Speedo Cable Length + Rear Suspension + Gearbox questions

[SmallFrowne]

Hi all,

I've started getting the track day fever, having done my first 2 in the last two weekends.. which was bloody good fun. Really though the bike needs quite a bit of love, it was meant to be off the road whilst I did a few bits, then back for summer - but I couldn't resist the cheap winter track day prices. So I hope you don't mind me asking a few questions, I've been doing a fair bit of searching and reading of previous posts but I think I've read so much I'm getting lost on a few things.

1. What should the speedo cable length be? Mine seems unnecessarily long and has a big bend in it, yet the only listings on ebay/online parts shops that actually give a length are the same size as what I've got, which is maybe a foot too long. Not really necessary for track days, it's just so wobbly.

2. The rear shock is the old type and the linkages are probably in need of a good fettle, possibly needing to replace the bush and bearings. Does anybody know the size of the bearings? Saying that, I might see if RO will do an exchange on the triangle part (rocker?). I'd like the shorter link he does, but at £75 I can't afford it (got to prioritise the funds), so will try to get someone to weld and drill my current dog bone link.. unless anyone has one to sell?

3. I've bought a fairly cheap later model shock (waiting for it to arrive) which I'll probably send to have new seals and to re-gassed. Any recommendations? Brooks suspension was mentioned in a thread somewhere and is about £120.. still recommended? Does the top bush get much wear? is it worth replacing, or would brooks do this as well if necessary? Also, now thinking about getting the shock vaguely set up for me - what weight of rider was the stock spring designed for? I think I'm about 11Stone ish with gear on. I could measure sag but I've stripped a lot of stuff off already and the sticky linkages might throw it out anyway. And what weight oil should I ask it to be refilled with?

4. I think it's developing the 2nd gear slip into neutral charade. It could be a few other things, like me not changing gear properly, but it does seem like what other people have mentioned being worn dogs (maybe as a result of me not changing gear properly). What exactly do I need to fix this? Replacement dogs (selector barrel)? Replacement gears? And which gaskets, having split the cases? Or Do you have to buy a full set to get them? I think I'll leave it for now and sort the suspension out and get a few bits powder coated then see for sure if it is me or the bike that is causing the issue, but I'd still like to know what I'm up against if the worst is happening.

There's a few other bits but that will do for now. Any help will be appreciated, sorry for for the waffle. I'm just trying to get organised but I'd like to get this sorted as I have my eye on another day at Cadwell on the 31st March

[SmallFrowne]

Well, I've found a thread on the stock shock weight, silly me. viewtopic.php?f=24&t=41616 Consensus being 850-900lbs. I think I'll leave it alone for now and see what the sag is like when it's all back together.

[28hodge]

Frowne,

Think it is my shock that you have bought off ebay?

I am pretty sure I have a set of standard linkages, I need to double check, I’m away with work till Thursday so will check and let you know, do you want me to hold off sending your shock until I have checked as if I have a set I can stick them in the same parcel and save a bit of postage for you?

The linkages I have are for a NC30, but like you say you are best off getting them welded and drilled, I think from memory it is shorter by 8mm C to C of the existing hole but give it a search as it on here somewhere.

Speedo cable no idea sorry never owned a road going NC30, but again I am pretty sure I have a standard speedo cable but would need to have a check. If I have again I can put it in with the shock if you want.

I haven’t got the shock reservoir mount sorry it was sold separately.

Gearbox issue is a new gearbox required sorry to say they ruin the dogs where 2nd gear engages and this allows them to slip out, which causes even more damage. You can change them from underneath, but there is one casing bolt that is difficult to get to so that you can undo it or torque it back up, Again I may have a gearbox available as I think I have 3 spares so could maybe part with one.

[SmallFrowne]

Ah cheers, yes it is :D
Yeah hold off if you will, whilst I make a shopping list...
How much do you want for the linkages? Are the bearings in good condition? I have a feeling mine are bad, it would save me having to do a refurb and I'd have an extra set of dog bones to shorten.
Same for the speedo, how much?

And then the gearbox... I'm willing to do the job if it puts it right, as painful as it might be. Is it just the dogs I'd need then? Plus whatever gaskets I'd disturb in the process. I'd quite like one if you'd be willing. In fact, having had a glance at the manual it says you can do it with the engine in the frame. No mention of splitting cases so far, removal of clutch and waterpump bolts though. Hmmm maybe not too bad, I just can't get out of my head something about 6th gear being an issue too, but can't find the post where it was mentioned.

There's probably some other stuff too, I'll be stripping it down further tonight, so I'll see if there's anything else I need - I'll be sure to bug you some more. Also, unlike through ebay, I can pay by bank transfer if you'd rather.

Cheers

[SmallFrowne]

I think I'm a bit confused as to what the "dogs" are... I think it might be becoming clear however. The dogs are part of the gear, if what I have just read is correct.



The "lumps" of steel on the side of the gear are the dogs, right? To start with I thought this referred to the selector drum for some reason. This isn't so good, meaning I do have to split the case to change the gears. Would it be best to remove the engine and flip upside down?

[28hodge]

Yeah no problem, make a list and i'll see what i can sort you out with.

The gearbox requires the entire shaft that 2nd and 6th gear sits on, Rick does and uprated and stronger 2nd gear, not cheap but should solve the issue unless your overly rough on the box, best way to avoid problems is to always do a clutched upshift between first and second, it'll help the longevity of the box. The dogs are the metal that engages with the next gear then are cast onto the cogs and once worn its a case of they are basically only any use as a paper weight. If you can find just the 2nd gear cog then you can replace that on the shaft i believe but more than likely you will have to exchange the entire shaft.

There is a post from rick about the 2nd and 6th gear upgrades whic explains it better.

without looking at the linkages I cant comment on the bearings, i'll advise on Thurs.

Let me find the bits and have a look and then anything else you may need and then i will PM regarding prices.

ta

[28hodge]

Yep you got it the dog is the metal lug that engages with the corresponding gear. it sits on the shaft and slides along to engage, if it dosent get seated properly before you hammer the throttle again, As you would without a clutched upshift it slipd and then slams into the dogs on the other gear on the next revolution at speed and chips it. this then leads to it getting damaged and slipping out of gear.

[SmallFrowne]

Cheers for the replies, i think i may have been guilty of a few bad geer changes too many then. Once I've fixed it though I'll be sure to treat it like it should of been

I've seen them gears from RO, I'd love a set, just have to wait for a bit till I can acrue the funds unfortunately. A second hand set, hopefully from yourself, will have to do for now + more mechanical sympathy.

Is this the bolt that's awkward to get to? (and same on the other side)?



I measured the speedo cable, it's about 90-100cm long.

So far I've got the engine pretty stripped down and ready for removal, just need a clutch tool and engine mount tool. Unfortunately i think one of the the exhausts has snapped in the middle as well as a stud on the front and a stud on the rear manifold. I'll compare mine to some pictures, it might just be how it's meant to come apart, but didn't look good.

[Tim400GB]

Yep that's the one. Careful not to round it, I had to take the rear head off my engine in the end.

I should have an nc30 rear shock reservoir mount available soon. Will know on Friday if the new shock arrives.

[SmallFrowne]

Ah bugger, hopefully I can get it free then (both sides). It does look very round-able Having enough fun with a snapped exhaust stud at the mo, don't really need that as well.

Might be a daft question, but do you have to remove the clutch to get the gearbox out? The manual doesn't mention the clutch as being a pre-req but it would make sense that the clutch is attached to the end of one of the gearbox shafts, surely? Still waiting for the clutch/swingarm tool to arrive - is it easier to remove the clutch with the engine in the frame and use 6th gear + rear brake, or just jam a copper washer in between the primary gear?

Ah, yes, I'd be interested in a mount, should you have one, cheers :)

Also, once I'm in to the bottom end, is it worth me measuring main bearings to check for wear? (or any other jobs) Never done that before, don't know how I would at this point. Micrometer? The bikes done about ~35k km. In fact, would I only be able to check the bottom ones since the crank and pistons will stay in the engine.. or would the top ones be accessible with some jiggling? I'm just thinking I'd rather not disturb anything that was working fine previously, but at the same time, a little preventative maintenance doesn't hurt either.

Having only ever torn down heads before (not on an nc mind), I'm a bit anxious about getting into a bottom end (ooh er)and not knowing what I'm doing... trying to get it right in my head first. Unity of body and mind if you will