Search found 33 matches

by baltipine
1 Jun 2017, 8:04pm
Forum: Bikes & Bits – Technical section
Topic: Wheel re-rim complication
Replies: 10
Views: 3971

Re: Wheel re-rim complication

In case anyone is interested I removed the old rim and then reversed the direction of each of the non drive side spokes i.e. spokes pointing inwards through the hub became outward facing and vice versa. Then I just re-laced it onto the new rim.

The rim I used in the end was the Exal zx19 which has (for a 36 spoke) 9 groups of 4 spokes. The bike shop (online) said that they didn't think that would make any difference to the spoke length required....

Does anyone else have experience of a rim with this spoking pattern?

My experience was that while the 2 inner spokes of each group of 4 were about right, the outer 2 should really have been 2mm shorter as they ended up with a couple of mm sticking out of the nipple! This meant that I couldn't get as much tension as I would have liked but I think it's just sufficient. It was a hub gear so very small amount of dish but on a derailleur wheel you would need 3 (probably 4) different spoke lengths to build on these rims.

These rims were cheap so I think I now know why!

I rode the new wheel to work today and it's OK so far!

Cheers,
BP.
by baltipine
29 May 2017, 10:19pm
Forum: Bikes & Bits – Technical section
Topic: Wheel re-rim complication
Replies: 10
Views: 3971

Re: Wheel re-rim complication

Thanks to everyone for your comments. I'll have a think and let you know how I've got on.
BP
by baltipine
28 May 2017, 9:58pm
Forum: Bikes & Bits – Technical section
Topic: Wheel re-rim complication
Replies: 10
Views: 3971

Wheel re-rim complication

I realised the other day that the rim on my Rigida / Ryde Zac2000 rear wheel had reached the wear limit. After a few hours on the interweb I found another rim with what should be roughly the same ERD as I was planning to just transfer the spokes one for one to the new rim.
Nothing ever seems to be that simple when bike wheels are involved as when I placed the new rim on top of the old wheel and lined up the valve holes I found that on the new rim the spoke holes on either side of the valve hole were for spokes on the opposite sides of the hub. I hopefully tried turning the rim the other way round (upside down) but (of course) that made no difference whatsoever!

I believe this means I'll have to strip the whole thing down again and re-build the wheel from scratch? I can do it if I have to but I was hoping there may be an easier and quicker alternative that some clever person may be able to suggest...
Thanks
BP
by baltipine
7 May 2011, 5:12pm
Forum: Bikes & Bits – Technical section
Topic: Shimano replacement cones for old 105 rear
Replies: 1
Views: 324

Shimano replacement cones for old 105 rear

I'm sorting out a nice old Joe Waugh bike I bought on fleabay.
When I opened up the rear 105 hub marked FH-1050 the cones are pitted and need replacing. I have looked on the interweb for hub spares but not found the exact cones.

Firstly does anyone know where to get the correct ones and if not, how close can I get away with as given the age of the rims it's probably not worth rebuilding.

If I get a different Shimano cone I guess I should be looking for one with the same curve on the bearing surface (obviously the same thread and diameter)? It is difficult to see that from the pictures on the net.

Any ideas?
by baltipine
22 Mar 2011, 11:03pm
Forum: Bikes & Bits – Technical section
Topic: SRAM S7 hub - bike build finished (almost)
Replies: 31
Views: 3564

Re: SRAM S7 hub - bike build finished (almost)

[quote]could you do a review of the front hub?[/quote]

Yes, where did you have in mind? Here?

After what period of use would you think it would be useful? After 100 miles in daylight all I can say is that the brake is poor and the dynamo works. I'm keeping my fingers crossed that the brake improves when it beds in a bit.
by baltipine
22 Mar 2011, 12:11pm
Forum: Bikes & Bits – Technical section
Topic: SRAM S7 hub - bike build finished (almost)
Replies: 31
Views: 3564

Re: SRAM S7 hub - bike build finished (almost)

The bars don't show well in those photos and there is a limit of 5 pictures.

But yes, they are BBB butterfly bars currently installed the unconventional way round (with the ends of the bars at the front). I think I may change to the more conventional way round some time but not quite sure yet.

If people are interested I'll try and host more and bigger pictures elsewhere?

I had never used butterfly bars before but I find straight bars uncomfortable even on my 5 mile commute. It's still early days but I think I like them! I thought for a long time about using drops with a hubbubb or something to allow the SRAM S7 shifter to fit but decided to try butterflys as the shifter fitted them and they allow a good range of positions. Once I've got a position I like sorted out I think I'll change the adjustable stem too as that weighs about as much as the entire frame!

The S7 gears are great but I'm less than impressed with the brakes. I've got my fingers crossed that they will improve after "bedding in" but so far I can't even lock the rear wheel on dry tarmac and it's a bit scary. Done about 120 miles so far I guess and they slow you down OK but sudden stopping is just not possible. Still - at least it will be the same in the wet!....

The pedals were just ones I found in the spares box - I'll try and get some others....

The half link chain is because although the frame has horizontal dropouts, because of the design of the SRAM lockwasher with a big tab on one end, the scope for sliding the hub back & fore to tension the chain is severely limited in practice. If you have to buy a half link chain you may as well get a coloured one!
by baltipine
21 Mar 2011, 10:15pm
Forum: Bikes & Bits – Technical section
Topic: SRAM S7 hub - bike build finished (almost)
Replies: 31
Views: 3564

Re: SRAM S7 hub assembly

I've asked advice in other threads during the build and been requested to post some pictures. Well here they are - the bike is now all but finished and I've been riding it to work for about a week now. I haven't even snipped off all the tie wraps but the main thing left to go on is the rear dynamo light.

The frame is a Dawes Galaxy (from the mid 1980's I think).

[attachment=2]P1010249s.jpg[/attachment]

[attachment=4]P1010232s.jpg[/attachment]

[attachment=3]P1010233s.jpg[/attachment]

[attachment=1]P1010243s.jpg[/attachment]

[attachment=0]P1010246s.jpg[/attachment]

[attachment=0]P1010246s.jpg[/attachment]

Those pictures all appeared in the wrong order but never mind :D
by baltipine
10 Mar 2011, 8:47am
Forum: Bikes & Bits – Technical section
Topic: SRAM S7 hub - bike build finished (almost)
Replies: 31
Views: 3564

Re: SRAM S7 hub assembly

[quote="pioneer"]50 mil seems like a wide chainline.[/quote]
Well with that hub it's the narrowest available with the sprocket dished inwards. The alternatives are 53 & 56!

Anyway, the 19T sprocket arrived yesterday, fitted, works and I rode the bike to work today 8)

It's far from finished and still needs a lot of tweaking but I had to take something different as my current commuting bike broke a rear axle on the way home :(

I'll see if I can get some pictures up soon.... :D
by baltipine
8 Mar 2011, 2:15pm
Forum: Bikes & Bits – Technical section
Topic: SRAM S7 hub - bike build finished (almost)
Replies: 31
Views: 3564

Re: SRAM S7 hub assembly

pioneer - the chainring is already on the outside of the spider to give the 50mm chainline. It's actually spot on with the rear sprocket dished inwards - I was very lucky with a bb I had had in the spares box for years.

I ordered a dished 19T Sturmey Archer sprocket (eBay) that was despatched today so if I can get the cir clip off (and back on again) it shouldn't be too bad.

Hmmm... I hope the SA sprockets are not dished any more than the SRAM ones :roll:
by baltipine
7 Mar 2011, 10:44pm
Forum: Bikes & Bits – Technical section
Topic: SRAM S7 hub - bike build finished (almost)
Replies: 31
Views: 3564

Re: SRAM S7 hub assembly

[quote="hubgearfreak"]if option 2 only requires a jump from 18 to 19, i'd be surprised if you notice 8)[/quote]

:shock: What are you implying, I have very sensitive legs I'll have you know! :)

But yes, my thoughts exactly.

I have found it now and it is detailed in the SRAM technical documents from 2008 onwards - as I said, I was using the 2007 version as mine is the one with the integral hub brakes (and the aluminium shell shaving a few grams off the weight). The chain line is a few mm different for that version compared to all the others but it makes no mention of the sprocket size limits at all! :evil:

Off to order another cog then! Anyone know what the diamater change is with a 1 tooth jump from 18 to 19?
by baltipine
7 Mar 2011, 9:14pm
Forum: Bikes & Bits – Technical section
Topic: SRAM S7 hub - bike build finished (almost)
Replies: 31
Views: 3564

Re: SRAM S7 hub assembly

Martin - I think you've got it - although I can't see it in the manual anywhere (certainly not with the chainline figures)! I'm using an 18T sprocket so that would explain the problem. Either turning it round or using a bigger sprocket would fix the issue!

If you can find where it says it I'd be grateful - like I said it doesn't seem to mention it in my technical manual that I downloaded. I'm using the 2007 version as that is the last version of the hub with the integral drum brake which I have.

So assuming that's the problem I have the choice of:
1) buying a larger dished sprocket and having to buy a new chainring to keep the ratio the same
2) buying a larger dished sprocket and keeping the chainring and living with a lower set of gears
3) turning this sprocket round which will add 6mm to my chain line and probably require a new bb!
4) buying a flat sprocket the same size and adding 3mm to chain line which I may be able to take up by spacing the chainring from the crank with washers.
5) is there a fifth option?

Hmmm I may try option 2 if a 19T sprocket will be OK.
by baltipine
7 Mar 2011, 9:43am
Forum: Bikes & Bits – Technical section
Topic: SRAM S7 hub - bike build finished (almost)
Replies: 31
Views: 3564

Re: SRAM S7 hub assembly

I tried both chain sizes and as you would expect the wider chain rubs worse than the narrower one!

I'm not actually sure what size chain the sprocket is designed for as the SRAM "bits bag" (accessory pack!) details didn't specify. That why I started with a 1/8" chain as it should be OK with sprockets designed for either. Is there a way to tell by taking a vernier to the cog, which chain it is designed for?

I am still hopeful that somebody who has fitted one of these will be able to remember if this dust cover clips or presses into place or if it is just held in by the cog and the cir-clip......

I will take the thing apart again when I get time and check the exact measurements on the dust cap and the hub body and see if it appears to be intended to be an interference fit or what.
by baltipine
6 Mar 2011, 10:08pm
Forum: Bikes & Bits – Technical section
Topic: SRAM S7 hub - bike build finished (almost)
Replies: 31
Views: 3564

SRAM S7 hub - bike build finished (almost)

[edit] jump to page 2 for photos I just uploaded! [/edit]

I'm building a commuter for myself using an S7 rear hub. I downloaded the assembly instructions from the interweb but I seem to have put it together slightly wrongly. :oops:

I put the rear wheel on the bike and fitted the chain when it became clear all was not quite as it should be. I used the dished sprocket that came in the "bits & pieces" kit that SRAM sells to go with their hubs and fitted the sprocket giving the narrowest chainline (ie with the sprockets nearest the centre of the wheel).

The problem is that the chain does not engage on the sprockets to their full depth due to the "dust cap" interfering with the inside edge of the chain. Now the SRAM instructions for assembling the sprockets onto the hub suggest the use of "Montagewerkzeug Art.-Nr. 0582 104 000" but I ain't got one! Actually searching the web for it only gave me all the different incarnations of the SRAM hub gear assembly instructions that are on the internet - so I suspect nobody else has one either! :D

Anyway, does anyone who has put one of these together before know if the "dust cap" - that's the big metal one that goes on first, not the small plastic one that goes on last - is supposed to clip into place or not? Mine does not clip in and doesn't look like it's doing much of a job as a dust cap to be honest! I've tried leavering it by putting two screwdrivers between the dust cap and the cog and pushing but it still doesn't budge. Any suggestions about how much brute force should be applied would be welcome - assuming that I've diagnosed the problem correctly? Interestingly it looks like if I had used the sprocket dished the other way then I would never have noticed that it was wrong!

For those who don't know what I'm on about (but would like to know) the SRAM instructions are at [url]http://www.sram.com/_media/pdf/sram/dealers/SRAM-TechManual-MY10-GearHubSystems-English-RevA.pdf[/url] and the bit I'm having problems with is on page 70 steps 1 & 2. Well at least that's the bit I think went wrong.....

Once I've got this sorted there shouldn't be much preventing me finishing the build in the next week or so - it's only taken me about 9 months so far! :oops:
When I posted some time ago somebody suggested I post some pics - I will try and do that soon. What's the appropriate section for that?

Thanks for the advice everyone.....
by baltipine
29 Jan 2011, 5:20pm
Forum: Bikes & Bits – Technical section
Topic: Getting brakes round the bends
Replies: 11
Views: 1093

Re: Getting brakes round the bends

Well thanks for the suggestions.

A little bit of filing, some lubrication in the form of grease and the application of significant heat from a hot air gun to the brake lever clamps and then without too much brute force they went round the bends!

Now I have to take them off again to fit the handlebar foam! :oops:

I'll be quite good at this soon!

Cheers,

BP
by baltipine
28 Jan 2011, 10:17pm
Forum: Bikes & Bits – Technical section
Topic: Getting brakes round the bends
Replies: 11
Views: 1093

Getting brakes round the bends

I have some butterfly bars and I'd like to put the brake levers on facing fore / aft rather than on the perpendicular bits of the bars. The problem (if you haven't guessed already) is that I can't get them round the bend! I hadn't realised there was so little clearance. I'm sure I've seen a photo on the interweb of a setup like this.

The bars are BBB butterfly and the levers are Shimano Deore LX BL-M570. I had a look at a couple of other levers on my other bikes and none look like they would go round the bend on the butterfly bars.

Is there a different bar with a (much) larger radius bend or a brake lever with a two part clamp (2 bolts instead of one)?

Any other ideas.....

I prefer drop bars to straight but I'm using hub gears with a shifter that will only fit straight bars. Hence the butterflys and I wanted to roughly emulate the hand position of riding drops on the hoods......

BP.