High Roller frame size

Joined
Oct 19, 2012
Messages
869
Location
Wakefield, UK
I've been using these:-


They are just the right width for a chain. You can also get them in singles on both ebay and Amazon. The downside is the 15mm inner diameter bearing with 15mm bolts a rarity but you can get a 15mm to 12mm adapter for a mountain bike front axle from ebay for a couple of ££.

A lot of pulleys have "V" grooves which are not ideal. You want a flat bottom or a toothed pulley.
 
Joined
Oct 28, 2019
Messages
15
Location
Sydney Australia
Latest update:
I have now test ridden the bike, or more correctly rolled the bike downhill, appropriately for the High Roller!

Wasnt game to lift my feet too far from the ground and onto the pedals. It is much harder to ride than a conventional bike.
The faster I went the more stable it seemed but I will need a lot of practice, anyone put training wheels on one?
https://flic.kr/p/2ihqqLA
Checked the head angle and its within 0.1 degree of the 73degrees called for in the plan, havent measured the trail as yet but since I used a pretty standard mountain bike fork it should be OK.

I made rollers ( as suggested) out of polyethelene chopping boards and ball races (from Bunnings for OZ viewers).
But ended up not using them, as yet anyway.
https://flic.kr/p/2iinApf
When I assembled it I found the chain missed the seat when it goes straight from the chainwheel to the rear cluster.
I have it going through a bit of plastic water pipe which stops it rubbing on your leg as well the front brake cable which I will secure back closer to the frame.
In the photo its not under tension but the tube can float up and swivel to align with the chain.
The chain return from the derailleur to the chainwheel currently uses a second derailleur idler ( as suggested in the plans) to guide it high enough to clear the front wheel. It is not welded to the frame but can pivot to align with the chain. I might cut the second wheel off it as its not necessary I think.

https://flic.kr/p/2iir8Y5
I have read that sometimes with suspension you get bobbing if the chain doesnt go through the line of the suspension pivot point, since the suspension is pretty stiff I dont think this will be a problem and anyway I have a roller to use if it is.
https://flic.kr/p/2iipZpc
The handlebars can be tilted so that I can fit the bike in the back of the car, they can also be tilted forward and back if needed for comfort.
The seat which is on angles and can slide along the frame but will be bolted on when Im happy with the position and also allows it to be removed for transport.
Id like to use skewers to secure them both, on one of the other threads this was being discussed.
https://flic.kr/p/2iipY1f
Skewers 5mm dia and about 50mm long is what I would need, does anyone know if its possible to get them that size.

Yet to be done are the rear brakes and cables for it and the derailleur, its just wired into a middle gear at the moment.

Regards
Stewart
 
Joined
Feb 7, 2008
Messages
2,618
Location
Nottinghamshire England
Checked the head angle and its within 0.1 degree of the 73degrees called for in the plan, havent measured the trail as yet but since I used a pretty standard mountain bike fork it should be OK.

Regards Stewart
OK first up if you hold the back of the seat and push the bike forward does it :-

A) front wheel swing suddenly left or right and cannot be corrected by simply tilting the seat back in the opposite direction ?

If yes trail is wrong

or

B) bike can be pushed and steered by tipping rear of seat left or right trail is ok

All forks are different some are dead straight and some have a bend and some have straight offsets.

the rest is riding experience :D
 
Joined
Oct 28, 2019
Messages
15
Location
Sydney Australia
Thanks for the replies.
The trail is OK as it responds correctly to tilting the seat side to side as in B in Stormbirds post above, though
the headset bearings might need a bit of greasing to make it smoother.
I looked up the links mentioned in the "building a woodie" thread on AZ. One of these links was to a http://www.wisil.recumbents.com page which calculates suggested trail dimensions for recumbents.


Putting in the values for my High roller it suggests for normal handling the trail should be about 10.5cm, and 15 cm for "freight train" and 5.3cm for "jet fighter"

You can also plug in the geometry of your bike to give its actual trail, on mine its 6.1cm.

This is closer to "jet fighter" than normal so I guess the issue is the rider since Im not a jet fighter pilot.
I could experiment by removing the spring and installing a shorter compression strut which would increase the head angle and thus the trail. Might do this and try it when it stops raining.
However I think it is probably a matter of getting more experience in riding it.

Did anyone else here find riding a 2 wheel recumbent harder than a conventional bike?

Regards
Stewart
 
Joined
Feb 7, 2008
Messages
2,618
Location
Nottinghamshire England
When you do ride it can you feel the individual pedal strokes moving the handle bars slightly ?

If yes you probably need a little more trail.

Of course being new to a recumbent nuances like that are hard to judge when you have a death grim on the bars and are hanging on for grim death :D

A compression strut is a great idea leaves the wheels and so the brakes alone so you can still ride it safely.
If you made it adjustable maybe one tube inside another you could explore a few different lengths at the same time.

I tamed a ' jet fighter ' by adding more rake with different forks , changed something that needed constant steering corrections and was a handful trying to ride single handed whilst signalling etc into a bike that could be ridden a short distance with the hands off the bars [ I do not recommend this except for testing purposes ;)]

At the end of the day there is no substitute for seat time ......

if the height is scary try either 24" or 20" wheels
 
Joined
Feb 20, 2013
Messages
722
Location
Axedale, Victoria, Australia
Website
axerail.coffeecup.com
I would not like to attempt to ride any commercial MTB that I have ridden in recent years without holding the bars. Use to be able to do it once but I am convinced that bike design has changed somewhere along the line. The ones I have tried seem to become instantly unstable to the point where I have not been able to go "Look Ma, no hands!" Not a good idea anyway. You are just that little bit further from recovery if something happens - like a stone under a wheel.
 
Joined
Oct 28, 2019
Messages
15
Location
Sydney Australia
Long time since the last post.....apologies for not answering your replies sooner.

I got sidetracked into putting power on to my shed.
For the last 20 years I had an extension lead from the house running to it with a tangle of leads and power boards inside.
I will post the long story in the "what jobs are we getting done due to the lock down" thread.

Anyway back to the bike.

I was a bit discouraged after trying to ride it, I felt so unstable I had my feet hovering just above the ground, I didnt even get them on the pedals as I rolled down the small hill.
After reading the info on the recumbents site I mentioned in post 25 I decided to increase the trail to see if it made any difference.

This was easily done, I experimented by taking the spring out and replacing it with a plywood strut, this changed the front fork rake from 73 to 70 degrees.
The difference was remarkable, balanced it relatively easily straight off, would not do no hands but one hand is OK.

For a permanent fix to the new rake I used a rubber door stopper, not the same cushioning as the spring but about the right length to get the required rake angle.
The other options were to find a front fork with less offset or cut the frame and insert a "dart" of steel which would also increase the trail as well as the wheelbase a bit.
I can always try these options in the future.

So I have now painted the frame and have to install cables for the brakes and gears to finish it.
The donor bike had cable stops fixed to the frame but looking at the AZ instructions I got from Brad it seems that the cables are run in the tubes all the way from the levers to the brakes or derailleurs.
Im curious as to why traditional bikes just run the tubing in the curved sections and have plain cable in straight sections between the cable stops, it would seem simpler to run them in tube all the way.

I have to get one cable stop for the front derailleur, the donor derailleur is operated by the cable being pulled up against the spring so needs a stop for the cable tube to fit into.
I will probably get a clamp on cable stop unless anyone has another suggestion. I cant find any weld on types on the internet, though there are some rivet on types advertised.

I guess I will have to build something else to use the spring I bought!

Stewart

Attached photos:

ply struts,
rubber stopper fitted,
Cad drawing of how I could install a dart in the frame and still use the spring.
Overall view




 
Joined
Feb 7, 2008
Messages
2,618
Location
Nottinghamshire England
Cabling can be a pain .....

Now day's I use re-usable cable ties just shorten them were appropriate so you don't have long bits of unused ribbing sticking out.

Much quicker than constantly threading and unthreading outer cable through tube keepers and means you can keep the cable end connectors on ?

reusable cable ties sometimes called releasable cable ties



If you need the odd lug ? cut one off a existing donor frame you have , cut about 1" around it to start with hammer the round tubing flat then trim to a need size for welding , a down pull front mech is probably the hardest one to do :rolleyes:

regards Paul
 
Joined
Oct 19, 2012
Messages
869
Location
Wakefield, UK
I have to get one cable stop for the front derailleur, the donor derailleur is operated by the cable being pulled up against the spring so needs a stop for the cable tube to fit into.
I will probably get a clamp on cable stop unless anyone has another suggestion. I cant find any weld on types on the internet, though there are some rivet on types advertised.
Try searching "cable braze" rather than weld.

 
Joined
Oct 28, 2019
Messages
15
Location
Sydney Australia
Had not thought of using the cable stops on the old frame, thanks. Checked and found a bit of the seat tube which had triple stops on it.
I can cut it out and use one for the front derailleur that I need. Pity I had painted that bit and now have to reweld.

I still would like to understand why they use cable stops and not run cables in tubes all the way, any ideas?

https://flic.kr/p/2jdfu9f
 
Joined
Oct 19, 2012
Messages
869
Location
Wakefield, UK
Outer cable isn't perfect. It squashes to a small degree which makes shifting gear more vague or braking more spongy. The less outer you have, the less ability to squash it, the more precise the shift or firm the brake. It's also why there's different outer cable for brakes and gears. Gear outer cable is not resistant to high loads but it resists lower loads better than brake cable does. Given gear operation is a low load operation it makes shifting more precise. Brake outer is made differently from gear and gives more on small loads but firms up much better than gear cable at higher loads. As braking is a high load operation it is better for that. There's also the weight. A couple of stops probably weigh less than the outer cable between them would weigh.
 
Joined
Feb 7, 2008
Messages
2,618
Location
Nottinghamshire England
You will not find ' weld on ' cable stops as the bicycle industry does not as a rule weld them on ? they are usually brazed on this means they are VERY small and even a TIG welder can reduce them to a pile of molten scap in the blink of an eye !

I suspect also bare cable is a throw back to the beginings of bicycles when the cables and inners were not as good/well made as they are today.

So it could reduce friction at the expense of risking the cables getting rusty picking up dirt etc
 

SirJoey

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My cozy little nook in the corner!
Back in the days when I was still building these things, I ultimately learned to braze, bought my own torch,
& started brazing on cable stops I had hacked from donor bikes. Initially, however, I didn't know how,
so I used 1/4" nuts, drilled halfway through, & welded them on! Not as pretty as regular cable stops,

but they work just as well!







Something to consider? :unsure:
***
 
Joined
Oct 28, 2019
Messages
15
Location
Sydney Australia
Thanks for the replies, I ordered a clamp on cable stop from an Australian Ebay supplier today, no welding or repainting required.

When I welded up the frame I used a bit of the downtube from the donor bike for the angled tube to attach the front derailleur onto.

Today I found the remaining bit of downtube which had the stop already on it, if I had planned ahead and used it the stop would already be in place!
 
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