"Grown Up" BMX project

[SkipdiverJohn]

Don't think I'm stripping another frame myself though, it's a right faff!

Why did you need to fully strip it though? Couldn't you have got the decals off with a heat gun & thinners then just given the old paint a rub down? That's all I've done with hack bikes I've repainted. If I wanted a quality job I would go for shotblasting & powder coat.

 

[ChrisEyles]

That's exactly what I've done when I've repainted bikes in the past, and it always works really well.

This time I wanted to try polishing up the bare frame, hence the need to strip off all the paint.

Quite looking forward to getting the buffing wheel out next weekend.

 

[ChrisEyles]

Managed to give the frame a quick buff and polish tonight. Was a lot quicker, easier and more rewarding than stripping the paint!

It's far from a mirror shine but I'm happy with how it turned out. Should look ok as the aluminium oxidises too. I might give it another polish before starting assembly.

What's less good is I found another crack while polishing the frame. This one's in the top tube just under the head tube. Doesn't look horrendous, but means I'd have to get another frame if I wanted to learn to do bigger jumps. Should still hopefully do the job for manual/wheelie practice and general messing around though... Guess that's what you get for buying cheap frames off teen-agers on facebook

 

[ChrisEyles]

Going to put the headset cups in next - lacking the proper tool, is it best to use a wooden mallet or a vice and two blocks of wood?

I've done the former in the past with no problems, but that was on a steel frame with external cups.

 

[ChrisEyles]

Gave the frame another polish today and finished it off with a rub down with some GT85. It looks good, I'm really pleased with it. Will be interesting to see how quickly it dulls as the aluminium oxidises.

Sold the old crankset and bought a new one - puts the total net spend so far up to £88... and I think I now have everything I need to build it up (granted quite a few bits are coming out of the parts bin so arguably cheating a bit on the sub-£100 build but never mind, they are just going to sit in the garage otherwise).

Had another close inspection of the frame and can't decide whether the marks on the seat and top tube are cracks or surface scratches. Either way they will need keeping an eye on when it's built up to ride.

 

[tom73]

Great work on the frame going to look great when you’ve finished

 

[ChrisEyles]

Managed to get the bike mostly built up yesterday evening.

I went with the wooden mallet method to install the headset races in the end - worked fine with no drama.

Re-used the old BB from the donor bike and gave it a bit of a clean and squirt of oil. It still feels a bit rough but should be serviceable enough.

Seat post & saddle, wheels, brakes/levers, grips, rear shifter and mech & all cables came off the donor bike and all seems good there. I also swapped out the broken 12t sprocket on the cassette for a 13t one and re-jiggled the sprockets with some from the parts bin to give more sensible ratios (I don't know if what was on there was original but it seemed oddly specced to me).

Bars & stem came out of the parts bin. I do have a set of GT bars/stem which look the business, but they have quite a bit more reach and less rise so I've used the ones pictured instead to give it a more playful feel with a short, high front end. I've got an old chain and chain ring set aside for the build too.

Just need to wait for the ebay'd cranks to arrive and I can finish the build. Pretty pleased with how it's looking now though.

Shifting was awful on the donor bike, and I'm not sure why, so keeping my fingers crossed the new chain and different sprockets might fix that. Also need to cut the seat post down a little so the seat can be properly slammed for practicing manuals.

Budget is going better than expected:

Frame £30
Donor bike £52
Crankset £12

Sold front shifter -£3
Sold old crankset -£10
Sold old handlebars & stem -£5

= Total net spend so far of £74

 

[tom73]

Nice one

 

[ChrisEyles]

Crankset arrived in the post this week so I've got all the bits I need to finish it off.

Just setting up the indexing on the rear mech and truing up the wheels before I take it for a spin.

 

[roadrash]

enjoy

 

[tom73]

 

[ChrisEyles]

Just got back from a quick spin around the local BMX track.

Everything's working nicely and the shifting now seems OK with a newer chain. The forks are a bit clunky but actually feel alright besides the noise they make.

With the seat down it feels a lot like a less twitchy BMX - which is great, just what I was aiming for. At the moment I am looping out the back a lot when trying to manual/wheelie, but if I ever get time to put in some proper practice it should be pretty good for that.

Will try it out on a local bridleway route when I get the chance to see how it feels on that, I reckon it could be quite good fun.

 

[ChrisEyles]

Couple of tweaks today - put on a 100mm stem and slightly narrower bars just to see what it would feel like. Getting to the manual balance point requires a slightly more forceful movement, but it seems easier to hold it there. Feels better jumping on the BMX track too.

Quite surprised as I'd have thought a shorter stem would have been better on both counts.

Tipped the seat angle back too, which made a big difference to ease of wheelies. It's not quite as drastic as the pic below now though.

I always assumed that my inability to manual/wheelie was solely down to lack of skills, but it seems bike set up is pretty important too.