Clean Custom Conversions

[PedalUma]

I am now working on the $899 Marin Kentfield 3. Again it has the same geo, groupset/brakes, as a $14,400 Creo SL that does not come with pedals. I can get the motors BB only an inch and a quarter in and it hits something. I have been grinding and filing for an hour. The owner has had surgery on her left foot, so I am making it a throttle ready bike. I normally don't but she is the kind of exception that proves that rule. Her foot is still in a Frankenstein velcro boot.

 

[PedalUma]

After hours of trial I finally got it. I wrapped a large bit with microfiber to almost 33.3 mm and then added 220 grit 3M emery paper and honed it out to a polish with a drill. It was just not one burr as usual. The entire center needed expansion. Now it it tight but goes in. I like things that are tight and go in all the way. The entire job should have been done in the time of fixing that one thing. What a PITA. I falafel. It was due tomorrow by train delivery but it will rain, so I bought an extra day to finish. Can't ride a new bike in the rain to the station. I hope you guys take satisfaction in my suffering.

 

[PCeBiker]

I hope you guys take satisfaction in my suffering.

Your suffering is uncalled for.

You need one of these,..

https://a.co/d/0aX0lEMX

Adjustable spring tension and everything.


I remember making a similar tool to what you made.
I was trying to hone out an aluminum tube for my windsurfing boom.

I needed a three foot long honing tool so I used an orange fiberglass rod from the dollar store, (a ¼" driveway marker rod) and taped a strip of emery cloth to the end.

I just coiled the strip up to the ~1" diameter of the tube, and stuffed in in the tube.
It worked, but it took forever.

 

[PCeBiker]

You need one of these,..

https://a.co/d/0aX0lEMX

I bought one of those with a freind about ten years ago to hone his cylinder on his 10 horse riding mower.

After we got home from the 1½ hour round trip to the store, we opened the package to find that it was used, then put back in the package and returned.

The guy even reused the staples in the package to make it look unused.

The guy must have honed his cylinder without removing the piston, because the stones were only worn and gouged half way up each stone.

After thinking about it for a while, I noticed that my freind had clothes line poles that were made from 3"-4" steel tubing, so I stuck the honing tool in the rusty pipe and managed to resurface the honing stones, and then we managed to get his cylinder honed out properly.

Here's what the robot says to do,..

We thought of that, but we knew that we'd make a Fricken Mess of the stones trying to keep them square and flush, so I still don't want to make freinds with any of those stupid robots.

 

[PedalUma]

This one came in yesterday for conversion. It is getting a lot of upgrades. All I have done so far is polish the frame, removed the cranks, and replaced the twenty-year-old bar tape.

The owner went to the Olympic training center and they put dots on each of his joints and filmed him riding adjustable stationary bikes for three hours. That data went to the builder, Tom Kellogg, to make the blueprint. The welds are beautiful. The bike fits in a suitcase. I need to work with that in mind. I have never seen a steer tube that long and check the seat stays.

 

[stompandgo]

That riding position is so wrong. Whatever the customer wants, but that bike is screaming for a proper fit.

Those are S&S couplers that break the frame in two.

Tom and I have spent many hours racing together. One of the last times we were in the field, five of us got off the front and lapped the field twice.

 

[PedalUma]

@Stompando, That is so cool. The owner has a highly unique body type, hence the custom build just for him. He has extra long arms and torso.

My plan is to move the connector to the display down to the joint at the downtube S&S. It sure saves on Bikefights.

Oh, Man! I wanted to put on a medium/long cage derailleur and a wider range cassette. When I removed the rear wheel, that is when it hit me. It is Campanonolo from like the year Ronald Reagan was first sworn in! Nothing modern, robust, and inexpensive is compatible with it. The hub, freehub body, and indexing are all proprietary. He is going to need to stick to the current cassette and derailleur until he wants new wheels. I talked about carbon rims and Onyx hubs. He is too heavy at 330 for the present wheels and will start popping spokes out on the hills of Western Marin where there are no cell towers.

 

[PedalUma]

The motor is in. Loosely at this point for any adjustments.
I wanted to route the shift cable over the BB so there is no chance it will get crushed, so I added housing and ran it over the bottom bracket shell. Turns out I could have left it under and been just fine. There is enough clearance with the DM02 motor. Not so with most others. I made a rubber bushing from an old tube and made a snake tongue 'V' slice before folding and rolling it with electrical tape. That way it will self center against the round downtube and lever up and forward provide maximal ground clearance, less than the chainring. I painted the motor with automotive ceramic enamel engine paint. It is not a perfect match to brushed Ti but will help it vanish to most eyes. Upps, a zip tie! But it is low and no one will see. I could paint it with silver nail polish. I will need to do that at the display connection. Maybe I will add a bit of bronze to better match the frame.

 

[Chazmo]

My goodness. 330 pounds. Is that frame titanium? What an interesting build, Pedal!

 

[PedalUma]

My goodness. 330 pounds. Is that frame titanium? What an interesting build, Pedal!

Yes, it is titanium. We had the wheel conversation again today and I referred him to a wheel builder. With weight wheels are always the first weak point. Once you pop one spoke it places more stress on the rest. Interestingly bikes do not push on spokes, they are suspended from the upper spokes alot like a suspension bridge.

 

[Chargeride]

I wonder do they make wheels where the spokes nipples are held in place so there could be some compression support

 

[PedalUma]

I wonder do they make wheels where the spokes nipples are held in place so there could be some compression support

There are some with mag wheels. Like on a motorcycle.

 

[Chargeride]

Anyway, old school clean.

 

[Chazmo]

Yes, it is titanium. We had the wheel conversation again today and I referred him to a wheel builder. With weight wheels are always the first weak point. Once you pop one spoke it places more stress on the rest. Interestingly bikes do not push on spokes, they are suspended from the upper spokes alot like a suspension bridge.

Interesting. Yeah, that makes sense.

I actually would’ve bet on the bottom bracket as being the first thing to fail, Pedal… Someone this big using a Ti frame is a surprising choice. Maybe Ti’s flexibility is a good thing here? I’ll be following along. Coolness.

 

[stompandgo]

Titanium frames do not have to be flexy.

 

[PedalUma]

Titanium frames do not have to be flexy.

I do not know about the metallurgy of Ti but can say I was able to hand expand the rear dropout to remove the rear wheel. It was tight. In my experience with that my impression is that it has more flex than 6061 Al.

 

[stompandgo]

There's different gauges of tubing, which can be mixed to allow flex in some areas and less flex in others.

 

[PedalUma]

There's different gauges of tubing, which can be mixed to allow flex in some areas and less flex in others.

Cool.

 

[PedalUma]

@stompandgo, Ideas often come to me when my mind is uncluttered on a ride. What you said about the tubes explains why the seat stays have S-curves. Compliance. They act like vertical springs. And are likely thinner tubes than the chain stays which need to transfer power.

 

[Chazmo]

Titanium frames do not have to be flexy.

That’s right, Chris. The material itself can flex, though. You’re not going to get that margin of error from other bike materials. I guess I was getting at whether this is a good or bad thing for an > 300lb rider. Maybe I’m all washed up.

For the record, I love titanium!