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Discussion Starter #41
Did you lose some top end? I’m not sure if I would benefit from any re-gearing or not.
Gearing is a very personal call.

Going up in the front will reduce your RPM at WOT for a given scenario all else being equal. For example, wide open on your favorite stretch of road in 4th gear if you go up one in the front, you will go faster IF the engine still has some power left to utilize that taller gearing. The downside of that move is that your acceleration to reach that speed will decrease. The reverse is true. Going down a tooth up front will slow your top speed all else being equal because your RPM will hit the limiter (assuming the grade and load are suitable), but you will get to that speed faster.

Go ride your bicycle for a while and play with the front derailleur and this will make sense.

Going up teeth in the rear will produce an opposite effect from the front. Going up in the rear will INCREASE RPM at WOT for a given scenario.

In my situation, I ride hilly terrain with frequent slowing and accelerating.

I want to be able to hit the limiter in 4th on certain sections, and as of now I cannot due to being over-geared, geared too tall, too few teeth in the rear for the increase in the front.The max power band with my engine setup ramps up from 8K to redline RPM. If I can't get there, I am overgeared.

36T should do it, if not I will try 37T.

I don't care about losing some mph top speed.

I am still in danger of getting a ticket for speeding when I ride 😀
 

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Discussion Starter #43
The 36T rear sprocket did the trick. Geared as well as can be for the power output now.

Eventually with likely try a 5 speed transmission, but until then this works well.

Love the look of this sprocket as well.


When I get the new extended kepspeed arm I will have to figure out how many links in a new chain will be required.

Running this chain now, and will likely just get a new one of longer length. May pick up a chain rivet tool which has been on my to do list.


Expensive tool, but will properly set a rivet on any motorcycle chain:

 

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I’m still running my stock chain. I didn’t know which brand and model to get, when I need one. I considered another chain without o-rings. From what I understand the o-rings cause there to be more drag, which the Grom doesn’t need. The D.I.D. chains are really good? Are there any other brands you like?

I’ve been thinking about installing my Kepspeed swingarm. It sucks that yours broke. Makes me lose some confidence in mine. If it doesn’t break, I believe it would function well having needle bearings.

I found some generic chain slider material at Webike that I could use to make a better chain slider if I really wanted to. None of that matters though if the welds simply can’t stay together.
 

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Discussion Starter #45 (Edited)
I did not notice any power loss with the O ring chain, but I did notice it stayed in spec much, much longer.

Stock chain is fine until it wears out.
 

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Discussion Starter #46
This is a pretty chain, but expensive:

 

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That is a good looking sprocket. I’m running a steel 34t Kitaco sprocket that is 1/2 pound lighter than stock. I just got a 15t Kitaco front sprocket that is all drilled out. I will install it soon. It looks nice.

Yeah, that chain looks bad ass. I imagine the gold pins would get pretty nasty though. You would likely need to clean it pretty frequently if you wanted to maintain the look. Maybe I will give one of those a try.
 

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Discussion Starter #48 (Edited)
More data on the kepspeed swingarm.

Decided to take a deeper look at the needle bearing implementation.

They occupy only half the swingarm pivot pass through. The other portion of the pivot is an oversized bore that allows too much play for the bushing which led to marring of the material and a seizing of the bushing in the bearing on one side of the swingarm. Not sure why there is not a full length bearing through the entire pivot assembly. The load is concentrated on only half of the assembly and it is not robust enough to handle it.

The bearing side of the passthrough, the lateral side, holds the bushing securely, but the medial side allows for play which as you can see led to failure of the assembly. This is a poor design.

The chain protector plastic piece also was about to work loose. Held on by two pop rivets that were about to pop out.

Not acceptable. Don't think I can recommend this product at all.

Then again, maybe the swingarm weld failure came first and placed extreme stress on one side of bearing assembly causing this seizure. Maybe if the swingarm structure is intact the assembly is adequate.


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This just gets worse and worse. What a silly oversight, the needle bearing doesn't stand a chance, its literally a ticking time bomb. Overloaded and under-supported...
 
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The one and only!
Hahaha, awesome! I'm considering joining the Hypermotard squad and have been lurking on that board. I saw your name there and wondered if it was you. If I make the leap it'll be good to have a familiar person on that page.
 

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Wow this is impressive. I’ll have to check the bearings on my Over swingarm to see how they’re fairing.
 

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It is looking like the G-Craft with the optional sealed bearing option is going to be the best bet for those of us wanting bearings.
 
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Do you have any close up pictures of that design?
I don’t know of any great photos of that design, but check out the G-Craft swingarm page on Webike’s website.

There is one photo of the G-Craft swingarm, where you can see the cartridge style bearings. It appears that there are 4 total. I think that would be a good design. That is what all of my mountain bike swingarms have used. I’ve never really had any trouble out of them. I did finally have to replace the pivot bearings on one of the eight different Cannondale full suspension bikes I’ve owned. Nothing difficult.

DY101’s build thread has some good photos of the swingarm in general.

The G-Craft swingarm appears to have arms that are more narrow than the Kepspeed. I think they measure 20mm x 55mm. The Kepspeed measures 25mm x 50mm.

The one thing I find interesting is that G-Craft doesn’t seem to provide the L-bracket for the brake hose. Why not? Neither G-Craft nor Kepspeed provide the tab for the fender hugger at the right front. I made one out of aluminum for the Kepspeed.

Takegawa has every feature of the stock swingarm, but I don’t think it has bearings, Why not?

It looks like I will either install MNNTHBX bushings and OTB chain adjusters, or I will eventually order a G-Craft. I might give my Kepspeed away or sell it if someone wants it. I will probably keep the bracket for the brake hose though and the tab I made for the fender hugger. I’d say I’m leaning toward the G-Craft. It looks sexy, plus it weighs five pounds less.
 

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Discussion Starter #58 (Edited)
Installed the MNNTHBX swingarm bushings and OTB spools.

The bushing install is simple thanks to the excellent tool that should be purchased along with the bushings. I used machining oil instead of grease throughout the process to keep the bolt and bushing lubed for easy removal and assembly.

Important note when re-installing the swingarm. The brass bushings have a bit of play side to side in the stainless sleeve. Must be by design, but this does allow the swingarm to move side to side about 1/2 mm. Not sure why that is required. I will ask MNNTBX about it. Seems unnecessary to me.

Additionally, as you can see from the pictures, the medial portion of the swingarm has a gap between the swingarm bushings and the frame. I found a suitable washer that removed that gap. The gap is maybe 1/2 mm small, but that play must be removed or the swingarm does not swing as well as it becomes torqued out of alignment when the swingarm pivot bolt is tightened down.

It is essential that there be no gap in the assembly all the way through from the rearsets through the frame and swingarm, otherwise, when you torque down the pivot bolt, it will torque the assembly out of alignment and then the swingarm will not move freely up and down as it should.

After assembly, a simple bounce test on the seat revealed a significantly freer assembly with MNNTHBX bushings compared to the stock rubber bushing setup.

However, it is absolutely still under some friction load compared to the super slick movement with needle bearings, assuming they work as they should.

I will report back after a test ride to let you know if I think it was worthwhile to go through all the trouble to put in the new bushings.

The OTB spools are fantastic. I love that chain adjuster and spool combo. Really worthwhile upgrade.


This is the left side medial portion of the swingarm with a washer in place under the red arrow.


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This is the medial portion of the right side swingarm with just the bushing against the frame, no washer.
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OTB spools are amazing.
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Discussion Starter #59
Received the new swingarm from kepspeed!

Beautiful unit.

The pivot is still half bearing half bushing, but the inner bushing is a tighter fit so that the load is shared between bearing and bushing, however, the medial part without the bearing is a roughish gold anodized surface which is a terrible solution when the goal is reducing resistance! No idea why they cant just either run a full length bearing or just two per side. Or forget the bearings and have a better bushing solution.

Will install with a longer chain and see how she rides.

Really liking the MNNTHBX bushings in action. The smallest changes to rebound settings on the rear ohlins are actually felt in the seat which I dont recall being able to sense before, so something is working in the swingarm pivot.


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