!
Here it is, i'll get some better pics up soon but thought I would post these now as I have them.
Well the time came, my Trek fuel has cracked, and in the weekend I brazed on the guides and stops.Richie came round also and I ran the reamer down the St till the post fitted. So I was standing in the work shop as it ticked over in my head, then in a 2hr strip and build frenzy it was pretty much ready to ride!
The plan for the E type front derailleur didn't work, there was more sticking out the back of the derailleur (the parallelogram parts) than I worked out, so there wasn't enough room for it.
Damn! On to the single ring programme!Which made life pretty easy on the build up as I just bolted up my spare Balfa pulley wheel and put a Black spire tensioner under the BB cup.
Pressed my FSA pig pro that I bought especially for the job, when I thought that I brazed in the HT to high!Damn! So I needed something that had a reasonable amount of stack at the bottom. It also will support the HT being a Dh headset.
It all went together really well with no major alignment/interference isses.
Then I pushed it out the door, got on and rolled down the street. It passed the curb test and the out of the seat climb test, so all is good.
The next day I bought a 28.6mm QR collar for the post, and the next morning I rode it to and from work.
The ride is really good being a high pivot it rides real nice through the rocks here, and maintains alot of momentum through the rough.It climbed really well up Rapaki which is cool.
Only thing is it had the 190mm shock from my fuel in there and I built around the 200mm/2.25" shock so it was very low and slack! I mashed quite a few rocks with my cranks! But it railled round the turns. The rear suspension is very efficient it was "pushing" the bike forward as the fork was pushing backwards strange feeling?! I think theres a little to much air in the fork and I need to valve the shock properly.
So I'm stoked to ride it, I'll give it a few weeks make sure its all good (no more naked flames required!) and then get some color on it.Will keep you posted.Rossco.
We had a small holiday down in Wanaka last week, that gave me a change to catch up with Al and Rick and to use the lathe at Als place, so I made the tube that spaces the linkage plates apart. Turned it down to 12.40mm and then shaped the end at 45 degrees, faced it off to 100.50mm then drilled and tapped it to M8.This was number 2 as I screwed the first one up by tapping it M9 DOH!!was trying to get it done to quick!!Any ways here it is, don't get to excited!!
Its the little alloy part in the middle, pretty exciting!While I was down I also dropped in on Doug and used his HT facer and reamer to finish the HT up so I could put the PIG Pro in.
It also soaked in a bath for 36hrs to dissolve the residual flux inside the tubing before it does any permanent damage.
I have been busy the last little while, and have been quite excited so I haven't taken many photos, whoops!
So since the last post I have tacked and brazed the rear tri, cut the seat stays to length and brazed them to the drop outs, also fitted the tube between the linkage plate tubes.
Firstly I cut both the seat and chainstay ends on my tube cutter with the angle set to 5 degrees, this took a bit of setting up on the clamp with the dropouts already brazed in, I just "eyeballed" them and they seemed to turn out really well, I had to do alot of cleaning and shaping with the file though.I figured that because they bolt up to the linkage plates, and long as I got the LH and RH sides parallel with each other that I'd be golden, and they were.
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So for the set up on the chain stays I made up a dummy axle and put it in to the drop outs, checked all the angles were right on the drawing and that they were parallel, and just put the axle in the vice and brazed the tube on, easy.
It was a bit more of a fiddle to get the seat stays set up but once they were set up I just tacked them and then brazed away! I then slotted and finished them with the grinder the same as the first ones.
Had a lot more fun brazing the drop outs into the seat stays this time, amazing what some time and experiance does for your skills!
They cleaned up really well and look pretty sweet. I wasn't sure about them because they were cut for a hard tail mtb and as you can see my seat stays are on a pretty flat angle, but I worked out a nice way to have them attached and brazed them in then cut the tabs that were left sticking out the top off to finish them. It doesn't look to strange, and the finish on the disc side looks clean.
Then I proceeded to braze in the conecting tube between the to linkage plate tubes, I just ran a slip braze around here because I didn't think it needed a fillet.
I had some issues with the plugs that I silver brazed in they didn't really flow very well and I had to do all of them again (1 with brass), I may end up doing all of them in brass or welding, which ever is easier!
I'm going to start another post that will fill in the gaps between photos.
Firstly thanks to Rich for turning up the parts for the main pivot/rear tri in his lathe at work, they worked a treat.
Here is the pivot tube that Rich turned down and put the bearing seats into.
These are the plugs that Rich turned down, drilled and threaded, I then silver brazed them in.
And this is where they go, the seat stays and chain stays will attach on to here.
With a little filing I got the hole to the correct size and fit, it was nice and square and came up really well.
Main pivot after filing, sitting square.
Then I mocked up the assembly with the shock and lower shock mount and it all looked sweet.The alinement was within 0.5mm, which is good enough for this first one, it was a little off because of the hole that was bored through the TT for the seat tube being slightly off to one side, but its pretty good with the ST.
Mocked up and looking good.
Looking straightish and squareish!?
I then sanded and cleaned all the areas where the filler was heading, fluxed it and brazed it in position, it was a nice easy join open and square.
These vent holes are going to be filled.
Daryl was hanging out so he took some pics, this one is especially good, the smoke floating around is from the burning bearing seals that I left in the pivot tube!
I love this photo, I played with it in photoshop, I think it looks better in B&W.
During......
I then checked the alinment again (not that I could do much if it was off !), and cleaned up the lower shock mount, fluxed it, and brazed it in to position too.
It was really hard to get the torch into this area and heat the correct parts but got it fiqured out and it came up really well, its also really hard to finish so it will be pretty much "as is" but it looks all good.
Sitting in position, looking sweet as!
On to the next part jigging the rear tri some how, I'm thinking of doing it in wood, I really just need to tack it then will braze it in the stand.I'll keep you posted.Rossco.
I have been really busy this past week and a half.
I did the two cuts on the seat tube brace, and it took quite a bit of fiddling and filing to get the two mitres equal and tight, but got there, drilled the vent holes, sanded and cleaned the joint, fluxed it up and brazed it in place.
Still more filing this joint took a while to get right.
This photos not the best, but you get the idea.Check the next one down.
This was pretty interesting the tubes where pretty thin and I took a lot of care not to flame them up to hard, and the beads came up good (the photos don't do them justice). Although the seat tube itself took a bit of a battering from the heat of the torch and has gone a little banana shaped, will sort that out next time the torch gets lit, I have to straighten it before the reamer goes down, other wise the cutter will go through the tube wall.
Got some motivation going and took the plunge on the downtube, I cut the mitre on the head tube and it took a lot of filing to get it right, square, centered and tight. Then I cut the end of the down tube for the tube joint at the bottom, this took a little bit of work to get lined up, I had the "eyecrometer" out to get this sorted and it came out pretty good, although I cut it a little long so I had some room to move.
I brazed in the tube to the end and cleaned it up, and it came together pretty square.
Next for the gusset, I cut this the same as the first, out of an old tube that I had lying around. Shaped it and squashed it to fit, then fluxed it and tacked it on.
I did it differently this time round because I didn't feel like I had alot of control of the heat on the gusset last time. So I chose to tack the gusset on the tube, then tack and check the junction, then do the tinning pass and fillet and then come back to the thin gusset, with all the residual heat around it wouldn't take much extra heat to draw the brass into the gusset area.
So next I set the frame up flat on its centre lines and put the down tube in and checked it for alinement, sanded the junction, cleaned it, fluxed it, then put some heavy weight on the tubes, started sweating! and lit the torch!
I was worried that as soon as I started heating the joint, that it would pull and move all over the shop but I put two tacks down, top and bottom. I let it cool and checked it with machinists square and it checked out good! Sweet! So I then proceeded to the park stand and brazed the joint, did the top of the joint first, then onto the bottom, then sides and finally the gusset area. This worked better than the first time so was pretty happy.
Next it was time to make the junction for the bb>square>dt. Got it kinda lined up on the drawing and marked it out with an old bit of tube the same diameter as the bb, then broke the angle grinder out with the cut off wheel and "roughed it " to size.After this a lot of filing was done to get them matching nicely.
On to the brazing after spending a lot of time sanding and cleaning the parts, fluxing then brazing.
The square took a lot of heat to get to temp and I was worried about the bb being pulled by this, it fared ok but not the tube that joins the square and the downtube, its pretty oval now!but its all good and i'll live with it.
So now on to the clean up I got excitied with the torch so now there are a lot of joints to finish off, slowly but surely!
Also have figured out where the lower shock mount is and made the mount itself hand filed and cut, it looks good. It will be the last thing to go on when the whole bike is mostly assembled. It took a bit of working out, and I hope that the angle of the shock is not to steep should be nice and plush though!
Now all thats left on this is to bore the main pivot in and braze it square and straight!?
On the drawing and looking really good.
Catch you soon.
