Help! SRAM p5 Rear hub for old giant twist/lafree

oznog

Pedelecer
Jul 22, 2007
34
0
Cumbria
Hello,
I have recently brought my old giant lafree twist out of retirement to do the school run with a Tagalong for my 6 year old. Unfortunately after about 3 months the sram p5 hub has broken. My local bike shop advised that they could not open the hub up and even if they could sram advised that there are no longer any parts. They quoted in the region of £400 to build a new hub wheel etc.
Give the age of the bike I’m not willing to spent this. Are there any other options?
 

peter.c

Esteemed Pedelecer
Apr 24, 2018
637
177
thurrock essex
Try on ebay look for Taylor wheels based in Germany very fast dispatch to the uk very good for wheels with hub gears mainly alfine but do other types, delivery only takes a few days no duty to pay postage was £12.00
 

flecc

Member
Oct 25, 2006
42,303
17,924
Surprised at that bike shop's inability, it only takes undoing a single nut to slide out the P5's core and slide a new one into the hub shell. Sadly the new cores are no longer available for your version, though there are still some new ones for the coaster brake (back pedal) version.

Best get in touch with Holland Bike Shop in the Netherlands, They have the P5 cargo version's core available at £35.76 and may be able to advise if it's internals will slide into your standard hub ok. Equally ask if the coaster brake version's internals can be used instead. Here's the link:

P5 Cargo Hub Gear

To ask them questions:
  • Do you have any questions? Our team of enthusiastic colleagues is ready to help you.
  • +31 (0)70 - 300 00 44
  • info@hollandbikeshop.com
Tell them your hub is the standard P5, not the cargo P5 or coaster brake version. The Dutch have far greater knowledge of hub gears than any cycle outlet in the UK.

Other shops like this one have the complete hub coaster brake version, so ask if that could be used with the coaster brake left off. If so you could have that built into a rim for you locally, total cost under £100. They also have the brake version core only, so probably compatible with your hub shell and that could save you the wheel build if the brake can be left off.
.
 
Last edited:

oznog

Pedelecer
Jul 22, 2007
34
0
Cumbria
Thanks for your advice. I was also disappointed by my local bike shop. They said they would need t buy special tools just to open the hub. They seemed to not want to deal with such an old bike. My only other option for mechanics is Halfords. If I am able to source the parts online, what’s the likelihood it could be sorted by them? I have pretty limited bike skills just changing tyres and adding racks etc. The bike is unrideable at the moment and does not wheel in reverse easily.
 

flecc

Member
Oct 25, 2006
42,303
17,924
I'm afraid Halfords are unlikely to have a mechanic with SRAM hub gear skills, unless they have a mechanic with skills going back a number of years. My trade days started in 1950!

If you find the cargo hub core can be used in the standard P5 hub shell, changing it over doesn't need any special tools.

It's disconnect the hub gear cable connector, undo the small retaining screw under the actuator housing on the side of the gear hub. Remove the actuator housing and withdraw the actuator rod from the spindle, noting which way round it goes in.

Then wheel out, remove the circlip that holds the 16 tooth sprocket on and remove the sprocket.

Then on the left hand side, take off all the spindle nuts on the left of the hub. With those off the complete core of the hub gear withdraws from the right hand side.

Then the new core can be inserted, all the parts above replaced and the cable adjusted to set the gear changing accuracy. All the details of the P5 hub are in the SRAM technical manual on this link, starting at page 40. The cable adjustment is on page 44.

If you feel unable to tackle this job, and it is a little complex, you could buy the new cargo hub gear from Holland Bike Shop and have that built into a rim as I suggested. Then you'd only have to fit your sprocket or a new sprocket and set the gear cable adjustment The shop you find to build the wheel could fit a new 16 tooth sprocket for you, they are the same for SRAM, Sturmey and Shimano hub gears so cheap and easy to obtain.

The only difference of the cargo gear from your one is that bottom gear is a little higher to increase it's strength under load. On an e-bike that would make little difference, but if you did find it awkward, just swapping the 16 tooth sprocket for an 18 tooth would correct that.
.
 

Jimo

Pedelecer
Nov 15, 2018
203
64
81
Fakenham, Norfolk
Wow flecc, you’re a mine of quality information, and all this for free!
Pedelecs is a quite unusual site - although I’m not in need at present......good reading.

Thanks a lot.

Jim
 
  • Like
Reactions: flecc

oznog

Pedelecer
Jul 22, 2007
34
0
Cumbria
Thanks Flecc,
I emailed the shop and all response was we don't know so probably won't work. However I've decided to gamble anyway and ordered the cargo hub to try and see. I'll attempt changing it myself as you outline. I'm wishing you had done similar to your bike in past so I could follow along with your excellent photo step guidance!
Mary
 

flecc

Member
Oct 25, 2006
42,303
17,924
Thanks Flecc,
I emailed the shop and all response was we don't know so probably won't work. However I've decided to gamble anyway and ordered the cargo hub to try and see. I'll attempt changing it myself as you outline. I'm wishing you had done similar to your bike in past so I could follow along with your excellent photo step guidance!
Mary
I did do a page on fitting a complete new P5 hub on this link, and did change a core later, but didn't web page that unfortunately Mary.

Hopefully the core will fit in the old shell. Be careful getting the circlip off that retains the sprocket on the old hub, circlip pliers may help a little but if prising off with screwdrivers or similar, be careful of your eyes as it flies off. If you are hesitant about that, just leave the sprocket in place on the old hub core and get a new sprocket and circlip for the new core, they are very cheap and widely available and the circlip much easier to put on.

Let us know how you get on and do ask if any further advice is needed.

If the core doesn't fit, just reassemble it back into its shell and find a bike shop to build it into a rim for you.
.
 

oznog

Pedelecer
Jul 22, 2007
34
0
Cumbria
Can any one help me interpret this hub gear mechanic s Advice as to why my hub gear might have broken ?
Running e-bike power thru a bicycle drivetrain is not recommended.
If you have a mid drive you will have problems. The most durable hub I know of for mid drive motors is the Shimano Nexus or Alfine 8
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
7,275
2,758
55
West Sx RH
Sram hub gears have a weak link in them , they seem to be prone to breaking and even worse on leccy drives bikes. Probably one reason why they stopped production last year as others do it better. Alfine 8 I use on a mid drive and abuse it by going lower then the 2:1 ratio inducing higher torque not broken it yet on mtb which is for off road use.

My Swizzbee Sram hub gears the pawls all snapped in half after the pawl spring broke, issue with ball bearing retainer spares are like hens teeth now.
 
Last edited:
  • Like
Reactions: oznog

vfr400

Esteemed Pedelecer
Jun 12, 2011
1,427
245
Basildon
Can't you use a different hub, like Shimano, Sturmey Archer or Nuvinci? There are loads of new and used ones on Ebay. Some are already laced to a wheel and come with the shifter, so you can upgrade to any number of speeds you want.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
7,275
2,758
55
West Sx RH
SA are tried and tested they have been making them since before I was a kid, my first ever bike (a Raleigh) had a 3 spd SA hub. Nexus/ Alfine 8 have a good rep but not so the Alfine 11.
 

oznog

Pedelecer
Jul 22, 2007
34
0
Cumbria
So I’ve managed to swap the hub internals. Have only had a very brief test as had to take kids to activities. It seems to have worked but gear 1 and 2 hardly seem to move the wheel. ( tested upside down and brief ride on the flat. )Fine in 3-5. Is this a sign of something wrong in the fitting or do I need to change something else?D2D3D69D-B7DA-47EB-975D-88FCAB5C2462.jpegD2D3D69D-B7DA-47EB-975D-88FCAB5C2462.jpegD2D3D69D-B7DA-47EB-975D-88FCAB5C2462.jpeg0D539A7E-4AD0-41A6-8114-9679CE7DCE11.jpegC4EFB4FA-F369-4146-85D4-00251FBD9D56.jpeg
 

flecc

Member
Oct 25, 2006
42,303
17,924
Glad it fitted ok, I thought it would. I haven't come across this problem with gears one and two which probably use the epicyclics in compound mode, so potentially a little more drag. I'm guessing that is what you mean, very difficult to turn, but it shouldn't be severe though. I'd suggest you try slacking off the left hand spindle inner nuts slightly since they might be clamping the internals too hard.

However, don't throw away the hub shell that came with it in case your old shell does prove incompatible in some way
.
 

oznog

Pedelecer
Jul 22, 2007
34
0
Cumbria
Glad it fitted ok, I felt sure it would. I haven't come across this problem with gears one and two which probably use the epicyclics in compound mode, so potentially a little more drag. I'm guessing that is what you mean, very difficult to turn, but it shouldn't be severe though. I'd suggest you try slacking off the left hand spindle inner nuts slightly since they might be clamping the internals too hard.
.
No it’s fine to turn no resistance. What I mean is the pedals are going round super fast but the wheel is barely turning forward from pedalling. This does not happen in 3-5. Is this a change in sprocket needed? When new I did change down to 16 ( on your advice Flecc) to handle hills.
 

flecc

Member
Oct 25, 2006
42,303
17,924
No it’s fine to turn no resistance. What I mean is the pedals are going round super fast but the wheel is barely turning forward from pedalling. This does not happen in 3-5.
The cargo hub does have a lower first gear as I mentioned before, so you will spin a bit faster for a given speed. That's to get heavy loads moving of course. As mentioned if you do find the gearing too low you'll need to change the sprocket. I absent mindedly mentioned a larger one previously, but of course you'd need smaller to raise the gearing.

That will raise your upper three gears as well of course, so you might want to live with it for a few days to assess what's best before changing anything.

The SRAM hub does tend to limit flat smaller sprockets since the chain then fouls the side of the hub wall. I can only suggest a small sprocket that Brompton add to the larger sprocket to make a three speed into a 6 speed by chain swapping across the sprocket derailleur style.

The 13 tooth one on this link is it and you may be able to use it in isolation if the chain clears the hub side. However I've never tried this so can't say if it will definitely work. Fortunately it isn't very expensive and you could return it if kept clean.

If it does work your top gear would assist with motor power to a bit over 17 mph.
.