Full Suspension Frame - new linkage

I have now made a carbon (with alloy inserts) linkage, I had taken about 20 photos of making it but they seem to have got corrupted somehow, so I guess a few photos of the finished article will have to do.

The change in linkage design has changed the travel slightly, but not by much (from 94mm to 96mm), it has also changed the leverage ratios to a falling rate, this is not what I was hoping for, but a quick spin suggests there is a little less pedal bob, so I'm going to test it as is for a while, as I would need to move the linkage pivot location to change to a rising rate.

I'll try to get out of a quick spin either this evening or tomorrow to test it out properly, but from a quick spin down the road and back it seems to work well!

Full Suspension Frame - first rides report

Ride 1

The cables and hoses arrived over the weekend so after fitting them I managed my first proper ride on the new frame today. 

I started of extremely cautious, but after a few minutes I had almost forgotten and started pushing quite hard and not slowing for bumps. Part of the route had a section of  dried plowed field and I was able to carry quite a bit more speed  compared to the hardtail, without any cracking or damage to the frame, both while standing and sat down. On long smooth climbs I found there was a little bobbing, but not too bad and putting the shock in pro-pedal mode stopped it completely. 

As would be expected from a full sus, on steep climbs traction was improved compared to the hardtail. I also didn't have any unexpected flex from any parts of the frame so I'm looking forward to testing it over the next few days!

Ride 2

On the second ride I noticed I rather alarming knocking sounds when pedaling hard - I tried to work out what it was and tighten all accessible bolts, but nothing seemed to do anything. When I got home I pulled the cranks out and tighten the main pivot and that seems to have sorted it - but can't see how it's making the noise so I'll be keeping an eye on it at afan!

Full Suspension Frame - Part 15 - It's done!!! (almost)

After nearly 3 weeks of building the frame is now functionally finished! I have taken it for a quick spin and it feels nice and stiff, with only a few minimal cracking sounds- I know from doing the hardtail to expect a few creaks/crack sounds for the first ride or so - but after that I hope it will be as silent as the hardtail is now.

I'm happy with the final look of the frame, although I need to do quite a bit of work on the finish quality on places. I'm still waiting on cables and hoses but from riding is ss with just the front brake I can tell it rides reasonably nicely, I set the pressure in the shock quite low and was able to bottom it out without any parts of the frame fouling on each other or the tyre.

The mod to shorten the chainstay/swingarm has also raised it by about 5-6mm, which also means that it is quite close to the chain, with a clutch mech and a chainstay protector it shouldn't be to much a problem, although on the V2 I will drop it by about 6mm..

The rear pivot and dropouts area need cleaning up and possibly painting, but nothing structural need to be done. 

The front mech looks pretty good, but I think direct mount mechs always look worse than band on types - but I would have had to compromise the strength of the frame to fit one.

Full Suspension Frame - Part 14 - final weights and a small clearance issue

With all the parts a nearly done, I decided to weigh them before assembly, to see how close to target weight I am. 

I weighed the front triangle with a BB in place so the actual weight is 1186g - which is 86g heavier than my target of 1100g so I'm reasonably happy with this. 

The swingarm ended up weighing in at 667g (pre discovering problem below) which is a 217g heavier than targeted, and will be the next area of development as I intend on remaking it in full carbon to hopefully get it down to about 450g.

The seatstay piece is 239g which is 61g lighter than I had targeted (300g). I'm happy with this, but it does leave room to beef it up if I feel it needs it after testing it.

I assembled the frame and it weighs in at 2580g (including shock and all hardware) this is heavier than targeted but for a first prototype I'm not too displeased and I know where I can reasonably easily shed 200g

I started to test components for fit and I came across a pretty major issue - the cranks didn't fit! - Where I had shortened the swingarm I had forgotten to recheck if the was enough room for chainrings, I have removed about 10mm of material off  the outside of the arm and built up the inner side so not to lose any strength, when I make the v2 swingarm I will make sure I remember to check for clearances before fitting it! 

Full Suspension Frame - Part 13 - derailleur mount and seatstay

 After leaving everything to set over a couple of days I was able to do another mockup of how the bike will be, I'm now a lot more happy with the chainstay (429mm) and was able to set the BB height with a block of foam.

A have also checked the amount of travel possible - and I think it would be able to get about 135 without touching the seattube

The wheel seems to be about 1-2mm of center - but this isn't to much of an issue- my hardtail is about 3mm off!

To fit a front derailleur I have had to make a aluminium plate for a direct mount front mech - using the dimensions from the drawing below

I'm setting the seatstay in situ so to make sure it is 100% aligned, but this means I'll have to do the rest of the finishing layup tomorrow.

Full Suspension Frame - Part 12 - measure twice, cut once.....

One update for two days work due to not getting much done (the F1 was on this weekend!) and having to go back a few steps due to a pretty major measurement mistake. 

 I put a set of wheels in the swingarm frame to test for fit as alignment and it was immediately apparent I had made an error due to having chainstays in the area of 465mm it was also obvious due to the gap between the rear wheel and the seattube.

After a bit of thinking I worked out what I had done to add 35mm to the chainstay length, firstly when making the parks of the swingarm I had used an old CAD drawing which used a pivot mount forward of the bb which accounted for about 30mm of the increase, secondly I had put the pivot 5mm further back than designed.

because of this I decided to cut and remove the metal inserts, which was a lot harder than I thought it would be, and then redesign it about 30mm shorter, I have also moved the pivot inboard by about 5mm, rebuilding that area for the 3rd time! 

 The new improved swingarm will use pretty much the same design, but with a smaller shelf between the tyre and the bb to cut some length out of it.

I also continued work on the seat stays, where I have now bonded the lower end onto them ready to be finished when the swingarm and main pivot are set completely and I can jig them up in the frame.