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By Daiwiskers
#88315
stinkwheel wrote:
Wed Mar 11, 2020 1:11 pm
Daiwiskers wrote: That was brave through that water !
I've seen the road enough to know there isn't a particularly deep hole there.

It was nothing compared to some of the floods I rode through on the way back from the Dragon Rally at the start of last month!
True I saw the video you put up

Cheers Dai
By Daiwiskers
#88316
Too late to edit again

Wheaters did a great thread about off roading a bullet this will be well worth reading

Cheers Dai
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By Wheaters
#88330
There is a lot of useful advice from a number of experienced owners on that thread.

I got more involved with the 5 speed gearbox conversion later on tho’; in retrospect I should have opened a separate thread on that.
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By stinkwheel
#93039
Today I came up with a cunning plan. I'm going to go the whole hog and fit a 21" wheen and go for way over standard shocks. The main issue here is chain tension and fouling the swingarm.

So I stood and looked at it for a while, definately a "three pipe problem". The obvious solution is a chain tensioner but it seems a bit of a fiddle welding a lug onto the swingarm and from experience of single speed bicycles, sprung tensioners are a constant source of grief, especially if I'm going to be doing long distance trials. It's a real potential fail point.

So I looked at the chain and moved the swingarm up and down a lot. The chain fouls the top of the swingarm pivot which is easy, just needs a rubbing strip. At this sort of extension though, the sprocket alignment is way off so the chain sags to the point you could lift it off the rear sprocket by hand at full extension.

Then it came to me. The frame lug for the rear brake pivot is very conveniently located and is a really meaty casting. If I have a new fulcrum stud turned up that protrudes further towards the inside of the bike, I can mount a skateboard wheel on it for the chain to run over the top of. With the right diameter wheel, it'll take up the worst of the slack in the chain at full extension but wont over-tighten it at full compression. In fact, it will come off the wheel altogether when compressed.

I've done a drawing of the new stud for my local light engineering guy (he'll play hell at wanting a 7/16" x 26 thread) and ordered a skateboard wheel (well, four, you can't just buy one).

I'll post pictures and the drawing if it all works. Should let me use a 350 or 360mm shock.
By Cranky
#93040
My 2 peneth is that what ever you do it will then not be very good at either.
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By stinkwheel
#95198
For reference, with a pair of 345mm shocks and a 21" front wheel, I get a rake angle of 26.5 degrees. That's really slack if it was for observed trials but about bang-on for twinshock long distance work. It's the same as a Yamaha TY250.

Still waiting for the chan tensioner bolt back from the machinist.
Image
By vince
#95199
Hi, I used my isdt bullet for commuting and the occasional enduro. The best conversion is the wide ratio box which allow standard top gear and very low first gear. It was particularly good for winter snow covered roads. Vince.
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By stinkwheel
#95201
That's my job for tomorrow. I'm leaving the plug out to drain as much of the elephant snot out as I can overnight. From memory, dealing with all that grease was the worst bit of servicing these gearboxes.

Also got a couple of bronze layshaft bushes to stop the kickstart whacking me on the shin when I set off briskly.
By vince
#95203
Hi, it helps when draining the gearbox to heat with a blowlamp and melt all the grease.

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