The T bike, Torq Radical project

[coops]

Did you have to increase the chain length to accommodate the extra gear teeth on the T & Q bikes flecc? Probably on the Q more than the T?

I know its more W-bike weather but how's the T-r doing now? Been out of the garage much lately?

 

[flecc]

Yes on both Stuart, I didn't note the amount but it's necessary to start with new chains anyway, no matter how few miles a chain has done. Re-using on a new freewheel will always bring coarse running.

Standard length chains are often not long enough for Megarange freewheels, so best to buy two of the same at the same time. The SRAM chains are supplied complete with their excellent Powerlinks® for joining, and you can take the lazy option of using two to splice in a short extra length.

I had a couple of fast rides up onto the Downs using the T-r a few days ago just for kicks, and also did one light 4 mile shopping trip using the old panniers. Great fun, 20 mph uphill all the way along Selsdon Park Road up into Selsdon. Certainly causes car drivers to do a double take.
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[coops]

Yes on both Stuart, I didn't note the amount but it's necessary to start with new chains anyway, no matter how few miles a chain has done.

Ah, yes, good point: I forgot about that. Thanks for the tips .

I'm glad to hear you're having fun with the T-r: I bet some drivers wonder if gravity is working backwards on some hills in your area!

 

[flecc]

I'm glad to hear you're having fun with the T-r: I bet some drivers wonder if gravity is working backwards on some hills in your area!

Indeed. One of the nearby homes had a visitor calling one day who saw me sprinting up the 14% / 1 in 7 at about 15 to 20 mph while sitting on the saddle!

He was in his car so heard no motor sound, and went into his friends recounting this amazing old man's exploit in wonderment. They told me this chuckling a couple of days later.
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[coops]

Hehehe! "Zut alors! Quel 'illclimbing, 'ee should be in le Tour de France!"

(With apologies to any french-speaking forum members/guests...)

 

[coops]

Do you use the same brake lever & cable, used for the roller brake, for the rear V-brakes flecc?

I'm thinking to fit them likewise, for the extra braking power, though I'm a little concerned about the "bossed" bit fouling my chain - which even now does occasionally lightly "touch" the top of rubber covered lug on the rear chainstay, only when the chain "jumps" slightly when changing gear though I think... do you think the brake "bosses" protrude more, or less, than the unused & capped lugs?

More to the point, do you think I can fit the "front as rear" V-brakes with the 40T chainwheel, which I'd prefer to keep, or will the lower chainline cause insurmountable problems as above? By eye, the front chainwheel currently lines up very centrally with the 8 rear sprockets, about 4th or between 4th and 5th.

Thanks

Stuart.

 

[flecc]

Yes, I used the same lever and cable Stuart, just shortening the cable of course. I'd also considered a rear disc brake since only limited power is needed on the rear brake, and would have used the same cable again for that.

I can't be certain on the V brake and chain with the 40 tooth chainwheel though. Vertically it will be very close at some gear points, but since your chainline is clearly different (and better) than the original with the previous mounting, I don't know where it would register in relation to the brake post bolt. An occasional touch won't matter though.

The only thing I can suggest is that you check it at each gear for clearance. The brake doesn't protude more, it registering level with the top of the boss, only the cap of the added bolt being higher, but that shouldn't be serious as the Torq had rubber caps over the bosses which themselves had thickness.

The major reason for that chain flick up and down at changes on the Torq is the silly plastic disc at the rear of the cassette which drags on the freewheel. If you still have that fitted, here's how to get rid of it.
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[flecc]

P.S. to the above.

Shimano brakes don't sit fully down on the Torq's posts, the post design is different. I couldn't find a source for the posts only, they seem to new bike only items, so I ground and turned my posts to fit. Not an easy job, and getting them out of the frame was difficult as some thread locking compound had been used.

The best answer would be to use the original equipment brake type, Tektro. If you can't find one anywhere, I'm sure 50cycles could supply a spare front brake. I'd have done that if I hadn't already bought the Shimano.
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[coops]

Thanks very much flecc, especially the tektro/shimano tip, glad I asked about it now!

Seems I have more of a problem with the chain proximity to the posts than I thought though...

When I fitted the smaller 40T chainwheel a few months/few hundred miles ago, I thought the chain would be very close to the posts with the rubber cap, but thought I'd got away with it - the chain cleared the post & cap in all gears...

I just checked, and it seems the chain has maybe "loosened" a little because its now slightly rubbing against the rubber cap from about 3rd (brushes the top) to 5th (brushes the side) but in 4th the outer & upper edge of the post & cap does just slightly "nudge" the chain as it passes... without the rubber cap in 4th the chain still just touches the upper outer edge of the metal post but clearly brushes against it while moving; the gears either side do clear the metal post without the rubber cap... I must have done a fair few miles with it like that but even so the rubber cap, though taped on, does not show much wear...

I did try removing the post when I fitted the chainwheel but as you, Pete & I think Ian have said, its not easy, and I was unable to do it.

Not sure what to do now - torn between trying to use the posts for brakes or remove them!! I suppose I could just remove the cap, put a thin & slippery cover over the metal post & avoid prolonged use of 4th gear (not a way I'd planned to reduce the number of gears ); I'd planned to change the freewheel & rear mech at some point for a megarange, but that would only swap the 19T problem cog for a 20T at the same point: 12-13-15-17-19-21-23-25 vs 11-13-15-17-20-23-26-34 so may not help much...

Do you have any other suggestions flecc? I'd prefer to keep the 40T as I said, but it seems to be causing trouble... I suppose disc brakes might work quite well as you say assuming there's no major problem fixing them in place of the roller brake, but I still need to resolve the fouled chainline problem I've got... .

Stuart.

 

[flecc]

Fitting a disc brake is very problematic Stuart, the hub centre being too large to take a standard disc mount.

This is what I'd do in your position. Fit the 11 to 34 tooth Megarange with appropriate rear mechanism like the Acera if necessary, and go back to the 52 tooth chainwheel. That will give you 42" and 56" low gears and right through to 132" top, everything you need for any hill or downhill.

Then fit the V brake, problem solved.

If you need a lower gear than 42", then fit a 44" chainwheel to bring the lows to 36" and 47" with a top of 112".
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[coops]

Thanks again,

Disc brake is out then. I think sub-42" gears may still be useful for me, so I'd likely have to buy another chainwheel, or at very least a new freewheel & rear mech to keep my existing lowest gear about the same with 52-34 instead of 40-25... just to fit V-brakes comfortably for the chain...

I'd still prefer more braking power, but I'll have to think about this some more I think... .

For now, as a stopgap measure, I think I'll remove the rubber cap & try wrapping the brake post in slippery thin PTFE tape to see how well that sits in 4th gear while I reconsider V-brakes, before deciding if I really need to remove that post...

 

[Ian]

I wouldn't worry too much about V brakes on the rear Stuart. As I have posted elsewhere I replaced the front V with a Shimano Deore XT parallel action V brake, in a really quick stop the rear wheel now leaves the ground making the rear brake irrelevant, and the existing roller brake is adequate for gentler stops.

 

[flecc]

I agree with Ian there, with a really good front brake a rear brake is almost redundant for emergency stops. In it's Torq form I only used the rear roller brake as a routine slowing brake, the front for the odd emergency situation.

I added the rear V brake partly because I could, partly because the rear wheel was gaining the motor weight so would be more firmly glued to the ground for braking, and partly because I knew it was to gain quite a lot higher performance.
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[Ian]

Removing the V post

I seem to remember using stillsons to get mine out, the post did get badly butchered by the stillsons teeth so theres no chance of re-using it. An alternative would be to simply cut it off with a hacksaw, the disadvantage being you'd have to drill the stump out if ever you wanted to replace it.

 

[flecc]

There is another way on the Torq Ian, which I used as I'd butchered one on the front fork and used the one I'd turned and ground there instead, leaving me with a butchered post with sound thread, which I cut from it to use as thread only in the rear frame tube.

The rear mount is not critical since the braking force is towards the frame tubes.

Therefore a post can be cut off with a hacksaw, a new post minus the thread section turned, then assembled onto the thread left in the frame with a through bolt. This photo shows just behind a spoke the black head of the high tensile through bolt I used on the right hand side to hold the new threadless post section and brake arm onto the old thread left in the frame:

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[coops]

Thanks very much for the good advice Ian & flecc,

On reflection, I hadn't thought the brakes through, and I can see the purpose of the roller brake now though it doesn't seem to slow me down much; the 100kg limit bothers me when my bike plus a small load is already over 125kg; with panniers, extra battery, & say a few kg of extras, could be nearer 135-140kg... and I can't lose that much weight!!

I never use the roller alone, for fear of overloading it, but at least I've never had a problem stopping when using both brakes.

While on the subject, I can't remember Ian - did your new V-brake reduce/stop the front brake judder, or did it return? Mine is back again .

As for the rear V-post, I'm reasonably happy that, with rubber cap removed, the post doesn't foul the chain while pedalling (chain tension pulls it clear, even in 4th gear) so I'll leave as is for now. I hope too that the larger megarange 4th gear sprocket will give a little more clearance too, as I said earlier.

I'm definitely getting soft grips though, hopefully m+ too and my seatpost is creaking, so thats in for a change too - think I'll go for a non-suspension post if I can.

Stuart.

 

[flecc]

You can load that roller brake as much as you like Stuart, the effect of pressure is cumulative to some extent. I could and often did lock the rear wheel momentarily just by maintaining a high brake pressure, the braking increasing second by second.

Similar advice can sometimes help with front judder. The instinct is to slacken off a bit when it occurs, but if you very firmly increase the pressure instead as soon as it occurs, you might find the judder disappears then as the clamping grip on the rim increases.

Try it, you might be pleasantly surprised.
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[coops]

That's very helpful, I'll try both .

I tend to try to keep rolling wherever possible, rather than have to stop, so I'll try to use the roller for gentle slowing and the V-brake for firm stops as you say .