Home Made Bikes

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Posted: Sep 3, 2020 at 4:38 Quote
Not if you've designed, manufactured and installed them properly. There's a reason they're so popular in so many fields!

Posted: Sep 3, 2020 at 8:09 Quote
R-M-R wrote:
chasewarner2,

Clean design. Some thoughts below.

Rear stiffness:
• Absolutely max out the width of the main pivot. Push it right out to the inner faces of the cranks. There are plenty of ways to space out the chainring to match the spacing of the idler. Chainline doesn't have to be perfect between the idler and the hub sprocket.
• If this is aluminum, consider larger tubing, especially for the seatstays. Disregard if it's steel.

Pivots:
• There is no such thing as overkill on pivot hardware! Large bearings, large axles, large fasteners.
• Bushings are better than rolling-element bearings at low-rotation pivots. I recommend a polymer bushing at the Horst pivot.

Kinematics:
• What centre of mass location did you use? Keep in mind the rider will usually be standing to pedal on such a bike, so CoM will be higher than when seated pedaling is expected.
• Since kickback will be low, you could increase the anti-squat a bit with little consequence.

Packaging:
• Ensure the forward end of the shock pocket can fit a variety of shocks. Looks like it may be tight to the modeled shock and may not accept others.

Thank you for the feedback, you bring up some very good points. I will take these into consideration and reevaluate some component design.

Also my CoM is modeled at X:0mm, Y:593mm, if you go this album, I have all the kinematic charts plotted. https://www.pinkbike.com/u/chasewarner2/album/CC-170-Bike-Project/

Posted: Sep 3, 2020 at 18:02 Quote
cedrico wrote:
Don't bushings have a tendency to develop play?

Every type of pivot eventually wears. Bushings are light, cheap, easy to replace, and well-suited to low-rotation systems.


secondtimeuser wrote:
Not if you've designed, manufactured and installed them properly. There's a reason they're so popular in so many fields!

Yep. There have been poor bushing implementations, just as there have been bikes with rolling-element bearings that last only a few rides.


chasewarner2 wrote:
Thank you for the feedback, you bring up some very good points. I will take these into consideration and reevaluate some component design.

Also my CoM is modeled at X:0mm, Y:593mm, if you go this album, I have all the kinematic charts plotted. https://www.pinkbike.com/u/chasewarner2/album/CC-170-Bike-Project/

Thank you for the link to the model data - and thank you for the willingness to share.

That CoM is about what I use for a size Small with seated rider. The gearbox will lower it, of course. Could go slightly higher, but it's reasonable.

Designing for standing pedaling is complex and not something I've explored in great depth. It may be best to use extremely low anti-squat to allow the bike to sink into the travel, providing additional spring support when the cranks hit BDC (6 o'clock) and the rider's mass changes direction. The exact movement of the rider's mass depends on the rider's biomechanics, but broadly speaking, these two forces causing squat are out of phase, so maybe a bike with low anti-squat would simply squat and stay down, wasting less energy than a bike with high anti-squat, which would remain neutral during the power phase (max. @ 3 o'clock) and rapidly squat at BDC. As I said, I haven't run such an experiment.

Posted: Sep 14, 2020 at 16:26 Quote
Almost done this sucker!
Will post better more detailed pictures once finished for anybody interested


Posted: Sep 14, 2020 at 16:40 Quote
Definitely interested.

Posted: Sep 14, 2020 at 18:04 Quote
Wow - you don't happen to have frame weights?

Posted: Sep 14, 2020 at 19:27 Quote
hmstuna wrote:
Wow - you don't happen to have frame weights?

If you have to ask... lol

Posted: Sep 15, 2020 at 7:00 Quote
Mega front end done

Nukeproofe mega front end done Smile

Posted: Sep 15, 2020 at 10:05 Quote
hmstuna wrote:
Wow - you don't happen to have frame weights?

Some bikes are made with a "price is no object" kind of idea. This is built with a "weight is no object" sort of idea.

I love it.

Posted: Sep 15, 2020 at 10:08 Quote
sherbet wrote:
hmstuna wrote:
Wow - you don't happen to have frame weights?

Some bikes are made with a "price is no object" kind of idea. This is built with a "weight is no object" sort of idea.

I love it.

I know, I know... I just have a sort of morbid curiosity.

Posted: Sep 15, 2020 at 13:00 Quote
hmstuna wrote:
sherbet wrote:
hmstuna wrote:
Wow - you don't happen to have frame weights?

Some bikes are made with a "price is no object" kind of idea. This is built with a "weight is no object" sort of idea.

I love it.

I know, I know... I just have a sort of morbid curiosity.

Once it is finished I will put it on a scale!
3mm steel tubing for the frame and 5mm steel for the rear.
It's gonna be a lot haha

Posted: Sep 15, 2020 at 19:43 Quote
Its going to be an interesting bike thats for sure. i would love to see some video of the suspension in action

Posted: 3 days ago Quote
I think you need to contact Bender for a first ride!

But I think it is awesome, can't wait to see it in action.

Posted: 2 days ago Quote
@SleepingAwake: That looks awesome, I am really looking forward to see that built and I hope you will share a lot of that building process! Smile

@chasewarner2: I love this design!

Two notes from my side:
1. I think you should consider dropping the upper (chain-)stay 5mm or so. On my HP-Build i did a quite similar degin and do have quite a lot of chain slap due to the low clearance.

2. at your anti squat calculations, did you thake into account, that the gear ratio of the gearbox does alter the chain force and, by doing that change the AS?

R-M-R wrote:
Pivots:
• There is no such thing as overkill on pivot hardware! Large bearings, large axles, large fasteners.
• Bushings are better than rolling-element bearings at low-rotation pivots. I recommend a polymer bushing at the Horst pivot.

Couldn´t agee more. I like to use Max or "V" Bearings that have the maximum count of balls instead of a cage.
I use polymer bushings from IGUS for my Horstlink too, no problems with (too much) play.

Posted: 1 days ago Quote
So this rats nest works but is a disaster
Need to think of something different

Also weighed it and it is 68 pounds.


 
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