Cycling UK Forum

If anyone is interested, it would appear to be ok to fit Ergon GP5 bar ends to a Bontrager Cruiser 6061-T6 handlebar.

Thanks Brucey.

For some time I haven't been able to shift from the middle to small chain ring when in the 3rd/4th through to 8th sprockets at the rear. I have no previous experience with front derailleurs but have followed the instructions that came with the shifter and when that didn't work some online tutorials, which also failed to fix the issue.

If I do set it to shift down from the middle to small chain rings when in the higher sprockets it won't shift back up from the small to middle chain ring. I took it to Halfords today and the mechanic couldn't do it either. He said the mech was old and it would be best to replace it.

I am happy to buy a new derailleur but wanted to first make sure that it really is faulty and, if so, to find out which derailleur to replace it with. So. . .

1. Could there be another cause for this problem?

2. Is there a more definitive way of testing a derailleur to establish whether it is faulty or not?

3. I measured the seat tube as best I could with a piece of string at the point where the current mech is sited. The length was 95 / 96 mm which gives a diameter of 30.2 / 30.5 mm. Measurements for seat tubes are 28.6, 31.8 and 35.0 mm. Do I therefore choose a 31.8 mm derailleur?

4. Does top swing or bottom swing matter?

5. Do I have to get an 8 speed front mech or could I use a 9 or 10 speed?

6. Can anyone recommend a serviceable bottom pull front derailleur that will fit my bike which is a 1990s Carrera Flex MTB with a 30.2 / 30.5 mm seat tube, a Shimano SIS chainset (48/36/26) and Alivio SL-M410 8 speed shifters?

Hi all, I'm wondering if anyone knows whether it would be ok to fit Ergon GP5 bar ends to a Bontrager Cruiser 6061-T6 handlebar. Ergon say that the bar ends should only be fitted to bars that can take bar ends, so I assume that some can't. The Bontrager bar is not double-butted as far as I know. The torque for the grips is 8 Nm. Cheers.

I have a headlight mounted on the steering tube, where the front mudguard would attach, secured by a bolt running right through. I wonder if the expander bolt was hitting that and, if the wedge was too low down the bolt when the stem was insterted, wasn't rising enough to meet the stem as the bolt wasn't actually descending any further.

531colin wrote:So what was wrong?

I don't know Colin. I made sure the surfaces were greased and repositioned the stem a little higher and it didn't work, then I took it out, screwed the wedge a little further up the expander bolt, repositioned it again and it worked! I'm guessing that the wedge had been lower down the expander bolt when the stem was inserted at the bike store and wasn't being brought into close enough contact with the stem. But then shouldn't the wedge rise up the bolt as it is tightened to meet the stem making its original position irrelevant?

Fixed! Thanks for all your help.

Thanks Gaz

Thanks sreten. I'll do one more check following Colin's suggestions and bearing yours in mind and, if it doesn't solve the problem, then it's back to the bike shop.

Thanks Colin, I'll try your suggestions tomorrow in the daylight.

rbreid wrote:Petition signed! Good link, many thanks.

Many thanks to you too.

Hi James and Colin,

I easily removed the stem without having to tap anything with a hammer, and could find no wear or damage to the threads of the bolt or the wedge, and there is a centimetre or two of bolt extending from the wedge. I wonder if the wedge is just too small for the tube, hence the ease with which it was withdrawn, though I hadn't noticed this problem in previous years. As it's beyond my skill level I'll take it to the bike shop. Thanks for your help.

After taking a tumble on a wet manhole cover last week I thought, 'surely there must be a way to make these things non-slip!' and a few minutes of googling revealed that there is. In fact there are several, but implementing such safety features is not a legal requirment, at the present time.

The motorcycling community have a campaign going to change this, and improve road safety generally in regard to issues of grip and poor surfacing, but it's not exclusive to motorcyclists. The following link is to the campaign website where you can find out more about the solutions, sign a petition and report a bad section of road or dodgy manhole cover. Writing a letter to your MP and local councillor would also be a great help.

http://www.getagripuk.org/Main-content/ ... we-do.html

If I stand with the front wheel trapped between my legs, facing toward the back of the back, I can tighten the expander bolt(?) [the one that runs down inside the stem and is accessible from above]. If I then try to turn the handlebars counter clockwise, with the wheel still trapped, they remain tight (as I imagine they should), but when I try to turn them clockwise they come loose with very little effort. I assume that shouldn't happen.

If it shouldn't happen what might be the cause? As I say, the bolt tightens down firmly so it doesn't seem to be a problem with worn threads.

Just before I noticed this happening, I had had the headset serviced at a bike store. Could they have put something back in the wrong place?

I want to find out what the cause might be before taking it back to them, as I imagine they would deny any failing on their part unless I could prove otherwise. I have considered first taking it to a different bike store, but thought I would check here first, especially as I'll be paying extra at a second bike store when the problem might have nothing to do with the previous service or might not even be a problem.

When I started to measure cadence I used a watch and counted how many revoutions of the cranks I made in one minute. Later I got a cheap cycle computer with a clock that showed seconds. After a few weeks I learnt to be able to tell what my easy-riding, comfortable cadence is without having to measure.